Fetal Complications of Pregnancy

Question 1

What factors lead to SGA?

Answer 1

Decreased growth potential
-Congenital abnormalities (trisomy 13, 18, 21, Turner 45XO, osteogenesis imperfecta, achondroplasia, NTD)
- Intrauterine infections (CMV and rubella)
- Exposure to teratogens (*alcohol and cigarettes, chemo)
Intrauterine growth restriction (before 20 weeks = symmetric, after 20 weeks asymmetric)
- Decreased nutrition and oxygen transferred across the placenta

Question 2

How can you differentiate between decreased growth potential and intrauterine growth restriction (IUGR)

Answer 2

Fetuses with decreased growth potential will start small and stay small
Fetuses with IUGR will progressively fall lower on the growth curve

Question 3

What is a sign of IUGR on doppler US?

Answer 3

In the setting of increased placental resistance (like thrombosis or calcified placenta) diastolic flow can become absent or reversed

Question 4

What is the definition of macrosomia?

Answer 4

> 4500 g

Question 5

What are complications of macrosomia?

Answer 5

Increased risk of shoulder dystocia and birth trauma with brachial plexus injury

Question 6

What are the etiologies of fetal macrosomia?

Answer 6

Gestational diabetes
Maternal obesity
post-term pregnancy
multiparity
increasing age

Question 7

What is treatment of LGA?

Answer 7

Primary prevention
Weight control in women with pre diabetes - diet and exercise
Glycemic control
labor induction before fetus reaches macrosomia

Question 8

Define oligohydramnios and polyhydramnios

Answer 8

Amniotic fluid index (AFI) 20/25

Question 9

What are consequences of oligohydramnios?

Answer 9

Umbilical cord compression leading to fetal asphyxiation

Question 10

What is a complication of Rh incompatiblity?

Answer 10

Maternal antibodies can cross the placenta and lead to hemolysis - erythroblastosis fetalis (fetal hydrops)

Question 11

What is characteristic of erythroblastosis fetalis?

Answer 11

Hyperdynamic state, heart failure, diffuse edema, ascites, pericardial effusion

Defined as accumulation of fluid in at least 2 body compartments
Jaundice can occur due to hemolysis

Question 12

How is Rh incompatibility managed?

Answer 12

RhoGAM at 28 weeks and postpartum

Question 13

How is Rh incompatibility evaluated?

Answer 13

Check antibody titers
Once more than 1:16, then serial amniocentesis as early as 16-20 weeks to analyze for Rh antigen
if positive, then fetal MCA dopper for PSV - if increased then that is sign of fetal anemia

Percutaneous umbilical blood sampling with intrauterine transfusion is beneficial for fetal anemia

Question 14

What is intrauterine fetal demise?

Answer 14

Occurs in 0.5-1% of pregnancies

Any cause of fetal death after 20 weeks

Question 15

What are the risk factors for IUFD?

Answer 15

Abruption, congenital abnormalities, infection, placental insufficiency leading to IUGR then IUFD

Question 16

What is a secondary consequence of IUFD?

Answer 16

Retained IUFD > 3 weeks can lead to hypofibrinogenemia because of released thromboplastic elements from the dead fetus, can lead to DIC

Question 17

What are the causes of postterm pregnancy?

Answer 17

Inaccurate dating
obesity
Rare conditions that have diminished circulating estrogen (anencephaly, fetal adrenal hypoplasia, absent fetal pituitary)

Question 18

What are the dangers of mo-di and mo-mo twins?

Answer 18

Mo-di can lead to twin-to-twin transfusion because of communicating vasculature
Mo-mo has very high mortality due to cord accidents/entanglement

Question 19

What are laboratory signs of twin gestation?

Answer 19

Increased b-hCG, HPL, AFP

Question 20

What is the treatment of multiple gestation?

Answer 20

Selective reduction down to twins or even singleton

Question 21

What is the treatment for twin-to-twin transfusion?

Answer 21

Serial amnio reduction

Laser coagulation of communicating vessels