Risk of miscarriage after in vitro fertilization

It is true that there is some research showing that pregnancies conceived through in vitro fertilization (IVF) carry a slightly increased risk of miscarriage, compared to spontaneous (natural) pregnancies. The exact level of increased risk varies by study.

The American Pregnancy Association states that in most healthy women who conceive naturally, the chances of having a miscarriage can range from 10% to 25%, with an average 15% to 20% chance of miscarriage. spontaneous abortion. In contrast, a 2003 study found that women who underwent IVF and became pregnant with only one child miscarried nearly 22% of the time, a slightly elevated risk of miscarriage for women using IVF who became pregnant with a single child. single embryo.

However, in twin pregnancies, once fetal heartbeats were detected, the risk of pregnancy loss was much lower, leading to the conclusion that twin pregnancies after IVF have a better chance of survival.

What is behind the elevated risk?

It is important to note that the researchers do not believe that the reason for the increased risk of miscarriage is necessarily related to the IVF procedure itself. Rather, the increased risk of miscarriage after in vitro fertilization (or other fertility treatment) is more likely to have more to do with the underlying reasons for the fertility treatment.

In other words, patients who need in vitro fertilization may simply be in a higher risk category for miscarriage, regardless of the unfair means of conception. Here are some possible explanations.

Advanced age

Women who undergo in vitro fertilization tend to be older than women who conceive naturally, and older maternal age is associated with a higher risk of miscarriage. For example, women between the ages of 35 and 45 have a 20% to 35% chance of miscarrying, and women over the age of 45 may have up to a 50% chance of miscarrying.

underlying health problem

Women using IVF are more likely to have an underlying health condition that could possibly contribute to an increased risk of miscarriage.

early awareness

When a woman uses IVF, she usually pays close attention to each cycle and finds out that she is pregnant very early in the process. Women who conceive naturally, on the other hand, may not know they are pregnant so soon, especially if the pregnancy is unexpected.

Because the risk of miscarriage is greatest during the first few weeks of pregnancy, many women who conceive naturally may have a miscarriage before they even realize they are pregnant. This is often referred to as a chemical pregnancy.

ovarian stimulation

A 2004 study found that the amount of ovarian stimulation a woman receives while using assisted reproductive technology may play a role. Those researchers saw an association between increased ovarian stimulation and the risk of miscarriage.

So don’t be dissuaded from IVF if you need it. Talk to your doctor to develop a plan that works best for your situation.

In fact, the use of preimplantation genetic diagnosis (PGD) can reduce the risk of miscarriage in an IVF pregnancy if you already have a history of miscarriage prior to treatment, especially if you are over 40 years of age.

For example, a 2006 study looking at more than 2,000 cycles at 100 IVF centers found that PGD reduced the miscarriage rate among women ages 35 to 40 from 19% to 14%, and among older women of 40 years, from 41% to 22%.

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