Barbara Luke studies issues of multiple births

Multiple births used to be such a rare occurrence that they were usually excluded from studies focusing on maternal and infant health issues. Today, however, the knowledge to be gleaned by such research is more important than ever.

"Multiple births have become much more common because more and more women are having babies later in life," says Barbara Luke, Sc.D., M.P.H., R.D., a professor at the School of Nursing and Health Studies and the author of 16 books (including a national bestseller about multiple births). "In addition to the established link between older mothers and multiple births, older women more often require fertility treatments to conceive, further increasing their likelihood of having twins or triplets."

Luke recently completed two NIH-funded historical studies about multiple births that were accepted this summer by leading peer-reviewed journals.The first, which will appear in Fertility and Sterility, correlated the risks of pregnancy complications and adverse outcomes with increasing maternal age."We found that with singletons [single infants], the risks for prematurity, tocolysis [drug therapy to delay preterm labor], and infant mortality showed a U-shaped relationship with age, with the highest risks at the youngest and oldest ages," says Luke. "But for mothers of twins and triplets, the risks for these three outcomes decreased with advancing age-good news for older moms pregnant with multiples."

The second study, accepted by Pediatrics, evaluated the impact of medical advances on neonatal survival rates during a recent ten-year period."We found that the technological advances of the 1990s greatly improved survival," notes Lukes, who authored the study with co-investigator Morton B. Brown of the University of Michigan."For births before 26 weeks of gestation, however, this was followed by a rise in mortality after the first week of life-indicating a postponement of deaths for some infants.

"In general, while the mortality rates were higher for multiples at every gestation age compared to their singleton counterparts, their improvement in survival over the past decade has been greater."

While her research confirms that multiple births raise issues about which prospective older mothers should be carefully counseled, Luke notes that she has worked over the years with many older mothers who are now raising healthy children-encouraging proof that such concerns can be effectively addressed.