Whether you’ve known about your babies for a bit or just heard those hearts beating together for the first time, we excitedly welcome you to week 9! Let’s talk about what to expect when you’re nine weeks pregnant with multiples.
This is an important week because your babies’ body parts are now mostly formed, although they’re far from being fully developed. From this point forward, your little ones will work on growing bigger and stronger in preparation for their grand entrance into the world.
How do twins and other multiples happen?
Finding out you’re expecting multiples can come as quite a surprise! Most multiple pregnancies aren’t visible on an ultrasound until between 6 and 8 weeks of gestation, so likely, you’ve only just caught wind of the news. It’s normal to feel ecstatic, nervous, or just plain overwhelmed when you find out you’re expecting multiples, especially if this is an unexpected surprise.
Multiple pregnancies happen in a few different ways. You’ll get a better understanding of your babies’ origin story when your provider identifies their arrangement within their sacs. Keep reading to find out more.
Identical twins (triplets, and beyond) happen when a single fertilized egg (zygote) divides into two or more identical zygotes. Multiples who are identical have the same exact genetic material; this means they will be of the same physical sex, and their appearance will be, well, identical — or very close to it!
This type of pregnancy happens simply by chance, so identical multiples do not run in families. Depending upon when in the process the zygote splits, your babies may share both layers of their sacs (amnion and chorion) and be in the same space as each other without any separating membrane. In this case, they would also share a single placenta. In other cases, they may have separate amniotic sacs (inner layers) but share the same chorion (outer layer of the sac). And in some cases, they may each have their own amnion, chorion, and placenta.
Fraternal multiples happen when more than one egg is released during ovulation, and each is fertilized by a different sperm cell. Because fraternal multiples come from their own eggs, they’re no more similar genetically than other full siblings. Fraternal twins, triplets, and even quadruplets have their own placentas and amniotic sacs, as well as chorionic sacs.
That said, it’s possible you could be carrying a mix of identical and fraternal multiples! For example, if one egg split in half but you released multiple eggs during ovulation, you could have two identical (twins) and one fraternal triplet.
What are your babies up to this week?
Your little ones have developed identifiable limbs and lost their embryonic tails, making them clearly recognizable as babies on an ultrasound. At 9 weeks, they are just shy of an inch long and weigh approximately 0.07 ounces each — roughly the size of a cherry! Their hearts are pumping, and they’ll continue to grow rapidly as the weeks progress.
What can I expect from a twin or multiple pregnancy?
It’s perfectly normal to feel a wide range of emotions when you first find out you’re expecting multiples. You likely envisioned one baby, and it can understandably take time to adjust to the news.
Twin or multiple pregnancies require a bit more monitoring, which often means more frequent appointments, typically later in pregnancy. Twins and multiples can pose a higher risk of certain complications, so it’s important to keep up with your appointments and listen to your provider’s recommendations for a healthy pregnancy.
The American College of Obstetricians and Gynecologists reports that women who are carrying multiples are likely to have more severe early pregnancy symptoms as compared with singleton pregnancies. This could mean increased nausea, breast tenderness, and fatigue. Listen to your body and rest as needed. Fortunately, these symptoms most often recede after the first trimester. You’re almost there!
Reviewed by the Ovia Health Clinical Team
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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 May 15 2021.
- Mayo Clinic Staff. “Twin pregnancy: What multiples mean for mom.” Mayo Clinic. Mayo Clinic, Updated December 17 2024. 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. Last reviewed: May 2025.
