Optimising Natual Fertility

Doctors are frequently consulted by couples concerned about their fertility potential.Some couples seek this information even before attempting pregnancy or meeting criteria for subfertility. These couples are especially motivated to listen to advice concerning the impact of lifestyle factors on fertility, as well as their general health. Some lifestyle factors appear to affect the duration of time before achieving pregnancy. Studies suggest that lifestyle modifications can improve fertility potential. Tobacco use, body mass index, alcohol and caffeine consumption, exercise, and stress can have an impact on fertility.


  • Fertility (also called fecundity) refers to the capacity to conceive and produce offspring
  • Infertility is the inability to conceive despite frequent coitus. Infertility refers to a state in which the capacity for fertility is diminished, but not necessarily absent. For this reason, the term subfertility is often used instead of infertility. Women under age 35 are evaluated for infertility after 12 months of unsuccessful attempts to conceive; women age 35 and older are evaluated after six months.
  • Sterility is the inability to produce offspring.
  • Fecundability is the probability of achieving a pregnancy in a single menstrual cycle.
  • Time to pregnancy refers to the length of time, usually measured in months, that it takes a couple to conceive.

Normal Fertility – Some General Advice

Most pregnancies occur during the first six cycles of intercourse in the fertile phase . Fecundability decreases as the number of consecutive months without achieving pregnancy increases. Overall, after 12 months of unprotected intercourse, approximately 85 percent of couples will become pregnant. The chance of conceiving gradually goes down over time. However, for couples where no cause is found for the problem, there is still a good chance of conceiving without treatment. In such couples, without treatment:

  • About half who do not conceive within one year conceive within the next year.
  • Those who do not conceive within three years still have about a 1 in 4 chance of conceiving over the following year. The 5 to 7 percent of couples who have not conceived after 48 months of attempted conception will only occasionally go on to achieve a spontaneous conception. Criteria for initiating an infertility evaluation vary depending on personal characteristics (eg, age).

Preconception Advice

Women are advised to:

  • Take folic acid each day to reduce the chance of a spinal cord problem in a baby.
  • Have a blood test to check that immunity to rubella (german measles). Immunisation to rubella is recommended if not immune. • Eat a healthy diet. In addition, the following may be relevant to some people.
  • Smoking can affect fertility in men and women. It has been estimated that in each menstrual cycle, smokers have about two thirds the chance of conceiving compared to non-smokers. Smoking is also harmful to a developing baby if the mother smokes. Therefore, it is a good time for either partner to stop if they are smokers.
  • Weight control. There is a reduced chance of conceiving in women very overweight or underweight. For the best chance of conceiving, the aim should be to have body mass index (BMI) between 20 and 30.
  • Alcohol in excess may affect male fertility. Also, for women trying to become pregnant, the recommendation is not to drink any alcohol. This is because alcohol may harm a developing baby.
  • Some street drugs can affect fertility and are best avoided.
  • Heat and sperm production. It is often advised for men who have a low sperm count to wear loose fitting underpants and trousers and to avoid very hot baths.This allows the testes to be slightly cooler than the rest of the body, which is thought to be good for sperm production. It is not clear whether these measures actually do improve sperm count.