While many factors can play a role in female infertility, experts agree that the most common causes fall into a few key categories: ovulation disorders, diminished ovarian reserve, structural conditions such as endometriosis or blocked Fallopian tubes, and uterine or cervical issues.
1. Ovulation Disorders
According to the American Society for Reproductive Medicine (ASRM), ovulation disorders are among the top causes of female infertility, accounting for approximately 25–40% of cases. When ovulation is irregular or absent, the odds of conception drop significantly.
Polycystic Ovary Syndrome (PCOS): PCOS affects 7–15% of reproductive-aged women. Hormonal imbalances disrupt ovulation, leading to irregular menstrual cycles and difficulty conceiving. The good news is that PCOS is one of the most treatable causes of infertility. Treatments often include ovulation-inducing medications such as letrozole or clomiphene citrate. For some women, intrauterine insemination (IUI) or in vitro fertilization (IVF) can further increase the chances of conception.
Primary Ovarian Insufficiency (POI): Also known as premature ovarian failure, POI occurs when ovarian function declines before age 40. Women may experience irregular or absent periods, reduced estrogen levels, and infertility. With diminished ovarian function, the likelihood of pregnancy depends on residual ovarian reserve and how well the remaining follicles respond to stimulation. In many cases, donor-egg IVF offers the highest chance of a successful pregnancy.
Hypothalamic Dysfunction or Hyperprolactinemia: Hypothalamic dysfunction occurs when the hypothalamus, the brain region that regulates reproductive hormones, fails to function properly. Hyperprolactinemia results from elevated prolactin hormone levels in the blood. Though less common, both conditions can interfere with ovulation and require medical treatment to restore hormonal balance.
2. Endometriosis
Endometriosis affects about 10% of women of reproductive age in the U.S. In this condition, tissue similar to the uterine lining grows outside the uterus, causing inflammation, scarring, and sometimes distortion of pelvic anatomy. These changes can interfere with the ability to conceive.
Fertility treatments such as laparoscopic surgery to remove endometrial implants or IVF can help women with endometriosis achieve pregnancy. The choice of treatment depends on disease severity, age, and overall reproductive goals.
3. Fallopian Tube Damage or Blockage
Damage or blockage in the fallopian tubes contributes to about 25–30% of female infertility cases. This may occur due to pelvic infections (including untreated chlamydia or gonorrhea), prior abdominal or pelvic surgeries, or severe endometriosis.
Treatment options depend on the extent and location of the blockage. For mild or partial blockage, laparoscopic surgery may be performed to remove scar tissue or repair the tubes, potentially restoring natural fertility. For more severe cases, especially when caused by infection or prior surgery in vitro fertilization (IVF) is typically the most effective approach, as it bypasses the fallopian tubes entirely.
4. Uterine or Cervical Factors
Problems with the uterus, such as fibroids, polyps, adhesions, or congenital anomalies, as well as cervical issues like inadequate cervical mucus, can interfere with sperm transport or embryo implantation.
Hysteroscopic surgery is often performed to remove growths or correct structural abnormalities within the uterine cavity, improving implantation and pregnancy outcomes. For cervical factors such as poor-quality cervical mucus or scarring from previous procedures intrauterine insemination (IUI) can be used to bypass the cervix entirely by placing washed sperm directly into the uterus. In some cases, medications that improve cervical mucus quality or reduce inflammation may also be recommended.
5. Unexplained Infertility
Up to 10–20% of couples experience infertility with no clear cause after a complete evaluation. Even without a definitive diagnosis, fertility treatments often significantly improve the chances of conception.
Treatment usually begins with ovulation induction medications combined with IUI to increase the number of eggs and optimize the timing of fertilization. If pregnancy does not occur after several IUI cycles, IVF is the next step. IVF not only increases success rates but also provides diagnostic insights, as embryos can be observed in the lab to identify potential fertilization or implantation issues that may not have been previously detected.
Lifestyle factors also play an important role. Maintaining a healthy weight, managing stress, and timing intercourse during ovulation can all support fertility treatment success.
Austin-based fertility specialist Dr. Shahryar Kavoussi explains, “Many women who experience infertility have a meaningful chance of conceiving, especially when given personalized treatments and appropriate fertility support.”
Dr. Kavoussi recommends that women over age 35 who have been trying to conceive for six months without success consult a fertility specialist for evaluation. For couples, seeking care from both a female and male fertility specialist provides a comprehensive approach that addresses all possible contributing factors and helps determine the most effective treatment path forward.”
