What's age got to do with it?
We hear it from well intentioned family members and the early morning new stories that the age of a woman has an effect on her fertility and chance to have a healthy baby. Advanced maternal age (AMA) is a cringe worthy phrase, but it is a concept that needs to be considered now that women are creating the careers they desire and having babies later in life. Recently, I came across a TedTalk, The Surprising Truth of Making Babies Late, given by Reisa Pollard in which she explains her story surrounding her fertility. She shares her struggles after deciding to become pregnant. Her journey started at about 40 years of age and ended when she was 46. She spontaneously conceived both of her healthy sons, yet in the time between conceiving the both of them, she had multiple miscarriages, used two donor eggs, and injected hormones for fertility treatments. She stated she was not well informed of the decreased ability to become pregnant and stay pregnant as a woman ages. She wished this was something discussed in high school health class.
As a woman plans for her career success, it should be with the understanding of her fertility success at each age, and the options she has regarding her fertility such as egg freezing, egg donation, or surrogacy. This idea of learning about female fertility is further discussed by Meg Jay, PhD in her book, The Defining Decade: Why Your Twenties Matter-And How to Make the Most of Them Now. For those 20-year-olds reading this article, Dr. Jay urges you to plan your fertility just as you would your career. Often, women in their 20s focus on “living it up” and plan to settle down in their 30s. Only until this decade will the search for a partner begin and the baby-making process may not start until her mid-thirties which is the time in which most research suggests a decline in fertility.
As a woman ages, there are some considerations to make regarding her fertility. Her health during a pregnancy is one but will not be covered during this article. The other two considerations are the chance to become pregnant and the chance to conceive a pregnancy with a chromosomal condition.
The chance to conceive a pregnancy as a woman ages decreases. One study found the pregnancy rate for women younger than 31 years is 74%, 62% between 31-35 years of age, and 54% after 35 years of age (1). Another study found the chance an IVF cycle would result in a baby as 22.1% in women aged 38–40 years, 12.4% in women aged 41–42 years, 5% in women aged 43–44 years, and 1 % for women older than 44 years (2).
For women, who do conceive a pregnancy, the next consideration is the chance of conceiving a pregnancy with a chromosomal condition. At 31 years of age, the chance is 1 in 384. Four years later, that chance is just about doubled at 1 in 178. At 40 years of age, the chance is 1 in 62 and steadily increases (5). If a pregnancy is conceived with a chromosomal condition, it often results in a miscarriage. Sometimes, the pregnancy continues and the three main chromosomal conditions that are most known to progress to the end of the pregnancy include Trisomy 13 (Patau syndrome), Trisomy 18 (Edward syndrome), and Trisomy 21 (Down syndrome). There are screening and diagnostic tests that can personalize the chance for a chromosomal condition rather than basing those chances on just age which are reviewed in this article What to expect with all the tests offered during pregnancy.
So much focus is placed on the woman and her age, yet there are considerations that need to be made when a man is over a certain age (usually 40 years of age) as well. Men produce sperm and conceive pregnancies well into their 60s. There have been studies that show associations of advanced paternal age with having children with autism, schizophrenia, and spontaneous changes to genes that cause conditions like Achondroplasia and Apert syndrome.
A new prenatal screen can assess the chance for select single gene conditions that occur spontaneously, without any family history. This screen uses the same methodology that cell-free DNA screening does for whole chromosomal conditions. This screen can look to see if there is an increased or decreased chance for about 20 conditions such as Achondroplasia, Apert syndrome, Crouzon syndrome, Rett syndrome, etc. Humans have 20,000 genes and many of those can cause conditions if they do not function properly, so this screen is not comprehensive for all the conditions that can occur secondary to advanced paternal age. However, it provides some information regarding these specific conditions.
Socially, we may not have any qualms about parenting at older ages when compared to generations in the past. However, our biology has a different view. Therefore, it’s important to know what happens to our fertility as we age to make informed decisions.
Resources:
Schwartz D, Mayaux MJ. Female fecundity as a function of age: results of artificial insemination in 2193 nulliparous women with azoospermic husbands. Federation CECOS. N Engl J Med 1982;306:404–6. [PubMed] ⇦
Centers for Disease Control and Prevention, American Society for Reproductive Medicine Society for Assisted Reproductive Technology. 2010 assisted reproductive technology: fertility clinic success rates report. Atlanta (GA): CDC; 2012. Available at: http://www.cdc.gov/art/ART2010/PDFs/ART_2010_Clinic_Report-Full.pdf. Retrieved September 13, 2013.
Advanced Paternal age: How old is too old? J epidemiol community health 2006
Reproductive functions of the ageing male kuhnert B and nieschlag E.
https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Gynecologic-Practice/Female-Age-Related-Fertility-DeclineHook and Chambers (1977) and Hook (1981)
* This blog constitutes general information about genetic testing and medical screening. This blog does not offer or provide medical advice or diagnosis, and nothing in this blog/webinar should be construed as medical advice or diagnosis. Do not rely on the information in this blog/webinar to make medical management decisions. Please consult with a medical professional before making those decisions. Do not delay in seeking professional medical advice if you think you have a medical concern. Do not disregard professional medical advice based on any information received in this blog.
