Age is one fertility factor you can not change. Several studies show that fertility starts declining in women (and possibly men) after age 35.
A recent study of nearly 3,000 couples showed the cumulative pregnancy rate at 1 year of trying to conceive to be about 79% for women aged 25-27 while women aged 40-45 had a cumulative pregnancy rate of about 55%.
A limitation of many age and fertility studies to date is low participation of the male partners.
Nature has designed us women to have fewer babies as we age for good reasons but does that mean we should not try to “buck the curve”?
How old is too old to have a baby?
While the odds of getting pregnant decrease with age, being over 35 years old (a.k.a. advanced maternal age) tends not to effect neonatal outcome – except in the chromosomal anomalies department. The literature clearly shows an increased risk of genetic abnormalities like Down's syndrome in children who are conceived by women older than 35.
American Family Physician reports Down’s syndrome risk to be 1 in 1,300 for a 25-year-old woman, 1 in 365 at age 35, then 1 in 30 by age 45. While the undisputed jump in risk means doctors recommend genetic screening for all women who will be 35 or older on their estimated due date, no one is saying: “you’re too old, don’t try to have a baby.”
Repeated for good measure: age alone is not a factor in the health of your future child – except for risk of genetic conditions.
Once pregnant, about 40% of American women over age 35 opt for prenatal counseling and screening tests like chorionic villus sampling and amniocentesis. That means that once pregnant, the majority of older mothers decide not to do these invasive tests.
For more information on the safety and effectiveness of this type of screening, check out this CDC report.
Having a baby at any age is a big, beautiful decision. Modern life has both challenged and equipped women nowadays to be more educated and supported as they think about motherhood.
Now that we’ve unpacked the biggest risk of advanced maternal age, let’s talk about hormones that help us understand our fertility. After all, it’s our specialty here at Proov!
AMH and LH in older women do not predict fertility
AMH stands for anti-mullerian hormone and is an indicator of a woman’s egg count or ovarian reserve. LH stands for luteinizing hormone which often rises a few days prior to ovulation.
While both hormones are commonly tested when there’s an interest in fertility, neither are predictors of the ability to conceive and carry to term in women over 35. AMH is actually not related to the ability to conceive regardless of whether you are over or under 35.
If you’ve been told you have low AMH, this is a must-read article that tells you what’s more important for getting pregnant. (Hint: Bring sexy back!)
Let’s talk more about LH.
Luteinizing hormone is a chemical messenger that is released from the brain in response to high estrogen levels from the ovary that is getting ready to release an egg (ovulation). Women have hundreds of thousands of follicles or fluid-filled sacs inside each ovary, and each follicle contains an immature egg.
As the follicles themselves grow, they secrete more and more estrogen. That’s how you arrive at the high estrogen levels that trigger your brain to release LH to help the biggest follicle ovulate.
You can not ovulate without what’s called an LH surge, termed such because LH spikes sharply 12-24 hours before ovulation but is low at other times in a normal cycle.
The trick to using this information about LH to your advantage in timing intercourse for conception is testing consistently to catch your LH surge. Read more about what this means here.
Having or not having an LH surge has nothing to do with how old you are and everything to do with your estrogen levels and your brain’s pituitary response to your estrogen levels. If you are serious about becoming a mother, regardless of age, it’s a good idea to know if and when you have an LH surge because it means you will be releasing an egg soon.
An easy way to do this without any blood work is via an at-home, urine based test kit like Proov Complete. Complete measures both estrogen and LH.
Learn more about the other hormones that are involved in fertility at any age here.
How does age affect fertility?
It is natural and well-known that women become less fertile as they age. This due to the natural, gradual diminishing of our egg stores within our ovaries in the years approaching menopause. One finding of the quantitative effect of age on chance of pregnancy has been stated in the first paragraph of this article.
What are the chances of getting pregnant as I get older?
At any given age, the “fertile window” or span of days when sperm can reach an egg is about 6 days — regardless of cycle length. This means the chances of conception at any age is roughly 6 divided by the length of your cycle.
For example, there’s about a 1 in 5 (20%) chance of conception in a woman who has a 30-day cycle and is having regular unprotected intercourse. Natural aging brings a natural drop in these chances.
What can I do to increase my chances of pregnancy?
Test your hormones sooner! Having a better understanding of where your fertility hormones stand can help you make a plan or talk to your doctor if you notice any potential imbalances.
Proov Complete measures the key 4 fertility hormones that control your cycle to help you screen for possible barriers to conception:
- FSH (follicle stimulating hormone): Check on your ovarian reserve, i.e. how many eggs you have left on hand
- E1G (estrogen marker) & LH: Identify your full fertile window – up to 6 days!
- PdG (progesterone marker): Close the fertile window and confirm successful ovulation during the implantation window
Better hormone knowledge leads to better fertility choices, no matter your age.