Clearly I’ve been neglecting this blog, but there’s a good reason – I’m pregnant … (wait for it) … with twins! We were pretty shocked when we found out we were going to have two, but now I can’t imagine only having one! I think there must be some kind of karmic balance at play here because I am confident that I was among the best prepared moms-to-be with one baby, but as soon as we found out we were having two, I had to start my research (and budget spreadsheet!) all over. There are SO many different things to learn about twin pregnancies. Here’s a quick list of things I found really interesting about twins. Sorry, I’m too tired to properly cite my stats!
- Only 1% of births are spontaneous twins (no fertility treatments used). The rate of twin births has gone up considerably in recent decades because of the increasing use of fertility treatments, so 3% of births are twins nowadays.
- The rate of twin pregnancies, both spontaneous and as a result of fertility treatment, is actually higher than twin births because some women never know they were pregnant with twins because one vanishes before their first ultrasound. An estimated 25-31% of pregnant women suffer from vanishing twin syndrome and 2/3 of twins that vanish do so before 9 weeks. Some researchers hypothesize that the majority of twins that vanish had serious genetic defects.
- 1/3 of twins are identical (monozygotic) and 2/3 are fraternal (dizygotic).
- Identical twins can be boy/girl, but if that happens, the girl has a genetic disorder called Turner’s Syndrome.
- There are some very unusual subtypes of twins (most are subtypes of monozygotic twins) like conjoined twins, twins conceived at different times (superfetation), including by different fathers (heteropaternal superfecundation), half identical twins (the egg splits, but then each half is fertilized by a different sperm), mirror image twins, parasitic twins. Who knew?
- Identical twins are not genetic, but fraternal twins are. So, if twins run in your family on the mom’s side and you have twins, they’ll probably be fraternal.
- Fraternal twins almost always have separate placenta and amniotic sacs (dichorionic/diamniotic). That is the safest situation. 75% of identical twins share placenta (monochorionic). Whether or not identical twins share depends on how far after fertilization they split. About 15% of monochorionic twins develop twin to twin transfusion syndrome (TTTS) and no one knows how to prevent this.
- If your babies share placenta, you have to cut the umbilical cord as soon as the first one is born because there is a risk that the 2nd baby won’t get enough blood if you don’t. If not, you can allow the first one to stop pulsing even as the other twin is being born. Either way, you can wait before cutting the 2nd baby’s cord.
- Twin pregnancies, by virtue of there being two babies, are considered high risk. Pregnancy complications (gestational diabetes, preeclampsia, premature birth) are more common for moms carrying identical twins and less common for spontaneous twins.
- The only thing correlated with reducing the chance of preterm birth with twins is gaining more weight. I was told to gain 45 pounds!!!
- You can deliver twins vaginally, but it depends greatly on their positioning. In 75% of cases, the first baby is head down and most doctors will attempt a vaginal delivery in that situation.
I know some of this sounds scary, but I actually found it really empowering to learn about what could happen even if there’s nothing I can do to prevent it. I feel like I’m ready to tackle whatever arises (although last time I felt that way, I ended up with one more baby than I planned for!) and also justifies my early gathering of baby gear! Having twins is like being in a special club. In fact, there are special clubs for twin families! More to come about our crazy adventures as twin parents-to-be.