While modern medicine has made childbearing relatively safe, it still entails a lot more risk than many people realize. In fact, childbirth may be the 11th leading cause of death among women 15 to 44, a study by the federal Centers for Disease Control in Atlanta indicates. "People don't see childbirth as a dangerous procedure," says George Rubin, director of the CDC's Family Planning Evaluation Division. "But our findings show it is more dangerous than generally assumed by the public and medical profession." The national Center for Health Statistics say the rate of maternal mortality from childbirth in 1978 was reported as 9.6 deaths per 100,000 live births. Based on these statistics, the latest available nationally, childbirth ranks as the 29th leading death cause for white women and 26th for nonwhites. But based on the new findings, the maternal mortality rate would be 14.4 per 100,000 births, or the 11th leading cause among women in their childbearing years. Dr. Warren Pearse, director of the American College of Obstetricians and Gynecologists, said specialists on maternal mortality agree that many childbirth deaths are not reported and that the death rate may be 50 percent higher than is being reported. The study, which included all live deliveries in Georgia in 1975 and 1976, showed that many childbirth deaths occur from complications that arise some time after delivery and therefore may not be associated with the birth or noted on death certificates, Rubin said. By matching death certificates with birth certificates to determine if a woman had delivered with 90 days of her death and then determining if her death were related to her delivery, CDC researchers found that the actual childbirth death rate was 50 percent higher than reported by the state. Georgia health officials reported a maternity mortality rate of 14.2 deaths per 100,000 live births, but the study showed that the actual childbirth death rate was 22.6 deaths per 100,000, Rubin said.