Expecting not one but two or more babies at a time can bring incredible joy, but it is also something that can make your pregnancy more difficult. Often when talking about multiples, there is a distinction between twins and higher-order multiples. The more babies you are carrying, the higher the risks.
The dramatic increase in multiples in recent years is due to the fact that more older women are having babies, and more people are using fertility treatments, both of which increase your chances of multiples.
The Facts about Multiples
Twins are the most common type of multiple, making up 95 percent of multiple births. While having twins is double the blessing, it can also mean more concerns. One third of twins are identical twins, formed from the same egg. Of these identical twins, 15 percent develop a serious condition called twin-to-twin transfusion syndrome, in which there is a connection between their blood vessels in the placenta. This can mean one twin can get greater blood flow than the other.
Twins make up 3 percent of all births in the United States, a number that is up 60 percent since the 1980s, according to the CDC. Age increases your risks of naturally conceiving twins. The likelihood of having twins peaks between ages 35 and 39.
African American women, women who are tall or large, and women who have had fraternal twins before are all at a higher risk for multiples. Additionally, the more pregnancies you have, the greater your risk for twins. Women over age 35 are more likely to have twins because their bodies produce more follicle-stimulating hormone (FSH), which causes more eggs to be released each month. In 2003, one out of 18 births to women over 35 was multiples, compared to one out of 33 in women under 35.
Multiples are diagnosed by ultrasound and are usually spotted by the beginning of the second trimester. An abnormal result on the triple or quad screen blood test at 16 weeks can also alert your health-care provider to multiples. If you have undergone fertility treatments, it is likely that your multiple pregnancy will be identified almost immediately. Additionally, your health-care provider may diagnose multiples by hearing two fetal heartbeats.
Complications with Multiples
The primary concern with multiples is preterm birth. When babies are born before 37 weeks gestation, they are likely to have problems and face disabilities. Sixty percent of twins, 90 percent of triplets, and almost all higher order multiples are born preterm, and the length of the pregnancy on average decreases with each baby in the uterus: 36 weeks for twins, 32 weeks for triplets, 30 weeks for quadruplets, and 29 weeks for quintuplets. Low birth weight is also common, not only because of the increased likelihood of preterm birth but also due to fetal growth restriction.
Multiples also increase the chances of the mother developing preeclampia and gestational diabetes. Gaining enough weight early in the pregnancy is an important way to help keep your pregnancy healthy. Your health-care provider will want to see you more frequently throughout a multiple pregnancy.
Mothers of multiples are also advised to cut back their activities by the twentieth or thirtieth week of pregnancy to reduce the risk of preterm labor. Placental abruption, where the placenta detaches from the uterine wall before delivery, is also common in multiple pregnancies. Miscarriage rates are also higher in multiple pregnancies.
If I undergo fertility treatments, will I have twins?
Fertility treatments greatly increase your risk of having multiples. Of women who give birth after undergoing fertility treatments, 56 percent have multiples. Reproductive specialists work hard to reduce the risk of multiples, but it is still a great concern.
Twin pregnancies can be delivered vaginally, although the chance of a C-section is increased. Other multiple pregnancies are always delivered by C-section. While all of this information might make you worry that your babies are at a greater risk, a National Institutes of Health study found that multiples of older moms were just as healthy as multiples of younger moms, so your age will not impact your babies' health.