title: The associations between bridal pregnancy and obstetric outcomes among live births in Korea: population-based study.
abstract: OBJECTIVE
  In East Asia the recently increased number of marriages in response to pregnancy is an important social issue. This study evaluated the association of marriage preceded by pregnancy (bridal pregnancy) with obstetric outcomes among live births in Korea.
  
  
  METHODS
  In this population-based study, 1,152,593 first singleton births were evaluated from data registered in the national birth registration database from 2004 to 2008 in Korea. In the study population, the pregnancy outcomes among live births from the bridal pregnancy group (N = 62,590) were compared with the outcomes of the post-marital pregnancy group (N = 564,749), composed of women who gave birth after 10 months but before 24 months of marriage. The variables preterm birth (PTB; <37 weeks gestation) and low birth weight (LBW; <2.5 kg) were used to determine the primary outcome. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated after controlling for socio-demographic factors.
  
  
  RESULTS
  The socio-demographic factors among the bridal pregnancy group were associated with a social disadvantage and particular risk factors. In the subgroup analyses of maternal age, differences in adverse pregnancy outcomes from bridal pregnancy were identified between women in the following age group: (i) ≤19, (ii) 20-39, and (iii) ≥40 years. After the multivariate analysis, the aORs for each age group were 1.47 (95% CI: 1.15-1.89), 1.76 (1.70-1.83), and 1.13 (0.77-1.66), respectively, for PTB and 0.92 (0.70-1.21), 1.60 (1.53-1.66), and 1.11 (0.71-1.74), respectively, for LBW. In the adjusted logistic regression models, bridal pregnancy was associated with PTB (1.76, 1.69-1.82) and LBW (1.53, 1.48-1.59).
  
  
  CONCLUSIONS
  Pregnancy outcomes among live births from bridal pregnancies are associated with higher risks for PTB and LBW in Korea.
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jung-Yun
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Joong Shin
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jong Kwan
authors.initials: JK
authors.lastname: Jun
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Ko
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Park
mesh_terms: D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D008393:Marriage / Q000208:ethnology* / Q000706:statistics & numerical data / Q000639:trends*; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D047928:Premature Birth / Q000453:epidemiology; D056910:Republic of Korea / Q000453:epidemiology; D012959:Socioeconomic Factors
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