Stillbirth Risk in Overdue Pregnancies

Answers to Common Questions About Post-Term Pregnancies

Caring doctor talking to pregnant woman
Still birth in overdue pregnancies. Hero Images / Getty Images

For several reasons, an overdue pregnancy can be risky both for the mother and the baby. In addition to higher odds of certain complications, there's said to be an increased risk of stillbirth in pregnancies that have progressed beyond 42 weeks.

But exactly how much increased risk is there?

What is the Stillbirth Risk in Overdue Pregnancies?

While the risk of stillbirth is increased in pregnancies that go beyond 42 weeks, it is still relatively small, at 4 to 7 deaths per 1000 deliveries, as opposed to 2 to 3 deaths per 1000 deliveries in women who deliver between 37 and 42 weeks.

This slightly elevated risk is one reason why doctors like to closely monitor women with overdue pregnancies and why doctors might recommend induction if you go beyond 42 weeks.

Here are some other questions you might have:

What Are Other Risks Involved in Having An Overdue Pregnancy?

There can be increased complications during delivery when the baby is larger, such as a longer labor and a higher risk of birth trauma, like a broken bone or nerve injury from challenges in delivering the baby's shoulders. The baby may also be more likely to pass the meconium during delivery, which can lead to respiratory complications. In addition, a syndrome called "postmaturity syndrome" may occur, in which the baby's growth in the mother's uterus is restricted due to problems receiving blood from the placenta.

What Will Doctors Do in Pregnancies That Progress Past the Due Date?

Obstetricians often will increase the frequency of prenatal monitoring, meaning they will suggest regular nonstress tests and possibly biophysical (fetal health) profiles.

Many doctors will recommend labor induction in pregnancies that are one to two weeks beyond the due date.

Who Is At Risk of Having An Overdue Pregnancy?

Up to 10 percent of all pregnancies go past the estimated due date. Women in their first pregnancies and those who have had a post-term pregnancy in the past seem to have the highest risk.

I'm 40 Weeks Pregnant. My Neighbor's Doctor Induced Her at 39 weeks. Why Won't My Doctor Induce Me?

People's circumstances differ, and there are many reasons why inductions might be recommended earlier in some situations than in others. In many cases, it is hard to determine with absolute certainty whether a baby is truly ready to be born.

Given the higher risk of complications, if the baby is born too early (such as if the due date has been miscalculated), many doctors will only recommend induction when it's clearly necessary.

In this specific instance, your doctor probably does not think there is a compelling reason to induce your labor at this time. But as long as your doctor is monitoring you and your baby, there's no need to worry. If you don't go into labor naturally within a week or two, or if any sign of complications develops, it's possible that your doctor might recommend a change of approach.

Source:

Norwitz ER. (April 2015). Patient education: Postterm pregnancy (Beyond the Basics). In: UpToDate, Lockwood CJ (Ed), UpToDate, Waltham, MA. 

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