Multiple Pregnancy

Most twin pregnancies result in healthy babies, but carrying two babies places additional demands on the body and increases the risk of certain pregnancy complications. Your prenatal care, ultrasound schedule, and delivery planning will therefore look somewhat different from a pregnancy with one baby.

More Monitoring During Pregnancy

Twin pregnancies usually require more frequent ultrasounds to monitor each baby's growth, amniotic fluid, and other aspects of the pregnancy.

The exact schedule depends partly on the type of twins. Twins who share a placenta require particularly close monitoring because they can develop additional complications related to their shared placental circulation. Additional fetal testing may also be recommended later in pregnancy depending on the type of twins, their growth, and whether other complications develop.

Pregnancy Symptoms & Nutrition

With two babies growing at the same time, some pregnancy symptoms may become noticeable earlier or feel more intense. Abdominal and pelvic pressure, back or hip discomfort, shortness of breath, swelling, heartburn, and difficulty sleeping can become more significant as pregnancy progresses.

Nutritional needs are also greater in a twin pregnancy. Paying attention to adequate calories, protein, iron, calcium, and other nutrients is especially important.

Recommended Weight Gain for Twin Pregnancy

• Normal weight (BMI 18.5–24.9):  37–54 pounds

• Overweight (BMI 25.0–29.9):  31–50 pounds

• Obesity (BMI 30 or higher):  25–42 pounds

These are general recommendations based on prepregnancy BMI. Your recommended weight gain may be individualized based on your health, pregnancy, and your babies' growth.

Increased Risk of Pregnancy Complications

Twin pregnancies have higher rates of several complications compared with pregnancies with one baby, including:

• Preterm labor and preterm birth

• Preeclampsia and other hypertensive disorders

• Gestational diabetes

• Anemia

• Fetal growth problems

• Differences in growth between the twins
  
  

Twin-to-Twin Transfusion Syndrome (TTTS)

Twin-to-twin transfusion syndrome (TTTS) is a complication that can occur in twins who share a placenta. Blood vessels within the shared placenta connect the babies' circulations. In TTTS, blood flow through these connections becomes unbalanced, causing one baby to receive less blood and fluid while the other receives more.

Because TTTS can develop even when earlier ultrasounds have been reassuring, Mono/Di twins are typically monitored with ultrasound every 2 weeks beginning at 16 weeks to look for early signs of TTTS and other complications.

Most monochorionic twin pregnancies do not develop TTTS. If significant TTTS does occur, referral to a specialized fetal treatment center may be recommended. In some cases, fetoscopic laser treatment can be used to treat the abnormal blood vessel connections within the placenta.

• Twin-to-Twin Transfusion Syndrome (Yale)

• Twin-to-Twin Transfusion Syndrome (Childrens Hospital Colorado, video)

When Will I Deliver?

Twin pregnancies are usually delivered earlier than pregnancies with one baby. The recommended timing depends on the type of twins, how the babies are growing, and whether any pregnancy complications develop.

Your care team will discuss the recommended timing of delivery as your pregnancy progresses. An earlier delivery may be recommended if concerns develop with fetal growth, blood pressure, amniotic fluid, fetal testing, or other aspects of the pregnancy.

Vaginal Delivery or Cesarean Delivery?

Twins do not automatically require a cesarean delivery. For appropriately selected twin pregnancies, either a planned vaginal delivery or a planned cesarean delivery may be reasonable.

A vaginal delivery may be an option when Twin A, the baby closest to the cervix, is head-down and there are no other reasons that vaginal delivery would be unsafe. Other considerations include the babies' estimated sizes and positions, gestational age, type of twin pregnancy, pregnancy complications, and the experience of the obstetrician attending the delivery. 

Some patients prefer to attempt vaginal delivery because of the potential for avoiding major abdominal surgery and having an easier recovery. Others prefer a planned cesarean because it offers greater predictability and avoids some of the uncertainty that can occur during a twin vaginal delivery.

There is not one delivery plan that is right for every twin pregnancy. Your individual circumstances and preferences can be considered when discussing the safest and most appropriate options for you.

What Happens During a Planned Vaginal Twin Delivery?

Even when both babies are head-down before labor, the position of Twin B can change after Twin A is delivered. Your obstetrician will reassess Twin B's position and heart rate after the first baby is born.

Depending on Twin B's position and how the baby is tolerating delivery, options may include vaginal delivery while head-down, breech extraction, or cesarean delivery. The available options may also depend on the experience of the obstetrician caring for you. 

Occasionally, Twin A is delivered vaginally but a cesarean becomes necessary for Twin B. This is sometimes called a combined delivery. Although uncommon, it is an important possibility to understand when choosing to attempt a vaginal twin delivery.

Because Twin B may require additional maneuvers or an urgent cesarean delivery, planned vaginal twin deliveries may take place in an operating room or another setting where cesarean delivery can be performed quickly if needed.

Cesarean Delivery

A planned cesarean delivery may be recommended based on the babies' positions, type of twin pregnancy, fetal growth, pregnancy complications, or other clinical factors. For example, cesarean delivery is generally recommended when Twin A is not head-down and for Mono/Mono twins. 

Some patients who are candidates for either approach may also choose a planned cesarean delivery because they value the greater predictability of a scheduled delivery or want to reduce the possibility of requiring an urgent cesarean after labor or after vaginal delivery of Twin A.

If you are planning permanent contraception after completing your family, a bilateral salpingectomy can often be performed at the time of cesarean delivery, avoiding the need for a separate procedure later.

After Delivery

Twin pregnancies also carry a higher risk of postpartum hemorrhage, in part because greater stretching of the uterus can make it more difficult for the uterus to contract firmly after delivery. Your delivery team will be prepared to monitor for and treat excessive bleeding.

Pregnancies with three or more babies carry higher risks than twin pregnancies, particularly preterm birth and fetal growth problems, and require close monitoring, typically with Maternal-Fetal Medicine.

Delivery usually occurs significantly earlier than with twins or a pregnancy with one baby. For uncomplicated triplet pregnancies, planned delivery is often around 35 weeks, although many triplet pregnancies deliver earlier and the recommended timing may vary based on how the placentas and amniotic sacs are arranged, fetal growth, and any complications that develop.

Triplets are typically delivered by cesarean section. Your Maternal-Fetal Medicine and obstetric teams will make an individualized plan for the timing and location of delivery.