Neonatal respiratory outcomes in pregnancy induced hypertension: introducing a novel index

<b>Objective:</b> To evaluate short-term respiratory outcomes, mortality and bronchopulmonary dysplasia (BPD) in preterm infants born to mothers with and without pregnancy induced hypertension (PIH). <b>Methods:</b> Exposed infants &lt;33 weeks’ gestation were matched to controls in a 1:2 ratio, based on gestation, sex and antenatal steroid exposure in this retrospective cohort study. Primary outcomes were a novel cumulative respiratory index (cRI) (product of mean airway pressure-hours and FiO₂-hours while on invasive ventilation during first 72 hours), mortality and BPD. <b>Results:</b> Seventy-nine exposed infants were matched with 158 controls. cRI was higher in exposed infants (median 1854; IQR 186–13,901) versus controls (median 1359; IQR 210–11,302) but not statistically significant (<i>p</i> = .63). On conditional regression analysis, PIH did not predict cRI (adjusted <i>β</i> = 0.96; 95% CI = 0.79–1.17; <i>p</i> = .712). No association between PIH and mortality (unadjusted odds ratio [OR] = 3.14; 95% CI = 0.76–13.0; <i>p</i>=.11) was identified. PIH was significantly associated with BPD on univariate analysis (OR = 2.29; 95% CI = 1.02–5.17; <i>p</i>=.046), but not after adjustment (aOR = 1.26; 95% CI = 0.38–4.19; <i>p</i>=.7). <b>Conclusions:</b> PIH was not associated with cRI, mortality or BPD in this study. Further validation of cRI and exploration of its relationship with PIH as well as neonatal outcomes is warranted.

**研究目的：** 评估伴与不伴妊娠高血压综合征（pregnancy induced hypertension, PIH）产妇所娩出早产儿的短期呼吸结局、死亡率与支气管肺发育不良（bronchopulmonary dysplasia, BPD）。
**研究方法：** 本项回顾性队列研究以胎龄、性别及产前类固醇暴露情况为匹配依据，按1:2的比例将胎龄<33周的暴露组早产儿与对照组进行配对。主要结局指标为新型累积呼吸指数（cumulative respiratory index, cRI）——即出生后前72小时有创通气期间平均气道压-小时数与吸入氧分数（FiO₂）-小时数的乘积、死亡率及支气管肺发育不良。
**研究结果：** 本研究共纳入79例暴露组早产儿，并匹配158例对照组早产儿。暴露组早产儿的cRI中位数为1854（四分位数间距（interquartile range, IQR）186~13901），高于对照组的1359（IQR 210~11302），但差异无统计学意义（p=0.63）。条件回归分析显示，PIH无法预测cRI水平（校正后β=0.96；95%置信区间（confidence interval, CI）0.79~1.17；p=0.712）。未发现PIH与死亡率存在关联（未校正比值比（odds ratio, OR）=3.14；95%CI 0.76~13.0；p=0.11）。单因素分析显示，PIH与BPD存在显著关联（OR=2.29；95%CI 1.02~5.17；p=0.046），但校正后该关联不再显著（校正后aOR=1.26；95%CI 0.38~4.19；p=0.7）。
**研究结论：** 本研究显示，PIH与cRI、死亡率及BPD均无关联。未来需进一步验证cRI的临床价值，并探索其与PIH及新生儿结局的关联。