OB shelf - quiz
Card Set Information
OB shelf - quiz
OB shelf preconception counseling genetics prenatal diagnosis
OB shelf quiz 1 of _
After initial SAB in first trimester, what is the risk of recurrence?
No difference than it was prior to miscarriage
15% of all known pregnancies end in first trimester SAB
What proportion of 45,X (Turner) and Trisomy 21 (Down) make it to term?
: 99% are lost before term. Frequency of live birth is 1:2000
: 75% are lost before term
Frequency of chromosomal abnormalities in SAB, stillbirths, and live births?
50% of SAB
5% of stillbirths
0.5% of live-born babies
After 3 first-trimester SAB, what is the chance of live birth of future pregnancy with and without treatment?
: live birth rate approaches 50%
: 70 to 85% live birth rate
After 3 consecutive T1 SABs, what is the proper evaluation?
Chromosomal analysis of the couple
What is the most common of T2 SAB?
Uterine or environmental
: thyroid, DM, collagen vascular disorders, hysterosalpingogram (structural abnormalities)
Does having ≥ 3 T1 SABs increase a patient's risk for having a baby with Down syndrome?
Yes, the risk of aneuploidy is increased with multiple miscarriages
Paternal age does not matter till after 55
Induced ovulation does not increase risk
Which of the following drugs has the lowest potential to cause birth defects?
Valproic acid (Depakote)
Progesterone: incidence of birth defects for women who are on birth control pills is the same as the general population
Threshold for X-ray in a pregnant woman, GA 10 weeks?
Generally thought to be 10 rads
: developing organ systems are affected
: brain is more sensitive
Exercise in pregnant women?
Can maintain exercise during pregnancy if they had previously been accustomed to exercising prior to becoming pregnant
There is no set pulse defined as an upper limit
Non-weight-bearing exercise will minimize the risk of injury
Physiologic changes persist from 4 to 6 weeks following delivery, women should not resume the intensity of prepregnancy exercise immediately following delivery
Usefulness of nuchal translucency?
10 and 13 weeks
, nuchal translucency is a useful marker for increased risk of
, including Down syndrome
Nuchal translucency will almost always disappear by 15 weeks
Autosomal dominant inheritance
New mutations account for
of all cases of the disorder
Achondroplastic women almost
require cesarean section
Achondroplastic fetuses should be delivered by cesarean section to minimize trauma to the neck
What happens to a parent who has a balanced translocation?
balanced translocations of the same chromosome are
Gamete formation: translocated chromosome cannot divide, resulting in either two copies or no copies in the meiosis product (trisomy or monosomy)
: many are lethal in utero (13, 18, 21 lead to syndromes)
: all are lethal except monosomy X
: outpouching of neural tissue through a defect in the skull
Often confused with an encephalocele
It emerges from the base of the neck with an intact skull
Increased size of the lateral ventricles
Absence of the skull and diminished neural tissue
Defect of the abdominal wall at the insertion of the umbilical cord, which may lead to herniation of the abdominal contents
maternal serum α-fetoprotein (MSAFP)
uses, timing, reasons for elevated MSAFP?
MSAFP may be performed between
15 and 21 weeks
neural tube defects
Early in pregnancy (<19weeks)
: if the value is <4.0 MOM, a second MSAFP is drawn
High value >4.0 MOM, or gestation approaching limit of test (19+ weeks)
: skip repeat and go to ultrasound and possibly amniocentesis
: anencephaly, twins, wrong GA, fetal demise
what is the fastest method of determining fetal cytogenetics?
Chorionic villus sampling
: direct, extremely rapid diagnosis
Amniocentesis, cordocentesis, cystic hygroma aspiration, and CVS are all able to obtain fetal tissue
: cells require culture to obtain adequate number
Percutaneous umbilical blood sampling (PUBS)
: 2 to 3 days of culturing before karyotype is obtained
CVS vs amniocentesis:
: transcervical catheter (painless), higher complication rate in midtrimester
: more complications than CVS in the first-trimester
Which immunization should be avoided in pregnancy?
Live attenuated viruses are contraindicated
: measles and mumps (and rubella, since it is contained with the others), varicella, polio
Bacterial vaccines (cholera, plague, typhoid)
: can be used
Which vaccines can be used in pregnancy?
Inactivated or formalin-killed
: influenza, typhoid fever, tentanus, pertusis, diphtheria toxoid, rabies, poliomyelitis, cholera, plague, Rocky Mountain spotted fever
Consequence of alcohol abuse in pregnant women?
Fetal alcohol syndrome
: microcephaly, growth retardation, cardiac anomalies, increased incidence of mental retardation
Treatment of UTI in pregnant women: which abx to use/avoid?
Penicillins and cephalosporins are ok
: fetal dental anomalies in T2-T3, teratogen in T1
: may cause gray baby syndrome (vomiting, impaired respiration, hypothermia, cardiovascular collapse)
: contraindicated in T3 (kernicterus)
Tx for woman at 12 weeks GA with gonorrhea cervicitis?
Neural tube defects
risk in population? risk with previously affected children?
: 1.4 to 2/1000
Previously affected children
: 3 to 4%
: hyperthermia (sauna baths), at time of neural tube formation
Not influenced by maternal age
Implications of decreased AFP?
MSAFP will pick up 90% of neural tube defects
Positive predictive value
: 2 to 6% (most elevated AFP pregnancies do not have NTDs!)
Unexplained high AFP
: associated with adverse pregnancy outcomes (low birth weight, placental abruption, oligohydramnios, fetal death in utero)
Obesity in pregnancy:
recommended weight gain?
Morbidly obese women do NOT need to gain the 25 to 35 lbs recommended to women of normal weight
: complications during pregnancy, diabetes, hypertension, fetal macrosomia, cesarian section
Epilepsy in pregnancy:
risk to fetus?
risk with medications?
Epileptics without medication
: offspring have 2 to 3 times the risk of congenital anomalies (seizures cause transient reduction in blood flow)
Risk with medications
: even greater risk. Many Rx impair folate metabolism
: 1 to 2% risk of spina bifida
increase risk for...
Tay-sachs (carrier 1/30)
Canavan's disease (carrier 1/40)
Gaucher's disease (carrier 1/12 to 1/25)
white northern european
: cystic fibrosis (carrier 1/25)
Vegetarian diet during pregnancy
animal sources of protein contain amino acids in the most desirable combination
: low in vitamin B12
Substance, risk in pregnancy:
: >5 cups of coffee is associated with slightly increased risk of SAB
: placental abruption, congenital anomalies (skull defects, disruptions in urinary tract development, limb defects, cardiac anomalies)
: no associated adverse effects
: not a human teratogen
: SAB, preterm labor, growth restriction, placental abruption, placenta previa, ADD, behavior and learning problems