Pregnancy: Basics of Multiple Births for Dads

By Mathew Miller, Sharon Perkins

The birth rate of twins, triplets, and more has exploded if you, the new Dad, and your partner use in vitro fertilization (IVF) and other advanced reproductive technology. Seventeen percent of twins and 40 percent of triplet births are results of infertility treatment. In 2012, the multiple-birth statistics in the United States broke down as follows:

  • Twin births occurred in 33 of 1,000 live births

  • Triplets or higher-order multiples (quadruplets, quintuplets, and more) occurred in 124 of 100,000 live births

What multiples are and who has them

Although infertility treatments are the largest risk factor for multiples, you’re more likely to have multiples if

  • Your partner is black. Black women have the highest natural twinning rate of the different racial groups; Asian women have the lowest.

  • Your partner is older than 35. Twins occur naturally around 3 percent of the time in women 25 to 29 and 5 percent of the time in women 35 to 39.

  • Fraternal twins (nonidentical) run in your partner’s family. Your family history doesn’t seem to have any bearing on the statistics, but if your partner is a fraternal twin, she has a 1 in 17 chance of having fraternal twins.

Twins can be either fraternal or identical. Fraternal twins are created from two different eggs and are no more similar than any other two siblings. Identical twins are the result of one embryo splitting into two at a very early stage of development. Siamese twins, also called conjoined twins, are always identical twins who didn’t completely split as embryos. Conjoined twins are usually identified on ultrasound before delivery.

Obviously, boy-girl twins are always fraternal, but if you have two of the same sex, identifying whether they’re identical or fraternal may be difficult at first. The majority of twins, especially twins from IVF cycles, are fraternal, although IVF also increases the risk of having identical twins.

DNA testing is the only definite way to determine whether twins are identical or fraternal, although sometimes it’s obvious that twins are fraternal if they look quite different.

Many IVF parents who implant only two embryos are surprised to find themselves carrying three fetuses. If this happens to you, don’t accuse the doctor of putting in an extra embryo he had lying around! What happened was that one of the embryos split into identical twins. Yes, it’s possible.

Health risks of a multiple pregnancy for mom

All the usual pregnancy complaints are intensified during a multiple pregnancy. Annoying issues such as morning sickness, weight gain, heartburn, constipation, shortness of breath (especially on any type of exertion), urinary problems, and hemorrhoids are all likely to be magnified.

Many of the health risks of pregnancy for your partner increase with the number of fetuses she’s carrying. Multiple pregnancies are often medically complicated by the following:

  • Anemia: This is low red blood cell count in the mother.

  • Cesarean deliveries: Cesarean deliveries are pretty much a given in higher-order multiple births because it’s unlikely that all the babies will be head down. Additionally, high-order multiples are so small that even if they’re all head down before birth, one or more are likely to flip as soon as the first baby is delivered and the rest have more room, possibly necessitating an emergency Cesarean.

  • Gestational diabetes: The increase in placenta size and hormone production may raise the risk of gestational diabetes in multiple pregnancies.

  • Hemorrhage: This is severe blood loss at the time of delivery.

  • Placental abruption: Women with multiples are three times more likely to have the placenta come off the uterine wall prematurely, possibly resulting in severe hemorrhage.

  • Pregnancy-induced hypertension (PIH): Defined as high blood pressure after 20 weeks of pregnancy, this affects one in three mothers of multiples.

For high-order multiples (triplets or more), bed rest during pregnancy is very likely.

Health risks of a multiple pregnancy for the babies

Twins are five times more likely than single babies to have problems at birth or to die before or soon after delivery. Multiple pregnancies often deliver early because the womb has less room for all the occupants, and preterm babies are known to have more complications, so these factors account for some but not all of the risks multiples face. Statistics show that

  • Approximately 60 percent of twins deliver before 37 weeks.

  • 36 percent of triplets deliver before 32 weeks.

  • 80 percent of quads and more deliver before 32 weeks.

Twins are also more likely to have the following complications:

  • Twin-to-twin transfusion syndrome occurs only in identical twins who share the same placenta. One twin receives too much blood; the other, too little. Both can cause problems.

  • Birth defects such as cerebral palsy are much more common in multiples, and the risk increases with the number of fetuses.

  • Cord accidents can occur, such as knots in the cord or entanglement in a cord. Cord accidents reduce blood flow to the fetus. Identical twins, who develop in one amniotic sac, are more likely to become entangled in their own or their twin’s cord.

Your medical practitioner may well suggest that you deliver at a medical center equipped for high-risk births, but if she doesn’t, you should still plan to do so. Knowing that your babies have all the technological advances that may be needed in place from the moment of delivery can really reduce the stress you and your partner feel.

Babies can be transported, if necessary, but doing so is stressful for the babies and for the parents. And if one baby is transported and the other isn’t, you’ll be trying to split your visiting time between two hospitals, which is unnecessarily stress-inducing.