Blood Clots and Artery Blockages More Common in IVF Pregnancies

Women who conceive with the help of In Vitro fertilization (IVF) treatment are at higher risk of some pregnancy related complications, a new study says.

The study published in the British Medical Journal (BMJ) found pregnancy via IVF escalating the risks of deadly blood clots and artery blockages.

IVF is one of the artificial methods known as Assisted Reproductive Technology (ART) adopted by people who experience difficulties in  conceiving naturally. It is the process of manually combining an egg and sperm in a laboratory.

ART has been prevalent in the U.S.from 1981 and each year, over 1 percent of American infants are conceived through ART.

For the study, a team of researchers from the Karolinska Institute in Sweden looked at more than 23,000 women who conceived via IVF and 116,960 women who conceived naturally, between 1990 and 2008. Researchers examined the occurrence of two conditions in participants - pulmonary embolism (PE) or blockage of the main artery of the lung and venous thromboembolism  (VTE) or blood clots.

Researchers found blood clots affecting more women conceiving via IVF (4.2 in 1000) than women who conceived normally (2.5 in 1000). Risks were higher during the initial stages of pregnancy. 

Similarly, artery blockage was found more common in IVF pregnancies (0.08 percent) than the other group (0.05 percent). The findings come at a time when artery blockage claims lives of a significant number of pregnant women in the world.

According to the researchers, hormonal drugs used for the IVF treatment may be leading to this occurrence.

"During the IVF procedure hormonal drugs are given to stimulate the egg follicles to grow more eggs. This increases oestrogen levels in the body between ten and 100-fold and is likely to impact on the coagulation of the blood and increase blood clot formation," study leader Professor Peter Henriksson, told Daily Mail.

"It is highest during the first third of pregnancy, then eases off and the risk goes down to about the level of a normal pregnancy."