A new study has suggested that minor weight loss in obese women could boost their chances of getting pregnant.
Professor Bill Ledger, from the University of Sheffield, and colleagues said conducted a three-month study of 40 obese women who were not ovulating.
Many of them suffered from polycystic ovary syndrome (PCOS).
The group's average age was 29 and their body mass index (BMI) was around 40. Health service guidelines do not recommend IVF treatment for women with a BMI of above 30.
The women were given weight loss drugs to help them lose 5 percent of their body weight over a three-month period.
The weight loss of 5 percent was connected with a 19 percent rise in blood flow to the womb.
This increase in flow could assist an egg's release from the ovaries and help with embryo implantation.
The researchers stated that the increase in blood flow worked like a "switch" to stimulate the ovaries.
Testosterone levels - which are higher in PCOS sufferers - also decreased as the blood flow picked up.
Ledger said that requesting that women lost 5-10 percent of their body weight was a 'modest target'.
"The message for women with PCOS is don't think you have to lose half your body weight. This could also encourage moderately overweight women to lose 5-10 percent," the BBC quoted Ledger as saying.
Women with PCOS, which is one of the most common causes of infertility, tend to put on weight because of their condition and struggle more than other women to lose it through diet and exercise.
The study was presented at the European Society for Human Reproduction and Embryology (ESHRE).