"Do you know if they are identical or fraternal triplets?" is one of the most common questions I get when I tell people we are expecting #triplets. (The other one is "But, are they natural?" 🙄) I usually assume most people don't want the complicated answer to the identical/fraternal question and respond with "we're not sure yet." But, if you've found yourself here you must be interested in the more complex response. I am by no means any kind of expert, but since I've been asked this question so frequently I've developed my own understanding of the real answer through asking my doctor questions, reading medical journal articles, and following all kinds of other #MoMs (#MomsofMultiples) online.
In order to really understand what's going on there are some often used words you should know:
Important terms:
zygote - a fertilized egg (when an egg and a sperm unite)
monozygotic - when all individuals are formed from the same egg that splits into two, and then splits again leading to three identical individuals.
dizygotic - in triplets, when two eggs are fertilized by two different sperm, but one of the eggs split leading to two identical individuals and one fraternal.
trizygotic - in triplets, when each individual forms from a separate egg/sperm union.
monochorionic - in triplets all share one placenta
dichorionic - in triplets, when two of the three triplets share a placenta.
trichorionic- in triplets, when all triplets each have their own placenta
monoamniotic - in triplets, when all triplets are in the same amniotic sac
diamniotic - in triplets, when two of the three individuals are in the same amniotic sac
triamniotic - in triplets, when all of the triplets each have their own amniotic sac
In our case, we have trichorionic/triamniotic (or tri-tri) triplets, but we can't be sure if they are trizygotic until after they're born because we haven't done any genetic testing. On an ultrasound we can see that our trips each have their own amniotic sac and each of them have their own placenta supplying their nutrients. Triplet pregnancies are a greater risk to begin with, but thankfully for us, tri-tri triplets tend to have less risks than other types of triplets since they are independent from one another. Tri-tri triplets do not have to worry about things like twin-to-twin-transfer-syndrome (TTTS). If any of the babies share placentas/amniotic sacs then they are certainly identical. Now, although in most cases tri-tri triplets are fraternal and not identical, we cannot know for sure if our triplets are fraternal or identical because we haven't tested their genetics. It is possible that an egg was fertilized and then split prior to implanting, which if that happened, would have allowed for two (or more) of our boys to be identical. So, although it's unlikely, we'll hold out and see if they drastically look different and are therefore obviously fraternal, or if we want/need to find out if they are identical. It can be useful to know if your babies are identical in the event of a medical emergency or need.
When doctors and/or ultrasound techs evaluate the development of triplets they often refer to the babies as Baby A, Baby B, and Baby C. Baby A is the baby closest to the cervix, Baby B the next closest, and Baby C the farthest away. When describing the sex of triplets you may see things like BGB tri-tris (Boy-Girl-Boy triplets who do not share placentas or amniotic sacs). The first B refers to Baby A's sex, The G to Baby B's sex, and the second B to Baby C's. So, with that in mind, there could be BBB triplets, GGG triplets, BGB triplets, GBG triplets, BBG triplets, GGB triplets, BGG triplets, or GBB triplets. Did I miss any combinations? 😆 Since our triplets are all boys they are often referred to in 'triplet circles' as BBB.
FUN FACT: images courtesy of my sister and I being sentimental hoarders. These were our toys when we were kids. Did anyone else have the Quints and Triplets dolls?
#triplets #tripletpregnancy #multiples #multiplespregnancy #twins #typesoftwins #typesoftriplets #montrealmom #montreal