Boland Rosemarie Anne, Dawson Jennifer Anne, Davis Peter Graham, Doyle Lex William
Department of Obstetrics and Gynaecology, University of Melbourne, The Royal Women's Hospital, Parkville, Vic, Australia; Murdoch Childrens Research Institute, Parkville, Vic, Australia; Paediatric Infant Perinatal Emergency Retrieval, Royal Children's Hospital, Parkville, Vic, Australia.
Aust N Z J Obstet Gynaecol. 2015 Apr;55(2):163-9. doi: 10.1111/ajo.12313.
Very preterm infants born in non-tertiary hospitals ('outborn') are known to have higher mortality rates compared with infants 'inborn' in tertiary centres.
The aim of this study was to report changes over time in the incidence of outborn livebirths, 22-31 weeks and infant mortality rates for outborn compared with inborn births.
We conducted a population-based cohort study of consecutive livebirths, 22-31 weeks' gestation in Victoria from 1990 to 2009. The relationship between birthplace, gestational age, birthweight, sex and infant mortality were analysed by logistic regression.
There were 13,760 livebirths, 22-31 weeks: 14% were outborn. The proportion of outborn livebirths fell from 19% in 1991 to a nadir of 9% in 1997, but climbed to 17% by 2009. At all times, outborns had higher mortality rates compared with inborns. The overall infant mortality rate was 250.6 per 1000 outborn compared with 113.3 per 1000 inborn livebirths (adjusted odds ratio (aOR) 2.76 (95% CI 2.32, 3.27, P < 0.001). There were no differences between outborn and inborn mortality risks for 22-week livebirths (OR 7.04, 95% CI 0.87, 56.8, P = 0.067), but there were at 23-27 weeks (aOR 3.16, 95% CI 2.52, 3.96, P < 0.001) and at 28-31 weeks (aOR 1.66, 95% CI 1.19, 2.31, P = 0.003). Over time, mortality rates fell for inborn 23-27 week infants. Mortality rates fell for outborn 23-27 week infants in 1990-2005, but rose in 2006-2009.
Outborn livebirths at 22-31 weeks' gestation occur too frequently and are associated with a significantly increased risk of mortality. Strategies to reduce outborn livebirths are required.
与在三级医疗中心出生的“院内出生”婴儿相比，在非三级医院出生的“院外出生”极早产儿死亡率更高。
本研究旨在报告院外出生活产儿的发生率、孕22 - 31周的院外出生活产儿以及与院内出生相比院外出生婴儿死亡率随时间的变化。
我们对1990年至2009年维多利亚州连续出生的孕22 - 31周活产儿进行了一项基于人群的队列研究。通过逻辑回归分析出生地点、孕周、出生体重、性别与婴儿死亡率之间的关系。
共有13760例孕22 - 31周的活产儿，其中14%为院外出生。院外出生活产儿的比例从1991年的19%降至1997年的最低点9%，但到2009年又攀升至17%。在所有时间段，院外出生婴儿的死亡率均高于院内出生婴儿。院外出生婴儿的总体死亡率为每1000例250.6例，而院内出生活产儿为每1000例113.3例（调整优势比（aOR）2.76（95%置信区间2.32, 3.27，P < 0.001）。孕22周活产儿的院外出生和院内出生死亡风险无差异（优势比7.04，95%置信区间0.87, 56.8，P = 0.067），但在孕23 - 27周时有差异（aOR 3.16，95%置信区间2.52, 3.96，P < 0.001），在孕28 - 31周时也有差异（aOR 1.66，95%置信区间1.19, 2.31，P = 0.003）。随着时间的推移，孕23 - 27周院内出生婴儿的死亡率下降。孕23 - 27周院外出生婴儿的死亡率在1990 - 2005年下降，但在2006 - 2009年上升。
孕22 - 31周的院外出生活产儿发生率过高，且死亡风险显著增加。需要采取策略降低院外出生活产儿的发生率。
