36 to 37 weeks pregnant with twins or multiples

It’s been a long road, but you’re almost there! While “full-term” in a singleton pregnancy generally means around 39 to 40 weeks, most doctors consider 37 to 38 weeks to be full-term for most twin pregnancies. Even with the definition of “term” moved back like this, many twin pregnancies end in delivery before 37 weeks. There’s some evidence to suggest that twins’ and multiples’ lungs develop more quickly than singletons, so they’re more ready to breathe on their own after these early deliveries than a singleton might be at the same gestational age.

Twin and multiple growth at 36 weeks

Twins and multiples – many higher-order multiples will have been delivered by this point – are going through the same physical changes that singletons might be around this time. Since most babies have reached the height they will be when they’re born by now, their growth has more to do with processing enough nutrients to gain a little weight. They’ll also be practicing using their respiratory systems (as they practice breathing that amniotic fluid), and their nervous systems (your babies now have the reflexes they’ll have once they’re born!).

Preparing for delivery

You’re probably spending more time with your doctor than ever by this point, and in these visits, you’ve probably talked about what your delivery might look like a few times now. If you’re carrying twins, the fact that you haven’t had complications that led to an earlier delivery means that your chances of a vaginal birth are higher than they were earlier in your pregnancy, but there’s still a strong chance that a C-section will end up being the safest choice for you and your twins. If you do begin to delivery vaginally, it’s very rare to end up delivering one twin vaginally and the other via C-section.

Making sure you and your twins or multiples have the safest delivery experience is the reason you’re seeing your doctor as often as you are during this point in your pregnancy. Checking in with your doctors helps them respond to any physical changes you may feel as quickly as possible. Preparing yourself to respond to changes flexibly, too, can help you feel better about whatever comes your way during delivery.

Sources

• American College of Obstetricians and Gynecologists. “Multifetal gestation: Twin, triplet, and higher order multifetal pregnancies.” National Guideline Clearinghouse. U.S. Department of Health and Human Services, May 2014. Retrieved January 25 2018. https://www.guideline.gov/summaries/summary/48025/multifetal-gestations-twin-triplet-and-higherorder-multifetal-pregnancies.
• Stephen T. Chasen, Frank A. Chervenak. “Twin pregnancy: Labor and delivery.” UpToDate. Wolters Kluwer, December 2017. Retrieved January 25 2018. https://www.uptodate.com/contents/twin-pregnancy-labor-and-delivery.
• Richard A. Ehrankranz, Mark A. Mercurio. “Periviable birth.” UpToDate. Wolters Kluwer, December 2017. Retrieved January 25 2018. https://www.uptodate.com/contents/periviable-birth-limit-of-viability?search=viability%20milestones&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2.
• William Goodnight, Roger Newman. “Optimal nutrition for improved twin pregnancy outcome.” Obstetricians & Gynecologists. 114(5): 1121-1134.
• Atsushi Kuno, Masashi Akiyama, Toshihiro Yanagihara, Toshiyuki Hata. “Comparisons of fetal growth in singleton, twin, and triplet pregnancies.” Human Reproduction. 14(5): 1352-1360. https://academic.oup.com/humrep/article/14/5/1352/766210.
• http://www.mfmsm.com/media_pages/MFM-Optimal-nutrition-for-improved-twin-pregnancy.pdf.
• Kenneth J. Leveno, J. Gerald Quirk, Peggy J. Whalley, Robert Trubery. “Fetal lung maturation in twin gestation.” American Journal of Obstetrics and Gynecologists. 148(4): 405-11. March 1984. Retrieved January 25 2018.
• Mayo Clinic Staff. “Twin pregnancy: What multiples mean for mom.” Mayo Clinic. Mayo Clinic, December 13 2014. Retrieved January 25 2018. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/twin-pregnancy/art-20048161.
• “FAQ: Multiple pregnancy.” American College of Obstetricians and Gynecologists. American College of Obstetricians and Gynecologists, July 2015. Retrieved January 25 2018. https://www.acog.org/Patients/FAQs/Multiple-Pregnancy.
• “Tracking your weight, for women who begin a twin pregnancy at a normal weight.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention. Retrieved January 25 2018. https://www.cdc.gov/reproductivehealth/pdfs/maternal-infant-health/pregnancy-weight-gain/tracker/twins/normal_twin_weight_tracker__508tagged.pdf.
• “Twin pregnancy obstetric care guidelines.” Brigham and Women’s Hospital. Brigham and Women’s Hospital, June 28 2016. Retrieved January 25 2018. http://www.brighamandwomens.org/Departments_and_Services/obgyn/Services/twin-pregnancy/twin-pregnancy-obstetric-care-guidelines.aspx?sub=6.