11 Things You Didn't Know About Twin Pregnancies
Experts share their advice for women who are pregnant with twins.
No. 7: Moms pregnant with twins may gain more weight than moms carrying one child.
"With twins, mothers gain more weight as there are two babies, two placentas, and more amniotic fluid," says Al-Khan. "You also need more calories for twin pregnancies."
Still, there is not a well-established formula for weight gain during twin pregnancies, says Monga. "The average weight gain is 25 pounds for singleton pregnancy and 30-35 pounds for twins. We don't want moms pregnant with twins to gain more than 40 [pounds] or less than 15 pounds."
The Institute of Medicine's provisional guidelines for weight gain in women expecting twins say:
- Women of normal weight should aim to gain 37-54 pounds
- Overweight women should aim to gain 31-50 pounds
- Obese women should aim to gain 25-42 pounds
Exactly how much weight should you gain? The IOM recommends that you talk to your health care provider about that, because every pregnancy is unique.
No. 8: Risk of developing gestational diabetes is higher in twin pregnancies.
"The gestational diabetes risk is higher in twin pregnancy," says Monga. That said, the biggest risk of gestational diabetes is having larger babies and requiring a C-section delivery, she says.
"While gestational diabetes is more common, the morbidity associated with it is less common because twin babies are not big babies."
Still, moms who develop gestational diabetes during pregnancy are more likely to develop type 2 diabetes later in life, she says.
No. 9: Risk of preeclampsia during pregnancy is higher in twin pregnancies.
"People really don't know what causes preeclampsia to start, but we know it occurs more frequently in twin pregnancies," Monga says. Preeclampsia is marked by high blood pressure, protein in the urine, and sometimes swelling in the feet, legs, and hands. It is the precursor to the more serious, potentially fatal eclampsia.
No. 10: Labor (and delivery) may come early with twin pregnancies.
Most moms carrying twins go into labor at 36 to 37 weeks, as opposed to 40 in a single pregnancy, Al-Khan says, and some may go even earlier. "Generally, if the twins are born after 34 weeks, there should not be a major concern, but a premature baby is still a premature baby," he says. "Twins are at higher risk of preterm labor and delivery and have higher degree of respiratory issues." As a result of being born too early, twins may be born at low birth weights, and such babies tend to have more health problems than babies born weighing more than 5.5 pounds.
Unfortunately, there is no evidence that bed rest alone prevents preterm labor or delivery in twin pregnancies, and the use of agents to stop preterm labor have not been proven to be effective either, he says. "Stopping premature labor is challenging in multiple gestations."