Pregnant With Twins? Here’s How Your Prenatal Care May Differ

Your family building just doubled when you learned you’re having twins, and your mind is swirling with questions. Well, allow the team here at Women’s Clinic of the Rio Grande Valley, under the direction of Dr. Fernando Otero, to shed some light when it comes to prenatal care, which is your most immediate concern. 

Since a twin pregnancy is classified as a high-risk pregnancy, you can expect your prenatal care will be different, as we’re going to want to monitor your pregnancy more closely. How different it will be depends upon several factors that we review here.

Types of twins

In 2022, there were nearly 115,000 twin births in the United States, and twin births, in general, are on the rise. But not all twins are the same.

Most people understand an important distinction in twins between fraternal and identical. In short, identical twins stem from one embryo that splits into two, so the fetuses carry the same genetic code. Fraternal twins occur when two different eggs are fertilized by two different sperm at the same time. These fetuses share genetics as regular siblings do, even those born years apart, but they’re not exactly the same.

There are other important twin distinctions that influence your prenatal care, and they have to do with fetal membranes — the chorion, which is the outer layer of the amniotic sac and the amnion, which is the innermost layer. How fetuses share these tissues can influence your pregnancy as they can be:

• Dichorionic diamniotic (di/di) twins that each have their own chorion and amnion
• Monochorionic diamniotic (mo/di)twins that share a chorion, but not the amnion
• Monochorionic monochorionic (mo/mo) twins that share both the chorion and amnion

In most cases, fraternal twins are di/di twins and identicals are usually mo/di twins, though they can also be di/di twins. Mo/mo twins are rare and require a much higher standard of care during the pregnancy.

We know this is all confusing. Rest assured, we’ll work with you to figure out which type of twin pregnancy you have so we can set up the best prenatal care for you.

Prenatal schedules for twins

We want to outline some broad guidelines when it comes to prenatal care for twins, but please bear in mind that these are just guidelines and each pregnancy is different.

First, a typical gestation period for one fetus is about 40 weeks, while most twins are delivered around the 36-week mark. So, your prenatal window may be shorter than normal.

During this smaller window, we want to check in with you more regularly, especially during the third trimester. How often depends on the type of twin pregnancy and many other factors, such as:

• Previous pregnancy history
• Maternal health
• Maternal age

We may also conduct additional testing throughout your pregnancy, and we can discuss which tests might make sense as we explore your unique circumstances and genetic background.

In many cases, we may recommend taking extra care during the third trimester and reducing activity so you can carry the twins as long as possible. In some cases, bed rest could be necessary after 28 weeks or so, but this is very individual and there are a lot of factors that go into this recommendation.

The best way to get a clearer picture about your prenatal care for your twin pregnancy is to come see us for an evaluation so we can discuss how to best move forward. To get that ball rolling, we invite you to contact one of our offices in McAllen or Edinburg, Texas, to schedule a visit.