A recent article published in the British Journal of Obstetrics and Gynaecology strives to answer this question. Thanks to the development of assisted reproductive techniques (ART) and a change in culture, women are now having children later and later. In fact, the average maternal age at delivery has increased from 26.4yrs in 1975 to 30yrs in 2013 and is still on the rise.
The national population based study in question looked at ladies that were at least 20 weeks pregnant who were all categorised as being of advanced maternal age; that is, having an age at delivery of 48 years or more. The study found 233 women willing to participate with ages ranging from 48 – 61 years, with a median age of 49. A control group of women with a mean age of 31 years was also used so that results could be compared against younger women to see which variables were contributing to put these older women into the high risk category.
The article suggests that it is not actually the age of the women in question that forces them into the high risk category, but the increase in complications that is associated with conceiving later in life. For example, 44% of women in the increased maternal age group had pre-existing medical conditions, compared with just 28% in the comparison group. However, the biggest influencing factor when talking about pregnancy risk has to be the use of assisted reproductive techniques. 78% of the women in the older age group had used some form of assisted reproduction, which is astonishingly high compared to the 4% of women in the younger age group that needed help conceiving. The impact of this meant that in the older age group, 18% of the women were carrying a multiples pregnancy, compared to only 2% in the control group, a factor that instantly increases the risk of any pregnancy.
Therefore, perhaps it is not maternal age itself that is to blame for the increased pregnancy risk but the fact that infertility correlates with increasing maternal age, leading to increased use of ART which causes more multiple pregnancies. Consequently, being able to give women confident and comprehensive advice about assisted reproduction techniques is paramount and although ART are an amazing and exciting development in fertility medicine, they have to be used both carefully and knowledgeably. What do you think?
Link to article; http://onlinelibrary.wiley.com/doi/10.1111/1471-0528.14269/epdf
Want more info on ART? Have a look at our IVF course; http://ibcme.com/med/conference/IVF/
Pregnancy at a very advanced maternal stage: a UK population-based cohort study. Fitzpatrick KE, Tuffnell D, Kurinczuk JJ, Knight M. BJOG Sept. 2016.