3 Factors that Increase the Chances of Multiples
Hyacinth Nicole Browne, MD posted:
Multiple births account for 3% of all births in the general population. However, this number is higher in couples with a family history of twins, in older women who are trying to conceive, and in women undergoing fertility treatment.

1. Family History. Who would have thought that having twins in the family could help increase your chances of having multiples? Twins can be hereditary -- especially if there is a family history of twins -- but it is not an absolute predictor of whether you will also have twins. But, it's always great to know a set of twins!

2. Maternal age. Older women are also likely to have multiples because of hormonal changes that occur during the late reproductive years. Higher circulating levels of follicle stimulating hormone (FSH) can stimulate the growth and development of more than one follicle during a cycle, and subsequently lead to the release of more than one egg. If this occurs, both eggs can fertilize at the same time and result in twins.

3. Fertility Treatments. Fertility treatment can also increase the likelihood of conceiving multiples. Certain fertility treatments are designed to stimulate a woman to produce more than one egg each cycle which can result in multiples. With in vitro fertilization, twin births can approach 30% and it is about 2-3% for triplets or greater. However, the multiple rate seen with in vitro fertilization can be reduced by transferring a single advanced embryo, while still being able to achieve a high success rate in a select group of women.