Diet and drugs and the impact on fertility
Diet is an important factor in fertility. Some vitamins and minerals (especially vitamin C, zinc and selenium) are known to be important factors in the production of sperm. Generally a diet low in fat with plenty of fruit and vegetables is recommended. It is also important that proper nutrition is taken and that couples are not overweight. Ideally a woman’s Body Mass Index (BMI) should be between 20 and 25; more information about BMI is available below.
Body Mass Index (BMI)
The Body Mass Index (BMI) is used to check that weight is in the normal range for height. This is calculated by dividing the weight (in kilograms) by the square of the height (in metres):
BMI = Weight (Kg) / Height2 (M2)
The lower limit of normal BMI is 19 but, for fertility purposes, a lower limit of 20 is often advised since some fat is required for hormone production. The upper limit of normal BMI is 25 and all couples trying to conceive should aim for their BMI to be between 20 and 25. For the woman the best response to all treatments occurs when her BMI is between 20 and 25. Treatment, particularly drug therapy, is unlikely to be successful in women who are overweight.
Some drugs are also known to contribute to infertility. It is important if a patient is taking any therapeutic drugs that they inform a member of staff.
Drugs which are commonly taken for recreational purposes include tobacco (smoking), alcohol and, more rarely, substances such as marijuana and heroin. Tobacco and alcohol, although not illegal, have a detrimental effect on fertility and it is recommended that all patients who smoke stop. Drinkers are encouraged to regulate their habit and reduce alcohol intake to 2-3 units a week. Of the illegal drugs marijuana has been shown to significantly reduce testosterone levels in men and heroin abuse is linked to poor sperm motility.
It is unit policy not to treat patients known to be current drug abusers.