Large birth weight and increased risk of stillbirth
Public health researchers have found that a large fetal birth weight is a significant risk factor for stillbirth.
USF College of Public Health alumnae Drs. Lindsey King, a clinical assistant professor in the College of Public Health and Health Professions at the University of Florida, and Korede Yusuf, assistant professor in the College of Nursing and Public Health at Adelphi University, along with Dr. Abraham Salinas-Miranda, associate director of the COPH’s Center of Excellence in Maternal and Child Health and director of the Harrell Center for the Study of Family Violence, were part of a research team that conducted a first-of-its-kind study examining macrosomia-related stillbirth for millions of births.
“We aimed to examine two very important public health problems, stillbirth and fetal macrosomia,” said King.
Stillbirth is the intrauterine death of a fetus beyond the age of viability at 20 weeks or more and fetal macrosomia is a birth weight larger than 8.818 pounds, regardless of gestational age, according to King.
Their research, “Phenotypes of fetal macrosomia and risk of stillbirth among term deliveries over the previous four decades,” has been published in Birth Issues in Perinatal Care.
The research team also included Dr. Hamisu Salihu, lead investigator and a world-renowned stillbirth expert, and Deepa Dongarwar, a senior programmer, both from the Baylor College of Medicine.
“Fetal macrosomia constitutes eight percent of all births,” said King. “Macrosomia has been found in previous studies as either a protective or risk factor for stillbirth. To clarify the inconsistent results from available studies, we decided to conduct this study, which examined the association between stillbirth and fetal macrosomia in a nationally representative dataset that covered a period of four decades.”
Using birth data and fetal death data that were made publicly available by the CDC and conducing a population-based retrospective cohort study using time-series analysis and Cox proportional hazards regressions, they found that macrosomia is clearly a strong factor for stillbirth.
“We also found a dose-effect relationship between severity of macrosomia grade and the risk of stillbirth,” Salinas-Miranda said. “Our results provide evidence for improving risk appropriate care of pregnancies where risk factors for fetal macrosomia are found (i.e. maternal diabetes). This is also important for perinatal surveillance.”
Salinas-Miranda said fetal macrosomia has not been examined much in the field of maternal and child health.
“We believe our research can be utilized to formulate national guidelines. From a personal standpoint, our research collaboration included an array of scientists from diverse backgrounds and universities, which we see as is an achievement that meant a lot to our team,” he said.
According to King and Salinas-Miranda, USF played a significant role in forming continued research collaborations.
“Our research team is a very productive one,” said Yusuf regarding the research team’s collaborative effort. “We meet virtually, almost weekly, to brainstorm, discuss research ideas, and work on manuscripts.”
Understanding the determinants of adverse perinatal outcomes is an important public health endeavor, according to King.
“Recognizing macrosomia as an important risk factor for stillbirth not only adds to the literature but also points to the need to address risk factors for macrosomia such as maternal diabetes, obesity, and weight gain during pregnancy,” she said. “Our next step is to share our findings with maternal child health programs, home visiting programs, health care providers, students, forums, policy makers and other public health professionals.”
Story by Anna Mayor, USF College of Public Health