Birth weight below the 10th percentile as a risk factor for the development of polycystic ovary syndrome a reproductive age: a cohort study

Abstract

OBJECTIVE: To determine whether term small for gestational age (SGA) newborns (NB) (gestational age of 37 to 42 weeks) have a higher prevalence of polycystic ovary syndrome (PCOS) at reproductive age compared to adequate for gestational age (AIG) NB in the cohort of infants born in Ribeirão Preto between 31.05.1978 and 01.06.1979. DESIGN: Prospective longitudinal study (cohort). MATERIALS AND METHODS: We invited 440 women to participate from Nov/2007 to Oct/2008). Of these, 356 (268 AIG and 88 SGA) agreed to participate, with 138 AIGs and 37 SGAs being excluded due to the use of a hormonal contraceptive (N = 97) or to pregnancy/breastfeeding (N = 78). Hormones (FSH, LH, prolactin, testosterone, DHEAS, 17-OH progesterone and TSH) and SHBG were determined by chemoluminescence. We also evaluated free androgen index (FAI), performed pelvic ultrasound (US) and classified the women with PCOS in four phenothypes (based on 2003 Rotterdam criteria): severe PCOS (three criteria), hiperandrogenism(HA) plus chronic anovulation (CA), HA plus US criteria and CA plus US. RESULTS: The prevalence of PCOS was higher in SGAs (32%) than in AIGs (13.8%), with a relative risk of 2.02 (95%CI: 1.27 – 3.21, p=0.0097). Regarding PCOS criteria, menstrual irregularity (SGA: 51% vs AIG: 25.4%, p=0.0012) and clinical or laboratory hyperandrogenism (SGA: 41.2% vs AIG: 22.3%, p=0.01) were more frequent in SGAs. In contrast, US criterion (SGA: 37.2% vs AIG:33.8%, p=0.6), FAI (SGA: 5.7 ± 4.6 vs AIG: 4.8 ± 3.9, p=0.2) and hormonal evaluation did not differ significantly between groups. Moreover, SHBG levels were more reduced in SGAs, but without a significant difference (SGA: 54.9 ± 24.3μg/dL vs AIG: 63.0 ± 36.7μg/dL, p=0.08). Finally, the PCOS phenotypes did not different between SGA and AGA [Severe (SGA: 50% vs AGA 55.5%, p=0.93), HA+CA (SGA: 12.5% vs 11.1%, p=0.93), HA+US (SGA: 12.5% vs AGA: 16.7%, p=0.93), HA+US (SGA: 25% vs AGA: 167%, p=0.93). CONCLUSIONS: SGA women represent a risk group for the development of PCOS during reproductive period.