How to know if you are infertile: a complete and reliable guide

Sterility: a definitive impossibility of conceiving

Sterility is defined as a definitive biological impossibility of conceiving a child [2]. It may be linked to a complete absence of sperm in the man, or to the absence of a uterus or functioning fallopian tubes in the woman. In this case, no medical or surgical treatment can restore reproductive capacity.

Infertility: a delay or difficulty in conceiving

Infertility, on the other hand, refers to a persistent difficulty in conceiving after 12 months of regular unprotected intercourse [3]. Unlike the previous case, infertility may be temporary or partial, and in many cases it can be addressed through medical treatment or through a IVF journey (medically assisted reproduction (MAR)).

After 1 year of trying without contraception, 18% to 24% of heterosexual couples do not achieve a positive pregnancy test. According to current data, 1 in 7 heterosexual couples consults at some point in their lives for a reproductive issue, and 1 in 10 undergoes treatment to address their infertility.

The answer to the question "how do I know if I am infertile" can only be provided by appropriate medical tests. The assessments differ depending on sex.

A consultation is strongly recommended after 12 months of unsuccessful attempts. If the woman is over 35, a consultation is recommended from 6 months of trying. The doctor reviews the following points for both partners: age, gynaecological or andrological history, chronic conditions, lifestyle (smoking, drugs, toxic exposure).

This appointment will help determine the possible cause of previous failures, the tests to be carried out, and the follow-up plan going forward [4] [5]. 

Fertility tests for women

Hormonal tests and cycle monitoring

A first medical assessment involves analysing the hormones responsible for ovulation, such as FSH, LH, oestradiol and progesterone. Blood tests are used to determine whether ovulation is regular and functioning normally. 

Hormonal assays:

• TSH → to assess thyroid function.
• Oestradiol, progesterone, LH, FSH: to detect ovulation or pituitary problems.
• Anti-Müllerian hormone (AMH): an assay oflow anti-Müllerian hormone is a marker of ovarian reserve in follicles. Requested when a decline in ovarian reserve is suspected or before assisted reproduction.

Screening for diseases is also carried out, including HIV, HBV, HCV, syphilis, rubella, toxoplasmosis, chickenpox, chlamydia, etc.

The pelvic ultrasound complements this assessment to observe the ovaries, determine whether there is a possible pcos (polycystic ovary syndrome), follicle development, uterine causes (fibroids, polyps, malformations) or endometriosis.

Studies of the uterus and fallopian tubes

Hysterosalpingography, an X-ray procedure, allows visualisation of the uterine cavity and fallopian tubes. It can detect fibroids, polyps, a septate uterus or tubal obstruction. This examination is carried out at the beginning of the cycle, after menstruation. 

A hysteroscopy or pelvic ultrasound may also reveal uterine abnormalities.

Abdomino-pelvic laparoscopy can diagnose fallopian tube damage and pelvic conditions such as endometriosis.

There are other possible complementary tests: 

• Endometrial biopsy (second half of the cycle) → study of the uterine lining.
• Additional hormonal profile: prolactin (pituitary abnormalities), androgens (suspected PCOS).
• Abdomino-pelvic MRI: more detailed exploration of the internal reproductive organs.
• Karyotype: chromosomal analysis.

Fertility tests for men

The semen analysis is the male fertility test reference. It analyses the concentration, motility and morphology of sperm. 

If the results show any abnormality, further complementary tests may be prescribed: 

• Additional semen analyses: testing for anti-sperm antibodies, abnormalities in composition.
• Ultrasound of the reproductive organs: testes, prostate, vas deferens.
• Hormonal profile: testosterone, FSH, LH… to evaluate spermatogenesis.
• Karyotype and genetic tests: in cases of suspected chromosomal infertility.
• Testicular biopsy: allows direct study of sperm production in the testes.

A serological screen is also carried out to check for the absence of: HIV, HBV, HCV, syphilis.

Fertility tests as a couple

This test is not carried out as a first-line investigation, but may be requested at a later stage. It is performed 6 to 12 hours after sexual intercourse.

It involves collecting the woman's cervical mucus to observe its quality and the presence and motility of sperm.

This test assesses the interaction between cervical mucus and sperm. It can reveal insufficient mucus, a sperm problem, or an immunological abnormality if everything else appears normal.

Possible signs of female infertility

Some signs can raise concerns, even if they are not enough to confirm a diagnosis. Very irregular menstrual cycles or absent periods, chronic pelvic pain, or a history of genital infections may indicate a reproductive function disorder.

Possible signs of male infertility

In men, the absence of visible signs often means diagnosis comes later. However, a reduction in ejaculate volume, erectile dysfunction, or testicular pain can be signals worth monitoring.

Among the most common causes of female infertility are: polycystic ovary syndrome (PCOS), endometriosis, blocked fallopian tubes, uterine fibroids, and age, which reduces ovarian reserve.

The main male-factor causes include low sperm concentration, motility abnormalities, varicoceles, past infections, and environmental factors such as tobacco, alcohol, and certain medical treatments.

There are many possible factors that can explain impaired reproductive capacity. We outline the most common ones below, though this list is not exhaustive [6]. 

Age: the primary factor in declining fertility

It is the most significant cause of infertility.

• Female fertility begins to decline from the age of 30 and drops markedly after 37, due to a reduction in both the number and quality of eggs. The risk of not becoming a mother is 4% at age 20, 14% at 35, 35% at 40, and 80% after 45. 

This trend is reinforced by the postponement of motherhood: in 2024, women were on average 31.1 years old at the time of giving birth.

• In men: the age of fatherhood is also rising (33.8 years on average). The older a man gets, the more the DNA in his sperm undergoes damage, leading to greater difficulty conceiving, more miscarriages, and genetic risks for the baby.
• At the couple level, the effect is cumulative. For example, the risk of miscarriage is multiplied by 6.7 when the man is over 40 and the woman is over 35.

Tobacco, alcohol and drugs: enemies of fertility

Tobacco significantly impairs both male and female fertility. In men, it causes a reduction in sperm count and motility, chromosomal abnormalities, and sometimes erectile dysfunction. In women, it disrupts the hormonal profile, reduces ovarian reserve, and brings forward the menopause by two years. Smoking also increases the risk of ectopic pregnancy, miscarriage, and pregnancy complications. In assisted reproduction (ART), tobacco reduces the effectiveness of treatments, with smokers having half the chance of becoming pregnant and twice the rate of miscarriage.
 

Regular cannabis use causes numerous health problems, particularly at the sperm level, with effects that are more persistent than those of tobacco due to its slow elimination from the body. 

Alcohol reduces fertility in both sexes and lowers the chances of success in ART. It is considered a teratogenic and neurotoxic agent, increasing the risks of malformations and developmental disorders in children, in addition to other potential effects on the body. Experts therefore recommend zero alcohol from the moment pregnancy is desired, for both partners.

Pollutants and endocrine disruptors

Many environmental pollutants (pesticides, plastics, cosmetics, household products) contain endocrine disruptors. These substances disrupt hormone production and affect every stage of reproduction: gametes, fertilisation, embryogenesis, and newborn health.

The importance of diet

Obesity and being significantly underweight are well-known factors in reproductive disorders. A sedentary lifestyle also plays a role. 
 

Diet should not be overlooked either. Consuming ultra-processed foods and foods high in pesticides can also disrupt reproductive capacity. 

Furthermore, vitamin and mineral deficiencies, in both sexes, have an impact on the chances of conception. Diet and fertility are inseparable. According to the data, inadequate nutrition is a factor in infertility in 46% of cases (far more than other factors such as body weight or physical activity) [7].

Zinc and selenium are two key nutrients in particular, whether for the healthy development of gametes, ovulation in women, and more. They are especially relevant when wondering how to improve egg quality or sperm-related. Women are often advised to take a pregnancy food supplement multivitamins from the conception period onwards, to ensure their nutritional needs are met. 

Specialists to see

When partners have been unable to achieve a pregnancy after a year of trying, it is recommended to see a gynaecologist or urologist specialising in fertility. These professionals will direct you towards the appropriate tests.

Fertility centres and clinics

Specialist ART centres offer solutions such as artificial insemination, in vitro fertilisation (IVF) and ICSI (intracytoplasmic sperm injection). These establishments provide essential medical and psychological support.

Wondering how to know if you are infertile is a difficult but necessary step for many couples. The distinction between sterility and infertility is essential, as is carrying out appropriate medical tests to reach a reliable conclusion. Thanks to advances in medicine and assisted reproductive technology (ART), many solutions now exist to help couples achieve their dream of having a child. Seeking an appointment early and surrounding yourself with specialists remains the best approach to moving forward with confidence.