There’s no single symptom that tells you whether you can have children. Infertility is typically identified after a specific timeline: 12 months of regular, unprotected sex without conception if you’re under 35, or 6 months if you’re between 35 and 40. If you’re over 40, doctors generally recommend starting an evaluation right away. But well before you hit those timelines, your body may be giving you clues worth paying attention to.
Signs That May Point to Fertility Problems in Women
Your menstrual cycle is one of the most visible windows into your reproductive health. Irregular periods, meaning cycles that vary widely in length or sometimes skip entirely, can signal that you’re not ovulating consistently. Without regular ovulation, conception becomes much harder. Periods that are unusually heavy or extremely painful may also indicate underlying conditions that affect fertility.
Two of the most common culprits are polycystic ovary syndrome (PCOS) and endometriosis. PCOS disrupts ovulation through a chain reaction: hormonal imbalances lead to excess androgens (male-type hormones), which trigger low-grade inflammation in the ovaries and prevent follicles from maturing properly. Instead of releasing an egg each month, the ovaries develop many small cysts from follicles that never fully developed. The resulting lack of ovulation also means progesterone stays low, which further impairs the uterine lining’s ability to support a pregnancy even if an egg is occasionally released.
Endometriosis, where tissue similar to the uterine lining grows outside the uterus, can cause severe pelvic pain and heavy periods. It can also damage the fallopian tubes or ovaries and create an inflammatory environment that makes conception difficult. If you’ve had pelvic inflammatory disease, a history of sexually transmitted infections, or previous abdominal surgery, these can also affect your fertility by causing scarring or blockages in the reproductive tract.
Signs in Men
Male factors contribute to roughly half of all infertility cases, yet men often assume the issue lies elsewhere. Physical signs to watch for include difficulty with erections, reduced ejaculate volume, pain or swelling in the testicle area, and noticeably decreased facial or body hair. That last one can signal a hormonal or chromosomal issue affecting sperm production.
Many men with fertility problems have no obvious symptoms at all. The only way to know for certain is a semen analysis, which measures sperm count, how well sperm move, and how many have a normal shape. Healthy parameters, according to the World Health Organization, are at least 15 million sperm per milliliter, at least 40% overall motility (meaning they’re moving), and at least 4% normal morphology (meaning they’re shaped correctly). Falling below these thresholds doesn’t guarantee infertility, but it does reduce the odds of natural conception.
How Age Affects Your Chances
Age is the single biggest factor in natural fertility, especially for women. In your 20s and early 30s, you have roughly a 1 in 4 chance of getting pregnant in any given menstrual cycle. By 40, that drops to about 1 in 10. This decline isn’t just about having fewer eggs. The eggs that remain are more likely to have chromosomal abnormalities, which increases the risk of miscarriage and makes successful implantation less likely.
Men’s fertility also declines with age, though more gradually. Sperm quality, including motility and DNA integrity, decreases over time. Studies show the combination of older age with lifestyle factors like smoking and heavy drinking compounds the effect significantly.
Lifestyle Factors That Reduce Fertility
Smoking has a dramatic effect on male fertility. One study found that smokers were about 12 times more likely to have a low sperm count than nonsmokers, and roughly 14.5 times more likely to have abnormal semen parameters overall. Among men diagnosed with the most severe form of infertility (producing no measurable sperm), all subjects in the study consumed both tobacco and alcohol. By contrast, only about 30% of the fertile control group smoked.
For women, smoking accelerates egg loss and can push menopause earlier. Being significantly underweight or overweight disrupts hormone balance in both sexes. Extreme exercise, chronic stress, and exposure to certain workplace chemicals (radiation, solvents, pesticides) are also recognized risk factors. These are worth mentioning to a doctor even before formal testing begins, because they represent things you can potentially change.
What Fertility Testing Looks Like
If you’re concerned, a fertility evaluation typically involves a few key tests. For women, blood work on day 2 or 3 of the menstrual cycle checks hormone levels that reflect how well the ovaries are functioning. One important marker is anti-Müllerian hormone (AMH), which estimates your ovarian reserve, essentially how many eggs you have left. A higher AMH level suggests a larger remaining supply, while a low level means your window may be shorter. It’s worth knowing that AMH tells you about quantity, not quality. It can’t predict whether you’ll get pregnant on its own.
Another common test checks whether the fallopian tubes are open by using imaging with a special dye. Blocked tubes prevent the egg and sperm from meeting, and this is one of the more straightforward structural causes of infertility to identify. Ultrasound imaging can also reveal ovarian cysts, fibroids, or other structural issues in the uterus.
For men, testing usually starts and sometimes ends with a semen analysis. It’s simple, noninvasive, and provides a clear picture of whether sperm count, movement, and shape are within normal ranges. If results are abnormal, hormone testing or imaging of the reproductive tract may follow.
When to Get Evaluated Sooner
You don’t need to wait the full 6 or 12 months if certain red flags are present. Seek evaluation sooner if you have any of the following:
- Irregular or absent periods, which may indicate you’re not ovulating
- Known conditions like PCOS, endometriosis, or a history of pelvic infections
- Previous cancer treatment, including chemotherapy or radiation to the pelvic area
- Two or more miscarriages, which may point to a hormonal, genetic, or structural issue
- Known male factor concerns, such as a history of undescended testicles, testicular injury, or prior surgery in the groin area
- Exposure to reproductive risks through jobs, medications, or substance use
Couples who are closely related by blood, or anyone with a family history of genetic conditions, may also benefit from genetic counseling before or during pregnancy planning. Women over 35 who haven’t conceived after 6 months should begin evaluation rather than continuing to wait, because the decline in egg quality accelerates from this point forward.
What the Results Actually Mean
Getting an infertility diagnosis doesn’t mean you’ll never have children. It means natural conception within the expected timeframe hasn’t happened, and there may be an identifiable reason that can be addressed. In many cases, the cause is treatable: irregular ovulation can be managed with medication, blocked tubes can sometimes be opened surgically, and lifestyle modifications alone can improve sperm quality meaningfully.
In roughly 10 to 15% of cases, no clear cause is found even after thorough testing. This is called unexplained infertility, and while it’s frustrating, it doesn’t mean nothing can be done. It simply means the standard tests haven’t pinpointed the specific barrier. Many people in this category still conceive with assistance or, occasionally, on their own with more time.