No Difference in Breastfeeding Rates in Women with Polycystic Ovary Syndrome Objective: Women with PCOS have increased rates of obesity and gestational weight gain compared to women without PCOS, factors which are associated with decreased breastfeeding (BF). Thus, our objective was to evaluate if women with PCOS were less likely to initiate BF. Design: Cross-sectional analysis of participants in the PRAMS (Pregnancy Risk Assessment Monitoring System) dataset, a national questionnaire from the Centers for Disease Control (CDC) sent to postpartum mothers 2–9 months after delivery. PCOS status and BF were by self-report. Logistic regression was used to assess odds of ever BF. Length of BF was assessed using Cox proportional hazards with right censoring for women who were still BF at the time of follow-up. PRAMS complex survey design was accounted for. Results: PCOS status was available for 14 states. Median response time was 3.7 months postpartum. Data from 16,036 participants were included which represents 855,302 women due to sample weights. 6.6% of women reported having PCOS and 83.8% reported ever BF. Compared to women with a normal BMI, women who were overweight or obese had decreased odds of BF (OR: 0.7, 95% CI: 0.6–0.9, P=0.01; OR: 0.6, 95% CI: 0.5–0.7, P<0.001 respectively); however, PCOS was not associated with BF (OR: 1.1, 95% CI: 0.9–1.3, P=0.6). In multivariate analysis, women with PCOS still were at no decreased odds of BF after adjusting for age, BMI, race, ethnicity, infertility treatment, and delivery factors (ORadj:1.1; 95% CI: 0.8–1.4; P=0.6). Variables associated with decreased odds of BF included: overweight/obesity, age ≤ 19 yrs (vs. 25–29), Black race, smoking, undesired pregnancy intent, gestational age ≤27 wks, and prior live birth. Variables associated with increased BF included: age 30–39 yrs, hospital stay 1–2 days (vs. 3–5), Hispanic ethnicity, and ≥ 3 life stressors. In multivariable Cox models, women with PCOS did not have a shorter length of BF (HRadj: 0.9, 95% CI: 0.8–1.1, P=0.3). Conclusion: Given the rise of the national rates of obesity and clear maternal and neonatal benefits to breastfeeding, understanding the predictors of BF success is paramount. In this national survey, women with PCOS were at no decreased odds of BF, despite confirming the association between overweight/obesity and decreased BF. However, our data still supports the clinical relevance of carefully targeting women with PCOS for BF education due to the association of PCOS with increased BMI. Additional prospective studies are needed to fully understand the association between PCOS and BF.