A mother's diet during her pregnancy may influence when her child goes through puberty, according to a study that found women with high fat diet may be affected by her mother's diet during pregnancy

Research at the Liggins Institute suggests that children whose mothers have a high-fat diet while they are pregnant and breast feeding may enter puberty earlier than their peers and are more likely to be obese as adults.

Liggins research fellow Dr Deborah Sloboda presented the results of a new animal-based study at The Endocrine Society’s 90th Annual Meeting in San Francisco on 18 June 2008.

Dr Sloboda said that an early first menstrual period, often used as a marker for early-onset puberty in girls, is a risk factor for obesity, insulin resistance, teenage depression, and breast cancer in adulthood.

"Other research suggests that a combination of prenatal and postnatal influences in girls can affect the onset of menarche [menstruation]," she said.

Dr Sloboda’s research team investigated how prenatal and postnatal nutrition affect reproductive maturation.

They fed pregnant rats a high-fat diet throughout pregnancy and lactation (breastfeeding) while control animals received a regular diet. After weaning the offspring ate either regular chow or a high-fat diet.

The onset of puberty was much earlier in all of the animals whose mothers had a high-fat diet, compared with the offspring of the controls. Controls’ offspring that ate a high-fat diet after weaning also entered puberty early. However the combination of a high-fat prenatal diet and a high-fat diet after birth did not make the early-onset puberty any earlier, Sloboda said.

"This might suggest that the fetal environment in high fat fed mothers has a greater influence in determining the timing of puberty than childhood nutrition," she said.

As adults, animals born to mothers on the high-fat diet had more body fat than controls did, even if they ate a regular diet while young. They also showed alterations in sex hormones, including increased levels of the ovarian hormone progesterone in females.

"Maternal high-fat nutrition may influence reproductive maturation and reproductive capacity in adult offspring," Sloboda said.