Abnormal Fetal Development

Question 1

How common is pregnancy loss?

Answer 1

Almost 25% of all pregnancies are lost, and most are sporadic meaning that there is no recurrence risk for the couple

Question 2

When do most pregnancy losses occur during gestation?

Answer 2

The earlier in pregnancy, the higher the risk for loss. Once a heart beat is seen on ultrasound, the chance of a successful pregnancy is 90+%

Question 3

What is the most common reason for pregnancy loss in the first trimester?

Answer 3

chromosomal abnormalities, which represent 50% of all first trimester loss (and 15% of second trimester losses, and 5% of third trimester losses)

Question 4

What is the most common type of chromosome abnormality?

Answer 4

aneuploidy: Trisome 16 (lethal) followed by trisomy 21

Question 5

Describe how an insufficient cervix might affect pregnancy

Answer 5

Insufficient cervices usually cause a painless, premature dilation resulting in early birth, most commonly in the second trimester before fetal life is viable

Question 6

How could insuffient cervices be treated/managed in subsequent pregnancies?

Answer 6

the placement of a cerlage

Question 7

Answer 7

Question 8

Answer 8

A.

Question 9

Answer 9

D.

Question 10

When are chromosomal or structural defects typically picked up?

Answer 10

During the week 18-20 ultrasound

Question 11

Further ultrasounds are needed

Question 12

How common are multiple gestations?

Answer 12

These are becoming more common with things like IVF

• 1/30 pregnancies start out as twin gestation
• 1/76 liveborn gestations are twins. 1/3 are monozygotic (identical) and 2/3 are dizygotic (fraternal)

Question 13

What are the risk factors for a dizygotic gestation?

Answer 13

black race, young or old (bimodal) age, maternal fam Hx

Question 14

What are the risk factors for a monozygotic gestation?

Answer 14

Monozygotic twinning is sporadic: only risk factor is IVF

Question 15

Question 16

What are the common maternal gestational complications of twins?

Answer 16

• prematurity
• maternal diabetes is more likely to develop due to increased placental mass (leading to more hPL)

maternal hemorrhage is more common

Question 17

What is a common complication of Monochorionic/monoamniotic monomzygotic twins?

Answer 17

cord entanglement and death

Question 18

What is a common complication of Monochorionic/diamniotic monomzygotic twins?

Answer 18

•Twin to Twin transfusion. Often one dies in utero or after delivery.

Question 19

T or F. In general, all fetal malpresentations require CD

Answer 19

T.

Question 20

Symmetric IUGR is usually caused by what?

Answer 20

usually from chromosomal abnormality. All measurements equally small

Question 21

Asymmetric IUGR is usually caused by what?

Answer 21

•All efforts are ‘head sparing’.

•Smoking

•Maternal disease that causes placental insufficiency where fetus does not get nutrition or oxygen

Question 22

What is the number one cause of fetal macrosomia?

Answer 22

maternal diabetes

Question 23

What are some neonatal complications associated with maternal diabetes?

Answer 23

•hypoglycemia, hypocalcemia,

hyperbilirubinemia

polycythemia,

Question 24

T or F. •Weights can be estimated by ultrasound and a delivery plan (vaginal delivery versus CD) can be made

Answer 24

T. BUT these ultrasound estimates typically become LESS accurate as term approaches