Multiple gestation

Learning objectives

Multiple gestation is pregnancy with more than one fetus at a time, occurring in approximately 3% of all pregnancies
Examples include pregnancy with twins, triplets, and quadruplets
High-risk pregnancy requiring extra care
Most women have multiple births via caesarean section
Babies are often born prematurely and with a low birth weight → need to spend some time in the NICU
The goal is to complete 37 weeks in twin pregnancies (considered term) → increases the chance that both babies will be born healthy and at a good weight

Exaggerated signs of pregnancy (e.g., extreme nausea and fatigue, severe vomiting)
Faster than usual weight gain in the first semester of pregnancy
Sore or very tender breasts
Higher than normal levels of pregnancy hormones (i.e., human chorionic gonadotrophin)
Higher than normal levels of protein alpha-fetoprotein in the mother’s blood
Larger than usual belly compared to most women at a similar stage of pregnancy
More than one fetal heartbeat

One fertilized egg (ovum) splits before it implants in the uterine lining → monozygotic or identical twins
Two (or more) separate eggs are fertilized by different sperm at the same time → dizygotic or fraternal twins
Fraternal twins are more common than identical twins
In a pregnancy with triplets or more, the babies could all be identical, all fraternal, or a mixture of both

Maternal

Fetal

Preterm delivery
Low birth weight
Congenital anomalies (e.g., cerebral palsy)
Polyhydramnios
Cord entanglement
Umbilical cord prolapse
Fetal growth restriction, intrauterine growth restriction (IUGR), or small for gestational age
Malpresentation (e.g., breech presentation)
Increased mortality (i.e., miscarriage, stillbirth)
Monochorionic twins (one placenta) risks that are unique to them
- Twin-twin transfusion syndrome
- Twin anemia polycythemia sequence
- Selective IUGR

Family history of twins, triplets, or more increases the chance of multiple gestation pregnancy
Fertility treatments
Age ≥35 years (women are more likely to release more than one egg per cycle)

All obstetric patients are considered to have a full stomach and be at risk for pulmonary aspiration, regardless of the time of last oral intake