Facts About Twins
Twins can be either identical or fraternal. Most are fraternal twins — each develops from a separate egg and sperm. Fraternal twins each have their own placenta and amniotic sac.

Identical twins are more rare. They occur when one fertilized egg splits early in pregnancy and develops into two fetuses.

Diagnosis
Most twins are diagnosed before delivery. Your doctor may tell you that you are carrying twins if:

• Your uterus grows more quickly or is larger than expected.
• More than one fetal heartbeat can be heard.
• You feel more fetal movement than you did in any pregnancies you had before.
• An ultrasound exam done for other reasons detects twins.

Prenatal Care
You will need special prenatal care with twins. You will need to see your doctor more often and you may have more medical tests.

Nutrition
When pregnant with twins, you will need to eat more than if you were carrying one baby. Your body must nourish the babies and meet your energy needs as well. You will need to eat about 2,700 calories every day.

You should gain more weight when carrying twins than if you were having only one baby.

Rest
Twins can make you more uncomfortable than usual during pregnancy because the uterus becomes much larger. Resting during the day will help give you energy.

Complications
The risk of certain complications is higher in a twin pregnancy. The mother is also more likely to go into preterm labor.

Preterm Labor
Preterm labor is labor that starts before the end of 37 weeks of pregnancy. This can result in preterm birth, the most common problem of multiple pregnancy.

If preterm labor is found early enough, delivery can sometimes be postponed.

Premature Rupture of Membranes
The membranes that hold the amniotic fluid rupture (break) at the start of labor. Sometimes the membranes rupture or leak before labor. This is called premature rupture of membranes.

Hypertension
High blood pressure that occurs for the first time in pregnancy is called pregnancy-induced hypertension.

Growth Problems
Twins are more likely to have growth problems. Intrauterine growth restriction (IUGR) is the term for slow growth of babies during pregnancy.

Twins are called discordant if one is much smaller than the other.

A condition that can cause one twin to be smaller than the other is twin-twin transfusion syndrome (TTS). TTS can develop when twins share a placenta.

Fetal Loss
In some twin pregnancies, one of the babies dies. In early pregnancy, this is called the vanishing twin. If this happens, you may have some spotting or bleeding from your vagina. This does not harm you or the other baby.

Monitoring Twin Pregnancy
Many techniques are used to check the well-being of your babies. They may be done to confirm other test results or to provide further information.

Sometimes, amniocentesis is needed. Amniotic fluid contains a substance that shows the maturity of the babies' lungs.

Delivery
In some cases, twins can be delivered by vaginal birth. In others, a cesarean birth may be needed. How your babies are born depends on certain factors:

• Position of each baby
• Weight of each baby
• Your health
• Health of the babies

Labor may take longer with twins.
Twins can usually be born vaginally if they are both in the head-down position.

Caring for Your Newborn Twins
Most twins do well at birth and can be cared for like any other healthy baby.

Many women wonder if they can breastfeed more than one baby. The answer is yes. Women who breastfeed need at least 500 extra calories a day.

Finally …
Having twins can be an exciting time. You can give your babies the best possible start by taking good care of yourself. Learn the warning signs of problems, and talk to your doctor or nurse about your questions and concerns.

This excerpt from ACOG's Patient Education Pamphlet is provided for your information. It is not medical advice and should not be relied upon as a substitute for visiting your doctor. If you need medical care, have any questions, or wish to receive the full text of this Patient Education Pamphlet, please contact your obstetrician-gynecologist.