OB Exam 52&53 Flashcards
Complications due to a woman being diabetic:
Macrosomia, Caudal regression syndrome, neural tube defect’s, anencephaly, transposition of the great vessels, pyelonephritis…
Know what day division occurs for each type of twin
Di/di: 0-4
Mono/di: 4-8
Mono/mono: after 8 days
Conjoined: 13
Preeclampsia and eclampsia
Preeclampsia as a pregnancy condition in which hypertension develops with proteinuria and edema.
Eclampsia is the occurrence of seizures or coma in a preeclamptic patient
What can immune hydrops lead to?
Congestive heart failure and anasarca.
What sonographic findings indicate hydrops
Scalp edema, pleural effusion, pericardial effusion, ascites, polyhydramnios, thickened placenta
Heart rate of 200 to 240 bpm
What is the most common cause of nonimmune hydrops
Cardiovascular lesions
What does the placenta look like for a hypertensive pregnancy? diabetic pregnancy?
Hypertensive pregnancies are associated with small placentas while diabetic mothers may have placentomegaly.
Difference between dichorionic, diamniotic, etc.
Dizygotic twins are fraternal and arise from two separately fertilized ova
Monozygotic twins are identical and come from a single fertilized egg that divides
Di/di has two placentas
Mono/di: 1 placenta but 2 amniotic sac’s
Mono/mono: share placenta and sacs; at high-risk
What confirms the presence of a diamniotic pregnancy?
A membrane separating the fetuses. A male and female fetus are going to be dizygotic, diamniotic, and dichorionic.
What abnormalities are possible in a maternal obese patient?
Neural tube defect’s, pregnancy induced hypertension, severe eclampsia, multiple births, UTI
What is caudal regression syndrome?
Lack of development of the caudal spine and cord found almost exclusively and diabetic individuals
Poly/oli (stuck twin syndrome)
Diamnionic pregnancy with poly in 1 sac and severe oligohydramnios and a smaller twin in the other sac. Manifests between 16 and 26 weeks. Mostly occurs in monochorionic pregnancies. Twin to twin transfusion syndrome can occur with this.
Acardiac twin
Where cardiac anomaly in monochorionic twins when one twin develops without a heart and often without the upper half of the body. Possibly due to artery to artery connection in the placenta that leads to perfusion of the abnormal twin via the co twin.
What week range does stuck twin syndrome occur
16 to 26 weeks
Twin to twin syndrome
Exist when there is an arteriovenous shunt within the placenta. The arterial blood of one twin is pumped into the venous system of the other twin. The donor twin becomes anemic and growth restricted with less blood flow through it’s kidneys and develops oligohydramnios. The recipient twin gets too much blood flow and has polyhydramnios. Can go into heart failure and become hydropic. Both fetuses are at risk of dying
Predictors for discordant growth
Difference in estimated fetal weight of more than 20%, difference in BPD of 6 mm, difference in AC of 20 mm, and difference in femur length of 5 mm
Advantages of CVS
Performed in first trimester at 10 to 14 weeks, results are available within one week, allows more options for parents
Cordocentesis
Also called pubs. Done at 17 weeks. Results are processed within 2 to 3 days. Analyzes chromosomes but more commonly used for transfusions to treat fetal isoimmunization
Amniocentesis
Offered to expectant patience, particularly advanced maternal age who are at risk for a chromosomal abnormality or bio chemical disorder. Performed at 15 to 20 weeks and results are back in 1 to 3 weeks.
Risks are uterine contractions, cramping, and oligohydramnios
Why might we do amniocentesis?
To relieve polyhydramnios, predict Rh incompatibility, document feeder long maturity, detect chromosomal abnormality’s
Sonographic findings that may suggest a chromosomal anomaly
Clenched hands, thickened nuchal fold, omphalocele
What fetal structures do we find AFP in?
Fedal spine, G.I. tract, liver, kidneys. Produced by yolk sac in early gestation and later by liver.
High AFP levels can indicate what?
Anencephaly, open spina bifida, Gastro ski sis, multiple gestations, incorrect dates
What are we evaluating in a quad screen?
AFP, hCG, unconjugated estriol, dimeric inhibin A
Aneuploidy definition
Abnormality of the number of chromosomes
An abnormal event that arises because of the interaction of one or more genes and environmental factors is termed?
Multifactorial
The occurrence of a gene mutation or chromosomal abnormality in a portion of an individual cells is…
Mosaic
What is NT used for?
Determines risk for aneuploidy, thickened NT is strongly associated with trisomy 13, 18, 21, turner syndrome
Markers for down syndrome
Abnormal NT, shortened femur, heart defects, absent nasal bone
Markers for trisomy 18/Edwards syndrome
Cranial anomalies, facial anomalies, choroid plexus cyst, rocker bottom feet
Markers for trisomy 13/Patau syndrome
Holoprosencephaly, proboscis, hypotelorism, microcephaly
Markers for turner syndrome
Cystic hygroma, coarctation of the aorta and, hydrops, renal anomalies
What are common reasons for elevation of AFP
Neural tube defect’s such as anencephaly and open spina bifida, incorrect dates, twins
When do AFP levels peak
15 to 18 weeks
names for sites of conjoined twins
Thoracopagus Omphalopagus Craniopagus Pygopagus- ischial Ischiopagus- buttocks
Optimum collection site for amniocentesis
Away from fetus, away from central placenta, away from umbilical cord, near maternal midline to avoid vessels
low AFP levels indicate what process?
Chromosomal abnormality’s such as trisomy 21, 18, 13. Also incorrect dates for younger than expected fetus, fetal death, molar…
A recessive disorder is caused by?
Pair of defective genes ; one inherited from each parent with a 25% chance of having a fetus with the disorder
A dominant disorder is a condition caused by
A single defective gene usually inherited from one parent who is also affected. 50% chance that each time pregnancy occurs the fetus will have the condition
X linked disorder
Boys inherit from their mothers; affected males do not transmit the disorder to their sons but all of their daughters will be carriers. Aqueductal stenosis is an example.
