The impact of lifestyle factors on the clinical outcomes of in vitro fertilisation-embryo transfer (IVF) treatment

Objectives: To determine the effect of female and male cigarette smoking, caffeine and alcohol consumption, stress and indicators of dietary status on the clinical outcomes of NF treatment. Design: Prospective cohort study. Setting: PIVET Medical Centre, Perth, Western Australia. Patients: Of 351 couples who commenced IVF treatment at PIVET Medical Centre between January 1997 and August 1998, 281 females and 247 males participated in this study, generating participation rates of 80.1% and 70.4%, respectively. Main Outcome Measures: Multivariate methods of data analyses were used to control for patient and treatment variables in the examination of the effect of lifestyle factors on the following clinical outcomes: 1) number of oocytes retrieved by transvaginal oocyte aspiration (oocyte production), 2) fertilisation, measured as the number of oocytes fertilised weighted by the number of oocytes inseminated, 3) B-hCG pregnancy, 16 days post-embryo transfer, and 4) <12 week pregnancy loss following confirmation of B-hCG pregnancy. As a measure of ovarian reserve, serum basal FSH levels were also investigated as a dependent variable. Lifestyle factors included years of cigarette smoking (smoke years), tobacco, alcohol, caffeine and fruit and vegetable consumption, and stress from daily living and NF treatment. Results: Daily stress, tobacco consumption and smoke years were the female lifestyle factors shown to have a significant effect on NF treatment. Oocyte production decreased with increasing levels of daily stress (P=0.039). However, female patients with high daily stress levels experienced higher than average rates of fertilisation in vitro (P=0.0059) and pregnancy (P--0.0207). Smoke years had an adverse effect on ovarian reserve (P=0.035), which in turn, compromised oocyte production.Female smoke years was negatively associated with rates of fertilisation (P<0.0001), and this effect was exacerbated by cigarette smoking at the time of treatment (P=0.0187). Of the male lifestyle factors, caffeine, alcohol and fruit and vegetable consumption and IVF stress affected fertilisation in vitro. Fertilisation increased with alcohol consumption (P<0.0001), and with fruit and vegetable consumption (P<0.0001). A significant interaction term between these two factors (P=0.0144) implied a threshold of benefit from the combined effect of the consumption of alcohol and fruit and vegetables. Caffeine consumption negated the beneficial effect of alcohol consumption, as shown by a significant interaction term between alcohol consumption and caffeine consumption (P=0.0007). Male stress from NF treatment had an adverse effect on rates of fertilisation in vitro (P<0.0001). Cigarette smoking by the male partner increased the likelihood of the female partner experiencing a