The body of a woman's weight before pregnancy, the greater the risk of pregnancy complications are encountered, according to a study.

Using data from more than 24,000 British women who gave birth between 1976 and 2005, researchers found that the risk of interference, such as high blood pressure, pre-eclampsia and premature births increased with weight gain during pregnancy of a woman.

The findings, published in the journal BMC Public Health Online, adding evidence that the obesity risk for both mother and baby. The findings also support the notion that all pregnancies in women fat should be viewed as "high risk", and handled carefully, concluded the study authors, led by Dr. Sohinee Bhattacharya of Aberdeen Maternity Hospital.

The researchers found that compared with normal bodied women, fat women 50% more likely to deal with post-birth bleeding and two times more likely to deliver premature. They are also more likely to require Cesarean birth or through force.

Fat woman who does not normally have the highest risk for having pre-eclampsia, complications are potentially serious birth was marked by an increase in blood pressure suddenly and kidney disorders.

Conversely, the study also found that lean women before pregnancy tend to have the lowest risk of all these complications. However, they are more likely than normal-bodied women to have babies with less body weight.

These results add more evidence about the importance of the mother's body weight in pregnancy outcomes, Bhattachrya team said.

"Evidence on the relationship of obesity in significant complications during pregnancy increased," the researchers wrote. "It is time for doctors to be aware of these findings and begin to use it in their practice."

In addition to good care before birth, they said, also need counseling to women with body fat in order to reduce their weight before they conceive.