Women who are pregnant with two or more fetuses are at an increased risk of developing serious health complications, compared with women pregnant with just one fetus, according to a study published in the December issue of the British Journal of Obstetrics and Gynecology, Reuters reports (Reuters, 12/1).

Dr. Mark Walker, an obstetrician with the Ottawa Health Research Institute, and colleagues reviewed data on approximately 45,000 multiple-birth deliveries in Canada between 1984 and 2000 and data on 165,000 singleton deliveries during the same time period, according to the Toronto Globe and Mail (Abraham, Globe and Mail, 12/1).

Women who were pregnant with twins, triplets or quadruplets were 13 times as likely to suffer heart failure, four times as likely to have a heart attack and two and a half times as likely to develop deep vein thrombosis during pregnancy as women who were pregnant with a single fetus, the CP/Yahoo! News reports (Branswell, CP/Yahoo! News, 11/30).

Women with multi-fetus pregnancies also had an increased risk of developing high blood pressure, postnatal bleeding and pulmonary edema, Canada's CTV News reports.

Walker said that women pregnant with more than one fetus should pay close attention to potential warning signs of such disorders, including leg pain, chest pain or shortness of breath (CTV News, 12/1).

Walker said the study's results may have implications for assisted reproduction, including in vitro fertilization, and may "encourage" clinics "to take whatever steps are necessary to ensure that there's just a singleton pregnancy where possible" (CP/Yahoo! News, 11/30).

He added, "I may lose my business as an obstetrician, but it's absolutely safer to have one baby, then wait nine months to have another" (Reuters, 12/1).