Women pregnant with twins, triplets or quadruplets are at greater risk of serious health complications than are women carrying just one fetus, according to a Canadian study published on Wednesday.

Researchers at the Universities of Ottawa and Toronto, who studied 4.4 million records for obstetric deliveries in Canada, found that women who carry two or more fetuses are almost 13 times more likely to experience heart failure and more than twice as likely to develop clotting in the legs and lungs - both leading causes of maternal death.

The findings published in this month’s British Journal of Obstetrics and Gynecology surprised the study’s lead author, Dr. Mark Walker, a scientist with the Ottawa Health Research Institute.

“These are young healthy women in the reproductive age window of 16 to 44 where you wouldn’t expect to see these health problems,” Walker told Reuters.

“And the implications of this are two-fold. With women who have multiple gestations, we need to counsel them about these risks and be vigilant for them,” he said. “So, if the mother has leg pain, shortness of breath or chest pain, our urgency to look into other problems should be increased.”

One obvious example is to consider administering blood thinners to women carrying multiple fetuses who are prescribed bed rest, he said.

Although the study did not distinguish between natural pregnancies and in vitro fertilization, Walker said he hopes his study will send a message to fertility clinics responsible for an explosion in multiple pregnancies in recent years.

“Here’s one more cogent reason to develop techniques to ensure that only one baby results from the procedure. I may lose my business as an obstetrician, but it’s absolutely safer to have one baby, then wait nine months to have another,” he said.

Dr. Jeff Haebe, a reproductive endocrinologist at the University of Ottawa, said 60 per cent of the in vitro fertilizations at his infertility clinic result in only one baby, and he transfers a maximum of two embryos for women aged 37 and younger and no more than three for women 38 and older. “And rarely we might go to four,” he said.

While there are no laws in North America limiting the number of embryo implants at one time, Haebe said Canada should follow the lead of some European countries that legislate a maximum of two embryos, regardless of age.

“And I think that’s a very good way of handling the problem of multiple births,” Haebe said.

SOURCE: BJOG, November 2004.