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Teratogenic Birth Defects

Congenital Congenital Chorioretinitis malformations or teratogenic birth defects are developmental disorders that arise before birth during the embryonic or fetal period Fetal period Prenatal and Postnatal Physiology of the Neonate. The rate of incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency for children born alive is approximately 3%. The cause may be genetic or contingent on external influences or teratogens Teratogens An agent that causes the production of physical defects in the developing embryo. Cleft Lip and Cleft Palate. Teratogens Teratogens An agent that causes the production of physical defects in the developing embryo. Cleft Lip and Cleft Palate are environmental factors that result in permanent structural or functional malformations, or the death of the embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week or fetus. Teratogens Teratogens An agent that causes the production of physical defects in the developing embryo. Cleft Lip and Cleft Palate include infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, certain medications, drugs, and radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma.

Last updated: Mar 29, 2023

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

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Epidemiology

  • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency rate of malformations: 4%–6%
    • 2%–3% of all newborns
    • 2%–3% of children < 5 years of age
  • Malformations are the most common cause of child mortality Mortality All deaths reported in a given population. Measures of Health Status (approximately 21%) and the primary cause of disabilities.
  • A direct cause is only known in 40%–60% of cases:
    • 15%: genetic factors (e.g., chromosomal anomalies and mutations)
    • 10%: teratogens Teratogens An agent that causes the production of physical defects in the developing embryo. Cleft Lip and Cleft Palate
    • 20%–25%: a combination of genetic and external factors
    • 0.5%–1%: development of twins

Classification

Primary malformations:

  • Occur during organogenesis (3rd to 8th week of gestation)
  • Complete or partial organ failure
  • Structural defects (e.g., agenesis)

Secondary malformations:

Double malformations or “Siamese twins:”

Two fetuses that have grown together due to incomplete intertwining of the embryoblast Embryoblast Embryoblast and Trophoblast Development in the blastocyst Blastocyst A post-morula preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper. Fertilization and First Week stage (13th day):

  • Symmetrical Symmetrical Dermatologic Examination double malformation: Both fetuses have a complete set of organs.
  • Asymmetrical malformation: Uneven allocation leads to the uneven development of both fetuses.

Terminology

  • Agenesis: an organ that has not developed
  • Aplasia Aplasia Cranial Nerve Palsies: organ develops with defective differentiation → regression Regression Corneal Abrasions, Erosion, and Ulcers or loss of function Loss of Function Inflammation
  • Hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS): organ grows insufficiently → functional disabilities
  • Hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation: organ grown too large → functional disabilities
  • Dysplasia: abnormal cell differentiation
  • Dystopia: An organ is not located in its normal physiological location.
  • Heterotopia: Typically differentiated tissue is found dispersed in ≥ 1 nontypical location in the body.
  • Chorista: a generic term for an aggregate of normal but ectopic tissue
  • Deformations: mechanical forces affecting the locomotor system (e.g., clubfoot Clubfoot Clubfoot, also called talipes equinovarus, is a complex condition with a plantar flexed foot (equinus), adductus of the forefoot, and an inversion deformity of the heel (varus). Foot Deformities)
  • Dysraphism: defective closure of the neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation (e.g., spina bifida)
  • Stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS): constriction within a hollow organ
  • Atresia Atresia Hypoplastic Left Heart Syndrome (HLHS): absence or occlusion of the lumen of a hollow organ
  • Syndromes include multiple malformations with the same cause and in a characteristic combination (e.g., Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21)).
  • Persistence: continued existence of an organ or part of an organ which, physiologically, only exists for a limited period during embryonic development
  • Association: frequent appearance of ≥ 2 malformations with an unknown shared cause

Pathophysiology

The development of malformations varies throughout different stages of embryological/fetal development and is referred to as phase-dependent vulnerability.

  • Gametopathy: preconception impairment of the maternal or paternal gamete Gamete Gametogenesis → structural or numerical chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics defects → abortion Abortion Expulsion of the product of fertilization before completing the term of gestation and without deliberate interference. Spontaneous Abortion
  • Blastopathy: impairments of the fertilized blastocyst Blastocyst A post-morula preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper. Fertilization and First Week (days 1–14 of gestation) → failure to implant, double malformations, or identical twins Identical twins Result from the division of a single zygote; share the same genetic material Multiple Pregnancy
  • Embryopathy: all impairments of the organs during organogenesis (weeks 2–8):
    • High vulnerability to teratogens Teratogens An agent that causes the production of physical defects in the developing embryo. Cleft Lip and Cleft Palate
    • CNS, neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation (weeks 3 to 32–40) → neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation defects such as spina bifida and mental disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment
    • Heart (weeks 3 to 7–9) → truncus arteriosus Truncus arteriosus Truncus arteriosus (TA) is a congenital heart defect characterized by the persistence of a common cardiac arterial trunk tract that fails to divide into the pulmonary artery and aorta during embryonic development. Truncus arteriosus is a rare congenital malformation with a high mortality rate within the 1st 5 weeks of life if not managed promptly. Truncus Arteriosus communis, atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). Atrial Septal Defect (ASD), and ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot
    • Extremities (weeks 4 to 6–9) → partial absence ( meromelia Meromelia The condition when a part of the limb is missing. This occurs due to a disturbance in development during the 5th week of development. Development of the Limbs) or complete absence ( amelia Amelia The absence of one or both limbs, which occurs due to suspension in development during the 4th week. Development of the Limbs) of ≥ 1 extremity
    • Ears (weeks 4 to 10–32) → deafness, auricular dysplasia, or a deep base of the ear
    • Respiratory tract (weeks 4 to 16–40) → fistulas, stenoses, and atresia Atresia Hypoplastic Left Heart Syndrome (HLHS)
    • Urogenital system (weeks 4 to 16–40) → urachal fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula, horseshoe kidney Horseshoe Kidney Congenital Renal Abnormalities
    • GI tract (weeks 5 to 32–40) → stenoses, atresia Atresia Hypoplastic Left Heart Syndrome (HLHS), rotational disabilities, hernias, or omphalocele Omphalocele Omphalocele is a congenital anterior abdominal wall defect in which the intestines are covered by peritoneum and amniotic membranes. The condition results from the failure of the midgut to return to the abdominal cavity by 10 weeks’ gestation. Omphalocele
    • Face, lips Lips The lips are the soft and movable most external parts of the oral cavity. The blood supply of the lips originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy, palate Palate The palate is the structure that forms the roof of the mouth and floor of the nasal cavity. This structure is divided into soft and hard palates. Palate: Anatomy (weeks 5–8 to 16) → cleft lip Cleft lip The embryological development of craniofacial structures is an intricate sequential process involving tissue growth and directed cell apoptosis. Disruption of any step in this process may result in the formation of a cleft lip alone or in combination with a cleft palate. As the most common craniofacial malformation of the newborn, the diagnosis of a cleft is clinical and usually apparent at birth. Cleft Lip and Cleft Palate and palate Palate The palate is the structure that forms the roof of the mouth and floor of the nasal cavity. This structure is divided into soft and hard palates. Palate: Anatomy
  • Fetopathy: impairments in the maturation/differentiation of organs (weeks 9–38) → functional disabilities
Periods of time within gestation in which organ systems are most susceptible to teratogens

Periods of time within gestation in which organ systems are most susceptible to teratogens:
Gray: less sensitive period (functional and/or minor structural anomalies)
Green: highly sensitive period (major structural anomalies)

Image by Lecturio.

Maternal Systemic Illnesses

  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus:
    • Maternal hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus → fetal hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus → fetal hyperinsulinemia Hyperinsulinemia Diabetes Mellitus + islet-cell hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation → macrosomia → higher risks of injuries during birth and neonatal hypoglycemia Hypoglycemia Hypoglycemia is an emergency condition defined as a serum glucose level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic patients. In nondiabetic patients, there is no specific or defined limit for normal serum glucose levels, and hypoglycemia is defined mainly by its clinical features. Hypoglycemia
    • Increased risk of:
      • Congenital Congenital Chorioretinitis malformations (especially cardiac and neural defects)
      • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care loss
      • Growth restriction
      • Diabetic ketoacidosis Ketoacidosis A life-threatening complication of diabetes mellitus, primarily of type 1 diabetes mellitus with severe insulin deficiency and extreme hyperglycemia. It is characterized by ketosis; dehydration; and depressed consciousness leading to coma. Metabolic Acidosis
      • Maternal and perinatal mortality Mortality All deaths reported in a given population. Measures of Health Status
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension → ↓ flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure of nutrients to the fetus + ↓ placental blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure fetal growth restriction Fetal growth restriction Fetal growth restriction (FGR), also known as intrauterine fetal growth restriction (IUGR), is an estimated fetal weight (EFW) or abdominal circumference < 10th percentile for gestational age. The term small for gestational age (SGA) is sometimes erroneously used interchangeably with FGR. Fetal Growth Restriction, preeclampsia Preeclampsia A complication of pregnancy, characterized by a complex of symptoms including maternal hypertension and proteinuria with or without pathological edema. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease. Hypertensive Pregnancy Disorders, preterm delivery, placental abruption Placental Abruption Premature separation of the normally implanted placenta from the uterus. Signs of varying degree of severity include uterine bleeding, uterine muscle hypertonia, and fetal distress or fetal death. Antepartum Hemorrhage, and need for cesarean section
  • Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity: BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity ≥ 30 kg/m²
    • ↑ Maternal risk of gestational diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, preeclampsia Preeclampsia A complication of pregnancy, characterized by a complex of symptoms including maternal hypertension and proteinuria with or without pathological edema. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease. Hypertensive Pregnancy Disorders, and sleep apnea Sleep apnea Repeated cessation of breathing for > 10 seconds during sleep and results in sleep interruption, fatigue, and daytime sleepiness. Obstructive Sleep Apnea
    • ↑ Fetal risk of macrosomia, preterm birth Preterm birth Preterm labor refers to regular uterine contractions leading to cervical change prior to 37 weeks of gestation; preterm birth refers to birth prior to 37 weeks of gestation. Preterm birth may be spontaneous due to preterm labor, preterm prelabor rupture of membranes (PPROM), or cervical insufficiency. Preterm Labor and Birth, and stillbirth
    • Neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation defects, heart defects, omphalocele Omphalocele Omphalocele is a congenital anterior abdominal wall defect in which the intestines are covered by peritoneum and amniotic membranes. The condition results from the failure of the midgut to return to the abdominal cavity by 10 weeks’ gestation. Omphalocele
  • Graves disease → neonatal thyrotoxicosis Thyrotoxicosis A hypermetabolic syndrome caused by excess thyroid hormones which may come from endogenous or exogenous sources. The endogenous source of hormone may be thyroid hyperplasia; thyroid neoplasms; or hormone-producing extrathyroidal tissue. Thyrotoxicosis is characterized by nervousness; tachycardia; fatigue; weight loss; heat intolerance; and excessive sweating. Thyrotoxicosis and Hyperthyroidism
  • Hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism congenital Congenital Chorioretinitis hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism growth failure Growth failure Chronic Granulomatous Disease and permanent intellectual disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment

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Substance Use Disorder

Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases

  • Nicotine Nicotine Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke. Stimulants is a strong vasoconstrictor → ↓ uterine and placental blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure → ↓ fetal blood supply
  • Significantly increases the risk of:
    • Spontaneous abortion Abortion Expulsion of the product of fertilization before completing the term of gestation and without deliberate interference. Spontaneous Abortion
    • Premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis birth
    • Placental abruption Placental Abruption Premature separation of the normally implanted placenta from the uterus. Signs of varying degree of severity include uterine bleeding, uterine muscle hypertonia, and fetal distress or fetal death. Antepartum Hemorrhage
    • Sudden infant death syndrome Sudden Infant Death Syndrome Sudden infant death syndrome (SIDS) describes the sudden death of an otherwise healthy infant (< 1 year of age) with no identifiable cause. Sudden infant death syndrome is the leading cause of death in children between 1 and 12 months of age in the United States. Sudden Infant Death Syndrome (SIDS) ( SIDS SIDS Sudden infant death syndrome (SIDS) describes the sudden death of an otherwise healthy infant (< 1 year of age) with no identifiable cause. Sudden infant death syndrome is the leading cause of death in children between 1 and 12 months of age in the United States. Sudden Infant Death Syndrome (SIDS))
    • Asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma
    • Upper respiratory infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
    • Orofacial clefts Orofacial Clefts Cleft Lip and Cleft Palate
    • Low birth weight
  • Moderately increases the risk for:
    • Transposition of the great arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
    • Atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). Atrial Septal Defect (ASD)
    • Pulmonary stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
    • Common truncus arteriosus Truncus arteriosus Truncus arteriosus (TA) is a congenital heart defect characterized by the persistence of a common cardiac arterial trunk tract that fails to divide into the pulmonary artery and aorta during embryonic development. Truncus arteriosus is a rare congenital malformation with a high mortality rate within the 1st 5 weeks of life if not managed promptly. Truncus Arteriosus

Alcohol use disorder Alcohol use disorder Alcohol is one of the most commonly used addictive substances in the world. Alcohol use disorder (AUD) is defined as pathologic consumption of alcohol leading to impaired daily functioning. Acute alcohol intoxication presents with impairment in speech and motor functions and can be managed in most cases with supportive care. Alcohol Use Disorder

Alcohol use disorder Alcohol use disorder Alcohol is one of the most commonly used addictive substances in the world. Alcohol use disorder (AUD) is defined as pathologic consumption of alcohol leading to impaired daily functioning. Acute alcohol intoxication presents with impairment in speech and motor functions and can be managed in most cases with supportive care. Alcohol Use Disorder fetal alcohol spectrum disorder Fetal alcohol spectrum disorder Fetal alcohol spectrum disorder (FASD) is a group of neonatal pediatric disorders caused by maternal alcohol consumption during pregnancy. The term entails a range of physical and neurodevelopmental effects. Classification is based on severity and clinical presentation. Fetal Alcohol Spectrum Disorder (FASD)/ fetal alcohol syndrome Fetal alcohol syndrome An umbrella term used to describe a pattern of disabilities and abnormalities that result from fetal exposure to ethanol during pregnancy. It encompasses a phenotypic range that can vary greatly between individuals, but reliably includes one or more of the following: characteristic facial dysmorphism, fetal growth retardation, central nervous system abnormalities, cognitive and/or behavioral dysfunction, birth defects. The level of maternal alcohol consumption does not necessarily correlate directly with disease severity. Alcohol Use Disorder (severe end of the spectrum for alcohol-related defects)

  • Approximately 1 in 100 children have FASD.
  • Leading preventable cause of intellectual disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment
  • Alcohol dehydrogenase Alcohol dehydrogenase A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of nad. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of nadh and hydrogen. Ethanol Metabolism activity is lower in fetal liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity acts as a reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli for alcohol → ethanol Ethanol A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in alcoholic beverages. Ethanol Metabolism and acetaldehyde Acetaldehyde A colorless, flammable liquid used in the manufacture of acetic acid, perfumes, and flavors. It is also an intermediate in the metabolism of alcohol. It has a general narcotic action and also causes irritation of mucous membranes. Large doses may cause death from respiratory paralysis. Ethanol Metabolism alter fetal development
  • The most severe is fetal alcohol syndrome Fetal alcohol syndrome An umbrella term used to describe a pattern of disabilities and abnormalities that result from fetal exposure to ethanol during pregnancy. It encompasses a phenotypic range that can vary greatly between individuals, but reliably includes one or more of the following: characteristic facial dysmorphism, fetal growth retardation, central nervous system abnormalities, cognitive and/or behavioral dysfunction, birth defects. The level of maternal alcohol consumption does not necessarily correlate directly with disease severity. Alcohol Use Disorder characterized by congenital Congenital Chorioretinitis abnormalities, growth retardation Growth Retardation Failure of a fetus to attain expected growth. Fetal Alcohol Spectrum Disorder, intellectual disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment, and characteristic craniofacial features:
Characteristic facial features of an individual with fetal alcohol spectrum disorder

Characteristic facial features of an individual with fetal alcohol spectrum disorder

Image: “FASkid” by NIH/National Institute on Alcohol Abuse and Alcoholism. License: Public Domain

Opioids Opioids Opiates are drugs that are derived from the sap of the opium poppy. Opiates have been used since antiquity for the relief of acute severe pain. Opioids are synthetic opiates with properties that are substantially similar to those of opiates. Opioid Analgesics

  • Opioid Opioid Compounds with activity like opiate alkaloids, acting at opioid receptors. Properties include induction of analgesia or narcosis. Constipation use increases the risk of:
    • Intrauterine growth restriction (IUGR)
    • Placental abruption Placental Abruption Premature separation of the normally implanted placenta from the uterus. Signs of varying degree of severity include uterine bleeding, uterine muscle hypertonia, and fetal distress or fetal death. Antepartum Hemorrhage
    • Preterm labor Preterm labor Preterm labor refers to regular uterine contractions leading to cervical change prior to 37 weeks of gestation; preterm birth refers to birth prior to 37 weeks of gestation. Preterm birth may be spontaneous due to preterm labor, preterm prelabor rupture of membranes (PPROM), or cervical insufficiency. Preterm Labor and Birth
    • Fetal death
    • Neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation defects
    • Heart defects
    • Gastroschisis Gastroschisis Gastroschisis is a congenital abdominal wall defect characterized by the complete lack of closure of the abdominal musculature. A portion of intestine does not return to the abdominal cavity, thereby remaining in its early embryonic herniated state but with no coverings. Gastroschisis
  • Once born, babies present with neonatal abstinence syndrome Neonatal Abstinence Syndrome Neonatal abstinence syndrome (NAS), or neonatal withdrawal syndrome (NWS), occurs when in-utero addictive substances are suddenly discontinued due to birth. The most common substances include alcohol, nicotine, and rapidly increasing opioids. Neonatal Abstinence Syndrome and withdrawal.

Marijuana

  • Linked to a number of adverse pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care outcomes irrespective of whether it is smoked or ingested
  • Associated with an increased risk of anencephaly Anencephaly A malformation of the nervous system caused by failure of the anterior neuropore to close. Infants are born with intact spinal cords, cerebellums, and brainstems, but lack formation of neural structures above this level. The skull is only partially formed but the eyes are usually normal. This condition may be associated with folate deficiency. Affected infants are only capable of primitive (brain stem) reflexes and usually do not survive for more than two weeks. Neural Tube Defects (drug use during the 1st 4 weeks)
  • Increases the risk of neurodevelopmental deficiencies:
    • ADHD ADHD Attention deficit hyperactivity disorder is a neurodevelopmental disorder characterized by a pattern of inattention and/or hyperactivity-impulsivity that occurs in at least 2 different settings for more than 6 months. Although the patient has normal intelligence, the disease causes functional decline. Attention Deficit Hyperactivity Disorder
    • Learning disabilities Learning disabilities Conditions characterized by a significant discrepancy between an individual’s perceived level of intellect and their ability to acquire new language and other cognitive skills. These may result from organic or psychological conditions. Relatively common subtypes include dyslexia, dyscalculia, and dysgraphia. DiGeorge Syndrome
    • Memory Memory Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory. Psychiatric Assessment impairment

Medications

Medications that are contraindicated during pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care and the potential complications they are associated with are as follows:

  • Antibiotics:
    • Aminoglycosides Aminoglycosides Aminoglycosides are a class of antibiotics including gentamicin, tobramycin, amikacin, neomycin, plazomicin, and streptomycin. The class binds the 30S ribosomal subunit to inhibit bacterial protein synthesis. Unlike other medications with a similar mechanism of action, aminoglycosides are bactericidal. Aminoglycosides ( ototoxicity Ototoxicity Damage to the ear or its function secondary to exposure to toxic substances such as drugs used in chemotherapy; immunotherapy; or radiation. Glycopeptides)
    • Tetracyclines Tetracyclines Tetracyclines are a class of broad-spectrum antibiotics indicated for a wide variety of bacterial infections. These medications bind the 30S ribosomal subunit to inhibit protein synthesis of bacteria. Tetracyclines cover gram-positive and gram-negative organisms, as well as atypical bacteria such as chlamydia, mycoplasma, spirochetes, and even protozoa. Tetracyclines (dental diseases or deafness)
  • Antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs:
    • ACE inhibitors ACE inhibitors Truncus Arteriosus ( oligohydramnios Oligohydramnios Oligohydramnios refers to amniotic fluid volume less than expected for the current gestational age. Oligohydramnios is diagnosed by ultrasound and defined as an amniotic fluid index (AFI) of ‰¤ 5 cm or a single deep pocket (SDP) of < 2 cm in the 2nd or 3rd trimester. Oligohydramnios, renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome)
    • ARBs ARBs Agents that antagonize angiotensin receptors. Many drugs in this class specifically target the angiotensin type 1 receptor. Heart Failure and Angina Medication ( renal dysplasia Renal Dysplasia Congenital Renal Abnormalities)
  • Anticonvulsants: phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs or valproic acid Valproic acid A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of epilepsy and bipolar disorder. The mechanisms of its therapeutic actions are not well understood. It may act by increasing gamma-aminobutyric acid levels in the brain or by altering the properties of voltage-gated sodium channels. First-Generation Anticonvulsant Drugs (facial dysmorphia, neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation defects, congenital Congenital Chorioretinitis heart disease)
  • Psychiatric medications: lithium Lithium An element in the alkali metals family. It has the atomic symbol li, atomic number 3, and atomic weight [6. 938; 6. 997]. Salts of lithium are used in treating bipolar disorder. Ebstein’s Anomaly (cardiac abnormalities, including Ebstein anomaly)
  • Isotretinoin (facial abnormalities, congenital Congenital Chorioretinitis heart disease, neural tube Neural tube A tube of ectodermal tissue in an embryo that will give rise to the central nervous system, including the spinal cord and the brain. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. Gastrulation and Neurulation defects)
  • Warfarin Warfarin An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide. Anticoagulants (skeletal abnormalities)
  • Thalidomide Thalidomide A piperidinyl isoindole originally introduced as a non-barbiturate hypnotic, but withdrawn from the market due to teratogenic effects. It has been reintroduced and used for a number of immunological and inflammatory disorders. Thalidomide displays immunosuppressive and anti-angiogenic activity. It inhibits release of tumor necrosis factor-alpha from monocytes, and modulates other cytokine action. Immunosuppressants ( amelia Amelia The absence of one or both limbs, which occurs due to suspension in development during the 4th week. Development of the Limbs/ meromelia Meromelia The condition when a part of the limb is missing. This occurs due to a disturbance in development during the 5th week of development. Development of the Limbs and cardiac disorders)
  • Diethylstilbestrol Diethylstilbestrol A synthetic nonsteroidal estrogen used in the treatment of menopausal and postmenopausal disorders. It was also used formerly as a growth promoter in animals. According to the fourth annual report on carcinogens, diethylstilbestrol has been listed as a known carcinogen. Noncontraceptive Estrogen and Progestins (vaginal clear cell adenocarcinoma)

Infections

  • Urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease during pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care increase the risk of low birth weight, premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis labor, sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock, pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia, and miscarriage Miscarriage Spontaneous abortion, also known as miscarriage, is the loss of a pregnancy before 20 weeks’ gestation. However, the layperson use of the term “abortion” is often intended to refer to induced termination of a pregnancy, whereas “miscarriage” is preferred for spontaneous loss. Spontaneous Abortion.
  • Rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus infection during pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care:
    • Can lead to a classic triad of cataracts, deafness, and patent ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA)
    • May also present with glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma, microphthalmia, pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS), intellectual disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment, microcephaly Microcephaly A congenital abnormality in which the cerebrum is underdeveloped, the fontanels close prematurely, and, as a result, the head is small. (desk reference for neuroscience, 2nd ed. ). Fetal Alcohol Spectrum Disorder, or hepatomegaly
  • Sexually transmitted infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease can cause several problems in pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care:
    • Gonorrhea Gonorrhea Gonorrhea is a sexually transmitted infection (STI) caused by the gram-negative bacteria Neisseria gonorrhoeae (N. gonorrhoeae). Gonorrhea may be asymptomatic but commonly manifests as cervicitis or urethritis with less common presentations such as proctitis, conjunctivitis, or pharyngitis. Gonorrhea and/or chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia:
      • Increased risk of miscarriage Miscarriage Spontaneous abortion, also known as miscarriage, is the loss of a pregnancy before 20 weeks’ gestation. However, the layperson use of the term “abortion” is often intended to refer to induced termination of a pregnancy, whereas “miscarriage” is preferred for spontaneous loss. Spontaneous Abortion and preterm birth Preterm birth Preterm labor refers to regular uterine contractions leading to cervical change prior to 37 weeks of gestation; preterm birth refers to birth prior to 37 weeks of gestation. Preterm birth may be spontaneous due to preterm labor, preterm prelabor rupture of membranes (PPROM), or cervical insufficiency. Preterm Labor and Birth
      • Congenital Congenital Chorioretinitis infection can cause conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis, pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia, and sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock.
    • Syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis:
      • Increases the risk of miscarriage Miscarriage Spontaneous abortion, also known as miscarriage, is the loss of a pregnancy before 20 weeks’ gestation. However, the layperson use of the term “abortion” is often intended to refer to induced termination of a pregnancy, whereas “miscarriage” is preferred for spontaneous loss. Spontaneous Abortion and often results in stillbirth
      • Congenital Congenital Chorioretinitis syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis can cause deafness, skeletal deformities, jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice, and facial abnormalities.

References

  1. Hegde, S., Aedulla, N.R. (2021). Secondary Hypertension. StatPearls (Internet). Retrieved November 14, 2021. Secondary Hypertension – StatPearls – NCBI Bookshelf (nih.gov)
  2. Tsamantioti, E.S., Hashmi, M.F. (2021). Teratogenic Medications. StatPearls (Internet). Retrieved November 14, 2021. Teratogenic Medications – StatPearls – NCBI Bookshelf (nih.gov)
  3. Vorgias, D., Bernstein, B. (2021). Fetal Alcohol syndrome. StatPearls (Internet). Retrieved November 14, 2021. Fetal Alcohol Syndrome – StatPearls – NCBI Bookshelf (nih.gov)

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