Leal Maria do Carmo, Esteves-Pereira Ana Paula, Nakamura-Pereira Marcos, Domingues Rosa Maria Soares Madeira, Dias Marcos Augusto Bastos, Moreira Maria Elisabeth, Theme-Filha Mariza, da Gama Silvana Granado Nogueira
Department of Epidemiology and Quantitative Methods in Health, Women's, Children's and Adolescents' Research Group, Sérgio Arouca National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Figueira National Institute for Women's, Children's and Adolescents Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
BMJ Open. 2017 Dec 27;7(12):e017789. doi: 10.1136/bmjopen-2017-017789.
To estimate the national rate of early-term live births in Brazil and to evaluate the effect of birth at 37 and 38 weeks' gestation, as compared with 39 and 40 weeks' gestation on infant outcomes according to precursors of birth and the existence of maternal/fetal medical conditions.
National perinatal population-based cohort study.
266 maternity services located in the five Brazilian macroregions.
18 652 singleton live newborns from 37 0/7 to 40 6/7 weeks of gestation.
Resuscitation in delivery room, oxygen therapy, transient tachypnoea, admission to neonatal intensive care unit (NICU), hypoglycaemia, use of antibiotics, phototherapy, phototherapy after hospital discharge, neonatal death and breastfeeding.
Early terms accounted for 35% (95% CI 33.4% to 36.7%) of all live births. Among provider-initiated births in women without medical conditions, infants of 37 and 38 weeks' gestation had higher odds of oxygen therapy (adjusted OR (AOR) 2.93, 95% CI 1.72 to 4.98 and AOR 1.92 95% CI 1.18 to 3.13), along with admission to NICU (AOR 2.01, 95% CI 1.18 to 3.41 and AOR 1.56, 95% CI 1.02 to 2.60), neonatal death (AOR 14.40, 95% CI 1.94 to 106.69 and AOR 13.76,95% CI 2.84 to 66.75), hypoglycaemia in the first 48 hours of life (AOR 7.86, 95% CI 1.95 to 31.71 and AOR 5.76, 95% CI 1.63 to 20.32), transient tachypnoea (AOR 2.98, 95% CI 1.57 to 5.65 and AOR 2.12, 95% CI 1.00 to 4.48) and the need for phototherapy within the first 72 hours of life (AOR 3.59, 95% CI 1.95 to 6.60 and AOR 2.29, 95% CI 1.49 to 3.53), yet lower odds of breastfeeding up to 1 hour after birth (AOR 0.67, 95% CI 0.53 to 0.86 and AOR 0.87, 95% CI 0.76 to 0.99) and exclusive breastfeeding during hospital stay (AOR 0.68, 95% CI 0.51 to 0.89 and AOR 0.84, 95% CI 0.71 to 0.99).
Birth at 37 and 38 weeks' gestation increased the risk of most adverse infant outcomes analysed, especially among provider-initiated births and should be avoided before 39 weeks' gestation in healthy pregnancies.
估计巴西早期足月活产的全国发生率，并评估孕37周和38周出生与孕39周和40周出生相比，根据分娩前体况以及母婴医疗状况对婴儿结局的影响。
基于全国围产期人群的队列研究。
位于巴西五个大区的266家产科服务机构。
18652例孕37⁰/₇至40⁶/₇周的单胎活产新生儿。
产房复苏、氧疗、短暂性呼吸急促、入住新生儿重症监护病房（NICU）、低血糖、使用抗生素、光疗、出院后光疗、新生儿死亡及母乳喂养。
早期足月产占所有活产的35%（95%CI 33.4%至36.7%）。在无医疗状况的产妇由医护人员发起的分娩中，孕37周和38周出生的婴儿接受氧疗的几率更高（校正OR（AOR）2.93，95%CI 1.72至4.98以及AOR 1.92，95%CI 1.18至3.13），入住NICU的几率也更高（AOR 2.01，95%CI 1.18至3.41以及AOR 1.56，95%CI 1.02至2.60），新生儿死亡几率更高（AOR 14.40，95%CI 1.94至106.69以及AOR 13.76，95%CI 2.84至66.75），出生后48小时内发生低血糖的几率更高（AOR 7.86，95%CI 1.95至31.71以及AOR 5.76，95%CI 1.63至20.32），短暂性呼吸急促几率更高（AOR 2.98，95%CI 1.57至5.
