Low weight at birth linked to infertility

Girls who were born unexpectedly small or underweight appear themselves to have twice the risk of having infertility problems in adulthood, compared with those born at normal weight, research at Linköping University shows.

Thanks to medical advances, more and more premature and very small babies now survive. But the downside is that more and more women risk having infertility problems, according to a study by researchers in obstetrics and gynaecology now being published in the scientific journal BMJ Open.

The research team headed by Josefin Vikström and Gunilla Sydsjö, bases its findings on 1,206 women born in Sweden in 1973 or after who, together with their male partners, sought help in becoming pregnant.

The main reason for the infertility was taken from the patients’ medical records, and the women’s birth data from the Swedish National Register of Births. It turned out that fewer than 4% of women in the study were born prematurely and an equally large proportion were born underweight; almost 6% were born unexpectedly small.

The data analysis showed that in those cases where the fertility problem could be traced to medical abnormalities in the woman, the probability that she herself had been born underweight was 2.5 times greater than when the cause lay with the man, or could not be ascertained.

One possible explanation, according to the researchers, is that weak growth in the womb might have an impact on the development of the reproductive organs of the foetus. Previous research has linked restricted growth during the embryo stage to reduced ovulation in the fertile years.

Article: Birth characteristics in a clinical sample of women seeking infertility treatment: a case–control study by Josefin Vikström, Mats Hammar, Ann Josefsson, Marie Bladh and Gunilla Sydsjö. BMJ Open 2014:4, 10 March 2014.

2014-03-11