The study, published in the current online version of Obstetrics and Gynecology, offers some additional insight into the incidence, predictors and outcomes of peripartum cardiomyopathy, which can occur during pregnancy or within a few months after delivery, said Erica P. Gunderson, PhD, an epidemiologist and research scientist with the Northern California Division of Research and the lead author of the study.
“In this study, we were able to identify, within a large-diverse population, independent risk factors for peripartum cardiomyopathy and to report adverse health effects for the newborn,” said Gunderson. She explained that the study expands on the existing knowledge base by identifying Filipino race, greater severity of hypertensive disorders, and severe anemia as important predictors of peripartum cardiomyopathy.
Compared with women who did not experience peripartum cardiomyopathy, women with the condition were more likely to be older, African American or Filipino, and to have experienced four or more total births, said Gunderson. Incidence rates for non-Hispanic African American Women were 1 in 664 and for Filipino women 1 in 978. Incidence rates were lower for Hispanic women (1 in 6,729) compared with Non-Hispanic white women (1 in 2,450). Researcher estimates of peripartum cardiomyopathy incidence were 1 case per 2,066 births, which is 55-95 percent higher than estimates from previous population-based studies, explained Gunderson.
Women who developed the condition were also more likely to have experienced (during the pregnancy immediately preceding onset) anemia, gestational diabetes mellitus (GDM), pre-existing or pregnancy-related hypertension, elevated liver enzymes, low platelets syndrome and a cesarean delivery. Gunderson explained that peripartum cardiomyopathy risk increased significantly with increasing maternal age and increasing severity of anemia and hypertensive disorders.
Compared to babies born to women without peripartum cardiomyopathy, babies born to women with the condition were more likely to be premature, low or very low birth weight, small for gestational age, and have lower 5-minute Apgar scores.
Researchers analyzed all live births that occurred at a Kaiser Permanente Northern California hospital between January 1, 1995 and December 31, 2004. To enhance the accuracy of identifying peripartum cardiomyopathy, researchers excluded women who had a diagnosis of heart failure or valvular heart disease before the selected pregnancy in the study period, leaving 227, 453 women for analysis.
Additional authors on the study include Lisa A. Croen, PhD; Vicky Chiang, MS; Cathleen K. Yoshida; Alan S. Go, MD, all with the Kaiser Permanente Northern California Division of Research; and David Walton, MD, with the UCSF department of epidemiology, biostatistics and medicine. The research was supported by a grant from the Kaiser Permanente of Northern California Community Benefit Program.