Pregnancy chances fall by half as women age in early 40s
Published 17/09/2015 | 02:30
Women who undergo fertility treatment have less than half the chance of getting pregnant at age 43-45 compared to 40-42, according to a major new study.
The pregnancy rate for women after 43 is just 5.04pc, compared with 12.5pc for those aged 40-42, a review of older women who attended the HARI clinic in the Rotunda Hospital in Dublin over 16 years reveals.
It also emerged that even among those in the mid-forties who did become pregnant, the risk of losing their baby was substantially greater than among the younger age group.
The authors of the study, embryologists Dr Linda O' Shea, Dr Ciara Hughes and Dr Ed Mocanu said the age cut-off point at the clinic was 45 years and the study had allowed better counselling of older women who were hoping for motherhood.
It comes against a background of growing numbers of Irish women in their 40s trying to beat the biological clock by seeking fertility treatment to get pregnant.
They made up 7.2pc of the clinic's patients in 1997, but now account for nearly one in five.
The ability to get pregnant through fertility treatment relies largely on the state of a woman's eggs and the ability to develop quality embryos, the study in the 'Irish Medical Journal' pointed out.
The doctors said a large proportion of miscarriages that happen in the first trimester were due to abnormalities associated with the eggs of older women.
Due to the low chances of success, the older women are also at increased risk of getting pregnant with twins or triplets because of the transfer of multiple embryos.
The authors said, however, that women may stand a better chance of getting pregnant by using donated eggs.
This is a "very promising option" for women over 40. They could also consider embryo donation.
However, it is necessary to extensively counsel women about the ethical and legal issues involved.
Currently, there is no legislation in Ireland covering egg or embryo donation.
Nor are there any laws yet governing surrogacy.
There is a greater chance of getting pregnant through transferring embryos, generated from the eggs of a young woman. One option for women is to 'self-preserve' their own fertility by banking their eggs in their 20s and 30s.
However, a large number are needed and there are risks associated with ovarian stimulation and egg collection.
For women aged 45-50, surrogacy may be a safer option. But the "ability to care for a teenager or young adult when a parent is over 60 remains a challenge".
The best interests of the child should always be paramount, they said.