Updated by the Progyny Clinical Team — September 2025.
When people talk about age and fertility, most of the focus is on eggs. As you get older, egg quality declines, which makes it harder to conceive and raises the risk of miscarriage. But researchers are also studying how the uterus itself may change over time — a process sometimes called uterine aging.
What is uterine aging?
Uterine aging refers to natural changes in the muscles, blood vessels, and lining of the uterus that occur with age. These changes may affect:
- How the uterus contracts during labor
- How well it supports a pregnancy
- How the lining responds to an embryo during implantation
Some studies suggest that with age, the lining of the uterus (endometrium) can become thinner and less receptive, and inflammation inside the uterus may increase. These changes do not make pregnancy impossible, but they may lower the chances of implantation or increase the risk of complications.
Egg quality vs. uterine health
Egg quality remains the main factor in age-related fertility decline. Chromosomal changes in eggs are well documented and account for most of the reduced success rates seen with advanced age.
Even so, research has found that pregnancy rates are sometimes lower in older people using healthy donor eggs, suggesting the uterus may also play a role. Some studies show that the uterine lining becomes less effective at supporting implantation over time, while others find no difference once embryo quality is controlled for.
This ongoing debate highlights how complex fertility can be. While eggs are the biggest factor, uterine health may matter too.
Other age-related health factors
Age also brings more opportunities for other health conditions to develop. These may affect fertility and pregnancy outcomes, including:
- Fibroids, adenomyosis, or endometriosis
- Uterine scar tissue from prior surgeries
- Diabetes and insulin resistance
- High blood pressure or cardiovascular disease
- Autoimmune conditions
These issues can contribute to lower live birth rates or higher risks during pregnancy.
Risks of pregnancy at advanced age
Pregnancies later in life, especially after age 45, are more likely to involve:
- Gestational diabetes
- High blood pressure or preeclampsia
- Placental complications
- Preterm birth
- Cesarean delivery
Babies born to older parents may also need more specialized care after delivery, such as time in a neonatal intensive care unit.
Can uterine aging be treated?
Scientists are exploring potential ways to slow or reverse uterine aging, such as medications that reduce inflammation or oxidative stress, and stem cell therapies. These treatments are still experimental and not part of routine fertility care.
For now, the best step you can take is to optimize your overall health before trying to conceive. Talk with your doctor about your medical history, fertility goals, and whether a uterine evaluation may help guide your care.
Key takeaway
Egg quality is the biggest factor in fertility as you age, but the uterus may also change in ways that affect pregnancy. By working closely with your care team and addressing both egg and uterine health, you can make informed decisions about family building and improve your chances of a healthy pregnancy.
If you have questions or concerns, Progyny is here for you. Please contact your Progyny Care Advocate for support.
Disclaimer: The information provided by Progyny is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider for medical guidance.