Maternal deaths resulting from in vitro fertilization (IVF) are relatively rare, but they do occur, British doctors warn in an editorial in the journal BMJ. In the U.S. there were more than 140,000 IVF cycles in 2008, according to the Society for Assisted Reproductive Technology (SART). During IVF, an egg and sperm are fertilized outside of the body in a laboratory and then implanted in the woman’s uterus. Fertility drugs are often used to stimulate a woman’s ovaries to produce eggs.
 
One leading U.S. fertility doctor says he is not aware of any deaths in the U.S. related to IVF pregnancies. In the new report, Susan Bewley, an obstetrician at Kings College in London, and colleagues cite a study in the Netherlands that shows that the rate of pregnant women dying during IVF pregnancies is higher than during pregnancies in the general population. Specifically, there were 42 deaths per 100,000 IVF pregnancies, compared with six deaths seen among 100,000 pregnancies in the general population.

Ovarian hyperstimulation syndrome can occur as a result of fertility drugs used to stimulate the development of eggs in a woman's ovaries. If the ovaries are overstimulated they can become enlarged and symptoms such as abdominal pain, nausea, and vomiting can occur. In severe cases fluid may accumulate around the lungs or heart.  

The authors call for tracking of IVF-associated risks including ovarian hyperstimulation syndrome to better understand risks associated with IVF. “More stringent attention to stimulation regimens, preconceptual care, and pregnancy management is needed so that maternal death and severe morbidity do not worsen further,” they write.