Antiphospholipid antibodies in women having in-vitro fertilization.

Antiphospholipid antibodies have an established association with pregnancy complications such as recurrent miscarriage, growth retardation, placental abruption and stillbirth but their mechanism of action is unclear. We have investigated whether antiphospholipid antibodies occur more frequently in women having in-vitro fertilization (IVF) and whether their presence is associated with the likelihood of failed implantation. We studied 240 women undergoing IVF treatment who were </=38 years and had attempted fewer than three previous IVF cycles. Antiphospholipid antibodies (anticardiolipin and antiphosphatidyl serine immunoglobulin G and immunoglobulin M) were present in 36 out of 240 (15%) of the study population and were not associated with a failed IVF cycle or miscarriage. There was no association between the cause of infertility and the presence of antiphospholipid antibodies. Antiphospholipid antibodies were not detected more frequently in women with previous attempts at IVF compared with women having their first cycle, indicating that the high incidence of these antibodies is not due to the IVF treatment. There was a strong association between the presence of antiphospholipid antibodies and intrauterine growth retardation in singleton pregnancies (P < 0.005). We recommend routine screening for the presence of antiphospholipid antibodies in women having IVF in order to identify those pregnancies at increased risk of intrauterine growth retardation.