Since the treatment first became available in 1978, more than five million babies have been born from in vitro fertilization (IVF). But a new study published in the British Medical Journal shows that women who are impregnated using IVF are at a greatest risk for blood clots and pulmonary embolism.
Pulmonary embolism is the leading cause of maternal death, though there has previously been no research on the risk associated with IVF. Any pregnancy carries the risk of blood clots, though doctors have often found the cases to be higher in women who've undergone IVF. These risks are highest during the first trimester of pregnancy.
Swedish researchers studied women who'd become pregnant after IVF and compared them with women who didn't use any fertility treatments between 1990 and 2008. As expected, the women who had used IVF suffered blood clots more often than women who hadn't. In both groups, the risk decreased after the first trimester. However, the overall rate of pulmonary embolism was lower in the IVF group, but the risk remained high throughout the pregnancies. Lifestyle factors such as smoking and BMI didn't affect outcomes. Women in both groups didn't have risks of either of these conditions after giving birth. Researchers are hoping this study will urge doctors to screen carefully for both conditions, but especially pulmonary embolism which can be hard to detect but does cause so many deaths during pregnancy.