Sharp rises seen in Canadian maternal morbidity factors.(Obstetrics)

EDMONTON, ALTA. -- Six contributors to severe maternal morbidity rose at least 50% over a 9-year period in Canada, quite likely reflecting changes in maternal demographics that parallel trends in the United States, Dr. Thomas F. Baskett reported at the annual meeting of the Society of Obstetricians and Gynaecologists of Canada.

The Canadian Perinatal Surveillance System tracks "near misses," those patients who survive because of access to modern medical care and sophisticated intensive care facilities, explained Dr. Baskett, professor of ob.gyn at Dalhousie University in Halifax, Nova Scotia.

Because Canada's maternal mortality rate is among the lowest in the world--approximately 6.1 per 100,000, compared with 13.2 per 100,000 in the United States--a close examination of severe maternal morbidity is often the best way to spot important trends, he said.

In a recent comparison of morbidity trends between 1991-1993 and 1998-2000 in every province except Manitoba, Quebec, and Nova Scotia, a number of conditions spiked precipitously. (See table.)

Shock (including obstetrical and septic shock) and postpartum hemorrhage requiring a transfusion declined over this period. Cerebrovascular disorders (including intracranial venous sinus thrombosis) in the puerperium increased moderately, reported Dr. Baskett.

To elucidate possible reasons for the trends, he discussed changes in maternal demographics in Nova Scotia, where--as in the rest of Canada and in the United States--significantly more mothers are having babies late in life, are entering pregnancy with a greater body mass index, are gaining significant amounts of weight during pregnancy, and are having more twins, triplets, and even higher order multiples than did mothers in previous generations.

To highlight the rapid change in just one of those factors, Dr. Baskett noted that 3.3% of Nova Scotia mothers had a prepregnancy weight of 90 kg in 1988, compared with 11.4% in 2001.