The terms sterility and infertility tend to be used interchangeably. However, although they are closely related, there are some differences in their meaning. Dr Ernesto Bosch, Medical Director at IVI Valencia, cleared up the difference for us.

When talking about couples:

• Sterility is when a couple, the woman being younger than 35, has been trying to get pregnant for one year by having regular, unprotected sexual relations without success. If the woman is older than 35 then the couple is considered sterile after six months. The cause may be either the woman or the man.
• Infertility is when a couple manages to get pregnant but these pregnancies are not successful and culminate in recurring miscarriages.

With women, we talk about:

• Female Sterility  is when pregnancies fail due to a problem with the female reproductive system. This could be a condition affecting the fallopian tubes, uterus or the functioning of the ovaries. Potential causes are endometriosis, polycystic ovary syndrome or the advanced age of the woman.

• Female Infertility is when a woman has several miscarriages and is unable to give birth to a healthy child. The causes may be chromosomal (karyotype abnormalities), uterine, blood (thrombophilia) or embryonic, due to chromosomal abnormalities in the embryo. The latter is more common in older women.

Learn more about female fertility

In the case of men:

• Male Sterility is when problems with the semen prevent pregnancy from occurring. There are different causes for this. The man may have a genital tract condition that prevents the semen from reaching the back of the vagina during coitus or he may suffer from erectile dysfunction. He may also have poor quality or insufficient semen. Technological advances mean that IVI can fertilise eggs with extremely small amounts of semen.
• Male Infertility: The only cause of infertility in men is structural chromosomal abnormality, which can be diagnosed by karotyping.

Learn more about male fertility.

If you would like more information about these terms and the treatments see our Infertility FAQs section.