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97 Cards in this Set
- Front
- Back
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Definition of malformation:
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a defect in structure of an organ, part of an organ, or larger region of the body resulting from intrinsically abnormal development due to defective genetic programming
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Definition of deformation:
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an abnormal form, shape, or position of a part of the body caused by mechanical forces
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Defintion of disruption:
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a morphologic defect of an organ, part of an organ, or a larger region of the body caused by extrinsic breakdown of, or interference with, an originally normal developmental process
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Definition of dysplasia:
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an abnormal organization of cells into tissue(s) and its morphologic result(s); i.e., dysplasia is the process and the consequences of dyshistogenesis.
Dysplasia example: Abnormal cell organization in the uteric buds leading to abnormal kidney development. |
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Timeline for teratogen effects on fetal development:
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What period of embryo/fetal development is most sensitive to insult?
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What is the most common aneuploidy?
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Monosomy X
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What is the most common group of aneuploidy?
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Trisomies
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Which trisomy is the most common?
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Trisomy 16
(usually lost in gestation) |
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Survival percentages of genetic abnormalities:
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Percentages reflect how many will survive to term.
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The risk of Downs syndrome increases with maternal age:
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Recall: maternal meiotic nondisjunction is the usual cause. When paternal nondisjunction occurs, there is no relation to paternal age. Translocation can also lead to a familial form of Down syndrome. Trisomy 21 is the most common aneuploidy at birth.
Most down syndrome births are born to women under 30; because this age bracket gives birth to way more children than the over 30 group. |
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In utero diagnosis of Downs syndrome:
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1. Maternal serum: high hCG and inhibin, low alpha fetoprotein and estriol
2. Chromosome analysis with CVS 3. Nuchal translucency on ultrasound |
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Clinical features of trisomy 21 (downs syndrome):
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- Cardiovascular anomalies
(AV communis (occurs in 50% of T21 and 50% of patients in cardiac clinics with AV communis will have T21) Atrial and ventricular septal defects) - Renal anomalies - Hypoplasia of the cerebellum - Duodenal atresia - Up slanting eyes - Small nose - Flattened nasal bridge - Short neck - Enlarged tongue - Abnormally shaped, small ears - Deep single palmar crease (Simian crease) - Clinodactyly (small bent 5th digit) - Short phalanges - Wide gap between 1st and 2nd toes |
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Characteristics of Trisomy 18 (Edwards syndrome)
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Baby has very little fat tissue; not the normal fat distribution of a newborn.
Most trisomy 18 babies that are actually born will make it up to 1 year. |
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Diagnosis of Trisomy 18 (Edwards syndrome):
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1. Maternal serum: low hCG, inhibin, alpha fetoprotein, estriol
2. CVS 3. Ultrasound (features very noticable) |
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Characteristics of Trisomy 13 (Patau syndrome):
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Diagnosis of Trisomy 13 (Patau syndrome):
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Summary of the most common Trisomies:
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Which chromosomal abnormality is NOT associated with advanced maternal age?
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- In humans, the only full monosomy is 45, X or Turner Syndrome
- Usually due to loss of the male X chromosome - Not associated with advanced maternal age |
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Characteristics of Turners syndrome part 1:
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Born with a full set of oocytes at birth, but by around 9 years of age, all the oocytes have died off leading to streak gonads
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Characteristics of Turners Syndrome Part 2:
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* Excessive fluid in the back of the neck
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Summary of trisomies of the sex chromosomes:
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What syndrome results from the loss of part of the short arm of chromosome 5?
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Most are de novo deletions (80-85%). Some derive from a familial rearrangement (12%).
Hypertelorism: wide set eyes |
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Robertsonian Translocations:
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Examples of microdeletions and microduplications:
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CATCH 22: Cardiac abnormalities, Abnormal facies, T-cell deficit due to thymic hypoplasia, Cleft palate, Hypocalcemia because of hypoparathyroidism, and microdeletion 22q11.
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Fragile X Syndrome:
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Daughters have a normal X to fall back on, while sons do not.
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Osteogenesis Imperfecta:
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Maternal screening in the 1st trimester:
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Maternal screening in the 2nd trimester:
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Between what weeks of gestation is CVS performed?
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Between 10-14 weeks
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Between which weeks gestations is amniocentesis performed?
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From 15 weeks till birth
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Gestational Hypertension:
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Mild pre-eclampsia:
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Severe Preeclampsia:
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HELLP = hemolysis (microangiopathichemolysis occurs), elevated liver enzymes, low platelets
Other maternal effect associated with severe preeclampsia s include pulmonary edema or cyanosis, hepatic rupture, LV dysfunction |
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Definition and timing of eclampsia:
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Pathogenesis of Eclampsia:
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Pathophysiology of Eclampsia:
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- Cerebral overregulation in response to high systemic blood pressure results in vasospasm of cerebral arteries, underperfusion of the brain, localized ischemia/infarction, and edema.
- Loss of autoregulation of cerebral blood flow in response to high systemic pressure results in hyperperfusion, endothelial damage, and vasogenic (extracellular) edema. |
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Syptoms of Pre-Eclampsia:
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* Swelling is due to fluid shift into extravascular spaces, not as a result of volume overload. Therefore it is BAD to give a diuretic to a women with pre-eclampsia swelling, as you may collapse her circulation and cause organ damage.
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What drug is the primary choice to treat/prevent seizures in eclampsia?
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Magnesium Sulfate
- MgSO4 for primary prevention of eclampsia more effective than phenytoin, or nimodipine in RCT for prevention seizures of recurrent eclamptic seizures - MgSO4 more effective at preventing recurrent seizures than a mixture of chlorpromazine, promethazine, and pethidine in RCT - Phenytoin second line agent if MgSO4 contraindicated (allergy or pulmonary edema) |
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Treatment of magnesium sulfate overdose:
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Glucose metabolism in pregnancy:
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What placental hormones are involved with glucose and insulin metabolism?
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- Human Placental Lactogen (HPL)
Produced by syncytiotrophoblasts of placenta Acts to promote lipolysisincreased FFA and to decrease maternal glucose uptake “Anti-insulin” - Estrogen and Progesterone Interfere with insulin-glucose relationship. - Insulinase Placental product that may play a minor role in insulin degradation |
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What is the risk to the fetus in diabetic mothers?
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- Infants of diabetic mothers are at a six-fold increased risk of congenital anomalies compared to the 1-2% baseline risk seen in the general population
- Most common anomalies involve cardiac and limb deformities, also renal and GI - With pre-existing diabetes and poor glycemic control, the rate increases significantly as control worsens: If 1st trimester HbA1C> 8%, sharp increase If HbA1C> 12%, 25% of babies will have major malformation |
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What effects on growth occur with maternal diabetes?
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Macrosomia
Definition: Birth weight >4,500 grams Affects 5-15% of diabetic pregnancies, a 4-fold increase over non-diabetic pregnancies Associated with numerous morbidities Growth Restriction Although diabetes typically associated with macrosomia, growth restriction relatively common among Type 1 diabetic mothers. Best predictor = presence of maternal vascular disease Macrosomia due to fetal metabolic effects of increased glucose transfer across the placenta In diabetic mothers with vascular complications, intrauterine growth restriction occurs as a result of uteroplacental insufficiency |
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Other complications of maternal diabetes in a fetus:
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Also Respiratory Distress Syndrome: Surfactant (composed of phospholipids) maintains patency of alveolar sacs and is thus necessary for normal lung function
Lung development and surfactant production delayed in fetuses of diabetic mothers Mechanism: increased insulin restricts substrate availability for surfactant production by blocking effect of cortisol on fibroblasts |
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Treatment of diabetes during pregnancy:
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May use all forms of insulin.
Oral hypoglycemics: Glyburide: may use up to 20 mg/day and can be given in all trimesters- crosses placenta Metformin: can be used up to 2,500 mg/day and can be given in all trimesters- crosses placenta |
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Thalidomide:
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What is the normal background rate for birth defects?
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2-4%
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Principles of Teratology:
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Critical periods for teratogens:
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In order for a substance to cross the placenta it must:
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Must not be degraded by:
Maternal metabolism Placental metabolism Must not be quickly excreted by maternal high GFR Must be small to allow simple diffusion The first trimester placental membrane is highly charged Must not be highly charged Must be lipophilic |
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Teratogenic drugs in humans:
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ACE inhibitors
Alcohol Alkylating agents Anti-metabolites Anti-thyroids Androgenic agents Anti-convulsants Diethylstilbestrol Lithium Misoprostol Retinoids Tetracycline Thalidomide Warfarin |
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How does disruption of folic acid metabolism cause defects?
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Folic acid is needed for methionine production
Methionine is needed for methylation and production of proteins, lipids and myelin Neural tube defects, cardiac defects, cleft lip and cleft palate and even Down’s syndrome arise from defects in folic acid metabolism |
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How much folic acid should pregnant women take?
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Neural tube forms by week 4-before most women know they are pregnant
Women not using contraception should take folic acid 400 mcg daily daily Most multivitamins contain 400 mcgs folic acid Women with a history of a child with neural tube defects or other risk factors should take 4 mg |
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Accutane:
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ACE Inhibitors:
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Warfarin:
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Fetal Alcohol Syndrome:
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TORCH infections:
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Affect the heart, skin, eye and CNS:
Chorioretinitis Microcephaly Petechial rashes Cerebral calcifications Hepatosplenomegaly |
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What is the most common defect in babies infected with Rubella in utero?
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Sensorineural deafness
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Phases of Parturition:
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Phase 3 is broken down into “Stages” of labor
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Quiescence:
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Activation and Stimulation:
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Induction of labor:
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Timing of Parturition
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- In sheep, the signal to begin birth appears to come from the fetus and requires intact HPA axis and functional placenta
- In humans, anomalies of the brain interfere with timing of the onset of labor(Congenital absence of the fetal pituitary prolongs gestation) |
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Role of oxytocin in labor:
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The 3 stages of labor:
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What is the definition of preterm birth?
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Birth before 37 weeks
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What is considered "late preterm birth"?
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34-36 weeks gestational age
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Spontaneous preterm labor pathogenesis:
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What is a major risk factor for preterm birth?
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- Major risk factor is prior PTB
- Risk is 3 fold higher with hx of PTB Hx of PTB x 2 – 41% will deliver preterm 70% deliver within 2 wks of time of previous PTB Cause of PTB typically recurred These pts are only 10% of total of all PTB |
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What is another major factor of PTB that has nothing to do with pregnancy history?
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Intrauterine infection trigger PTL by activation of immune system
Bacteria trigger cytokine release which triggers PG and matrix degrading enzyme PG trigger uterine contraction Enzymes degrade matrix in fetal membranes leading to PROM 25-40% of PTB caused by infection |
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Which two bacteria are mainly associated with PTB?
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Ureaplasma urealyticum
Mycoplasma hominis |
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What fetal secretion in cervical fluid may indicate risk of PTB?
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Fetal fibronectin; should normally only be present at full term
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What treatments are available to prevent PTB?
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- Progesterone injections or suppositories.
- Cervical cerclage - Administer corticosteroids to hasten fetal lung development |
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What treatments slow down the advent of preterm labor by 24-48 hours?
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- Ritodrine
- Terbutaline - Magnesium Sulfate - Indomethicin (prostaglandin inhibitor) - Calcium channel blockers |
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Weight gain recommendations during pregnancy:
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How many calories per day should intake increase during 1st, 2nd and 3rd trimesters?
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Calories
Increase 250–300 cal/day 340 2nd trimester 450 3rd |
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How much should protein intake increase per day during pregnancy?
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Increase by 25g per day
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By how much should intake of carbohydrates and fats increase during pregnancy?
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- Carbohydrates
Main source of extra energy, 175 g/day Fiber important to prevent constipation and hemorrhoids Decrease simple carbs (empty calories) - Fats Doesn’t change during pregnancy but important Focus on essential fats (Omega 3s) Nuts, oils, whole grains |
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Vitamin and mineral supplements during pregnancy:
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The picture used in this slide represents food sources of folate. Folate occurs naturally in many dark green leafy vegetables, beans, citrus fruits, whole grains, poultry, pork, and shellfish. For many pregnant women, folate may not be adequately available in modern Western diets—in the 1970s, a deficiency in dietary folate became clearly linked to neural tube defects. The neural tube develops into the brain and spinal cord during the first twenty-eight days of pregnancy. Without adequate folate the tube may not close completely. One possible outcome of this incomplete closing is known as spina bifida, a condition in which the lower end of the spinal cord may be exposed. Paralysis or weakness of the legs, bowel, or bladder can result.
The U.S. Public Health Service and the March of Dimes recommend that all women of child bearing age consume 400 mcg of folate per day. This recommendation is made for all women because adequate intake is so crucial in the first twenty-eight days of pregnancy, which typically pass before most women know they are pregnant. In addition, low folate levels in the mother increase the risks of a preterm delivery, a low-birth-weight baby, and slow fetal growth rate. Vitamin A supplementation is not recommended during pregnancy, except at very low levels. |
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Nutrient recommendation changes in pregnancy:
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Iron needs increase for hemopoiesis. Even moderate iron deficiency anemia is associated with a two fold higher risk of maternal mortality. Also associated with pre term delivery, low birth weight, and perinatal mortality. However, fetal iron needs are met at the expense of maternal needs. Iodine is particularly important because it is an essential part of thyroid hormones which is important to myelination of the central nervous system. Lack of Iodine is damaging to brain development and can lead to retardation, hypothyroidism and goiter. The iodine requirements are based on the iodine content of the newborn thyroid gland. Zinc has catalytic, structural and regulatory functions. Almost 100 enzymes depend on it. Maternal Zinc deficiency can lead to prolonged labor, intrauterine growth retardation, teratogenesis and embryonic or fetal death.
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Herbal supplements during pregnancy:
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By how much should intake of fluids increase during pregnancy?
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General fluid requirements increase during pregnancy to aid fetal circulation, create amniotic fluid, and provide a higher blood volume. Assuring adequate fluid intake also helps prevent constipation by keeping things moving through the intestines. Individuals generally need 1–1.5 mL of water for each calorie consumed (e.g., a person eating a 2000-calorie diet would need 2000–3000 mL (about 64 ounces or 8–10 cups) of fluid each day). Most pregnant women are advised to increase their caloric consumption by about 300 calories, beginning in the second trimester. Therefore, they would need at least 300 mL of additional fluids.
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Exercise and pregnancy:
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Current research, although limited, consistently shows that women who exercise before pregnancy can continue to do so once pregnant. Moderate-intensity aerobic exercise has been shown to be safe in pregnancy. Many studies indicate that trained athletes may be able to exercise at a higher level than is currently recommended by the American College of Obstetricians and Gynecologists, but pregnant women in this category should consult their health-care professional before doing so.
Compared to women who are inactive, those who exercise during pregnancy are reported to have an approximately 50 percent reduction in the risk for gestational diabetes mellitus and an approximately 40 percent reduction in risk of developing high blood pressure. It was initially thought that exercising during pregnancy leads to an increased risk of neural tube defects if overheating occurs. This belief came from animal studies, but today the risk is no longer thought to be as great in humans; our bodies get rid of heat differently and more efficiently than do those of animals. Nonetheless, because overheating does occur in humans, extra care should be taken to maintain adequate hydration during exercise and to avoid extreme temperatures. A body temperature of 102 degrees or higher experienced in the first 6 weeks of pregnancy has been shown to increase the risk of neural tube defects. Research suggests that moderate exercise may enhance birth weight, while intense or frequent exercise maintained into the third trimester may result in lower-birth-weight babies. Therefore, strenuous exercise, such as sprinting, or any exercise that may involve impact, such as martial arts, should be avoided. Studies of pregnant women engaging in moderate resistance training while avoiding maximal lifts have reported no negative outcomes. Exercise is not recommended for women with complications during pregnancy or with a history of complications. Exercise can be done safely while breast-feeding as long as the woman consumes enough calories to compensate for the calorie needs of exercise and lactation. |
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Morning sickness and food cravings:
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Although morning sickness is not a big threat to the outcome of a pregnancy, it may make it difficult to consume all of the nutrients needed at the outset of pregnancy (first trimester), which is crucial. For some women, morning sickness occurs throughout their pregnancy, but for most it subsides by the second trimester.
“Morning” sickness may not be the best term for this condition, as many pregnant women suffer from nausea at various times of day. It is most commonly experienced in the morning because long periods without food can trigger it. To help alleviate this feeling upon wakening, many women keep crackers or dry cereal at their bedside so they can eat something before getting out of bed. Smaller, more frequent meals may also help, along with avoiding strong smells that appear to trigger the nausea. Some women find that somewhat acidic foods are tolerated especially well. Pickles, citrus fruits, apples, and even salsa may taste unexpectedly good. That preference for tart and sour tastes, combined with a rising desire for calories and a tendency to prefer cold to hot foods, may be the source of the old “pickles and ice cream” jokes about pregnancy cravings. Some women do experience specific food cravings during pregnancy. Typically, these preferences are for sweet or salty foods, such as that old cliché of pickles and ice cream. These cravings are harmless and can easily be fulfilled. They are not, however, typically associated with the body’s need for certain nutrients as was once thought. Occasionally, cravings are harmful, particularly when they involve something other than food—ice chips, clay, chalk, or even dirt. This behavior is called pica and generally refers to the compulsive eating of nonfood substances. Women who are inclined to consume these nonfood substances may have been exposed at some time in their lives to lead or other environmental toxins. Pica may lead to an iron deficiency in the mother and a smaller head circumference for the infant. It may also lead to inadequate weight gain, intestinal blockages, diarrhea, vomiting, infections, and other health complications. Therefore, any woman experiencing these cravings should consult a health-care professional to discuss strategies to address the issue as soon as possible. |
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What is the recommended caffeine intake during pregnancy?
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- Avoid caffeine or limit daily caffeine intake to no more than 300 mg per day
136 mg in 8 oz. of coffee, 48 mg in 8 oz. of tea, and 35 mg in a 12 oz. soda |
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Nutritional requirements during breastfeeding:
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What foods are considered to be a cause of colic?
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Colic is extended crying in babies that are otherwise healthy and well nourished. In the past, it was thought to be caused by digestive system symptoms, like painful gas. It is now believed to have more to do with an immature nervous system. Some studies among colicky breast-fed infants suggest that it may help to remove certain foods from the mother’s diet that are considered high-allergy foods; the results of these studies are inconclusive. Exactly how these foods (or their antigens) might cause colic is not known. However, antigens from cow’s milk, peanuts, eggs, and wheat have been found in human milk. Therefore, eliminating these foods in the mother’s diet might help to alleviate symptoms of colic in the infant.
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How does the fetal heart work in parallel, rather than in series?
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Fetal oxygenation:
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Although fetal partial pressure of oxygen is much lower, the saturation is relatively higher than in the adult. This is because HbF (75% of hemoglobin at birth) has a greater affinity for oxygen than adult hemoglobin. The fetal oxy-Hgb dissociation curve is displaced to the left.
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Fetal kidney development:
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- New nephrons formed until 36 weeks
- Ability to concentrate and modify pH is limited even in mature fetus - Fetal urine hypotonic with respect to fetal plasma - Important in control in composition and volume of amniotic fluid - Kidneys - Not essential for survival in utero - Failure to form can cause Lung hypoplasia and limb Deformities |
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Fetal lung development:
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- Lungs develop late
- Limitations in the pulmonary vessel capacity - Fluid build up in lungs - High resistance - Blood flow bypasses lungs through ductus arteriosus (90%) - 10% of fetal cardiac output to lungs |
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Role of surfactant at birth:
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- At birth, with first breath,
Air to tissue interface produced in the alveolus - Surfactant uncoils from lamellar bodies and spreads to line alveolus to prevent collapse during expiration - Composition: 90% lipid, 10% protein Glycerophosphlipids: 80% Phosphatidylcholine: Dipalmitoylphosphotidylcholine - Phosphatidylglycerol Induced by glucocorticosteroids L/S ratio – lung maturity studies |
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Changes that occur with the first inflation of the lungs:
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Circulatory changes that occur at birth:
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- Umbilical vessels, ductus arteriosus, foramen ovale, and ductus venosus normally constrict or collapse
- Functional closure of ductus arteriosus and expanding lungs results in: Blood leaving right ventricle enters the pulmonary vasculature to become oxygenated - Ventricles work in series |
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Remnants of fetal bypass veins after birth:
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- Ductus arteriosis closes within 1-2 days
- Replaced by connective tissue ligamentum arteriosum - Clamping/cutting of cord leads to no blood flow through umbilical arteries/veins causes degeneration - Increase in peripheral resistance in systemic circulation - Increase in pressure in aorta DA becomes left to right shunt - Pressure/Oxygen increases in aorta (lungs functioning) - DA closes |
