Multiple Births in the First Trimester

Although prenatal care during the first trimester is important for any pregnancy, it is vitally important if you are carrying twins or other multiples.

You may feel excited and perhaps overwhelmed by the idea of having twins or other multiples. When you are pregnant, you have a new reason to take care of yourself. Your health can affect the babies' growth.

• Once you know that you're pregnant with multiples, you should ask your health care provider if he or she has experience with multiple births. You and your health care provider will form a team, along with your spouse or partner.

• You and your provider will establish a schedule of prenatal care visits. Plan ahead so that you don't miss any of these appointments. You may need to schedule time off from work.

• If you smoke, stop. Smoking increases the risk of losing the babies or that they will be born small for gestational age (SGA). Ask your health care provider for help.

• If you drink alcohol or do drugs, stop. Alcohol and drugs cause miscarriages, birth defects, mental retardation and low birth weight. If you need help to stop, talk to your health care provider.

• Find your due date, the approximate date your babies will be born, but keep in mind that twins and other multiples are more likely to arrive prematurely than single babies.

Multiple births

About 3 percent of pregnancies are multiple. About one in three sets of twins are identical. If your twins formed from a single fertilized egg that split in two, your children will be identical twins, always of the same sex. They will have the same blood type, hair color and eye color. If your twins developed from two separate fertilized eggs, they will be fraternal, and may or may not be the same sex.

If you are having triplets or more, the babies can be identical, fraternal or a combination.

You will have an ultrasound test during this trimester to try to determine whether the multiples are identical or fraternal. Your provider will look to see whether there are one or more placentas. DNA testing also may be done; it is a more accurate way of determining whether the multiples are identical. It's important to determine this because identical babies have a greater risk for birth defects than fraternal babies or single babies, and pregnancies with identicals are at greater risk for complications because the babies share a placenta.

Changes in You

Almost every part of your body is affected by a multiple pregnancy. Your uterus and cervix will begin to change right away. Because you are carrying multiples, you may begin to look pregnant in this trimester, and you probably will have some common signs of early pregnancy. Every pregnancy is unique and you may not have all the signs. If this is not your first pregnancy, you may have signs at different times than in past pregnancies.