Advances in medicine increase the likelihood of survival for underweight babies into adulthood, but does not assure that baby girls born underweight will not have problems later on in life.
A new study has shown that female babies who are born small or underweight are more likely to have fertility problems when they reach adulthood compared with female babies who are born within the normal weight range.
Researchers studied data gathered from the Centre of Reproductive Medicine in Sweden, specifically those women born from 1973 onwards and who sought treatment for infertility from the Center between 2005 and 2010. The study analyzed a group that was made up of 1,293 women in a heterosexual relationship, and their medical details, such as birth size, age and weight, taken from the national medical birth register in Sweden.
The analysis, published in BMJ Open revealed that of the women studied, two thirds were of normal weight, a fourth were overweight, and one in 20 were obese, while 2.5 percent were underweight. Around four percent of these women were born prematurely, four percent were born underweight, while less than six percent of them were described as unexpectedly small at birth.
The study, led by Josefin Vikström, a faculty member of health sciences at Sweden's Linkoping University, has found that, of these women seeking infertility treatment, 38.5 percent of the fertility problems in the couples were attributed to the women, while 27 percent were attributed to the men. Cases in which both partners had fertility problems accounted for only seven percent of the cases. There were 28 percent of the cases in which fertility problems were unexplained.
The researchers have found that women with fertility problems undergoing treatment at the Center were almost three times more likely to have been born small or underweight, even after other factors have been taken into account, such as current weight - including the condition of being overweight - and previous pregnancies and motherhood.
The researchers explained that growth restriction in the womb could affect the development of the organs of the fetus inside. Although the study did not prove a cause-and-effect link, knowing about the association is still important, as improvements in health care mean that more underweight babies survive into adulthood and, therefore, may experience fertility problems as well. However, the research team admits that this study is the first of its kind, and more research needs to be done.
"Women born with LBW or SGA seem to suffer an increased risk of infertility due to a female factor. Thus, infants born with birth characteristics that deviate from the norm may be at greater risk of difficulties in childbearing later on in life. Since this study is the first of its kind, more studies are needed to verify the associations found in this study and to determine their nature," the researchers concluded.
