Pear-Shaped Women More Fertile than Apple-Shaped, Study says
LONDON (AP) _ A new study suggests fertility is not only affected by weight, but by how it is distributed.
According to a Dutch study of 500 women, women who tend to gain weight in the waist - developing an apple shape - take longer to conceive than their pear-shaped counterparts - women who tend to gain in the hips.
The study was published in the Feb. 20 issue of The British Medical Journal.
Doctors have long known that women who are too skinny or obese have more difficulties getting pregnant than women of average weight.
″Our study shows women who are of normal weight and apple-shaped have a lower probability of conception than normal-weight women who are pear- shaped,″ said Dr. Boukje Zaadstra.
She is an epidemiologist at the Institute of Preventive Health Care of the Netherlands Organization for Applied Scientific Research in Leiden, Netherlands.
Dr. Alan DeCherney, chairman of obstetrics and gynecology at Tufts University, said the study confirms earlier observations. ″Look at all the old fertility goddesses, they are all pears,″ he said.
Though scientists do not know why body shape correlates with fertility, they have speculated that fat can act like a chemical signal, triggering the release of hormones.
Apple-shaped women, the typical male shape, may have higher levels of male hormones compared to pear-shaped women, the typical female physique, DeCherney said in a telephone interview.
Previous American research tied other health benefits to the pear shape.
One study suggested pear-shaped women have higher levels of HDL, the ″good″ cholesterol associated with a lower risk of heart disease. Another study said pear-shaped women are less likely to get breast cancer compared with apple-shaped women.
Such clues prompted Zaadstra to wonder whether abdominal fat provokes hormonal changes that may also affect fertility.
Investigators examined women attending a fertility clinic between January 1986 and January 1988 because their partners were infertile or because they did not have a partner.
The 500 women, who had normal menstrual cycles, were trying to conceive by artificial insemination. The doctors took body measurements and monitored how many cycles it took each woman to conceive.
Zaadstra said 212 women had hefty stomachs, with a ratio of waist-to-hip size greater than 0.8-to-1.
She said 32 percent of women with the highest waist-hip ratio conceived after 12 attempts compared to 63 percent of women with the lowest ratio, less than 0.7.
Zaadstra advises women who are both obese and apple-shaped to lose weight to improve their chances of getting pregnant.
Unfortunately, ″you can’t decide where you want your fat distribution to be,″ said Zaadstra, because fat distribution is genetic.