Choosing to have kids at an older age is an increasing trend in high-income countries. In parallel, severe maternal morbidity – childbirth complications resulting in short or long-term health consequences to the mother and possibly the baby – are increasing as well. A group of scientists from The Hospital for Sick Children (SickKids), Sunnybrook Health Sciences Centre and the Institute of Health Policy, Management and Evaluation at the University of Toronto (IHPME) wanted to investigate whether there’s an association between increased maternal age and a higher risk for severe maternal morbidity.
They analyzed data from 3.1 million pregnancies across Canada and revealed mothers under the age of 19 or over 30 were at an increased risk for severe maternal morbidity and mortality, with women over the age of 44 being at the greatest risk compared to mothers aged 20 to 24 who are at the lowest risk. The findings were recently published in JAMA Network Open.
Using data from the Canadian Institute for Health Information (CIHI), the researchers confirmed severe maternal morbidity is on the rise in Canada. There was a 9.8 per cent increase over the study period from 17.2 incidents per 1,000 deliveries in 2004-05 to 18.9 incidents per 1,000 deliveries in 2014-15. This trend coincided with an increase over time in maternal age and in the proportion of pregnancies to older mothers.
The researchers say the typical physiological changes from aging may make older mothers more vulnerable to the significant physiological impacts of pregnancy. For example, increased blood pressure and lower cardiac output can occur as natural effects of aging. In pregnant women, these may also contribute to placental insufficiency, a pregnancy complication where the placenta is unable to deliver an adequate supply of nutrients to the fetus, which can impact fetal growth.
“The increased risk of severe maternal morbidity with increasing maternal age in Canada should be an important consideration for prospective parents,” says the study’s lead author, Dr. Kazuyoshi Aoyama, anesthesiologist in the Department of Anaesthesia and Pain Medicine and associate scientist in the Child Health Evaluative Sciences program at SickKids. “But this finding is also a clear sign to public health professionals and clinicians that early interventions are needed to detect acute complications and prevent their progression in high-risk mothers.”