MedicalResearch.com Interview with:
Dagfinn Aune MS
Department of Epidemiology and Biostatistics
School of Public Health
Imperial College London
St. Mary’s Campus
Norfolk Place, Paddington, London W2 1PG, UK
MedicalResearch.com: What are the main findings of the study?
Answer: We conducted a systematic review and meta-analysis of studies examining the association between maternal body mass index (BMI) and risk of fetal death, stillbirth, neonatal, perinatal and infant death. We found that the risk of all these outcomes increased with greater BMI in a dose-response fashion. For example even within the high end of what is considered the normal BMI range (BMI of 24-25) there was a 10-20% increase in the relative risk, but the strongest relations were seen for those who were obese and morbidly obese with 30-60% and 2-3 fold increases in the relative risk respectively (depending on the outcome examined).
MedicalResearch.com: Were any of the findings unexpected?
Answer: We knew that many studies had previously reported increased risk so in that sense we were not surprised. The findings are consistent with an increasing number of pregnancy complications that are related to overweight and obesity.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: The findings show that excess body weight is an important risk factor for fetal death, stillbirth and infant death and suggest that being quite lean within the normal BMI range is associated with the lowest risk. As the BMI increases the risk increases with a dose-response relationship. Although these are quite rare outcomes in high-income countries and the absolute risk is low, they are devastating for the parents that are affected. In addition, there are a number of other more common pregnancy complications that are strongly linked to overweight and obesity, including gestational diabetes, preeclampsia, gestational hypertension, and macrosomia, so it’s an important issue that needs to be addressed.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: We need more data regarding the optimal gestational weight gain in relation to stillbirths and studies of weight change between pregnancies and risk of stillbirths in the latter pregnancy. In addition, studies are needed to clarify whether physical activity could reduce the risk. There are some data showing reduced risk of other obesity-related pregnancy complications such as gestational diabetes and preeclampsia in women who are physically active compared to inactive women, but we need to expand those investigations into stillbirths and other pregnancy outcomes as well.