For years, British Columbia has had the oldest average age of mothers in Canada.[1] In 2016, the average age of a person giving birth in BC was 31.5 years; as of 2020, this average reached a new high of 32.1 years.[1] What’s most remarkable to me is that in a single generation, our society has shifted from persons historically giving birth in their 20s to the majority giving birth in their in their 30s.[2] To demonstrate just how much we’ve changed, consider some American data, which showed that for persons born in 1960, waiting until after age 30 to have children was quite rare.[3] The median age of first birth for a cohort of persons born in 1910 was 21.1 years, and 22.7 years for a similar cohort born in 1960. In the mid-1970s, the average age of a Canadian person was 26.7 at childbirth.[4]

I am not sharing this data to criticize millennials; I am these statistics! I had my first baby at 32, toward the end of my fellowship, which was the culmination of 14 years of postsecondary education. I was one of the earliest in my residency cohort to be pregnant. You can probably relate to the reasons why medical school and residency might seem like inconvenient times to start a family. Studying for exams, 24-hour shifts, moving cross-country for training, and student debt are just a few reasons why physicians might feel they can’t have babies during their reproductive prime. There are also wider societal pressures that contribute to delayed childbearing that are not unique to physicians. As a fertility specialist, my patients talk to me about why it took them some time to start a family: finding the right partner, buying a house, traveling, or finishing education.

Much has been written about older mothers, both in medical journals and in the popular media.[5-8] It is a relatively frequent news topic. In 2018, I wrote a BCMJ guest editorial titled “How old is ‘too old’ to have a baby?” [2018;60:246 [10]]. However, despite writing, reading, lecturing, and talking to patients about reproductive aging for years, my speech about older childbearing appears to be the same old story (no pun intended). The conversation needs to evolve.

Advancing reproductive age is a public health issue. Even though society has changed since my parents’ generation, an egg’s fundamental biology has not. People with ovaries have their maximum number of eggs by 20 weeks gestation—6 to 7 million in total. Egg numbers decline throughout life, but after age 35 the drop is much more dramatic. Egg quality also decreases with age, resulting in chromosomal errors, which lead to infertility and miscarriage. The reproductive lifespan can be extended with assisted reproductive technology, but it is not a cure-all. Even with in vitro fertilization, the odds of a live birth at age 45 are less than 2%.

Canada’s fertility rate is at an all-time low at 1.4 children per childbearing person.[9] The media have written about a pandemic-driven fertility decline, but blaming COVID is overly simplistic.[10,11] A Statistics Canada survey published in December 2021 made headlines for the 19.2% of respondents who “would have fewer children or later childbearing” as a result of the pandemic, when in fact, the vast majority (76.5%) had “no change” in plans.[9] American research suggests that would-be parents of lower socioeconomic status could be those most likely to have adjusted their family planning.[12] Perhaps we can say that the pandemic accelerated an already-concerning trend.

Physicians are well positioned to talk to patients about their childbearing plans. A study of UBC undergraduates showed that “although most women were aware that fertility declines with age, they significantly overestimated the chance of pregnancy.”[13] Whether it’s life planning, egg freezing, or just having children earlier, a little conversation might go a long way. In my daily work I am constantly humbled by Mother Nature and the heartache of unintended childlessness.
—Caitlin Dunne, MD, FRCSC

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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License [11].

References

1.    Statistics Canada. Mean age of mother at time of delivery (live births). Accessed 5 January 2022. www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=1310041701 [12].

2.    BC Vital Statistics Agency. 2015 annual report. Accessed 5 January 2022. www2.gov.bc.ca/assets/gov/birth-adoption-death-marriage-and-divorce/statistics-reports/annual-reports/2015/pdf/annual-report-2015.pdf [13].

3.    Kirmeyer SE, Hamilton BE. Childbearing differences among three generations of US women. Centers for Disease Control and Prevention, National Canter for Health Statistics. Accessed 5 January 2022. www.cdc.gov/nchs/data/databriefs/db68.pdf [14].

4.    Statistics Canada. Fertility: Fewer children, older moms. Accessed 5 January 2022. www150.statcan.gc.ca/n1/pub/11-630-x/11-630-x2014002-eng.htm [15].

5.    Nelson J. COVID has changed fertility plans of many, says survey, local doctor. St. Albert Today. Accessed 5 January 2022. www.stalberttoday.ca/local-news/covid-has-changed-fertility-plans-of-many-says-survey-local-doctor-4883515 [16].

6.    Martins N, Gul M. COVID-19 pandemic may cause births to decline in Canada: Study. CityNews. Accessed 5 January 2022. https://vancouver.citynews.ca/2021/09/25/covid-pandemic-birth-rates [17].

7.    Fernandes M. How far can female fertility be extended? BBC. Accessed 5 January 2022. www.bbc.com/future/article/20200828-how-fertility-changes-with-age-in-women [18].

8.    The American College of Obstetricians and Gynecologists Committee on Gynecologic Practice. Female age-related fertility decline. Committee Opinion No. 589. American College of Obstetricians and Gynecologists. Obstet Gynecol 2014;123:719-721.

9.    Fostik A, Galbraith N. Changes in fertility intentions in response to the COVID-19 pandemic. Statistics Canada. Accessed 5 January 2022. www150.statcan.gc.ca/n1/pub/45-28-0001/2021001/article/00041-eng.htm [19].

10.    Ibbitson J. Pandemic-driven fertility decline a challenge for Canada, a crisis for China. Globe and Mail. Accessed 5 January 2022. www.theglobeandmail.com/politics/article-pandemic-driven-fertility-decline-a-challenge-for-canada-a-crisis-for [20].

11.    Lewis T. The pandemic caused a baby bust, not a boom. Scientific American. Accessed 5 January 2022. www.scientificamerican.com/article/the-pandemic-caused-a-baby-bust-not-a-boom [21].

12.    Kahn LG, Trasande L, Lui M, et al. Factors associated with changes in pregnancy intention among women who were mothers of young children in New York City following the COVID-19 outbreak. JAMA Netw Open 2021;4:e2124273.

13.    Bretherick KL, Fairbrother N, Avila L, et al. Fertility and aging: Do reproductive-aged Canadian women know what they need to know? Fertil Steril 2010;93:2162-2168.