Preconception Care, Prenatal Counseling, Teratology and Prenatal Diagnosis -Castro

Question 1

Who is generally responsible for preconception care? What are common issuers to address?

Answer 1

the primary care provider

family planning, weight, nutrition and exercise, substance use, medications, screen for infections/immunize

Question 2

How much folic acid is recommended for a normal woman? for a patient with an increased risk for neural tube defects?

Answer 2

normal: 300 mcg/day preconception through pregnancy

increased risk: 4 mg/day 1 month preconception and in 1st trimester then decrease to 400mcg/day later

Question 3

If a woman is not vaccinated against Rubella, when should the vaccine be given?

Answer 3

3 months before pregnancy

Question 4

What are some class D medications that should be avoided during pregnancy?

Answer 4

ACE Inhibitors
tetracycline
coumadin

Question 5

What are some class X medications that should be avoided during pregnancy?

Answer 5

valproid acid and accutane

Question 6

What are the different categories of medications: A, B, C, D, X?

Answer 6

A=no risk in human studies

B=no evidence of risk in studies

C=Risk cannot be ruled out (animal studies show adverse effects on fetus or no studies in animals or women)

D=human risk. Only use if benefits outweigh risks

X=do NOT use in preggos

Question 7

What are the target goals for pre gestational diabetes (Hgb A1c, FBS, PPBS)? When is the ideal time to control diabetes?

Answer 7

Hgb A1C < 6.5

FBS (fetal blood sugar): 70-90

1 hour PPBS (post prandial (after eating) blood sugar): 100-130

control BEFORE pregnant

Question 8

What are the potential diagnostic methods used after a positive abnormal prenatal screening?

Answer 8

invasive testing (CVS, Amniocentesis, Cordocentesis) (all corey some risk of fetal loss)

high resolution fetal ultrasound

Non-invasive testing for cell free fetal DNA in maternal blood

Question 9

What is genetic counseling?

Answer 9

non-directive

involves:

• educating patient re: screening vs. diagnostic testing
• discussing potential risks and benefits of testing
• information about conditions tested for
• information on options

Question 10

What prenatal diagnosis is offered to all women?

Answer 10

diagnosis for aneuploidy

Question 11

What are some common carrier screening tests used to detect asymptomatic carriers?

Answer 11

Cystic fibrosis: DNA based. Defective chloride channels. 1/25 Caucasions

Tay Sachs: Enzyme or DNA. Hexosaminidase A deficiency (Ashkenazi Jews and French Canadians)

Canavan disease: DNA

Alpha Thalassemia: MCV

Beta Thalassemia: MCV and Hgb

Sickle Cell Disease: Hgb. defective gene for beta chain. 1/10 African Americans

Question 12

If a pregnant woman tests positive for a carrier screening, what is your next step?

Answer 12

Offer partner testing and/or prenatal diagnosis

Question 13

What is Fragile X Syndrome?

Answer 13

X-linked, look for # triplet repeats on long arm of X chromosome.

most common inherited form of disability

screen women with premature ovarian failure, and individuals with autism or low IQ of unknown cause

Question 14

What does increased maternal age put a fetus at risk of? Is paternal age also associated with this?

Answer 14

aneuploidies

normally from meiotic nondisjunction

Paternal age is not associated with aneuploidies but is associated with skeletal dysplasias

Question 15

What is the first trimester screening? At what gestational age should this be done? What should be offered with a positive screening?

Answer 15

US for fetal NT (nuchal translucency)

serum free beta hcg

9-13 weeks GA

offer CVS diagnosis or 2nd trimester screen

Question 16

What does the second trimester serum screening include? When is this done? What should be offered when there is a + screen?

Answer 16

AFP, estriol, Beta hcg and inhibin A (quadruple test)

15-18 weeks (can be offered to women that missed the first trimester screen)

+ test==> offer diagnostic amniocentesis

Question 17

What can an elevated AFP in the 2nd trimester screen indicate?

Answer 17

open neural tube defects

Question 18

Which screening test provides 95% detection for T-21 with only a 5% false positive rate?

Answer 18

Integrative screening (combines first and second trimester tests)

Question 19

What are some characteristics of Trisomy 21?

Answer 19

(Down syndrome):

• short stature
• classic facies
• developmental delay
• IQ 40-90
• can be assoc with other anomalies (duodenal atresia, cardiac)

Question 20

What are some characteristics of Trisomy 18?

Answer 20

(Edward’s Syndrome):

• severe growth restriction and multiple congenital anomalies.
• Clenched fist
• overlapping digits
• rocker bottom feet.
• May have: cardiac defects, omphalocele, NTD’s.
• Most die by age 2.

Question 21

What are some characteristics of Trisomy 13?

Answer 21

(Patau’s syndrome):

• growth restriction with multiple anomalies—often midline defects of brain and face such as holoprosencephaly, cleft palate, proboscis
• club feet
• polydactyly
• omphalocele
• Usually don’t live past first year of life.

Question 22

What does an elevated 2nd trimester serum AFP screen for? What are the most common types? What tests confirms a diagnosis?

Answer 22

open neural tube defects

anencephaly, spina bifida (myelomeningocele), encephalocele

diagnosis confirmed by fetal ultrasound with or without amniocentesis for amniotic fluid AFP/acetylcholinesterase

Question 23

What are some other causes of elevated AFP?

Answer 23

• fetal abdominal wall defects (gastroschisis, omphalocele) (gut makes AFP –> more into the maternal flow)
• placental abruption
• fetal demise
• multiple gestation
• wrong gestational age

Question 24

What is a teratogen? What are the most common ones? When is it most important to avoid these?

Answer 24

anything that causes a birth defect in the exposed fetus—includes anatomic abnormalities, growth abnormalities, fetal loss, mental or developmental abnormalities

Historical teratogens: thalidomide (phocomelia), and DES (vaginal adenocarcinoma), alcohol, tobacco, cocaine, meth, warfarin, anti-HTN meds, chemo agents, radiation, isotretinoin, dilantin, valproic acid, phenobarbitol,

most important in the first trimester*

Question 25

What are some signs of Fetal Alcohol Syndrome? What is a safe amount of alcohol in pregnancy?

Answer 25

• microcephaly,
• IUGR or post-natal growth deficiency
• midfacial defects (short palpebral fissures, short nose, thin vermillion border, hypoplastic philtrum, possible cleft lip/palate)
• possible cardiac defect

*no alcohol has been proven to be safe

Question 26

What can coumadin cause in a fetus? What can be used in pregnant women instead?

Answer 26

• fetal loss
• IUGR
• postnatal growth deficiencies/skeletal dysplasia
• craniofacial anomalies
• crosses placenta
• can cause fetal hemorrhage

*heparin/lovenox does NOT cross the placenta

Question 27

What fetal problems can valproic acid cause?

Answer 27

facial dysmorphisms

neural tube defects