infertile
Meaning of infertile: The word describes a couple as often as a person, since the cause lies with either partner or with both about equally often.
Definition of infertile
Infertile describes an inability to achieve pregnancy after a defined period of regular intercourse without contraception. It is applied to one partner or to a couple together, because the cause may lie with either or with a combination of factors in both. It is not the same as sterile, which means a complete and permanent inability to conceive.
What causes it?
Conception requires an egg released, a clear path for it, healthy sperm in sufficient number, fertilization, and a uterus able to accept an embryo. A fault at any of those points produces the same outcome, which is why both partners are assessed together rather than in sequence.
| Where the problem lies | Common examples |
|---|---|
| Ovulation | Polycystic ovary syndrome, thyroid disorders, high prolactin, very low body weight |
| Tubes and pelvis | Scarring after infection, endometriosis, previous surgery |
| Uterus | Fibroids distorting the cavity, adhesions, congenital differences |
| Sperm | Low count, poor movement, abnormal shape, blockage, hormonal causes |
| Unexplained | Standard testing finds nothing abnormal in either partner |
Age affects fertility on the egg side more sharply than on the sperm side, since the number and quality of eggs decline with time and are not replenished.
How is it assessed?
Evaluation is deliberately parallel. Semen analysis is straightforward and is usually done early because it is simple and identifies a large share of causes. Ovulation is confirmed from the cycle history and a blood hormone level timed to the second half of the cycle. An imaging test checks whether the fallopian tubes are open. Ovarian reserve markers estimate how many eggs remain, though they indicate quantity rather than the chance of conceiving. Pelvic ultrasound looks at the uterus and ovaries themselves.
Infertile, subfertile or sterile?
The three are often used loosely and mean different things. Sterile denotes a complete and permanent inability, such as after removal of both ovaries or the absence of any sperm production. Subfertile denotes reduced but real chances, which describes most people given the label infertility. Infertile itself is a time-defined description rather than a verdict, and many couples who meet it conceive later, with or without treatment.
Used in a sentence
The couple was referred to a fertility specialist after being unable to conceive and evaluated as infertile according to standard criteria.
Good to know
Infertile does not mean sterile; many causes of infertility are partial or treatable, whereas sterility denotes a complete and permanent inability to conceive.