Fertility After 40: Realistic Options and What to Expect

Why does fertility decline with age?

The number of eggs a person is born with is fixed — it does not replenish. Over time, both the quantity and quality of eggs decline. The quality decline is particularly important: older eggs are more likely to have chromosomal errors (aneuploidy), which causes embryos not to implant or to miscarry early. This is why the rate of miscarriage rises with age even when pregnancy does occur.

Egg quality also means that the cells' energy-producing structures (mitochondria) function less efficiently, which affects fertilization and early embryo development. These changes are in the eggs themselves — the uterus ages much more gradually and can usually carry a pregnancy into the mid-40s and sometimes beyond, which is why donor egg IVF remains highly effective in older recipients.

What does a fertility evaluation show at 40?

An ovarian reserve evaluation will typically include:

• Anti-Müllerian hormone (AMH) — a blood test reflecting the pool of remaining follicles; can be done on any cycle day
• Antral follicle count (AFC) — a vaginal ultrasound on or around day 2–3 of the cycle to count small follicles visible in the ovaries
• Day 3 FSH and estradiol — elevated FSH suggests the pituitary is working harder to stimulate the ovaries, which can be a sign of declining reserve

These tests tell you about quantity (how many eggs are likely available). They do not directly measure egg quality, though quality and quantity tend to track together with age. A comprehensive evaluation also checks the uterus and fallopian tubes and includes a semen analysis if there is a male partner 1Ref 1Practice Committee of the American Society for Reproductive Medicine (2021).Fertility evaluation of infertile women: a committee opinion.Recommendation for expedited evaluation (after 6 months at age 35–40, and promptly after 40) and the components of the fertility workup including ovarian reserve assessment.

Results need to be interpreted in clinical context — one abnormal number does not close all options, and your reproductive endocrinologist will explain what the results mean for your specific situation.

What are the options after 40?

Trying naturally or with timed intercourse monitoring: For people in their early 40s with regular ovulation and adequate ovarian reserve, a period of monitored natural attempts may be reasonable — especially if there is no known fertility problem other than age. The concern is that time matters: each month at 40 represents a meaningful fraction of remaining fertile time, so extended unassisted attempts without evaluation are generally not recommended.

IUI (intrauterine insemination): IUI with ovarian stimulation may be considered if ovulation is the only issue, there are open tubes, and the male partner's sperm is adequate. However, IUI success rates decline with age, and many specialists move to IVF more quickly after 40 to avoid prolonged, lower-yield treatment.

IVF with your own eggs: IVF involves stimulating the ovaries to produce multiple eggs, fertilizing them in the lab, and transferring an embryo. Success rates with a person's own eggs at 40 are lower than at 35, and they fall further in the mid-40s. The CDC/SART national ART data show that live birth rates per intended egg retrieval were approximately 19% for patients aged 38–40 and only 3.2% for those over 42 3Ref 3Centers for Disease Control and Prevention (2024).ART Surveillance — National ART Surveillance System (NASS): 2022 national summary.Live birth rates per intended egg retrieval by age: 43.1% (<35 years), 19% (38–40 years), 3.2% (>42 years) — from 2022 national ART data. Chromosomal testing of embryos (PGT-A) can identify which embryos are euploid, improving the per-transfer success rate — but if there are few eggs to begin with, there may be few tested embryos to choose from.

IVF with donor eggs: For people in their mid-40s, or those with very diminished ovarian reserve at any point in their 40s, donor egg IVF is often the most effective path. Because the eggs come from a younger screened donor, the per-transfer success rate reflects the donor's age and egg quality rather than the recipient's. The recipient carries the pregnancy and is biologically connected to the child through the gestational experience — the child will carry the donor's genetics 2Ref 2Practice Committee of the American Society for Reproductive Medicine (2021).Evidence-based outcomes after oocyte cryopreservation for donor oocyte in vitro fertilization and planned oocyte cryopreservation: a guideline.Donor oocyte IVF as an effective option for patients with diminished ovarian reserve or advanced reproductive age; outcomes reflect donor age rather than recipient age.

This is a significant personal decision that deserves careful reflection and, often, counseling from a therapist experienced in third-party reproduction.

How quickly should I act?

The general guidance is to seek evaluation without extensive delay after 40, rather than waiting the 12-month threshold that applies to younger patients. Many specialists recommend evaluation after 6 months of trying at 35 and even sooner if you are approaching or past 40 1Ref 1Practice Committee of the American Society for Reproductive Medicine (2021).Fertility evaluation of infertile women: a committee opinion.Recommendation for expedited evaluation (after 6 months at age 35–40, and promptly after 40) and the components of the fertility workup including ovarian reserve assessment.

If your ovarian reserve testing reveals a very low AMH or AFC, your clinician may recommend moving to IVF relatively quickly, or discussing donor eggs, because waiting further reduces the already smaller pool of available eggs. The window of opportunity is real — acting thoughtfully and promptly gives you more information and more options.

What about the pregnancy itself?

Pregnancies after 40 are associated with higher rates of gestational diabetes, hypertension, placenta previa, and cesarean delivery. This does not mean a pregnancy at 40 or 45 cannot be healthy — many are — but it does mean closer monitoring. A high-risk obstetrician (maternal-fetal medicine specialist) is often involved in the care team.

The risk of chromosomal conditions (including Down syndrome) rises with maternal age. Prenatal testing — cell-free DNA testing from a blood draw, chorionic villus sampling (CVS), or amniocentesis — can evaluate for these conditions early in pregnancy and support informed decision-making.