How You Get Pregnant Can Signal Health Risks

In vitro pregnant women are more at risk for blood clots and embolisms

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) In vitro fertilization can help infertile women get pregnant. But getting pregnant using in vitro may also put the pregnant mom at risk for health problems.

Over five million babies have been born to infertile women using in vitro fertilization. During in vitro, a woman's eggs are fertilized outside the body and then surgically placed in her uterus.

Pregnancy can be physically hard on a woman's body. Many things can go wrong. Thus, it is important to make sure the mother and baby stay healthy.

A recent study found that women with in vitro pregnancies had a higher risk of developing blood clots and clogged lung arteries compared to women with natural pregnancies.

"Attend all of your prenatal office visits."

Peter Henriksson, PhD, of the Division of Cardiovascular Medicine at Karolinska Institutet in Stockholm, and colleagues led the study to look at the risk of pulmonary embolism and venous thromboembolism in women who became pregnant through in vitro fertilization.

Pulmonary embolism is a blockage in the main artery of the lung. Venous thromboembolisms are blood clots. These two conditions can cause serious problems for pregnant women and new moms. These problems can even result in death.

The study included 23,498 women that gave birth after having an in vitro pregnancy. The in vitro pregnant women were compared to 116,960 women who had natural pregnancies.

Researchers found that blood clots occurred in 4.2 out of 1,000 women who had in vitro pregnancies. In comparison, blood clots occurred in 2.5 out of 1,000 women who had natural pregnancies. The risk of blood clots was highest during the first trimester for the in vitro pregnant women.

While embolisms were found in three out of 1,000 in vitro women during their first trimester, less than one out of 1,000 women with natural pregnancies had embolisms.

The authors commented that the risk of blood clots and embolisms seemed low. However, these conditions are difficult to detect. Doctors should be aware of these conditions and should check for problems if they are at all suspicious. In vitro pregnant women, already at risk for these conditions, may be good candidates for preventive treatments.

There were some limitations with the study. Data was collected between 1990 and 2008. The authors noted that medical advances and screening tools could result in fewer diagnoses of blood clots and embolisms than in the earlier years. Data did not include the severity of the two conditions. Also, data only included women who gave birth to live babies. Further, in vitro pregnant women may have the conditions before pregnancy. Having the conditions before pregnancy may be a related to their infertility.

The study, titled "Incidence of pulmonary and venous thromboembolism in pregnancies after in vitro fertilization: cross sectional study," was published online in the BMJ. It was funded by Stockholm Count Council and Karolinska Institutet. Dr. Henriksson and colleagues disclosed no conflict of interest.

Reviewed by: 
Review Date: 
January 17, 2013
Last Updated:
January 20, 2013