Study finds high fetal death rate in sickle cell patients: rate pegged at 10% after first trimester.(News)

SCOTTSDALE, ARIZ. -- Pregnant women with sickle cell trait may be at far greater risk for fetal harm than has been recognized, results of a large, retrospective study suggest.

Analysis of hospital records revealed that sickle cell patients had a fetal death rate of 10% after the first trimester. This figure was nearly three times higher than the 3.5% that Michelle Y. Taylor, M.D., and her colleagues at the University of Mississippi Medical Center in Jackson calculated for a control group of women with normal hemoglobin.

The sickle cell carriers also gave birth three weeks earlier on average: at 33 weeks' gestation, compared with 36 weeks' gestation in the control group. In turn, the babies of sickle cell carriers had a mean birth weight about 500 g less than the average for newborns from the control group.

"Further investigation in the form of a comprehensive prospective clinical trial is needed to confirm these findings and determine if there may be a benefit to antenatal surveillance or other interventions," Dr. Taylor said at the annual meeting of the Central Association of Obstetricians and Gynecologists.

A fellow in maternal fetal medicine at the hospital, Dr. Taylor received the association's Young Investigator's Award for the study.

Sickle cell trait is considered benign in pregnancy, according to Dr. Taylor, with anemia and genitourinary infections being the only added risks for most of these patients. In an interview she suggested that greater morbidity and mortality risks might not have been recognized previously because many of the women lose their babies before 20 weeks' gestation. The Mississippi study found 42% of fetal deaths happened between the 16th and 20th week.

"Late fetal losses are usually well documented," she said, speculating that some early losses could be undocumented miscarriages.