Older mothers have higher rates of severe complications in childbirth: study

A pregnant woman is shown in this undated photo. (Pexels)

The risk of potentially life-threatening complications during childbirth increases in older mothers, especially after the age of 39, according to a new study led by a Canadian researcher.

The study, published Tuesday in PLOS, examined data on nearly 830,000 singleton births to women in Washington State from 2003 to 2013.

The research team led by Dr. Sarka Lisonkova, a professor at the University of British Columbia’s department of obstetrics and gynecology, compared age-specific rates of childbirth complications and maternal mortality.

The study found increased risks of severe complications among mothers over the age of 35, even after they accounted for such risk factors as obesity, high blood pressure and diabetes.

More specifically, they found that the rates of obstetric shock and amniotic fluid embolismincreased among mothers who were 40 and older.

Obstetric shock is a life-threatening condition that can cause heart failure or hemorrhaging. Amniotic fluid embolism is a rare but serious condition in which fluid that surrounds the baby enters the mother’s bloodstream.

Among mothers between the ages of 45 and 49, the researchers found increased rates of renal failure, complications due to obstetric interventions and intensive care unit admissions.

In an email to CTVNews.ca, Dr. Lisonkova said that while the overall results of the study were not surprising, she was surprised to see that the increase in relative risk to older mothers was exponential, “meaning that the rate of increase was higher as maternal age increased beyond 39 years.”

“This is important for counselling women who contemplate to delay childbirth to their forties,” Dr. Lisonkova said.  “While a delay of childbirth by a few years does not make a large difference in early 30s, a few years delay in late 40s increases the risks significantly.”

She added that the rate of any potentially severe adverse outcome during childbirth rises to approximately 10 per cent among women in their fifties.

Looking at young mothers, the study also found that maternal sepsis, caused by an infection, was “significantly higher” among teenage mothers than among those between the ages of 25 and 29.

But despite the large sample size used in the study, researchers say they couldn’t statistically measure the association between maternal age and maternal death or very rare, severe complications.

“As maternal age continues to increase, the rate of severe maternal morbidity is likely to increase in the future," the study concludes.

Last week, the Society of Obstetricians and Gynaecologists of Canada (SOGC) urged physicians to start talking to women as early as in their 20s about “the realities of their biological clock.”

Because many Canadian couples are delaying having children until their 30s and 40s, the society published new clinical practice guidelines that recommend women in their 20s and 30s should be counselled about the risk of infertility as part of their “primary well-women care.”

The new guidelines also recommend that doctors counsel women on the risks of pregnancy that come with advanced age.

However, Dr. Lisonkova doesn’t think doctors should explicitly advise women to avoid getting pregnant after the age of 40.

“Women are in a difficult position when they contemplate delaying childbirth in order to advance their education and career,” she told CTVNews.ca.

All women age differently and that includes their reproductive age, she noted, adding that doctors should counsel older women about their potential childbirth risks.

“Staying active and having a healthy lifestyle is the best possible prevention of health problems at any age,” she said.

Once pregnant, older women should not feel anxious about childbirth and should focus on keeping a healthy diet, normal blood pressure and glucose levels, Dr. Lisonkova said.

“As the risks to mom and baby increase significantly with age after 39 years, it is our responsibility to create a society where women do not feel disadvantaged by having children in late twenties or early thirties when the rates of adverse outcomes are lowest,” she said.

“Healthy mothers and babies are our healthy future.”