What Is A Multiple Pregnancy?
A pregnancy with one fetus is called a singleton pregnancy. The term "multiple pregnancy" refers to carrying more than one fetus at a time.
Currently, according to the March of Dimes, the multiple rate is approximately 3%, a decline of 21% since its peak in 1998.
After the age of 30, women are more likely to have multiples. Similarly, fertility drugs and treatments are more commonly used as fertility technology and medications have been developed, which drastically increases the likelihood of multiples.
What Are The Types of Multiples?
Twins refers to two babies who are born from the same pregnancy.
- Identical Twins (also known as monzygotic twins) occur when a single fertilized egg splits and develops into two fetuses. These fetuses typically share a placenta. Identical twins have the same genes, so they're always the same sex. Identical twins are not related to age, race, family history or fertility treatments.
- Fraternal Twins (also known as dizygotic twins) occur when two separate eggs are fertilized by two separate sperm. Each twin generally has its own placenta. Fraternal twins are not identical and may not look the same.
Higher Order Multiples (triplets and beyond) can result from three (or more) eggs being fertilized, one egg splitting twice (or more) or a combination. A higher order multiple pregnancy may have all fraternal siblings or identical and fraternal siblings.
What Are The Complications Associated With Multiple Pregnancies?
Multiples often pose an increased strain and risk to the fetuses and the mother, and so the pregnancy may be classified as high risk. Because of these special concerns, more frequent prenatal care and testing are typically ordered to identify and manage any possible complications as early as possible.
Common complications include:
- Premature labor and birth: 60% of twins, 90%+ of triplets and most quadruplets and up are born prematurely
- Low birthweight due to Intra-uterine Growth Restriction, particularly with higher order multiples. Growth of twins begins to slow at around 30-32 weeks, triplets at 27-28 weeks, and quads at 25-26 weeks.
- Twin-To-Twin Transfusion Syndrome
- Preeclampsia: Twice as likely to occur in multiples pregnancies, this can be dangerous for the mother and the fetuses, and may lead to induced premature birth.
- Gestational Diabetes: This can cause babies to grow especially large, causing birth issues.
- Surgical (cesarean section) birth is more likely due to difficulties in infant positioning within the uterus and is recommended in higher order multiple pregnancies.
- Placental Abruption (separation of placenta from the uterine lining), usually in the third trimester.
What is Vanishing Twin Syndrome?
Vanishing Twin Syndrome (also known as fetal resorption) is when a multiple is detected early on, and is later found not to be there. The vanished twin is often reabsorbed by the surviving fetus or the mother. The surviving twin is not typically harmed and there is little understanding or explanation of this syndrome.
If Vanishing Twin Syndrome occurs in the first trimester, there may be no symptoms beyond some minor bleeding.
If Vanishing Twin Syndrome occurs in the second or third trimester, serious complications, such as preterm labor, infection of the uterus due to the deceased multiple, or hemorrhage may occur.
It is impossible to note precisely how often VTS occurs, but it's been reported that one of every eight multiples pregnancies may have a vanishing twin. This may occur without knowledge by the mother or doctors.
How Are Multiple Pregnancies Diagnosed?
Multiples are diagnosed typically in the first trimester using a Doppler device or during the first routine ultrasound.
Other symptoms of multiple pregnancy may be detected by the mother or a doctor, including:
- Rapid weight gain during the first trimester
- Larger than expected uterus
- Severe nausea and vomiting (pregnancy related)
- Multiple heartbeats
- Extra fetal movement
- Abnormal blood results taken at 16 weeks
Prenatal Care for Multiples Pregnancy:
Mothers pregnant with multiples may be considered high risk. In addition, more frequent prenatal check-ups and care are usually ordered in order to:
- Monitor weight gain to ensure the mother is gaining enough to sustain the pregnancy and her own health
- Assess activity level that is safe depending on the number of multiples, any complications, and possible need for bed-rest
- Determine when disability leave should begin, which is generally earlier than in a singleton pregnancy
- Discuss nutrition requirements
- Monitor blood pressure
- Monitor any contractions or signs of impending labor in case of prematurity
- Determine whether vaginal or cesarean birth is more likely
- Monitor growth of each baby to watch for Twin-to-Twin Transfusion and and Intra-Uterine Growth Restriction
Multiples increase the typical stresses that come with having a baby. There are two (or more!) mouths to feed, less sleep, and major financial impacts. Premature birth and other complications may result in hospital stays or medical treatment, and there is an increased risk of disability. Mothers of multiples are also at a higher risk of postpartum depression due to the increased and unique stressors placed upon her.
It is not uncommon to be unable to tell babies apart when they are first born. Many parents use the hospital bracelets or other identifiers to tell the babies apart until it becomes more obvious.
Similarly, it is important to give each multiple an individual identity. Kidshealth.org recommends the following ways of supporting individuality development:
- Distinctly different names
- Refer to the babies or children by name, not as "the twins"
- Avoid dressing them alike
- Give them their own toys, clothes, and other objects
- Give them separate gifts and cakes on birthdays or celebrations
- Encourage different pursuits and skills
- Give them time apart
While comparisons are inevitable, it is important that the child feels loved for who he or she is, not for being part of a set.
Additional Multiples Resources:
The March of Dimes offers information, resources, and support about pregnancy and multiple pregnancy.
Kidshealth.org provides insight in to caring for multiple babies, and the unique challenges that presents.
American Pregnancy Association provides significant information and resources about pregnancy, multiples, and complications of multiples.
Multiplebirthfamilies.com provides information regarding multiple births, as well as bereavement information and support.
Center for Loss in Multiple Birth is an international organization dedicated to twin loss or loss related to multiple births.