Q: What is the average gestation for each type of multiple pregnancy?
A: 40 weeks is considered a full-term pregnancy; however few higher-order multiple birth pregnancies last a full 40 weeks because the length of pregnancy decreases with each additional baby.
Around 57% of twins and more than 96% of triplets and higher multiples are born preterm. (source #1)
On average most:
- singleton pregnancies last 39 weeks
- twin pregnancies last 35.2 weeks
- triplet pregnancies last 32.0 weeks
- quadruplets pregnancies last 29.3 weeks (source #2)
According to our Medical Birth Survey, the average gestation for families who contact Raising Multiples is approximately:
- 35.5 weeks for twins
- 33.1 weeks for triplets
- 31.3 weeks for quadruplets
- 29.7 weeks for quintuplets
- 29.1 weeks for sextuplets
Important note: The numbers above are averages, not goals. Most perinatologists who have extensive experience with higher-order multiple pregnancies agree that your goal is to reach a gestational age of:
- 37 weeks for twins
- 35-36 weeks triplets
- 33-34 weeks for quadruplets and quintuplets
Even if you reach these optimum goals, remember that your babies will still be considered premature and not full-term infants.
1. Martin JA, Hamilton BE, Sutton PD, Ventura SJ, Mathews TJ, Kirmeyer S, Osterman MJK. Births: Final data for 2007. National vital statistics reports; vol 58 no XX. Hyattsville, MD: National Center for Health Statistics. 2010. http://www.cdc.gov/nchs/data/nvsr/nvsr58/nvsr58_24.pdf
2. Martin JA, Hamilton BE, Sutton PD, Ventura SJ, et al. Births: Final data for 2006. National vital statistics reports; vol 57 no 7. Hyattsville, MD: National Center for Health Statistics. 2009. http://www.cdc.gov/nchs/data/nvsr/nvsr57/nvsr57_07.pdf