Fertility Over 35

Today more than ever, women are facing problems with fertility over 35. Approximately 1 in 5 women has their first child after age 35, according to the American Society for Reproductive Medicine.

If you are over 35 you may face a tough hurdle when it comes to your fertility. On average, women over 35 have just a 35 percent chance of conceiving in the first year of trying to get pregnant.

Why does age affect fertility over 35?
The following reasons explain the slowing down of fertility after age 35.

  • Females are born with a finite number of eggs. As women age, the number of eggs rapidly decreases. Thus, a woman’s fertility typically begins to decline in her early 30s.
  • Ovulation, when the egg is released from the ovary, tends to slow down and occur less frequently over time. This is a natural occurrence in preparation for menopause. However, it also makes fertility over 35 more challenging.
  • There are also health issues that are more common in women over 35 that can interfere with pregnancy, including fibroids, endometriosis, cysts, and other problems.

Twins and multiples are more likely after 35
Another fact about fertility over 35 is that the chance of giving birth to twins or multiplesincreases as a woman ages. In 2006, almost 5 percent of births among women over 35 were twins. That number increases to almost 20 percent for women over 45. Comparatively, only 2 percent of women ages 20 to 24 had twins.

Birth defects after 35
Older women face increased chances of having babies born with various degrees of mental retardation or physical defects. A woman’s eggs decrease in quality over time, increasing the risk of mutations in the cell division process.The most common chromosomal abnormality after 35 is Down syndrome.

  • This disorder affects about 1 in 400 babies born to mothers 35 to 39.
  • The risk of a 25 to 29 year old mother having a baby with Down syndrome is 1 in 1250.

Miscarriage and complications increase
Women over 35 face higher chances of having a miscarriage. This is due in part to the fact that they have more eggs with chromosomal abnormalities.

  • About 20 percent of pregnancies to women 35 to 39 end in miscarriage.
  • Only 10 percent of pregnancies end in miscarriage for women in their 20s.

After 35, women also have a greater chance of pregnancy complications such as:

  • Higher risk of cesarean section. Approximately 41 percent of 35-39 year old women had a c-section compared to only 27 percent of those between ages of 20-24.
  • Gestational diabetes. This form of diabetes develops during pregnancy and puts the mother at risk for having a very large baby. These babies are also more likely to have health problems. The chance of developing gestational diabetes increases by 50 percent for women over 35.
  • High blood pressure: Pregnancy induced hypertension is more common in women over 35. Patients need to be monitored closely. Preeclampsia, the most severe form of hypertension, can be extremely dangerous for mother and baby.
  • Placenta previa: Women over 35 are more likely to develop this condition where the placenta covers all or part of the cervix. This can cause severe bleeding, thereby endangering the mother and baby.
  • Premature birth/ low birth weight: Mothers ages 35 and older seem to have a greater risk of having a premature or low birth weight baby. The chances increase the most for women over 40.

If you’re over 35 and haven’t been able to conceive within 6 months of trying, it may be time to seek the help of a fertility specialist.



  • American Society for Reproductive Medicine: Age and Fertility. A Guide for Patients.
  • IntegraMed: Can we wait to get pregnant?
  • National Vital Statistics Reports: Births: Final Data for 2006