Multiple Pregnancy Flashcards

Flashcards covering the key aspects of multiple pregnancies, including definitions, types, risk factors, diagnosis, complications, and management.

What is a multiple pregnancy?

A pregnancy in which more than one fetus develops simultaneously in the uterus.

What is a twin pregnancy?

The simultaneous development of two fetuses in the uterus.

What are the two main types of twin pregnancies?

Dizygotic (fraternal) and Monozygotic (identical).

What percentage of twins are dizygotic?

Approximately 80%.

What is the genesis of dizygotic twins?

Fertilization of two ova by two sperm.

What percentage of twins are monozygotic?

Approximately 20%.

What is the genesis of monozygotic twins?

Fertilization of one ovum, which then divides.

List some risk factors associated with twin pregnancies.

Increasing maternal age, increasing parity, nutritional factors, pituitary gonadotropin, infertility therapy, assisted reproductive therapy, genetic/hereditary factors, and race.

How do placentae typically present in dizygotic twins?

Two placentae, either completely separated or fused at the margin. Each fetus has a separate amnion and chorion.

What can be said about the sex and genetic features of dizygotic twins?

The sex may differ, and genetic features (blood group, fingerprints) also differ.

What determines the characteristics of monozygotic twins based on the timing of the division?

The earlier the splitting of the single zygote occurs, the more independently the twins will develop.

If division of a monozygotic twin occurs within 72 hours, what is the chorionic and amniotic arrangement?

Two separate placentae, chorion, and amnions (diamniotic-dichorionic).

If division of a monozygotic twin occurs between the 4th and 8th day, what is the chorionic and amniotic arrangement?

Diamniotic monochorionic twins develop.

If division of a monozygotic twin occurs after the 8th day, what is the chorionic and amniotic arrangement?

Monoamniotic monochorionic twins.

What happens if division of a monozygotic twin occurs after two weeks?

Conjoined twins may form.

Are monozygotic twins affected by heredity?

No, they are not affected by heredity.

What are some symptoms suggestive of a twin pregnancy?

Exaggerated nausea and vomiting, cardiorespiratory embarrassment, swelling of legs, varicose veins, hemorrhoids, unusual rate of abdominal enlargement, and excessive fetal movement.

What are some findings on general examination that might indicate a twin pregnancy?

Increased prevalence of anemia, unusual weight gain, and evidence of preeclampsia.

What are some findings on abdominal examination that might indicate a twin pregnancy?

Elongated shape of the uterus changing to a more barrel shape, height of uterus more than expected for gestational age, disproportionately larger fetal bulk, palpation of too many fetal parts, finding two fetal heads, and two distinct fetal heart sounds.

How can sonography aid in the diagnosis of twin pregnancies?

By identifying separate gestational sacs early, or by seeing two fetal heads or abdomens in the same plane.

What are some maternal complications during pregnancy in twin pregnancies?

Exaggerated early symptoms, increased miscarriage risk, malpresentation, increased minor disorders, anemia, placenta previa, preterm labor and delivery, risk of hypertensive disease, and antepartum hemorrhage.

What are some maternal complications during labor in twin pregnancies?

PROM, cord prolapse, prolonged labor, increased operative interference, bleeding (intrapartum), and PPH.

What are some maternal complications during the puerperium in twin pregnancies?

Subinvolution, increased risk of infections, and lactation failure.

What are some complications to the fetus in twin pregnancies?

Stillbirth/neonatal death, abortion, single fetal death, IUGR, SGA, higher risks of congenital anomalies, risk of cord accidents, risk of asphyxia, operative vaginal delivery, and twin entrapment.

Name some congenital anomalies more common in twin pregnancies.

NTD (neural tube defects), cardiac anomalies, bowel atresia, conjoint twins, and TRAP sequence.

What is TRAP sequence?

Twin reversed-arterial-perfusion sequence, a rare complication of monochorionic, monozygotic multiple gestation where one twin lacks a heart and other structures.

What is Twin-to-Twin Transfusion Syndrome (TTTS)?

Blood is transfused from a donor twin to its recipient sibling, leading to anemia in the donor and polycythemia in the recipient.

What are some fetal consequences of TTTS?

Circulatory overload with heart failure, occlusive thrombosis, polycythemia which may lead to severe hyperbilirubinemia and kernicterus.

How is TTTS typically diagnosed postnatally?

Weight discordancy between twins of 15-20% and hemoglobin level difference of 5 g/dL or greater.

What is a discordant twin?

Size inequality of twin fetuses, which may be a sign of pathological growth restriction in one fetus.

What is the significance of early vs. late discordancy?

Earlier discordancy is usually symmetrical and indicates higher risk for fetal demise, while later discordancy is often asymmetrical.

What is the likely pathology in monochorionic twins with discordancy?

Placental vascular anastomoses that cause hemodynamic imbalance between the twins.

What are some antenatal management strategies for twin pregnancies?

Dietary advice (increased caloric intake), increased rest, increased number of antenatal visits, and supplementary therapy (iron, vitamins, calcium, and folic acid).

When should corticosteroids be given in the context of preterm labor in a twin pregnancy?

At a gestational age of less than 34 weeks.

What are essential aspects of management during labor in a twin pregnancy?

Bed rest, fetal monitoring (electronic), internal examination after rupture of membranes, and IV access with Ringer's lactate.

What is the recommended interval between delivery of twins?

Not to exceed 20 minutes.

What are the common presentation combinations in twin pregnancies and their delivery approach?

Vertex-Vertex (Vaginal delivery), Vertex-Breech (Vaginal by senior obstetrician), Breech-Vertex (CS), and Breech-Breech (CS).

When is Cesarean delivery generally the method of choice in twin pregnancies?

When the first twin is noncephalic.

What special considerations are there for delivering the first baby in a twin pregnancy?

Avoid general anesthesia, don't give ergometrine, and leave 8-10cm of the cord for administration of drugs or transfusion.

What should be done immediately after delivery of the first baby?

Ascertain the lie, presentation, and size of the second baby through abdominal examination.

Are trials of labor after Cesarean (TOLAC) contraindicated in twin pregnancies?

If twins have a first vertex, a trial of scar should not be an absolute contraindication.