Found this article about twin pregnancies:
You’ve seen the pregnancy calendars (40 weeks’ worth). You might have estimated your due date (40 weeks from LMP). But before you circle that due date with a permanent red marker, consider this: A twin pregnancy is considered full-term at 37 weeks. (Three fewer weeks of heartburn and puffiness — whew!)
Happily, by 37 weeks, your babies will have fully mature lungs and will likely be able to leave the hospital safe and sound within a few days. But just as 95 percent of all singleton births fail to fall on their due date, you shouldn’t count on your D-day hitting the 37-week bull’s-eye either. If your pregnancy ends up going past your estimated due date (EDD), your practitioner might likely induce at 38 weeks, maybe longer, depending on how you’re progressing. (It’s a good idea to have an “end-game” discussion with your practitioner long before week 37, since many doctors differ on how they typically handle the latter stages of twin pregnancy.)
More typical for multiples, however, is that the pregnancy will end up being shorter than full-term singletons — and many multiple moms-to-be find themselves in a race with the calendar, trying to maintain the pregnancy long enough to ensure healthy outcomes for the babies. Here are some multiple-pregnancy milestones:
- The first major milestone is 24 weeks: the threshold of viability. Babies born this early will likely spend at least three months in the neonatal intensive care unit (NICU), and a third of them will survive with no long-term problems.
- The second milestone is 28 weeks, when viability skyrockets. Ninety percent of babies who make it to this stage of gestation survive. Long-term complications — including cerebral palsy, vision and breathing problems — are still a possibility, however.
- The next milestone is 32 to 34 weeks. Babies born now generally have an excellent chance of survival, without any major long-term complications, though they might not have full lung maturity (which generally occurs between 33 and 37 weeks) and will need to spend time in the NICU. Some babies born at this stage may require oxygen to help them breathe, while others may need to be fed through a nasogastric tube (which runs through the nose into the stomach). “Super-twins” (triplets or more) almost always spend time in a NICU, but if you can get past that 32-week mark, chances are excellent that the babies will be healthy.
To ensure that your pregnancy — and your babies’ growth and maturity — is on the right track, your practitioner will probably order a barrage of tests as the end of your pregnancy approaches (generally at around the 32-week mark, when all is well). You can expect nonstress tests, biophysical profiles, or even late-stage amniocentesis to check for lung maturity and other indicators of how the fetuses are developing. Depending on the test results, your practitioner may decide to deliver your babies early or leave them cooking in the womb a little longer.