The Korean Pregnancy Outcome Study (KPOS): Study Design and Participants.

BACKGROUND The Korean Pregnancy Outcome Study (KPOS) was established to investigate the determinants of adverse pregnancy outcomes among Korean women. METHODS We recruited 4,537 pregnant women between 2013 and 2017 from two tertiary centers located in Seoul, Korea, and a total of 4,195 Korean women met inclusion criteria in the baseline analysis. A range of data on socio-demographics, past medical histories, reproductive information, health-related behaviors, psychological health and clinical information were obtained using interviewer-based questionnaires and clinical assessment at 12, 24, and 36 gestational weeks (GW), delivery and 6-8 weeks postpartum. Blood samplings were performed at 12, 24 and 36 GW, and placental tissues were obtained after delivery. The main outcome of this study was pregnancy-related complications including gestational diabetes mellitus (GDM), gestational hypertension, and screening positive for peripartum depression. Depression was assessed using the Korean version of the Edinburgh Postnatal Depression Scale, and a score of ≥10 indicated a positive screen for depression. RESULTS Among 4,195 eligible pregnant women with a median age of 33.0 years, 3,565 (85.0%) pregnancy outcomes were available in this study, including 30 miscarriages, 16 stillbirths, and 3,519 deliveries. Mean gestational age was 38.8 GW, and mean birth weight was 3,236 gram. The prevalence of pregnancy complications such as GDM, hypertensive disorders, and screening positive of depression during pregnancy and postpartum was 7.0%, 1.4%, 27.8%, and 16.6%, respectively. CONCLUSIONS We designed KPOS to identify the determinants of pregnancy-related outcomes, and it may provide effective strategies for the prevention of pregnancy complications in Korean pregnant women.