Recent research finds that women that are healthier than the average mother are more likely to naturally conceive twins. It makes sense that nature would work this way, given that twins are generally more a burden on their mother than one baby. The research, published in the journal Proceedings of the Royal Society and undertaken by Shannen Robson and Ken Smith of the University of Utah, shows that mothers of twins are healthier than other mothers, have more children at shorter intervals over a longer period of time, and are older at their last birth. Demographer Ken. R. Smith, senior author of the study and a professor of family and consumer studies states that:
“The findings do not mean having twins is healthy for women, but instead that healthier women have an increased chance of delivering twins…The prevailing view is that the burden of childbearing on women is heavier when bearing twins. But we found the opposite: women who naturally bear twins in fact live longer and are actually more fertile.”
“Having twins will not make you stronger or healthier, but stronger, healthier women are more likely to have twins naturally” says Shannen Robson, the study’s first author and a recent Ph.D. graduate in anthropology.
However, this research only studies women who gave birth to twins naturally. Modern society is seeing a boom in the numbers of women giving birth to twins in the 33 – 39 age bracket, largely due to unnatural methods of conception such as IVF. These women are having not only twins, but triplets and even quadruplets.
Dr. Gary W. Devane, an infertility specialist, estimates that 25 percent of all women over 30 might need a fertility drug to assist in conception because many don’t ovulate properly as they get older. Such drugs increase the chance of multiple births and are being used by more and more women due to a decision to have children later in life. For example, the native population of Denmark is fairly stable, but about 3.9% of babies born there in 2003 were actually the result of IVF. Interestingly, without IVF, the number of Danes would be shrinking fast.
But is this healthy for women in light of this new study which finds that naturally it is the healthier and stronger women who are ‘selected’ to have twins? It is possible that we will see a decrease in the quality of life of older women due to the burdens put on their bodies and lives by having multiple births at an age when it is not natural for them to do so. It will be also interesting to note the effects of older, possibly less healthy parents, on our children.