About 1 in 7 US couples experiences infertility, and the female partner contributes to roughly half of cases — either as a primary factor or alongside male factor issues. Female infertility is generally defined as the inability to conceive after 12 months of regular unprotected intercourse, or 6 months for women age 35 and older. Earlier evaluation makes a meaningful difference because some causes are time-sensitive and treatment success rates decline with age. Infertility is common, it is rarely anyone’s fault, and it is often treatable — the first step is understanding what may be going on.
What Female Infertility Is and How Common It Is
Infertility affects an estimated 6.7 million US women aged 15 to 49 according to the CDC, with the overall prevalence of impaired fecundity (difficulty conceiving or carrying a pregnancy to term) around 13 percent. Estimates vary by data source and definition, but a widely cited breakdown is that female factors contribute to roughly 50 percent of infertility cases, male factors to about 30 percent, combined factors to 20 percent, and unexplained infertility to about 10 to 15 percent. These categories overlap, and more than one factor is present in many couples.
The American Society for Reproductive Medicine (ASRM) recommends evaluation after 12 months of unprotected intercourse for women under 35, after 6 months for women 35 to 39, and without delay for women 40 and older or for those with known risk factors such as irregular cycles, prior pelvic surgery, endometriosis, or chemotherapy exposure. The clock matters because both egg quantity and egg quality decline with age, so waiting can narrow the options. For broader context, see our medical conditions hub.
It is worth saying plainly: struggling to conceive can be emotionally heavy, and many people carry guilt or shame that the medical facts do not support. Infertility is a medical condition, not a personal failing, and evaluation is a practical step toward answers rather than a judgment.
Common Causes
Ovulatory dysfunction accounts for about 25 percent of female infertility. Polycystic ovary syndrome (PCOS) is the most common cause of anovulation, followed by hypothalamic dysfunction (sometimes from very low body weight or intense exercise), hyperprolactinemia, thyroid disorders, and primary ovarian insufficiency. Symptoms often include irregular or absent periods — see our amenorrhea guide for details on the underlying conditions.
Tubal and pelvic factors account for another 30 to 35 percent. Causes include prior pelvic inflammatory disease (often from chlamydia or gonorrhea), tubal damage from endometriosis or surgery, hydrosalpinx (a fluid-filled blocked tube), and pelvic adhesions. Uterine fibroids distorting the cavity, adenomyosis, endometrial polyps, intrauterine adhesions (Asherman syndrome), and Mullerian (uterine shape) anomalies can impair implantation.
Diminished ovarian reserve becomes increasingly relevant with age. Female fertility peaks in the early to mid 20s, declines gradually until about age 32, and falls more steeply after 35 and dramatically after 40, per ASRM data. Endometriosis is found in a substantial share of women evaluated for infertility. Other contributors include lifestyle factors (smoking, obesity, low body weight, heavy alcohol use), environmental exposures, autoimmune conditions, and certain medications. According to the American College of Obstetricians and Gynecologists, multiple causes frequently coexist in the same couple.
Causes at a Glance
| Category | Common examples | Frequent clues |
|---|---|---|
| Ovulatory disorders | PCOS, thyroid disease, high prolactin, primary ovarian insufficiency | Irregular or absent periods |
| Tubal / pelvic | Prior infection, hydrosalpinx, adhesions | History of PID or pelvic surgery |
| Uterine | Fibroids, polyps, adenomyosis, uterine-shape anomalies | Heavy or painful periods, recurrent loss |
| Age / ovarian reserve | Declining egg quantity and quality | Age over 35, low AMH |
| Endometriosis | Endometrial-like tissue outside the uterus | Painful periods, pelvic pain |
| Unexplained | No cause found on standard testing | Normal workup in both partners |
This table is a general overview, not a diagnosis; the same symptom can point to several conditions, and only an evaluation can sort them out.
Symptoms
Infertility itself is the symptom — inability to conceive after the appropriate trial. However, related findings often point toward underlying causes. Irregular or absent periods suggest ovulatory dysfunction. Severe menstrual pain or heavy bleeding raises concern for endometriosis, adenomyosis, or fibroids. Hirsutism, acne, and weight gain suggest polycystic ovary syndrome. Galactorrhea (milky nipple discharge) points toward hyperprolactinemia. Hot flashes and irregular cycles in younger women raise concern for primary ovarian insufficiency. Many women with infertility, however, have no outward symptoms at all, which is why testing is important rather than relying on how you feel.
The Male Partner Matters Too
Because a male factor is involved in roughly half of couples — as the primary issue or alongside a female factor — a semen analysis is a standard, early part of the workup and should not be skipped or delayed. Evaluating both partners at the same time is faster and fairer than testing the woman first and the man only if nothing is found. It also avoids putting the full weight of the process on one person. If you have a partner, ask that both of you be evaluated together from the start.
How Female Infertility Is Evaluated
The basic evaluation is structured around three questions: Is ovulation occurring? Are the fallopian tubes patent (open)? Is the uterine cavity normal? Male partner evaluation occurs in parallel since male factor is common.
Ovulation assessment includes menstrual history, mid-luteal progesterone (drawn about 7 days before expected menses), and sometimes basal body temperature charts or ovulation predictor kits — see our context on cycle tracking for related discussion. Ovarian reserve testing includes anti-Mullerian hormone (AMH), antral follicle count by transvaginal ultrasound, and day 3 FSH and estradiol. AMH has become the most useful single marker, though it estimates the size of the egg pool rather than guaranteeing whether or when pregnancy will happen.
Tubal patency is typically evaluated with hysterosalpingography (HSG), an X-ray dye test that also gives information about the uterine cavity. Saline infusion sonohysterography or hysteroscopy provides more detailed cavity evaluation. Transvaginal ultrasound assesses ovarian morphology, fibroids, ovarian cysts, and uterine structure. Additional testing may include TSH, prolactin, androgens (when polycystic ovary syndrome is suspected), and, in selected situations, karyotype and screening for genetic conditions such as the fragile X premutation, per ASRM guidance. Which tests are appropriate depends on your history, so the plan is individualized.
Treatment Options
Treatment depends on the cause, your age, ovarian reserve, and how long you have been trying, and every option below is prescriber-directed rather than something to start on your own. Ovulation induction with letrozole (now first-line for polycystic ovary syndrome per the international evidence-based PCOS guideline) or clomiphene restores ovulation in most anovulatory women. These are prescription medications that require monitoring; metformin is sometimes added for women with insulin resistance, and weight optimization can improve outcomes substantially in those with an elevated BMI. Dosing and cycle monitoring are decided and supervised by your clinician.
Intrauterine insemination (IUI) is often combined with ovulation induction for unexplained infertility, mild male factor, or cervical factor infertility. Per-cycle pregnancy rates are typically in the range of 10 to 20 percent depending on age and underlying cause. In vitro fertilization (IVF) is considered for tubal factor infertility, severe male factor, advanced maternal age, diminished ovarian reserve, endometriosis, and after failed ovulation induction or IUI cycles. The CDC’s National ART Surveillance System reports live birth rates per cycle that vary considerably by age — very roughly 35 to 45 percent under age 35, 25 to 30 percent at 35 to 37, 18 to 22 percent at 38 to 40, and under 10 percent over 42 using a woman’s own eggs. These are population averages; your own odds depend on many personal factors, so ask your clinic for figures specific to your situation and verify current statistics, which are updated regularly.
Surgery — laparoscopic excision of endometriosis, hysteroscopic removal of polyps or submucosal fibroids, lysis of adhesions, or tubal repair — improves fertility in selected cases. Donor eggs, donor sperm, gestational carriers, and adoption are options when other approaches are not successful or appropriate. Correcting hormonal problems (thyroid disease, hyperprolactinemia, congenital adrenal hyperplasia) often restores fertility before assisted reproductive technology becomes necessary. A reproductive endocrinologist can help you weigh the benefits, risks, costs, and time involved in each path and match a plan to your goals.
Lifestyle, Fertility Preservation, and Preconception Care
Everyday factors matter. Stopping smoking, reaching a healthier weight, limiting alcohol, moderating caffeine, and treating conditions like thyroid disease can meaningfully support fertility, and in women with PCOS even modest weight loss often restores ovulation. None of this guarantees pregnancy, and it is not a substitute for evaluation, but it is generally worth doing.
Couples planning a future pregnancy who have known risk factors — endometriosis, polycystic ovary syndrome, or previous cancer treatment — benefit from a preconception consultation rather than waiting. Egg or embryo freezing is an option for people who want to preserve fertility before age-related decline accelerates, including before certain medical treatments; a specialist can explain realistic expectations and costs.
When to See a Doctor
Schedule an evaluation after 12 months of unprotected intercourse without conception in women under 35, after 6 months in women 35 to 39, and without delay at age 40 and older. Earlier evaluation is appropriate for irregular or absent menses, known endometriosis, prior pelvic surgery or pelvic inflammatory disease, prior chemotherapy or radiation, family history of early menopause, or recurrent pregnancy loss. There is no downside to asking sooner if you are worried — an evaluation can be reassuring even when nothing is wrong.
When to seek emergency care: Call 911 or go to the nearest emergency room if you experience sudden severe pelvic or abdominal pain, especially if combined with a positive pregnancy test (possible ectopic pregnancy, which is a life-threatening emergency); heavy vaginal bleeding causing dizziness or fainting; high fever with pelvic pain; or, during fertility treatment, severe abdominal distension, rapid weight gain, and shortness of breath (possible ovarian hyperstimulation syndrome).
Frequently Asked Questions
How does age affect female fertility?
Female fertility declines gradually until about age 32, more steeply after 35, and substantially after 40. Egg quantity and quality both decrease, miscarriage rates rise, and time to conception lengthens. ASRM data show that the monthly chance of conception falls from roughly 20 percent at age 30 to under 5 percent at age 40, though individual results vary.
What is AMH and what does it tell me?
Anti-Mullerian hormone is produced by small follicles in the ovary and reflects the size of the remaining egg pool — ovarian reserve. Low AMH suggests diminished ovarian reserve. AMH does not predict natural fertility well in young women but is useful for predicting response to fertility treatment and for timing decisions. It is one piece of a larger picture, not a verdict.
Can lifestyle changes help with fertility?
Yes, they can help. Smoking cessation, achieving a healthy weight, limiting alcohol, regular moderate exercise, and treating underlying conditions like thyroid disease can meaningfully improve fertility. In women with polycystic ovary syndrome, even modest weight loss often restores ovulation. Lifestyle changes complement medical care rather than replace it.
Does endometriosis always cause infertility?
No, but it is associated with it. A substantial share of women with endometriosis have difficulty conceiving, and disease severity correlates loosely with infertility risk. Many women with endometriosis conceive without intervention; others benefit from surgical excision, ovulation induction, or IVF. A specialist can advise on the best approach for your situation.
Should my partner be tested too?
Yes. Because a male factor is common, a semen analysis should be part of the initial workup and done alongside the woman’s evaluation, not afterward. Testing both partners together is faster and gives a more complete picture.
Sources
- American College of Obstetricians and Gynecologists (ACOG) — Evaluating Infertility (definition, evaluation timing, causes, workup)
- American Society for Reproductive Medicine (ASRM) — Practice Committee documents (evaluation, ovarian reserve, age-related decline)
- Centers for Disease Control and Prevention (CDC) — Infertility statistics and Assisted Reproductive Technology (ART) surveillance
- MedlinePlus — Female infertility and assisted reproductive technology overviews
- International evidence-based guideline for the assessment and management of PCOS (letrozole as first-line ovulation induction)
The bottom line: Female infertility has many causes — ovulation disorders such as PCOS, tubal and pelvic disease, endometriosis, uterine problems, age-related decline, and unexplained cases — and most are diagnosable through a structured workup and treatable with a graduated set of options from ovulation medications to IUI and IVF. Because a male factor is common, both partners should be evaluated together. Age is the single strongest predictor of treatment success, which is why earlier evaluation is recommended as a woman gets older. Treatment decisions, including any medications, are individualized and made with a reproductive specialist; do not start medications on your own. This article is educational and is not a substitute for personalized care from a qualified clinician, and statistics and guidelines change, so verify current figures with your provider.