Promising Infertility Survey Results

29.12.2010

Centre of Neuroendocrinology researcher Dr Janette Quennell studies how reproductive centres in the brain are affected by metabolism and nutrition.

She was speaking at the Medical Sciences Congress in Queenstown this week.

Hormones in the brain affect puberty, ovulation and sperm, and research has found if women are too thin or obese fertility rates decrease.

Dr Quennell said this is more apparent in women, such as high-performance athletes, those with anorexia and the morbidly obese.

"They don't have enough body fat so they stop menstruating.

"If you get too fat, those hormones get messed up."

Dr Quennell studied leptin, a hormone produced by white fat that acts as a kind of appetite and metabolism thermostat.

Leptin also tells the body how much fat is stored.

By studying the ways in which leptin and other key brain regulators directly or indirectly affect fertility, the research aims to help understand polycystic ovarian syndrome.

Scientists are unsure which comes first, hormone imbalances linked to nutrition and body type or the syndrome, which affects up to 10 per cent of all pre-menopausal women.

"The syndrome is the biggest inhibitor of female infertility.

"We are interested in testing where leptin acts to affect fertility hormones," she said.

There was a proven link between leptin production and fertility but the relationship was not clear, she said.

Polycystic ovarian syndrome is not fully understood but tends to run in families and is linked to excessive levels of male hormones in the ovaries, insulin metabolism and genetic predisposition.

Symptoms can include irregular periods, excess facial and body hair, acne, enlarged ovaries and infertility.

Women with high or low amounts of body fat had trouble reproducing, and defective leptin production can lead to obesity.

A prolonged high-fat diet can create the same effect because the brain becomes unresponsive to leptin, she said.

The Centre of Neuroendocrinology has nine laboratories and is the largest of its kind in the southern hemisphere.

Research focuses on the effects of hormones on the brain, reproduction, body weight and stress.

The Medical Sciences Congress ended yesterday.

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