A multiple gestation pregnancy is one where the mother carries more than one fetus.
According to March of Dimes, 3 percent of women will experience a multiple pregnancy each year. Most multiple gestation pregnancies are with twins.
This article looks at what happens with a multiple gestation pregnancy, the different symptoms that may occur, potential risks, and care options that are available.
Contents of this article:
Having a multiple gestation pregnancy
The chance of multiple gestation pregnancies may be higher when there is a family history.
Women and their partners may ask, "will my babies look alike?" The answer is that it depends. In cases of identical twins, for example, they look exactly alike because one egg was fertilized and split into two embryos.
Fraternal twins are not identical and occur when two eggs are fertilized by two separate sperm. In cases of fraternal multiples, the fetuses are not genetically identical.
Certain women are more likely than others to have a multiple gestation pregnancy. These women include:
- Those who have undergone fertility treatments
- Women over the age of 30
- Those with a family history of multiple gestation pregnancy
- Obese women
- Black or Caucasian women
In twin gestations, it is necessary to work out if each fetus has its own chorion and amniotic sac. The amniotic sac is a bag of fluid in the womb where the fetus grows. It is formed of two membranes, and one of these is the chorion.
Doctors can find this out by carrying out an ultrasound exam. Twins are defined into one of three categories:
- Dichorionic-diamniotic: These are either fraternal or identical twins who most commonly have their own placenta, chorions, and amniotic sacs.
- Monochorionic-diamniotic: These are identical twins who share a placenta and chorion but have their own amniotic sacs. These twins can experience a complication known as twin-twin transfusion syndrome. One twin "donates" blood to the other, resulting in one twin with too much blood and the other with too little.
- Monochorionic-monoamniotic: These are identical twins sharing a chorion, amniotic sac, and placenta. These twins more frequently experience complications, including problems with the umbilical cord.
Symptoms of a multiple pregnancy
Some women may experience symptoms or happenings out of the ordinary for a single gestation pregnancy. These signs and symptoms can include:
- Very sore breasts
- Excessive hunger or rapid weight gain in the first trimester
- Simultaneous fetal movements in different areas
- Severe morning sickness
- Multiple fetal heartbeats
- A larger uterus
- A rise in levels of certain substances in the blood known as human chorionic gonadotrophin and alpha-fetoprotein
A healthcare provider will confirm the presence of a multiple pregnancy on an ultrasound exam.
Multiple gestation pregnancies may require more visits to a healthcare provider.
Women who are experiencing a multiple gestation pregnancy may require more frequent health visits and testing, such as more frequent ultrasounds. At times, it may be recommended that maternal-fetal medicine is used, especially in cases of higher risk pregnancies.
As with any pregnancy, diet and exercise are important factors in maintaining the health of mother and fetuses. While there is no special diet to follow, additional folic acid, protein, iron, and calcium are needed.
Prenatal vitamins are a great way to be sure that women are getting some of the additional nutrients they need. Women who are carrying more than one fetus do not need to increase the dose, however. These vitamins should be taken as with a single pregnancy or as directed.
Exercise and weight gain
Exercise should be discussed with a healthcare provider as certain exercises may not be recommended. Yoga, swimming, and walking are generally good options. Each pregnancy is unique, however, and so these may or may not be recommended.
At times, multiple pregnancies require the following:
- Less activity later in pregnancy
- Bed rest
- Reduced travel or work activities
Generally speaking, it is recommended that women get an average of 30 minutes of exercise daily.
Women who are carrying more than one baby will gain more weight than their single gestation counterparts.
According to March of Dimes, women carrying twins who were a healthy weight before conception should gain anywhere from 37 to 54 pounds during their pregnancy.
This amount decreases if they were overweight or obese before conception. For overweight women, 31 to 50 pounds is recommended, whereas obese women are only recommended to gain 25 to 42 pounds.
If genetic testing is desired during a multiple pregnancy, it is important to note that tests using maternal blood are less sensitive than in single baby pregnancies.
Tests such as chorionic villus sampling and amniocentesis are also more challenging to complete due to the need to test each fetus. One fetus may be affected by a genetic abnormality while others are not.
Risks and complications
Multiple gestation pregnancies experience higher rates of complications than single gestation pregnancies. Most commonly, women experience preterm birth, defined as delivery before 37 weeks' gestation.
Preterm infants may experience health complications including breathing, eating, and temperature control problems. They may also experience complications that can lead to cerebral palsy, a group of movement disorders.
At times, some preterm infants may go on to develop behavioral or learning problems during both childhood and adulthood.
If born at or before 32 weeks' gestation, babies can experience more severe health conditions or death.
Cesarean deliveries may be more common in multiple gestation pregnancies.
Other multiple gestation pregnancy complications that can affect the mother include:
- Gestational diabetes
- Preterm labor - labor before 37 weeks
- Severe morning sickness
- Excessive amniotic fluid
- Miscarriage and stillbirth
- Postpartum depression
- Postpartum hemorrhage
Possible fetal and newborn complications can include:
- Disabilities, such as spina bifida, cerebral palsy, and congenital heart defects
- Unequal growth in which one baby is significantly smaller than the other
- Low birth weight, where a baby is born at less than 5 pounds 8 ounces
- Twin-twin transfusion syndrome
Multiples can be delivered either vaginally or via cesarean delivery. The decision on mode of delivery is based on several factors. These include:
- The number of babies
- Their position
- Weight and health status
- Health of the mother
- How the labor is progressing
- Experience of the doctors present
Most often, multiple gestation pregnancies are delivered via cesarean delivery.
Pregnancy can raise a lot of questions. Women should speak with their healthcare provider if they think they may be experiencing a multiple gestation pregnancy. They should also speak with their provider if they have specific questions or have experienced symptoms related to their pregnancy.