Women who gain too much weight during pregnancy are placing themselves and their unborn child at risk of problems, scientists have warned.
Experts reviewed 150 studies that focussed on the impact of maternal weight gain on pregnancy, mothers, foetuses and children.
The findings, which are published on the US government's Agency for Healthcare Research and Quality (AHRQ) website, reveal a strong link between high maternal weight gain and increased foetal growth and infant birth weight, which can cause problems during labour and lead to long-term health problems for the child.
Excessive weight gain during pregnancy is also linked to a higher risk of caesarean delivery and maternal weight retention after giving birth.
Dr Anna Maria Siega-Riz, an associate professor in the University of North Carolina School of Public Health's epidemiology and nutrition departments, noted: "To fully understand the effects of maternal weight gain on short- and long-term health outcomes for both women and infants, future studies will need to adopt standard measures and consistent definitions of exposures and outcomes."