Multiple Pregnancy: Twins or More
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This topic is for women who are pregnant with more than one baby. It focuses on the questions that are specific to multiple pregnancies. For information on what to expect during pregnancy, labor, and childbirth, see the topic Pregnancy.
What is a multiple pregnancy?
A multiple pregnancy means that a woman has two or more babies in her uterus. These babies can come from the same egg or from different eggs.
Babies that come from the same egg are called identical. This happens when one egg is fertilized by one sperm. The fertilized egg then splits into two or more embryos. Experts think that this happens by chance. It isn't related to your age, race, or family history.
If the babies you're carrying are identical, they:
- Are either all boys or all girls.
- All have the same blood type.
- Probably will have the same body type and the same color skin, hair, and eyes. But they won't always look exactly the same. They also won't have the same fingerprints.
Babies that come from different eggs are called fraternal. This happens when two or more eggs are fertilized by different sperm. Fraternal twins tend to run in families. This means that if anyone in your family has had fraternal twins, you're more likely to have them too.
If the babies you're carrying are fraternal, they:
- Can be both boys and girls.
- Can have different blood types.
- May look different from each other or may look the same, as some brothers and sisters do.
See a picture of identical and fraternal babies in the uterus.
What causes a multiple pregnancy?
Fertility drugs help your body make several eggs at a time. This increases the chance that more than one of your eggs will be fertilized. When in vitro fertilization is used to help a woman get pregnant, the doctor may put several fertilized eggs in the uterus to increase the chances of having at least one baby. But this also makes a multiple pregnancy more likely.
You're also more likely to have more than one baby at a time if:
- You're age 35 or older.
- You're of African descent.
- You've had fraternal twins before.
- Anyone on your mom's side of the family has had fraternal twins.
- You've just stopped using birth control pills.
What are the risks of a multiple pregnancy?
Any pregnancy has risks. But the chance of having serious problems increases with each baby you carry at the same time.
If you're pregnant with more than one baby, you may be more likely to:
- Develop a problem that causes your blood pressure to get too high (preeclampsia).
- Develop a type of diabetes that can occur while you're pregnant (gestational diabetes).
- Deliver your babies too early. When babies are born too early, their organs haven't had a chance to fully form. This can cause serious lung, brain, heart, and eye problems.
- Have a miscarriage. This means that you may lose one or more of your babies.
- Have a baby born with a birth defect that occurs when something is wrong with the genes or chromosomes. Certain genetic disorders may be more likely to occur in multiple pregnancies.
Keep in mind that these problems may or may not happen to you. Every day, women who are pregnant with more than one baby have healthy pregnancies and have healthy babies.
How can you tell if you're carrying more than one baby?
While you may feel like you're carrying more than one baby, only your doctor can say for sure. He or she will do a fetal ultrasound to find out. This test can give your doctor a clear picture of how many babies are in your uterus and how well they're doing.
If the test shows that you're carrying more than one baby, you'll need to have more ultrasounds during your pregnancy. Your doctor will use these tests to check for any signs of problems that your babies may have as they grow.
What type of treatment will you need?
If you're pregnant with more than one baby, you'll need to see your doctor more often than you would if you were having just one baby. This is because you and your babies have a greater chance of developing serious health problems.
Your doctor will do a physical exam at each visit. It's important that you go to every appointment. Your doctor may also do a fetal ultrasound, check your blood pressure, and test your blood and urine for any signs of problems. Early treatment can help you and your babies stay healthy.
You're having multiples. Now what?
The thought of having more than one baby may be scary, but it doesn't have to be. There are some simple things you can do to keep you and your babies healthy.
The best thing you can do is take care of yourself. The healthier you are, the healthier your babies will be.
While you're pregnant, be sure to:
- Go to every doctor's appointment.
- Eat healthy foods. Take in plenty of calories from foods rich in folic acid, iron, and calcium. These nutrients are essential for the healthy growth of your babies. Breads, cereals, meats, milk, cheeses, fruits, and vegetables are all good choices. If you're not able to eat enough because of severe morning sickness, call your doctor.
- Don't smoke, drink alcohol, or use illegal drugs.
- Avoid caffeine.
- Avoid using any medicines, vitamins, or herbs unless your doctor says it's okay.
- Talk to your doctor about what activities are okay for you to do while you're pregnant.
- Get a lot of rest.
After your babies are born, you may feel overwhelmed and tired. You may wonder how you're going to do it all. This is normal. Most new moms feel this way at one time or another.
Here are some things you can do to ease the stress:
- Ask your family and friends for help.
- Rest as often as you can.
- Join a support group for moms with multiples. This is a great place to share your concerns and hear how other moms cope with the demands of raising multiples.
- If you feel sad or depressed for more than 2 weeks, call your doctor.
Health Tools help you make wise health decisions or take action to improve your health.
If you are pregnant with more than one fetus, you can expect to have the same symptoms as those of a pregnancy with one fetus (called a singleton pregnancy). But the symptoms may happen earlier and may be worse. A multiple pregnancy is likely to cause:
- Early and excessive nausea and vomiting in the first trimester.
- Extra weight gain.
- A uterus that is larger than expected for your due date.
- More fetal movement than expected during the second trimester and later.
Later in the pregnancy, you are more likely to have:
- Varicose veins.
- Increasing backache.
- Trouble breathing (caused by pressure on the lungs from the uterus pushing up on the diaphragm).
- Indigestion (caused by pressure on the stomach from the large uterus).
- A very large belly
- Gestational diabetes.
- Preeclampsia, a serious disorder of circulation and blood pressure that affects both mother and fetuses.
- Preterm labor.
Exams and Tests
Most multiple pregnancies are now identified during the first or second trimester.
A fetal ultrasound can show whether there is more than one fetus in the uterus. If you have more than one fetus, you will have an ultrasound several times during the pregnancy to monitor fetal growth and amniotic fluid.
Sometimes the first sign of a multiple pregnancy is from a test that was done for another reason. For example, a very high level of human chorionic gonadotropin (hCG), the "pregnancy test" hormone, can be a sign of multiple pregnancy.
Tests used during a multiple pregnancy
- Blood pressure checks at every prenatal appointment are used to monitor you for high blood pressure or preeclampsia.
- Blood testing is used to check you for low iron (anemia). Anemia is a common problem for women with multiple pregnancy, because the fetuses use a great amount of the mother's iron stores.
- A urine test and urine culture can be used to screen you for a urinary tract infection (UTI).
- Transvaginal ultrasound may be used to check the length of your cervix. A short cervix is a sign of an increased risk of preterm labor.
- In the second trimester, you may have an oral glucose screen to check for gestational diabetes.
- Electronic fetal heart monitoring may be used before or during delivery, to make sure the fetuses are doing well.
Tests used to check for birth defects
Fetuses in multiple pregnancies have an increased risk of genetic disorders and birth defects.
There are two types of birth defects tests: screening and diagnostic.
Screening tests show the chance that a baby has a certain birth defect. But they can't tell you for sure that your baby has a problem. Some of the available screening tests for birth defects are not as accurate when used for women carrying more than one baby. Talk to your doctor about your options for screening tests.
Diagnostic tests show if a baby has a certain birth defect. Diagnostic test options may include:
- Chorionic villus sampling (CVS). It uses a tiny piece of the placenta, taken by passing a thin tube through your vagina and cervix and into the uterus. It can also be done through the abdomen with a needle. The sampling and genetic testing are done between 10 and 13 weeks of pregnancy.
- Amniocentesis, which uses a small amount of amniotic fluid, taken by inserting a needle into your abdomen and uterus. The sampling and genetic testing are usually done between 15 and 20 weeks of pregnancy.
CVS and amniocentesis both have a slight risk of miscarriage. You may want earlier CVS results if you have to make decisions about treating or continuing a pregnancy.
For more information, see the topic Birth Defects Testing.
Always be sure to take extra good care of yourself when you are pregnant. When carrying twins or more (multiple pregnancy), be sure to eat a balanced and nutritious diet of quality calories. And make sure that you get enough calcium, iron, and folic acid.
You can expect to gain weight more quickly than you would with one fetus. With each additional fetus a woman carries, her range of weight gain will increase. Your range of healthy weight gain will also be different if you started your pregnancy underweight or overweight.
Prenatal care during a multiple pregnancy
If you are pregnant with twins or more, good prenatal care will help you and your health professional prevent and watch for problems. You will have more frequent checkups than you would for a pregnancy with one fetus. These checkups are important both for monitoring your own health and your fetuses' health and for giving you and your health professional time to build a working relationship.
Because you are more likely to deliver early, be sure to plan ahead. Ask your health professional about making arrangements to deliver at a hospital that has facilities for emergency cesarean delivery and a neonatal intensive care unit (NICU).
Watch for problems
Possible pregnancy problems that can be more likely when you are carrying twins or more include:
- Preeclampsia and high blood pressure. Treatment depends on how severe your condition becomes. It may include medicine, bed rest, fetal monitoring, and early delivery. For more information, see the topic Preeclampsia and High Blood Pressure During Pregnancy.
- Problems with the placenta, such as placenta abruptio or placenta previa. For more information, see Placenta Abruptio and Placenta Previa.
- Anemia, which is treated with iron-rich foods and iron supplements. If this doesn't help, you can be tested for other problems that can cause anemia.
- Too much amniotic fluid in the uterus (polyhydramnios). Treatment can include medicine and removal of amniotic fluid.
- Urinary tract infection (UTI), which is treated with antibiotics.
- Heavy blood loss after delivery (postpartum hemorrhage), which can require a blood transfusion.
- The need to deliver by cesarean section (C-section). You will likely need a C-section if your babies (fetuses) are not turned head-down in time for birth (breech or transverse fetus).
Any pregnancy can have these complications, but there is more concern about them happening during a multiple pregnancy.
Preterm labor is more common in a multiple pregnancy than in a pregnancy with one fetus. If you go into preterm labor and premature delivery is likely, your health professional may recommend taking one or more precautions, such as:
- Limiting your activity level.
- Staying in the hospital. This is often so that you can receive steroid medicine to help your babies' lungs develop faster. In some cases, tocolytic medicine is used in an attempt to delay preterm birth. You are closely watched if you are treated with a tocolytic medicine.
For more information, see the topic Preterm Labor.
Possible problems for the babies (fetuses) during multiple pregnancy can include vanishing twin syndrome, twin-to-twin transfusion, twins that share one amniotic sac (monoamniotic twins), and locking twins.
Early pregnancy decisions about triplets or more
When there are three or more fetuses in the uterus, their risks of disability or death are higher with each additional fetus. If you are carrying triplets or more after infertility treatment, your doctor may offer the option of multifetal pregnancy reduction (MFPR) near the end of your first trimester. A successful MFPR increases the chances of healthy survival for the remaining fetuses and reduces risks to you. But MFPR sometimes leads to miscarriage.footnote 1
The decision to have a multifetal pregnancy reduction is difficult and may be traumatic. If you are faced with this decision, talk to your doctor about your personal risks from trying to carry multiple fetuses to term compared to the risks of choosing MFPR. Also consider discussing your decision with a counselor or spiritual adviser.
A multiple pregnancy can make morning sickness worse during the first months of pregnancy. You can treat your symptoms at home, unless you have become dehydrated or are not getting enough to eat because of vomiting.
Learn the signs of preterm labor. They may include:
- Cramping similar to menstrual cramps.
- Abdominal cramps, possibly with diarrhea.
- Contractions of your uterus that don't go away, about 6 or more in 1 hour.
- Pressure in your lower back, especially if it comes and goes.
- An increase in your usual amount of vaginal discharge.
Call your health professional immediately if you have symptoms of preterm labor.
Call your health professional or go to the hospital if you begin bleeding from the vagina or if your water breaks.
Self-care for multiple pregnancy
If you are pregnant with twins or more, it's important to:
- Get enough nutritious calories, folic acid, iron, and calcium to nourish you and your babies (fetuses).
- Avoid things that could hurt your babies, such as:
- Talk to your doctor about what type and level of activity is safe for you. Your doctor may recommend that you stop physically demanding exercise.
- Get plenty of rest.
- Consider whether you need to change your daily work activities, based on how well your pregnancy is going. Be sure to follow any advice to reduce your activity level.
- See your health professional often. Beginning in the 20th week of pregnancy, you may be checked every other week. Beginning at the 30th week, you may be checked more often.
For more information on what to expect during pregnancy, labor, and childbirth, see the topic Pregnancy.
After the babies are born
Coping. Having a multiple pregnancy and caring for two or more infants at the same time can be overwhelming and exhausting. Lack of sleep, the increased amount of work, less personal time, and trouble maintaining the home are common sources of frustration for parents of multiple infants.
With multiple newborns to care for, it is common to feel frustrated or guilty about not managing your life as easily as before. This is normal. Get extra help for as long as possible after your babies are born. Rest as often as you can during the day. Accept help from friends and family. They can bring meals, go grocery shopping, do household chores, or care for your children while you take some time for yourself.
Some women feel sad or depressed after having twins or more. If you feel depressed for longer than 2 weeks or if you have troubling or dangerous thoughts, see your health professional. It is important that you get treatment. For more information, see the topic Postpartum Depression.
Consider joining a support group for parents of twins or more. Sharing your experience with other people who are in a similar situation may help you with the demands of caring for your babies. For more information, see the Other Places to Get Help section of this topic.
Breastfeeding? Breastfeeding more than one baby can be challenging, but it helps to build the bond between you and each baby. It gives your babies excellent health benefits. If you plan to breastfeed your babies, seek out support and information from your health professional, the hospital, or a lactation consultant before and after the birth. For more information, see Breastfeeding and Bottle-Feeding.
Parenting. Look for your new babies' personality differences and help them build their own identities over time. Give each of your children time alone with you. If you have an older child or children, schedule individual time with them too.
- American College of Obstetricians and Gynecologists (2014). Multifetal gestations: Twin, triplet, and higher-order multifetal pregnancies. ACOG Practice Bulletin No. 144. Obstetrics and Gynecology, 123(5): 1118–1132. Accessed July 8, 2014.
Other Works Consulted
- American College of Obstetricians and Gynecologists (2013). Multifetal pregnancy reduction. ACOG Committee Opinion No. 553. Obstetrics and Gynecology, 121(2): 405–410.
- Cunningham FG, et al. (2010). Multifetal gestation. In Williams Obstetrics, 23rd ed., pp. 859–889. New York: McGraw-Hill.
- Marquard K, Moley K (2012). Multiple gestations and assisted reproductive technology. In CA Gleason, SU Devaskar, eds., Avery's Diseases of the Newborn, 9th ed., pp. 60–66. Philadelphia: Saunders.
Current as of: May 29, 2019
Author: Healthwise Staff
Sarah Marshall MD - Family Medicine
Adam Husney MD - Family Medicine
Elizabeth T. Russo MD - Internal Medicine
Kathleen Romito MD - Family Medicine
William Gilbert MD - Maternal and Fetal Medicine
Current as of: May 29, 2019