Health professionals treating pregnant women need to be even more alert to signs of pulmonary embolism and venous thromboembolism if their patient conceived using in vitro fertilization.
Researchers have found that women who became pregnant using IVF are more likely to develop the medical problems before 12 weeks gestation.
The study, published on bmj.com, assessed the risk of blood clots and artery blockage after the fertility treatment, which has been used by infertile couples for the last 35 years, creating around five million babies.
Scientists from Sweden’s Karolinska Institute studied 23,498 expectant mothers who conceived using IVF and 116,960 women with normal pregnancies. Participants were matched according to age and when they gave birth, with 33 being the average age in both the groups.
In the IVF group, 4.2 in every 1,000 suffered from VTE compared to 2.5 in 1000 in the normal group. The risk was significantly bigger during the first trimester of pregnancy - 1.5 in the IVF group and 0.3 in the non-IVF group.
However, the risk of suffering from blood clots was the same after the baby was born and before the women became pregnant.
Out of the almost 23,500 women who had undergone IVF treatment, 19 developed PE, a major cause of maternal death. This represented 0.08% of the IVF group while 70 (0.05%) of the unexposed group suffered from a blockage of the pulmonary artery.
Those who had conceived using IVF were found to be more likely to develop the problem throughout their entire pregnancy, especially the first 12 weeks.
The researchers said it was important for medical professionals to know about the raised risk associated with IVF even though the chance of suffering from PE was still very low as it was such a difficult condition to spot in patients.