Risk of Miscarriage After In Vitro Fertilization (IVF)

Find Out If Using IVF Increases Miscarriage Risk

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Question:

Does Conceiving via In Vitro Fertilization (IVF) Mean Higher Risk of Miscarriage?

"I heard that conceiving with in vitro fertilization means a higher risk of miscarriage. Does that mean that I should just keep trying naturally even though we're having trouble getting pregnant?" —About.com Reader

Answer:

What the Research Shows:

It's true that there is some research showing that pregnancies that are conceived via in vitro fertilization (IVF) carry a slightly increased risk of miscarriage, compared with spontaneous (natural) pregnancies.

The exact level of the increased risk varies by study.

For instance, one 2003 study found that women who underwent IVF and got pregnant with a single child miscarried 22% of the time. For contrast, the American Pregnancy Association states that most healthy women who conceive naturally have a 15% to 20% chance of miscarriage. So that research found a slightly elevated risk of miscarriage for women who use IVF and get pregnant with a single embryo. However, it should be mentioned that in that same study, the risk of miscarriage for women using IVF who carried twins was just 18%, which is within the typical range of miscarriage risk for natural conception.  

What's Behind the Elevated Risk of Miscarriage?

It's important to note that researchers do not believe that the reason for the increased risk of miscarriage relates to the IVF procedure itself. Rather, it is more likely that the increased risk of miscarriage after in vitro fertilization (or another fertility treatment) has more to do with the underlying reasons for the fertility treatment.

In other words, patients who have a need for in vitro fertilization may simply be in a higher risk category for miscarriage, regardless of the means of conception—unfair as that may be. 

Here are a few 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 miscarriage and women over age 45 can have up to a 50% chance of miscarriage, according to the American Pregnancy Association. 
  • An underlying health problem: Women who use IVF are more likely to have an underlying health condition that could possibly contribute to a higher risk of miscarriage.
  • Early awareness: When a woman uses IVF, she generally pays very close attention to each cycle and finds out that she's pregnant very early in the process. Women who conceive naturally, on the other hand, may not know they're pregnant as early—especially if the pregnancy is unexpected. Since the risk of miscarriage is highest during the first few weeks of pregnancy, many women who conceive naturally may miscarry before they even realize that they're pregnant. This is often referred to as a chemical pregnancy. 
  • Ovarian stimulation: One 2004 study found that how much ovarian stimulation a woman receives while using assisted reproductive technology may play a role. Those researchers saw an association between higher ovarian stimulation and miscarriage risk. 

So, don't be dissuaded from pursuing IVF if you need it. Talk to your doctor to develop a plan for what works best for your situation.

In fact, using preimplantation genetic diagnosis (PGD) may reduce your risk of miscarriage in an IVF pregnancy if you already have a history of past miscarriages prior to the treatment—especially if you're over the age of 40. For example, one 2006 study that looked 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 that it lowered the miscarriage rate among women over the age of 40 from 41% to 22%. 

Sources:

Munné S, Fischer J, Warner A, Chen S, Zouves C, Cohen J; Referring Centers PGD Group. "Preimplantation genetic diagnosis significantly reduces pregnancy loss in infertile couples: a multicenter study." Fertil Steril. 2006 Feb;85(2):326-32.

Tummers, Phillippe, Paul De Sutter and Marc Dhont. "Risk of spontaneous abortion in singleton and twin pregnancies after IVF/ICSI." Human Reproduction Aug 2003. 18(8): 1720-1723.

Wang, Jim X., Robert J. Norman and Allen J. Wilcox. "Incidence of spontaneous abortion among pregnancies produced by assisted reproductive technology." Human Reproduction Feb 2004. 19(2):272-277.

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