Overweight mums likely to have big babies
Being overweight or obese in pregnancy causes babies to be born larger, according to new research.
The study, led by the Universities of Bristol and Exeter, also found mothers with a higher blood sugar - even within a healthy range - tend to have bigger babies.
However, having higher blood pressure in pregnancy causes babies to be born smaller, the international research collaboration found.
Researchers found that mothers' blood lipids, which are also related to being overweight, did not seem important in determining the baby's size.
Dr Rachel Freathy, of the University of Exeter Medical School, said: "Being born very large or very small can carry health risks for a newborn baby, particularly when that's at the extreme end of the spectrum.
"Higher and lower birth weights are also associated with diseases such as Type 2 diabetes later on in life.
"Understanding which characteristics of a mother influence the birth weight of her offspring may eventually help us to tailor management of a healthy pregnancy, and reduce the number of babies born too large or too small."
The work, published in medical journal 'JAMA', used data from more than 30,000 healthy women.