It is well known that women who are under or overweight have difficulty with reproduction. Obese women are at risk for miscarriage, gestational diabetes, gestational hypertension, pre-term delivery, macrosomia, low birth weight, stillbirth, delivery via operative route, and postoperative complications. Underweight women are also at risk for miscarriage, low birth weight, pre-term delivery, and stillbirth. Therefore, preconception counselling about weight and lifestyle management is very important.

During this counselling, one should evaluate the patient’s diet, frequency and intensity of exercise, toxic habits, and use of drugs that affect body weight. The best way to assess weight is to calculate the body mass index (BMI) using the following equation: weight (kg) / height2 (m2).

A BMI between 18.5 and 24.9 kg/m2 is considered normal. Women with a BMI < 18.5 kg/m2 are underweight, whereas women with a BMI > 25 kg/m2 are overweight, and those with a BMI > 30 kg/m2 are obese.

Underweight women should be screened for eating disorders and thyroid dysfunction. In some cases, it may be appropriate to work together with a nutritionist and a psychologist. Low body weight is associated with ovulatory dysfunction. Usually, minimal weight gain (3 to 5 kg) is sufficient to restore ovulation and to improve the outcome of a subsequent pregnancy.

Overweight women also need to undergo a throrough endocrinology evaluation (thyroid function, Cushing’s syndrome, polycystic ovary syndrome (PCOS). They should be screened for diabetes, lipid abnormalities, and hypertension and should be advised about a lower-calorie diet with appropriate nutrients. Women with PCOS may benefit from a diet that is low in saturated fat and high in low-glycemic-index-carbohydrate. Besides adhering to a healthy diet, regular exercise is needed to burn excess calories and to help to maintain a lower weight. Daily moderate exercise for about 30 minutes is recommended. Very often ovarian activity is restored by losing 5% to 10% of weight, even without reaching the ideal range.

Drugs that improve insulin resistance also improve reproductive outcome among women with PCOS. They should not be used alone, rather should be combined with a healthy diet and regular exercise. Adequate folic acid intake is essential for reproductive-age women, as it can reduce the incidence of fetal neural tube defects and cardiac anomalies.

Weight control is very important for those women who enter an assisted reproductive technology (ART) program. Treatment outcome is clearly worse among obese patients. Aside from the lower pregnancy rates and higher miscarriage rates and other obstetric complications, they are at higher risk during the entire process. Obesity can limit the accuracy of ultrasound monitoring. Obese patients are at higher risk during the procedures (eg, oocyte collection), especially when anesthesia is provided. Thin women are also at increased risk during ART, for example, ovarian hyperstimulation (OHSS) occurs more commonly among thin women.

Toxic habits not only adversely affect the developing fetus but also compromise gonadal function. In men, smoking has been associated with lower sperm number and motility, and in women, smoking has toxic ovarian effects. Drug use may also affect gonadal activity by altering the stimulatory pathways of the central nervous system. Consumption of alcohol and caffeine adversely affects fertility, and their intake needs to be limited before attempting pregnancy.

Whether stress predisposes to infertility is a question commonly asked during pretreatment counseling. It is not easy to answer this question, as it is rather difficult to measure the degree of stress objectively. Many experts believe stress can affect the outcome of infertility treatment. The condition itself, with its social consequences, including the treatment process, success and failure can have a major impact on a patient’s psychological well-being. Thoroughly explaining the steps and process of treatment and providing the patient with a plan if the first few attempts are not successful may reduce the psychological burden. It is also important to explain to the patient what she may reasonably expect. A patient with irrational expectations will have even greater difficulty accepting a treatment failure.

In summary, patients who lead a healthy lifestyle before initiating infertility treatment are optimizing the potential for a good outcome. Those who are not, need to be encouraged and supported to alter their habits and counseled about the associated risks to which they and their fetus will be exposed. Finally, it is very important to have well trained medical and paramedical staff that can provide medical and psychological information and support during the course of infertility treatment.