Sallys Pregnancy Secrets

Your Guide To A Healthier, Happier And More Comfortable Pregnancy With Tips On Pregnancy Week By Week And Much More!

Wednesday, September 13, 2006

"Placental problem more likely with test-tube pregnancy"- Article

Technique used in assisted reproductive technologies may explain increased risk

Placenta previa, a potentially serious pregnancy complication, may be more common among pregnancies conceived through assisted reproductive technologies than among those conceived naturally, new research suggests.

In placenta previa, the placenta covers the cervix, potentially blocking the baby's exit from the uterus and leading to bleeding as the cervix begins to thin and dilate in preparation for labour. As a result, the baby usually needs to be delivered by caesarean section.

A Norwegian study of more than 845,000 pregnancies showed the incidence of placenta previa increased from about three in 1,000 naturally conceived pregnancies to 16 in 1,000 pregnancies achieved with techniques such as in vitro, or test-tube, fertilization.

In the 1,300 women who had both natural and assisted pregnancies, the risk of placenta previa was three times higher in the assisted pregnancy, suggesting the assisted reproduction techniques themselves, rather than characteristics of the individual mothers, may explain the increased risk.

"The underlying mechanism causing the placenta previa is not clear, but we have speculated whether the technique used to transfer the embryo into the uterus may be involved," says study co-author Dr. Pal Romundstad of the Norwegian University of Science and Technology in Trondheim, Norway.

"The procedure may induce uterine contractions . . . leading to more embryos implanting low down in the uterus.

"In addition, because research has shown that transferring the embryo to a position low in the uterus may improve implantation rates, current practice tends to favour placing the embryo low down."

But Romundstad adds that placenta previa is rare even in assisted pregnancies, affecting between 1.5 per cent and two per cent. "Thus this finding should not prevent people from seeking (assisted reproduction)."

With files from The Medical Post. Copyright www.macleans.ca


0 Comments:

Post a Comment

<< Home