A multiple pregnancy almost always surprises expectant parents. However, because of today’s advanced testing techniques, especially ultrasound, most parents know about it early enough to prepare for their new arrivals.
The rate of multiple births has increased greatly in recent years. Since 1980, the rate of twin births has increased 70%, and statistics show that over 3% of all births in the United States are multiple births. If you’re expecting more than one baby, you’re not alone!
Women having babies later in life accounts for nearly 35% of all multiple births. Age 30 seems to be the magic age beyond which the number of multiple births increases. Over 70% of all multiple births are to women over age 30. In the United States, the highest number of multiple births occurs in women over 40; the next highest group is women between the ages of 30 and 39.
When talking about pregnancies of more than one baby, in most cases we refer to twins. The chance of a twin pregnancy is more likely than pregnancy with triplets, quadruplets or quintuplets (or even more!). However, we are experiencing more triplet and higher-order births. A triplet birth is not very common; it happens about once in every 7000 deliveries. (Dr. Curtis has been fortunate to deliver two sets of triplets in his medical career.) Quadruplets are born once in every 725,000 births; quintuplets once in every 47 million births!
A multiple pregnancy occurs when a single egg divides after fertilization or when more than one egg is fertilized. It also happens with fertility treatments, when more than one fertilized egg is placed in the uterus.
Twins from one egg occur about once in every 250 births around the world. Twins from two eggs occur in 1 out of every 100 births in white women and 1 out of 79 births in black women. In certain areas in Africa, twins occur once in every 20 births! Hispanic women also have a higher incidence of twins. The occurrence of twins in Asian populations is less common—about 1 in every 150 births.
No matter how it occurs, being pregnant with two or more babies can affect you in many ways. Your pregnancy will be different, and the type of adjustments you may need to make may be more extensive. These changes and adjustments may be necessary for your health and the health of your babies. Work closely with your doctor and other healthcare professionals to help ensure your pregnancy is healthy and safe.
The increase in multiple births among older women has been attributed to higher levels of gonadotropin, the hormone that stimulates the ovaries to develop and to release eggs. As you age, the level of gonadotropin increases, and you’re more likely to produce two eggs during one menstrual cycle. Most twin births in older women are fraternal twins—babies born from two different eggs.
Twin fetuses usually result (over 65% of the time) from the fertilization of two separate eggs; each baby has his or her own placenta and amniotic sac. These are called dizygotic (two zygotes) twins or fraternal twins. With fraternal twins, you can have a boy and a girl.
About 35% of the time, twins come from a single egg that divides into two similar structures. Each has the potential of developing into a separate individual. These are known as monozygotic (one zygote) twins or identical twins.
Either or both processes may be involved when more than two fetuses are formed. What we mean by that is triplets may result from fertilization of one, two or three eggs, or quadruplets may result from fertilization of one, two, three or four eggs.
The incidence of twin births can run in families, on the mother’s side. One study showed that if a woman is a twin, her chance of giving birth to twins is about 1 in 58. If a woman is the daughter of a twin, she also has a higher chance of having twins. Another study reported that 1 out of 24 (4%) twins’ mothers was also a twin, but only 1 out of 60 (1.7%, about the national average) of the fathers was a twin.
Multiple births are also more common with in-vitro fertilization. This may be due to the frequent use of fertility drugs to increase the chance of pregnancy or the introduction of several fertilized eggs into the uterus in hopes that at least one will implant. Pregnancy with twins as a result of a fertility treatment most often results in fraternal twins. In some cases of higher-number fetuses, a pregnancy can result in fraternal and identical twins, when more than one egg is fertilized (dizygotic twins) and, in addition, one or more of the eggs divides (monozygotic twins).
The percentage of male fetuses decreases slightly as the number of fetuses in a pregnancy increases. In other words, as the number of babies a woman carries increases, her chances of having more girls also increases.
Your chance of having triplets is 1 in 7000. One patient came to the office for her visit wearing a memorable T-shirt:
Not one
Not two
But three …
and no drugs.
(The “no drugs” meaning “no fertility drugs.”)
With monozygotic (identical) twins, division of the fertilized egg occurs between the first few days and about day 8. If division of the egg occurs after 8 days, the result can be twins that are connected, called conjoined twins. (Conjoined twins used to be called Siamese twins.) These babies may share important internal organs, such as the heart, lungs or liver. Fortunately this is a rare occurrence.
Identical twins may face some risks. There is a 15% chance they will develop a serious problem called twin-to-twin transfusion syndrome. There is one placenta, and the babies’ blood vessels share the placenta. The problem arises when one baby gets too much blood flow and the other too little. See the discussion that begins on page 126.
With monozygotic twins, there is a chance several different types of diseases may occur in both twins during their lifetimes. This is less likely to happen with dizygotic twins.
Due to health concerns, it may be important later in life for your children to know whether they were monozygotic or dizygotic. Before delivery, tell your doctor you would like to have the placenta(s) examined (with a pathology exam) so you will know whether your babies were monozygotic or dizygotic. It may be valuable information in the future. Even if there are two placentas, research shows it doesn’t mean twins are dizygotic; nearly 35% of all monozygotic twins have two placentas.
If you have already given birth to a set of fraternal twins, your chance of having another set of twins quadruples! Other reasons for multiple fetuses include some women having more children, being very tall or obese, recently discontinuing oral contraception or taking large doses of folic acid. Studies have shown the twin birth rate for women who took folic acid can be as high as double the rate of women who did not take large doses of folic acid.
Having more children (or pregnancies) can also result in more than one baby. This is true in all populations and may be related to the mother’s age and female hormone changes.
Diagnosis of twins was more difficult before ultrasound was available. However, most multiple pregnancies are discovered well before delivery. Today, it’s uncommon to discover twin pregnancies just by hearing two heartbeats. Many people believe when only one heartbeat is heard, there could be no possibility of twins. This may not be the case. Two rapid heartbeats may have a similar or almost identical rate. That could make it difficult to determine that there are two babies.
Measuring and examining your abdomen during pregnancy is important. A healthcare provider usually finds out a woman is carrying more than one baby because she has a larger-than-expected uterus. Usually a twin pregnancy is noted during the second trimester because you are too big and growth seems too fast for a single pregnancy. Other signs include more severe nausea and/or vomiting, and hearing more than one fetal heartbeat.
Ultrasound examination is the best way to diagnose a multiple pregnancy.
If a woman is pregnant with more than one baby, her risk of problems during pregnancy increases. You can minimize your risks, and possibly avoid them, with good prenatal care and careful attention to your health. Possible pregnancy problems include the following:
•increased risk of miscarriage
•fetal death
•fetal malformations
•low birthweight or growth restriction
•pre-eclampsia
•problems with the placenta, including placental abruption and placenta previa
•maternal anemia
•maternal bleeding or hemorrhage
•problems with the umbilical cords, including entwinement or tangling of the babies’ umbilical cords
•hydramnios or polyhydramnios
•labor complicated by abnormal fetal presentation, such as breech or transverse presentation
•premature labor
•difficult delivery and Cesarean delivery
Birth defects are more common with identical twins than fraternal twins. The incidence of minor malformations in a multiple pregnancy is twice as high as it is in a singleton pregnancy, and major malformations are also more common.
One of the biggest problems with multiple pregnancies is premature delivery. As the number of fetuses increases, the length of gestation and the birth-weight of each baby decreases, although this is not true in every case.
The average length of pregnancy for twins is about 37 weeks. For triplets it is about 35 weeks. For every week the babies remain in the uterus, their birth-weights increase along with the maturity of organs and systems.
It’s important to continue your pregnancy as long as possible, which may best be accomplished by bed rest. You may not be able to carry on with regular activities during your entire pregnancy. If your healthcare provider recommends bed rest, follow his or her advice.
Weight gain is important with a multiple pregnancy. You will probably be advised to gain more than the normal 25 to 35 pounds, depending on the number of fetuses you are carrying. With twins, if you were normal weight before pregnancy, you may be advised to gain 40 to 54 pounds (18 to 24.5 kg). For overweight women, a weight gain between 31 and 50 pounds (14 to 22.7 kg) may be recommended. A weight gain between 25 and 42 (11.3 to 19 kg)pounds may be recommended for obese women. If you’re expecting triplets, your weight gain will probably be between 50 and 60 pounds (22.7 to 27.2 kg) if you are normal weight before pregnancy.
Pay strict attention to your eating plan; eat wisely and nutritiously for all of you. Extra rest is essential. Most pregnant women need at least 2 hours of extra rest each day.
When you’re pregnant with more than one baby, you will probably be monitored more closely. You may have more frequent checkups and more tests.
Beginning around 20 weeks of pregnancy, you will probably visit your healthcare provider every other week until week 30. Then you may be seen once a week until delivery. You may have ultrasound more frequently to monitor babies’ growth. Your blood pressure is watched closely because of preeclampsia, which is twice as common in multiple pregnancies.
Follow your doctor’s instructions closely. Every day and every week you’re able to keep the babies inside you are days or weeks you won’t have to visit them in an intensive-care nursery while they grow, develop and finish maturing.
Twin-to-twin transfusion syndrome (TTTS), also called chronic intertwin transfusion syndrome, occurs only in identical twins who share the same placenta. The condition can range from mild to severe and can occur at any point during pregnancy, even at birth.
TTTS cannot be prevented; it’s not a genetic disorder nor a hereditary condition. We believe it occurs in 5 to 10% of all identical-twin pregnancies. These problems do not occur in twins who each have a placenta.
In TTTS, twins also share some of the same blood circulation. This allows the transfusion of blood from one twin to the other. One twin becomes small and anemic. Its body responds by partially shutting down blood supply to many of its organs, especially the kidneys, which results in reduced urine output and a small volume of amniotic fluid.
The other twin grows large, overloaded with blood. It produces excessive amounts of urine so it is surrounded by a large volume of amniotic fluid. Its blood becomes thick and difficult to pump through its body; this can result in heart failure, generalized soft-tissue swelling and death.
When a Multiple Pregnancy Isn’t a Multiple Pregnancy
Some women are told early in pregnancy they are carrying twins, only to discover later they are carrying only one baby. Early ultrasound exams reveal two babies; later ultrasounds of the same woman show one baby disappeared, but the other baby is OK. We believe one of the pregnancies dies and is absorbed by the mother’s body. This is one reason many healthcare providers prefer not to predict a twin birth before 10 weeks of pregnancy.
Twins are often very different in size. There can also be a large difference in their weights. TTTS is a progressive disorder, so early treatment may help prevent complications.
There are symptoms of the syndrome your healthcare provider looks for. If your abdomen enlarges quite rapidly over a 2- to 3-week period, it may be caused by the buildup of amniotic fluid in the recipient twin. The result can be premature labor and/or premature rupture of membranes. If one twin is small for its gestational age or one is big for its gestational age, it may indicate TTTS. In addition, your healthcare provider may suspect TTTS if any of the following is seen during an ultrasound:
•large difference in the size of fetuses of the same gender
•difference in size between the two amniotic sacs
•difference in size of the umbilical cords
•one placenta
•evidence of fluid buildup in the skin of either fetus
•indications of congestive heart failure in the recipient twin
An additional problem may develop in either twin. With this condition, fluid accumulates in some part of the fetus, such as in the scalp, abdomen, lungs or heart.
Report any of the following to your healthcare provider, especially if you know you’re expecting twins:
•abdominal pain, tightness or contractions
•sudden increase in body weight
•swelling in the hands and legs in early pregnancy
The syndrome may also be detected with ultrasound examination of the uterus. It’s important to find out whether twins share the same placenta. It’s preferable to learn this in the first trimester because in the second trimester it can be harder to discover whether they share a placenta.
If the syndrome is mild or undetected on ultrasound, the appearance of the babies at birth may identify it. A complete blood cell count done after birth will show anemia in one twin and excess red blood cells (polycythemia) in the other.
If diagnosed, the Twin to Twin Transfusion Syndrome Foundation recommends weekly ultrasounds after 16 weeks until the end of the pregnancy to monitor the condition. They recommend this be done even if the warning signs of TTTS have decreased.
The most common treatment for TTTS is amnioreduction, in which large volumes of amniotic fluid are drained from the sac of the larger twin. A needle is placed through the mother’s abdomen, and fluid is drained. The procedure is repeated, as necessary.
In another procedure, a hole punched between the two amniotic sacs can help equalize the fluid between the sacs. However, neither of these procedures stops the twin-to-twin transfusion.
Some cases of TTTS do not respond to amnioreduction. A small-scope laser procedure may be done to seal off some or all of the blood vessels the twins share. Usually only one procedure is necessary during the pregnancy. Survival rates are also about 60% with this procedure. This treatment is most successful if done before 26 weeks of pregnancy.
With laser treatment, a detailed ultrasound exam is done first to help locate the abnormal connection. Then a thin fiber-optic scope is placed through the mother’s abdomen, through the wall of the uterus and into the amniotic cavity of the larger twin. By looking directly at the placenta, blood connections can be found and sealed with a laser beam. This separates the circulation of the fetuses and ends twin-to-twin transfusion. However, this requires doing the procedure while the babies are still in the womb and may cause complications.
The most conservative treatment is to watch and wait. The pregnancy is followed closely with frequent ultrasound exams, with the choice of delivering the twins by Cesarean delivery if medically necessary.
Newborns with twin-to-twin transfusion syndrome may be critically ill at birth and require treatment in a neonatal intensive care unit (NICU). The smaller twin is treated for anemia, and the larger twin is treated for excess red blood cells and jaundice.
Taking care of yourself when you are expecting more than one baby is the best way to take care of your developing babies. An important thing to remember with a multiple pregnancy is to take things more slowly from the beginning of your pregnancy until delivery.
A multiple pregnancy is more stressful for your body than a singleton pregnancy, and your needs increase in many areas. You may need bed rest in your second trimester, even hospitalization, if you experience complications. With some multiple pregnancies, planned hospitalization at 28 to 30 weeks may be recommended. Bed rest at home or in the hospital can help prevent or stop premature labor. It gives the babies the best chance to grow because bed rest increases blood flow to the uterus.
When you’re expecting more than one baby, your discomfort may be more pronounced; you may experience more problems, or problems may last longer. When you’re carrying twins, you get “big” earlier, and you are larger than with a singleton pregnancy. This can cause you more discomfort, such as difficulty breathing, back pain, hemorrhoids, varicose veins, pelvic pressure and pelvic pain. Treatment is often the same for you as for a woman with a singleton pregnancy.
It may be harder to lose your pregnancy weight after having twins, so stick to the weight-gain goal your healthcare provider gives you during your pregnancy. Carrying two or more babies causes greater hormonal and physiological changes in your body, which may cause you to hold onto the weight you gain during pregnancy for a longer period.
As a general rule, women carrying more than one baby should not exercise during pregnancy because of problems with premature delivery. Walking and swimming may be permissible for you, but check with your healthcare provider first.
If you do get the OK to exercise, don’t do anything strenuous—stop immediately if you feel overexerted! As much as you want to stay in shape, you may have to forgo all exercise until after your babies are safely delivered.
If you’re expecting more than one baby, your nutrition and weight gain are extremely important during pregnancy. Food is your best source for nutrients, but keep taking your prenatal vitamin every day. The vitamins and iron in prenatal vitamins are necessary to your well-being and the well-being of your babies.
Iron supplementation may be essential. If you’re anemic at the time of delivery, a low blood count could have a negative effect on all of you. Your chance of needing a blood transfusion could be higher.
If you don’t gain weight early in pregnancy, you have a greater chance of developing pre-eclampsia. Your babies may also be tiny. Don’t be alarmed when your healthcare provider discusses the amount of weight he or she wants you to gain. Studies show if you gain the targeted amount of weight with a multiple pregnancy, your babies are often healthier. In addition, gaining half of your weight by week 20 can be beneficial for your babies, especially if they are born early.
How can you gain the amount of weight you need to gain? Just adding extra calories won’t benefit you or your growing babies, so avoid junk food because it’s full of empty calories.
Get your calories from specific sources. Make your calories count—eat nutritious foods. In addition, eat an extra serving of a dairy product and an extra serving of a protein each day. These will provide you with the extra calcium, protein and iron you require to meet the needs of your growing babies. Discuss the situation with your doctor; he or she may suggest you see a nutritionist.
Multiple fetuses are often delivered early. How babies are delivered often depends on how they are lying in the uterus. All possible combinations of fetal positions can occur. Possible complications include abnormal presentation of one or more of the babies, prolapse of the umbilical cord (the umbilical cord comes out ahead of the babies), placental abruption, fetal stress or bleeding after delivery.
Because there is higher risk, precautions are taken before delivery and during labor. These include the need for an I.V., the presence of an anesthesiologist, the ability to perform an emergency Cesarean delivery and the availability and possible presence of pediatricians or other medical personnel to take care of the babies.
With twins, all possible combinations of fetal positions can occur. Both babies may come head first (vertex). They may come breech, meaning bottom or feet first. They may be lying sideways or oblique, meaning at an angle that is neither breech nor vertex. Or they may come in any combination of the above.
I’m carrying twins. Will I need a Cesarean delivery?
Not necessarily. Delivery of twins has more complications than delivering one baby, but many twins can be delivered vaginally. Discuss it with your healthcare provider.
When both twins are head first, a vaginal delivery may be attempted and may be accomplished safely. It may be possible for one baby to deliver vaginally. However, the second one could require a Cesarean delivery if it turns, the cord comes out ahead of the baby or the baby is stressed following delivery of the first fetus. Some doctors believe delivery of two or more babies is more safely accomplished with a Cesarean delivery.
After delivery of two or more babies, medical personnel pay close attention to maternal bleeding because of the rapid change in the size of the uterus. With more than one baby, it is greatly overdistended. Medication, usually oxytocin (Pitocin), is given by I.V. to contract the uterus to stop bleeding so the mother doesn’t lose too much blood. A heavy blood loss could produce anemia and make a blood transfusion or long-term treatment with iron supplementation necessary.
Often a physician advises a woman expecting twins to stop working at least 8 weeks before her due date. Ideally, you should stop working at 28 weeks with a twin pregnancy—24 weeks if your job requires standing or other physical exertion. Your healthcare provider may recommend full or partial bed rest. These are only general suggestions and will not apply in every case.
It’s a great idea to take childbirth-education classes for any pregnancy. If you’re expecting twins, triplets or more, schedule your classes to begin at least 3 months before your due date. If you have time, a brief course in Cesarean birth might also be worthwhile if you can find one in your area.
One of the greatest challenges for parents of multiples is deciding how to feed them. If you have more than one baby, you should be able to breastfeed them. You may find it a little more challenging, but many mothers have done it. You may have to be creative in your approach, but with time, you’ll probably work it out quite well.
Breastfeeding your babies, even if it’s only for one or two feedings a day, gives them the protection from infection that breast milk provides. Research has shown that even the smallest dose of breast milk gives babies an advantage over babies only fed formula.
If babies are early, and you can’t nurse them, begin pumping! Pump from day one, and store your breast milk for the time babies are able to receive it. In addition, pumping tells the body to produce breast milk—pump and the milk will come. It just takes some time.
There is no one way to feed a baby. You may find your baby does well with breast and bottlefeeding. Bottlefeeding doesn’t always mean you feed your baby formula. You can also bottlefeed expressed breast milk. Supplementing with formula allows your partner and others to help you feed the babies. You can breastfeed one while someone else bottlefeeds the other. Or you can nurse each one for a time, then finish the feeding with formula. In either case, someone else can help you feed the babies.
Even the most efficient woman discovers that having more than one baby can be exhausting. Extra help can make a tremendous difference in everyone’s life. Your time of greatest need is immediately after your babies are born. Ask for help from family, neighbors and friends for the first 4 to 6 weeks after you bring your babies home. You might also consider hiring someone to come in to help, such as a nurse, postpartum doula or other healthcare professional.
In addition to doulas who help during pregnancy, labor and delivery, there are also postpartum doulas. These women help ease the transition into parenthood for any parent, not just those of multiples. A postpartum doula will help a new mother and her family learn to enjoy and to care for the new baby through education and hands-on experience.
A postpartum doula provides emotional and breastfeeding support and ensures a new mother is fed, well hydrated and comfortable. She may go with mom and baby to pediatrician appointments. A postpartum doula may also take care of grocery shopping, preparing meals and other household tasks. She may even help tend older children.
Time-Saving, Energy-Saving Tip
Before your babies’ births, consider hiring someone to come in for the first few weeks or months to help you out. Caring for more than one baby is exhausting, and you’ll need time and help to discover efficient ways to care for your babies and yourself. Having someone available at night can be especially convenient. If you cannot afford help, ask a relative who is able to come for an extended visit to help you get back on your feet.
Services provided by a postpartum doula are most often used in the first 2 to 4 weeks after babies are born, but support can last anywhere from one or two visits to visits for 3 months or longer. Some doulas work all day; others work 3- to 5-hour shifts during the day or after-school shifts until dad gets home. Some doulas work evenings, and some work overnight.
If you think you may want a postpartum doula to help you with the babies, make arrangements a few months before your due date. Even though you don’t know exactly when babies will arrive (unless you’re having a scheduled Cesarean delivery), contract with a postpartum doula in advance to be sure of her availability. Costs range between $15 and $30 an hour for this service, depending on a postpartum doula’s additional training and experience.