Home / Fertility impact How conditions affect fertility Hub guide: perimenopause, PCOS, thyroid, GLP-1, HRT and their effects on fertility windows. Editorial team reviewed.
ℹ Medical disclaimer: Content is educational. Not medical advice. Always discuss your specific situation with a qualified clinician.Perimenopause Ovarian reserve declines rapidly. Cycles irregular, ovulation unpredictable. Natural conception possible but much less likely.
Window: Variable — typically 5-10 years before menopause. Fertility usually ends 1-3 years before final period.
What to do Test AMH + FSH if pregnancy desired Consult a reproductive endocrinologist if under 40 Consider IVF c donor eggs if natural cycles fail What to avoid Assuming birth control still needed without provider input Delaying fertility evaluation past 6 months of trying Related: AMH lab reference · Modern Fertility brand
PCOS Anovulation common — eggs not released regularly. Most PCOS-related infertility is treatable with medication (letrozole, clomid) or IVF.
Window: No accelerated decline. Standard age-related fertility curve applies. Many PCOS patients conceive with support.
What to do Phenotype workup (Rotterdam criteria) Insulin resistance management (metformin/lifestyle) Letrozole ovulation induction if trying What to avoid Assuming PCOS = infertility (treatable) Untreated insulin resistance during pregnancy attempts Related: PCOS phenotype quiz · Allara brand
Thyroid disorders Both hypo + hyperthyroidism reduce fertility. Untreated hypothyroidism affects ovulation, pregnancy maintenance, and miscarriage risk.
Window: Once treated to normal levels, fertility returns to baseline (age-adjusted).
What to do Test TSH, free T4, TPO antibodies before trying Treat to TSH < 2.5 if planning pregnancy Recheck thyroid 6-8 weeks after dose adjustment What to avoid Untreated hypothyroid during pregnancy attempts Self-adjusting thyroid medication during fertility treatment Related: TSH lab reference
GLP-1 therapy Can affect contraceptive absorption (oral). Pregnancy contraindicated on GLP-1 — must stop 2 months before conception. May restore ovulation in PCOS via weight loss.
Window: Once stopped, fertility unaffected long-term.
What to do Backup contraception if on oral birth control + GLP-1 Stop GLP-1 2 months before planned conception Discuss with both prescriber + reproductive specialist What to avoid Conceiving on GLP-1 — fetal safety not established Continuing GLP-1 if pregnancy possible Related: GLP-1 + pregnancy
HRT (general) HRT is not contraceptive. Pregnancy is possible on HRT (especially peri). HRT dosing differs from contraceptive dosing.
Window: Started typically when fertility already declining — but not reliable contraception.
What to do Use barrier contraception OR IUD if pregnancy not desired Pregnancy test if cycles unpredictable Discuss transition to contraceptive-dose hormones if in peri What to avoid Assuming HRT prevents pregnancy Stopping contraception too early in perimenopause Related: Can I get pregnant on HRT?