In 1980, one in every 53 children born was a twin, but according to a recent study performed at Michigan University, today that number has risen to one in every 30. Although this might seem like a simple statistic, it has far-reaching implications for the health of both mothers and infants according to Barbara Luke, who performed the study.
Luke notes that the 1980 numbers on twin births had remained relatively stable for decades, which points to some sort of outside change. In this case there are actually two changes responsible: more women are having children later in life, and more women are conceiving with the assistance of fertility treatments.
It has long been known that the likelihood of conceiving twins increases as the mother’s age increases. In fact 17% of mothers over the age of 45 — almost a full 1/5 — can expect to have twins.
As for fertility treatments, different types of treatments increase the chance of a twin birth for different reasons. It is important to note here that we are discussing fraternal twins specifically. Unlike identical twins, which are the result of a single egg splitting in two, fraternal twins occur when multiple eggs are released and fertilized.
Fertility treatments that stimulate egg production are an obvious culprit for an increase in the number of twins born. In-vitro fertilization is also a fairly straightforward reason, since the procedure involves implanting multiple fertilized eggs into the uterus.
It would be wonderful if these were simply interesting statistics, but unfortunately multiple births carry multiplied risks.
Sharing a womb is stressful on infants, and can often result in premature birth and low birth weight, among other complications. This stress is increased by the fact that human mothers aren’t built to carry multiples. The need for blood flow to the uterus is increased, and nutrient intake must account for two fetuses rather than one.
In addition, mothers carrying twins are more likely to suffer from gestational diabetes, and they experience more heart attacks due to increased strain on the circulatory and respiratory systems.
This is not to say that mothers shouldn’t be overjoyed when they learn that they are expecting twins, but it does mean that the requirements for care and monitoring by an OB/GYN are vastly increased.
If you are carrying twins, be sure to follow your doctor’s instructions carefully. Take all recommended supplements, restrict your activities to reduce additional strain on your body, and be prepared to gain more weight than you would with a single pregnancy to account both your babies’ needs and your own.