Why Can’t I Get Pregnant? A Compassionate Guide to the Possible Reasons

First, Some Reassurance

Healthy couples under 35 with no known issues have roughly a 20–25% chance of conceiving in any given cycle. That means even when everything is working perfectly, the odds say it takes time. Most fertility specialists won’t begin a workup until you’ve been trying for 12 months if you’re under 35, or 6 months if you’re 35 or older.

That said, there are situations where waiting isn’t the right call. If you have very irregular or absent periods, a known medical condition like endometriosis or PMOS (formerly PCOS), a history of pelvic infections, or if your partner has known sperm issues, it’s completely reasonable to seek help sooner.

The Most Common Reasons: Female Factors

Ovulation Disorders

Ovulation problems account for approximately 25–30% of female infertility cases. If you aren’t releasing an egg regularly, conception can’t happen—no matter how well-timed everything else is. The most common ovulation disorder is PMOS (Polyendocrine Metabolic Ovarian Syndrome, formerly known as PCOS), which affects roughly 1 in 8 women of reproductive age.

Signs that you might not be ovulating regularly include cycles shorter than 21 days or longer than 35 days, absent periods, very light or very heavy bleeding, and a lack of the telltale cervical mucus changes that signal an approaching egg release.

The good news: ovulation disorders respond well to treatment. Medications like Clomid (clomiphene citrate) and letrozole help roughly 80% of women with ovulatory issues begin ovulating within three months.

Fallopian Tube Damage or Blockage

Your fallopian tubes are where sperm meets egg. If they’re blocked or damaged—from a previous infection, endometriosis, or prior surgery—the egg and sperm simply can’t connect. Tubal factor infertility accounts for about 20–25% of cases. An HSG test (hysterosalpingogram) is the standard way to check, and it can be done in your doctor’s office in under 30 minutes.

Endometriosis

Endometriosis affects roughly 1 in 10 women of reproductive age, and up to 30–50% of women with endometriosis experience difficulty conceiving. The condition causes tissue similar to the uterine lining to grow outside the uterus, leading to inflammation, scarring, and sometimes fallopian tube damage. Even mild endometriosis can affect egg quality and embryo implantation.

Uterine Issues

Fibroids (noncancerous growths in the uterine wall), polyps, an unusually shaped uterus, or scar tissue inside the uterine cavity can all interfere with embryo implantation. These are often discovered during an ultrasound or saline sonogram.

Age-Related Decline

Women are born with all the eggs they will ever have—roughly 1 to 2 million at birth, declining to about 300,000 by puberty. Both the number and quality of eggs decrease over time, with a more noticeable decline after age 35 and a steeper drop after 40. This is not a cliff—it’s a gradient—and many women conceive naturally into their late 30s and early 40s. But it does mean that time matters, and that’s worth knowing early rather than late.

The Other Half: Male Factors

Male factor infertility is involved in 40–50% of all cases, yet it’s dramatically under-discussed. A simple semen analysis—checking sperm count, motility (movement), and morphology (shape)—is one of the first tests that should happen in any fertility workup.

Common male factor issues include low sperm count, poor motility, abnormal morphology, varicocele (enlarged veins in the scrotum that raise testicular temperature), hormonal imbalances, and blockages in the reproductive tract. Lifestyle factors like excessive heat exposure, heavy alcohol use, smoking, and certain medications can also suppress sperm production.

The Frustrating Middle: Unexplained Infertility

Up to 15–30% of couples receive a diagnosis of “unexplained infertility”—meaning every standard test comes back normal, but pregnancy still isn’t happening. This is not a dead end. It often means something is happening at a level that current testing can’t detect: subtle egg quality issues, minor implantation barriers, or subclinical endometriosis.

Lifestyle and Environmental Factors

While lifestyle factors rarely cause infertility on their own, they can significantly compound other issues or delay conception:

Weight: Both being significantly underweight and overweight can disrupt ovulation. Body fat plays a role in estrogen production, and extremes in either direction can interfere with the hormonal cascade needed for regular cycles.

Stress: Chronic stress doesn’t “cause” infertility in the way that blocked tubes do, but elevated cortisol levels can suppress GnRH (the hormone that kicks off the whole ovulation chain), delay ovulation, and shorten the luteal phase.

Thyroid: Subclinical hypothyroidism affects 4–8% of women and can interfere with ovulation, implantation, and early pregnancy maintenance. A simple TSH blood test can catch this, and treatment with thyroid medication is straightforward.

Environmental exposures: Endocrine-disrupting chemicals in plastics (BPA, phthalates), pesticides, and certain personal care products have been linked to reduced fertility in both men and women. The evidence is growing, though individual exposure is hard to quantify.

What to Do Next

If you’ve been trying for the recommended timeframe (12 months under 35, 6 months at 35+, or sooner if you have known risk factors), the next step is a basic fertility workup. This typically includes:

These five tests will answer most of the big questions. From there, your doctor can recommend a path—whether that’s lifestyle changes, medication like Clomid or letrozole, IUI, IVF, or something else entirely.

Frequently Asked Questions