Multiple Births: Risks, Rewards, and Reality

Multiple Births

Learn the facts about multiple pregnancy.

Fertility treatments, such as in vitro fertilization (IVF), have made possible the gift of children for many people not able to conceive on their own. But as with many medical advances, there comes a delicate balance of risk to reward.

With IVF, women have a much higher risk (1 in 3) of having multiple births – twins, triplets or even more babies. For an infertile couple, the choice of more babies versus no babies may seem like a great idea.

But there’s a down side. Doctors know firsthand the toll of difficult pregnancies, problem births and babies struggling with multiple complications.

For this reason, the American Society for Reproductive Medicine (ASRM) recommends that doctors work with women to transfer the fewest number of embryos for the highest likelihood of pregnancy. For a woman under 35 who has good chances of a pregnancy developing, the guideline is to transplant only one embryo during IVF.

But the chances of the embryo transplant succeeding drop as women age. For women over 35 (and those younger women who have a higher likelihood of failure), the guidelines suggest that doctors transplant more than one and up to five embryos. This increases the chance that a pregnancy will develop. But it also increases the chance of multiple births.

How is IVF done?

IVF is the most common form of assisted reproductive technology, or ART. While there are many variations to these procedures, the basics are:

  • Fertility drugs are used to cause a woman to release more than one egg from the ovary in any one month.
  • The eggs are then removed from the woman’s body and mixed with a man’s sperm in a lab (in vitro fertilization).
  • The fertilized eggs (embryos) are then transplanted back into the womb so they can grow.

All, some or perhaps none of the embryos may develop. That’s why fertility doctors often transplant more than one embryo to increase the chances that one will take hold and develop into a baby. But, transplanting more embryos raises the risk of multiple births.

It’s important for you and your doctor to discuss how many embryos to transplant based on your age, health, the quality of your eggs and other factors. The goal is to conceive and deliver one healthy baby.

What are the risks of multiple pregnancy and multiple births?

In general, the more babies in the womb, the higher the risk for problems. These include miscarriage and premature birth. Multiple babies compete for space and nutrition in the womb.

Most multiples are born prematurely. If they survive, many have underdeveloped lungs. This can lead to serious breathing problems and often months in the neonatal intensive care unit. Some have higher risk for infections, or problems with nerve and brain development that may not be obvious for years after.

There can also be life-threatening risks to the mother who is carrying multiples. Multiple pregnancy adds significant stress to the woman’s body. This can cause dangerous nausea and vomiting, high blood pressure, gestational diabetes or anemia.

Aside from the physical risks to mother and babies, multiple babies can bring about significant financial and emotional stress to a family. Doctors and potential parents continue to grapple with these and many other ethical considerations around fertility treatment, its rewards and consequences

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