ENVIRONMENTAL FACTORS AND POLYCYSTIC OVARIES

This study was designed to investigate the effect of environmental factors on the appearance of polycystic ovaries (PCO) during the first two decades of life. Ninety-four female-female twins who underwent a transabdominal ultrasound at the Royal Hospital for Women were sent a questionnaire asking about their birth details, feeding history as a baby, childhood illnesses and vaccination as well as exercise patterns. Seventy-seven subjects returned the questionnaire. All of the variables were studied in two groups of subjects those with ultrasound evidence of polycystic ovaries (US-PCO, n= 37) and those with normal ovaries (US-normal, n= 40). The data were also analyzed in a group of scan-discordant twins (7 pairs) in whom one of the twins had US-PCO and the co-twin had normal ovaries. Analyzing the data from the whole database suggested that US-PCO subjects had lower birth weight compared to US-normals. Vaccination against mumps was also found to be significantly higher in the US-PCO group compared with US-normals. Matched results for scan-discordant twins did not confirm these results. Other environmental variables such as feeding history, type of delivery, birth order and physical activity during the first 20 years of age did not seem to have any significant influence on the prevalence of PCO. No significant difference was found in childhood illnesses between the groups. In conclusion, this study examined the effect of some environmental factors during childhood and early adulthood. Analyzing the whole database and scan-discordant twins failed to show any particular environmental factor associated with PCO.