Age is often brought up in conversations around female fertility. The number “35” will get thrown around, and while it is a crucial age, it’s also important to understand why 35 has become the benchmark for discussions around fertility (and infertility).  

According to the American College of Obstetricians and Gynecologists, there is a sharp decline in fertility throughout a woman's 30s. 

“For healthy couples in their 20s and early 30s, around 1 in 4 women will get pregnant in any single menstrual cycle,” explains the ACOG. “By age 40, around 1 in 10 will get pregnant per menstrual cycle. A man’s fertility also declines with age, but not as predictably.”

Shahab Minassian, M.D., the Director of Reproductive Endocrinology and Infertility of Main Line Fertility at Reading Hospital, walked us through key questions patients have concerning fertility decline and aging.

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Why is 35 the benchmark age for fertility decline? 

“We know that fertility begins a significant, slow decline starting in the early 30s,” explains Dr. Minassian. “This decline speeds up more in the mid-30s. The age of 35 has been a benchmark for this life event for many years. However, turning 35 is not the switch that turns on the process. It’s gradual.” 

35 is the age at which egg quality and quantity begin to shift. 

“Women are born with a fixed number of eggs,” explains Dr. Minassian. “As women go through their reproductive lifetime, they grow and develop those eggs during their menstrual cycle, eventually leaving them with none at menopause. The eggs that are left in later years do not work as well and have a higher chance of having an abnormal chromosome number when they try to fertilize with sperm. The result is called aneuploidy. When embryos are aneuploid, they are less likely to implant and when they do, will almost always (but not always) result in a miscarriage.” 

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Are there tests that can help calm anxiety if someone is nearing a specific age and wants to understand their fertility health better? 

“There are some tests that could help someone understand their egg reserve,” explains Dr. Minassian. “These include the antimullerian hormone (AMH) level, the cycle day 3 follicle-stimulating hormone (FSH) level, and the antral follicle count (AFC), which is done by ultrasound of the ovaries. They can be useful as a guide, reassuring the person or alerting them to a low reserve.”

While nothing can specifically be done to stop the natural progression of egg reserve, having a clearer understanding of one’s fertility health may clarify what next steps work for you and your future family. 

Dr. Minassian adds: “Other tests are a bit more invasive such as tests to see if the fallopian tubes are open. These include the saline tubal perfusion test (done in the office) or hysterosalpingogram (done in a hospital outpatient radiology unit).” 

What other factors can impact fertility decline? 

“There are various genetic and hormonal factors that can reduce egg numbers in our patients,” shares Dr. Minassian. “Endometriosis, fibroids, pelvic infection, autoimmune diseases, chromosome abnormalities, and abnormal gene mutations are sometimes found to be causes. In some cases, no cause is found, which shows the need for more research into causes and tests that reveal them.” 

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Unexplained fertility causes many patients to struggle with their emotional, physical, and mental health.

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How does Main Line Fertility support patients in this journey? 

Dr. Minassian serves many patients daily who are navigating the emotional rollercoaster of family planning, understanding their fertility, or diagnosing their infertility. 

“We are very sensitive to our patient’s concerns about this problem and evaluate them at their first consultation for risk factors of fertility decline such as low egg reserve,” shares Dr. Minassian. “All potential options for treatment are explored. We understand the concerns and provide as much support as possible, both medical and emotional.” 

​​Vivian Nunez is a writer, content creator, and Happy To Be Here podcast host. Her award-winning Instagram community has created pathways for speaking on traditionally taboo topics, like mental health and grief. You can find Vivian @vivnunez on Instagram/TikTok and her writing on both Medium and her blog,