If you’re pregnant or trying to get pregnant, you may have had a picture in your head of a healthy baby, sleeping peacefully in your arms. You probably weren’t picturing two babies! But if you’ve found your way to this blog, you may have figured out that a twin pregnancy adds a whole new set of questions to the pregnancy process. Here are some answers to get you started.
What are the chances of having a twin pregnancy?
Here in the United States, twins are much more common than they used to be. According to federal government data, about 34 sets of twins are born for every 1,000 births. This is a big jump from 1980, when the number was just under 19.
What’s changed since then? Well, most of that increase is due to wider use of assistive reproductive technologies. Another reason might be that more women are having babies in their 30s and 40s: Hormonal changes may make older women more likely to release more than one egg at a time.
The likelihood of having twins depends on a few factors, but the main one is whether or not fertility treatments are involved. According to a recent report from the National Center for Health Statistics, about 40 percent of live U.S. births in 2014 that resulted from assisted reproductive techniques were twins.
Here are a few other factors that can increase your chances of having twins:
- there’s a history of twin pregnancies on your mother’s side of your family
- you’ve had twins before
- you’ve been pregnant before
- you’re an older mom-to-be
- you’re African-American
- you’re taller or heavier than average
- your body is producing prolactin for breastfeeding
What is the difference between fraternal and identical twins?
While the frequency of twin births in the United States has jumped more than 75% in the past 30 years, this increase has been made up entirely of fraternal (also called non-identical) twins. Identical twins, which occur in only about 3.5 out of every 1,000 U.S. births, come from a single fertilized egg that splits in half; this is a random and rare event and it’s not affected by any of the factors listed above. Fraternal twins come from two separate eggs, each fertilized by a different sperm.
There’s a bit more too it, though. Most fraternal twins and some identical twins are “di/di” (dichorionic/diamniotic), which means that each twin has their own placenta and their own amniotic sac. This is the most common scenario, and the biggest concerns are preterm labor and making sure both babies are growing adequately. This is the most common kind of twin pregnancy.
Then there’s “mo/di” (monochorionic/diamniotic) twins, which have individual amniotic sacs but share a placenta. These twins are always identical, and they face a higher risk of complications from the blood and nutrients from one baby passing through the placenta to the other twin, which can cause a dangerous condition called twin-to-twin transfusion syndrome (TTTS).
The least common scenario is called “mo/mo” (monochorionic/monochorionic), which is when twins share a single placenta and a single amniotic sac. These twins are always identical, and they face a higher risk of complications from TTTS and tangled umbilical cords.
How does a twin pregnancy affect prenatal care?
An ultrasound can usually detect twins as early as 8 to 14 weeks into the pregnancy. While most twins are carried to term without complication, twins do have a higher risk of health complications than single-baby pregnancies. The biggest concern is premature birth (before 37 weeks of pregnancy). Mo/di and mo/mo pregnancies are considered higher risk than di/di pregnancies.
So, if you’re expecting twins you’ll need to go to extra prenatal care checkups. You can expect more ultrasounds, more blood pressure tests and more fetal testing. Your healthcare provider may also recommend that you limit some of your activities and get extra nutrients such as folic acid, calcium, iron and protein. Finally, your healthcare provider might recommend labor induction or a C-section by week 38 or 39 of pregnancy, which is two or three weeks earlier than for most singleton pregnancies.
How is a Twin Pregnancy Different?
If you’re carrying twins, you may show earlier than normal. Some women who have been pregnant with twins report higher-than-normal levels of morning sickness. You can expect to gain more weight than with a singleton pregnancy, and you may be more likely to experience varicose veins, hemorrhoids, nausea, dizziness, acne, brittle nails and hip pain. As we mentioned, you may feel like you live at the doctor’s office. And beyond your scheduled appointments, you’ll probably make a few extra trips to labor and delivery along the way, because it’s harder to know if everything is okay than it is with a singleton pregnancy, especially if you start experiencing Braxton Hicks contractions (the contractions that occur before real labor). So never feel silly for making a “false start” trip to the hospital or calling your doctor with questions or concerns about your pregnancy. Speak up if you need information about pregnancy support services. And remember: Your qualified Ob/Gyn should be able to handle just about every possible complication related to your twin pregnancy care.
If you have any questions about twin pregnancy, feel free to contact us for more information and to discuss your particular situation. Other information resources can be found below. You can also download the guide, “Prenatal Care Visits – From Pre-Conception to Labor & Delivery.
- American College of Obstetricians and Gynecologists: Multiple Pregnancy
- Mayo Clinic: Twin pregnancy: What multiples mean for mom
About the Connecticut OBGYN Practice
Dr. John Garofalo, M.D., is a gynecologist located in Fairfield County, Connecticut, providing care for Norwalk, Darien, New Canaan, Weston, Rowaytan and the surrounding areas. He has more than 20 years of practice and surgical experience covering many facets of obstetrics and gynecology.
Laury Berkwitt, APRN, is a nurse practitioner specializing in women’s health in Fairfield County, Connecticut. Laury has a passion for providing quality women’s healthcare in a safe and comfortable manner by creating a trusting patient-practitioner relationship. She has been in practice for more than 10 years, caring for women of all ages.
For more information, go to www.garofaloobyn.com. John Garofalo, M.D., and Laury Berkwitt, APRN, can be reached for personal consultations by calling 203.803.1098.