Fertilidad

Age and fertility

Revisado: 4 de octubre de 2026

Solo en inglés por ahora

Fertility falls with age, from around 30 and more steeply from the mid-30s. Most couples where the woman is under 40 still conceive within a year.

Why fertility changes with age

You are born with a limited supply of eggs. Over the years both the number of eggs and their quality go down. Lower egg quality is the main reason fertility falls with age. The change becomes more noticeable in the mid- to late 30s. Because of this, getting pregnant can take longer as you get older.

What the numbers say

The US Centers for Disease Control and Prevention (CDC) says a woman's chance of having a baby falls quickly each year after about age 30. Even so, more than 8 in 10 couples where the woman is under 40 get pregnant within a year of regular sex without contraception. Age also raises the chance of miscarriage and of a baby having a genetic condition. A man's age matters too: couples where the man is 40 or older are more likely to have trouble conceiving.

Pregnancy after 35

Many people have healthy pregnancies and babies after 35. Twins become more likely, and some risks are higher, including diabetes that starts in pregnancy (gestational diabetes), high blood pressure, a baby born early or small, and needing a caesarean birth. The risk of miscarriage, stillbirth and chromosome conditions also rises with age. Regular check-ups during pregnancy help.

Getting ready

If you hope to get pregnant later in life, the same steps help at any age. Take folic acid, stop smoking and alcohol, and ask a doctor or nurse to review any health conditions and medicines before you try. Once you are pregnant, going to all your check-ups lets a doctor or midwife spot problems early.

When to get help

If you are under 35, see a doctor or nurse after a year of trying. From 35, US guidance advises going after 6 months of trying, and UK guidance says women aged 36 and over should not wait a full year. If you are over 40, consider asking for tests straight away. At any age, go early if your periods are irregular or have stopped, or you know of a possible fertility problem.

This is general information. Everyone's fertility is different. If you are worried about your age and fertility, talk to a doctor or nurse.