Age vs Fertility: The clock is ticking…


Since the 1960s, with the introduction of birth control, people have been able to plan pregnancies. Combined with an increase in women with high educations and extended careers, parenthood in general is postponed compared to just 70 years ago.

Back then, the average age for a first-time mother in Denmark was 22.7 years old; today, the average is now 29.7.

The natural consequence is an increase in involuntary childlessness and infertility, causing a rise in fertility treatments. As an example, in Denmark in 2011, 13.8% of women aged 35-40 who gave birth, had received assisted conception.

Start early
A study among 10.000 couples attempting to conceive shows that the sooner you start, the better your chances are. And if you want more than one child, you should start even earlier.

Women with no evident fertility issues who only want a single child, should start trying to get pregnant no later than at the age of 35 for a 90% chance to conceive – and be prepared for the possibility of fertility treatment.
Women who want two children, should start at 31, and at 28 for three children.

If the woman does not wish to receive fertility treatment and otherwise has no evident fertility issues, she should start trying 3-5 years earlier than the above. This means that for a 90% chance of having three children, she should start trying to get pregnant at 23.

According to fertility specialist Doctor Kathrine Birch Petersen (MD, PhD, OB/GYN), these numbers will probably surprise many people. Doctor Kathrine Birch Petersen works at the fertility counselling at Seeland University Hospital in Denmark, and she believes that many women have unrealistic expectations of their own fertility:

”The majority of women over 35, who come to our counselling centre, want to know how long they can wait before having their first child. They claim to know that age is the key factor for female fertility, but clearly they are unaware of the actual ages – or they think, that the facts do not apply to them”, she says in an interview.

First-time mothers around the world


This chart, based on information from CIA World Factbook, UNICEF and China’s Sixth Nationwide Census, shows the average age of first-time mothers around the wold in 2015. The age of the mothers in 141 countries range from 18 to 31.2 years, with the oldest ages being more common in Greece, Italy, Spain, Ireland, Australia and South Korea.
Note, however, that the study only registers ages 18 and up.

The top countries with the oldest first-time mothers:

  1. Greece (31.20)
  2. Australia (30.50)
  3. South Korea, Japan and Italy (30.30)
  4. Switzerland and Luxembourg (30.20)
  5. Singapore, Spain, Hong Kong and Ireland (29.80)
  6. Netherlands (29.40)
  7. Germany and Portugal (29.20)
  8. Denmark (29.10)
  9. Sweden (28.90)
  10. Slovenia (28.80)

Other factors play a role
Even though age is the significant factor for female fertility, other factors can affect or even help to improve fertility. So-called “fertility risk factors” like weight, smoking, alcohol, exercise and sexual transmitted infections affect your fertility.

//posted by Michael. Communications specialist at European Sperm Bank