22nd December 2014 | by MFC Team
Rising number of twins and triplets born to mothers in their 40s
As more women are using IVF to have children in their 40s, the number of multiple births to this group of parents is rising. The latest figures from the Office for National Statistics (ONS) in the United Kingdom indicate that in 2013, due to efforts to limit the number of embryos transferred during an IVF cycle, the rate of multiple births has dropped in every age group except for women in the 40-44 age range. In this group, the multiple maternity rate was 95 per 1,000 births, whereas women under 20 had the lowest multiple birth rate at 6.1 per 1,000 births.
Women are more likely to have multiple births (twins, triplets) when they have fertility treatments like IVF or take medication to stimulate ovulation. According to the Human Fertilisation and Embryology Authority (HFEA) in Europe, approximately 1 in 5 IVF pregnancies result in multiple births, in contrast with 1 in 80 for women who conceive naturally.
In the United States and Canada, single embryo transfer is recommended to avoid the significant health risks to mothers and babies caused by multiple pregnancies – risks that increase for older mothers. In 2009, the HFEA followed suit, implementing a policy to reduce the number of multiple births by encouraging single embryo transfers. As a consequence, the multiple birth rate for women under 40 has been reduced in recent years, in the US, Canada and Britain. However, many women in their 40s still elect to have more than one embryo transferred during an IVF cycle, due to the reduced likelihood of a pregnancy occurring at more advanced ages. In some of these cases more than one of the embryos becomes viable, resulting in a higher risk twin or triplet pregnancy.
Read more about the latest ONS figures here.