Twin Gestation With Vasa Previa

Question 0

Velamentous cord insertion? Susceptible to?

Answer 0

Umbilical vessels separate before reaching placenta (protected only by the informed of amnion, instead of the cord or placenta itself)

Vessels susceptible to tearing after rupture of membranes

Question 1

Vasa previa? Most commonly occurs with?

Answer 1

Umbilical Vessels not protected by cord or membranes cross internal os in front of presenting part

Velamentous cord insertion or placenta with one or more accessory lobes

Question 2

Succenturiate?

Answer 2

Placenta with one or more accessories lobes

Question 3

Chorionicity?

Amnionicity?

Answer 3

Number of placentas in a multiple gestation (dizygotic twins are always dichorionic)

Number of amniotic sacs in multiple gestation (monozygotic twins could be either, dizygotic twins are always diamnionic

Question 4

Multiple gestations are at higher risk for?

Answer 4

1. Neonates - IUGR, Hydramnios, Congenital malformations, twin-twin transfusion syndrome
2. Mother - Preterm delivery, Preeclampsia, Gestational diabetes, DVT, placenta previa/abruption, Postpartum hemorrhage

Question 5

Type and mechanism of contraception can increase twinning?

Answer 5

OCP; slows tubal motility

Question 6

Type of twins associated with higher spontaneous abortion rates?

Answer 6

Monochorionic

Question 7

Timing of division and resulting chorionicity and amnionicity?

Answer 7

1. Within 3 days – dichorionic/diamnionic
2. Day 4-8 – monochorionic/diamnionic
3. Day 8 – monochorionic/monoamnionic
4. After day 8 – conjoined twins

Question 8

Increased incidence of twinning if?

Answer 8

1. Maternal age 37
2. Mother is a dizygotic twins
3. Clomiphene (promotes maturation of multiple follicles)
4. IVF

Question 9

Physiologic changes in twin pregnancies?

Answer 9

1. Blood volume and stroke volume are increased
2. RBC mass increases less (greater physiologic anemia)
3. BP is lower 20 weeks, but higher at delivery

Question 10

Twin-twin transfusion syndrome? Treatment?

Answer 10

One twin is larger with more amniotic fluid and other twin smaller with oligohydramnios

Laser ablation of shared anastomotic vessels, or cereal amniocentesis for decompression

Question 11

50% perinatal mortality rate if?

Answer 11

No dividing membrane between twins (cord entanglement occurs)

Question 12

Test to diagnose vasa previa? Management? What is contraindicated?

Answer 12

Color Doppler ultrasound; C-section at 35-36 weeks

Digital vaginal examination

Question 13

Patient with twin-gestation at 30 weeks gestation presents with low oxygen saturation and contractions – suspected diagnosis? do not give? Treat with?

Answer 13

Patient has pulmonary edema

Tocolysis and corticosteroids ( in multiple gestations increase pulmonary edema)

Give IV furosemide and magnesium sulfate and prepare for delivery