Lynch Anne M, Wagner Brandie D, Hodges Jennifer K, Thevarajah Tamara S, McCourt Emily A, Cerda Ashlee M, Mandava Naresh, Gibbs Ronald S, Palestine Alan G
Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO.
Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO.
Am J Obstet Gynecol. 2017 Sep;217(3):354.e1-354.e8. doi: 10.1016/j.ajog.2017.05.029. Epub 2017 May 22.
Retinopathy of prematurity is an adverse outcome of preterm birth and is a leading cause of childhood blindness. The relationship between the subtypes of preterm birth with retinopathy of prematurity is understudied.
To investigate whether there is a difference in the incidence of type 1 or type 2 retinopathy of prematurity in infants with preterm birth resulting from spontaneous preterm labor, a medical indication of preterm birth, or preterm premature rupture of the membranes.
A retrospective cohort study was conducted of 827 infants screened for retinopathy of prematurity who were delivered at a single tertiary care center in Colorado. All infants fulfilled the American Academy of Pediatrics 2013 screening criteria for retinopathy of prematurity defined as "infants with a birth weight of ≤1500 g or gestational age of 30 weeks or less (as defined by the attending neonatologist) and selected infants with a birth weight between 1500 and 2000 g or gestational age of >30 weeks with an unstable clinical course, including those requiring cardiorespiratory support and who are believed by their attending pediatrician or neonatologist to be at high risk for retinopathy of prematurity." Two independent reviewers masked to retinopathy of prematurity outcomes determined whether preterm birth resulted from spontaneous preterm labor, medical indication of preterm birth, or preterm premature rupture of the membranes. Discrepancies were resolved by a third reviewer. Data were analyzed with univariate and multivariable logistic regression.
In our cohort, the frequency of preterm birth resulting from spontaneous preterm labor, medical indication of preterm birth, or preterm premature rupture of the membranes was 34%, 40%, and 26%, respectively. The mean gestational age (weeks, days) ± SD (range) in the cohort and across the preterm birth subtypes was as follows: entire cohort, 28 weeks, 6 days ± 2 weeks, 3 days (23 weeks, 3 days - 36 weeks, 4 days); spontaneous preterm labor, 28 weeks 1 day ± 2 weeks, 3 days (23 weeks, 3 days - 33 weeks, 4 days); medical indication of preterm birth, 29 weeks, 1 day ± 2 weeks, 2 days (24-36 weeks, 4 days); preterm premature rupture of the membranes, 28 weeks, 4 days ± 2 weeks, 1 day (24-33 weeks, 1 day). Among infants with type 1, type 2, or no retinopathy of prematurity, the incidence of type 1 or type 2 retinopathy of prematurity in births from spontaneous preterm labor, medical indication of preterm birth, and preterm premature rupture of the membranes was 37 of 218 (17%), 27 of 272 (10%), and 10 of 164 (6%), respectively. Adjusted for gestational age, birth weight, and multiparity and compared with the preterm premature rupture of the membranes group, the odds ratios of spontaneous preterm labor and medical indication of preterm birth for type 1 or type 2 retinopathy of prematurity were 6.1 (95% confidence interval, 1.8 to 20, P = .003) and 5.5 (95% confidence interval, 1.4 to 21, P = .01), respectively. Among neonates born after preterm premature rupture of the membranes, the probability of developing type 1 or type 2 retinopathy of prematurity was greatest in infants with rupture of membrane duration of up to 24 hours. After 24 hours, the probability of developing type 1 or type 2 retinopathy of prematurity declined. The odds of developing type 1 or type 2 retinopathy of prematurity was 9.0 (95% confidence interval 2.3 to 34, P = .002) in infants who had preterm premature rupture of the membranes ≤ 24 hours compared with infants who had preterm premature rupture of the membranes > 24 hours.
Type 1 or type 2 retinopathy of prematurity are adverse ocular outcomes linked with not only lower gestational age and birth weight at delivery but also with events in the intrauterine environment that trigger a preterm birth. The reduced incidence of type 1 or type 2 retinopathy of prematurity in the preterm premature rupture of the membranes group compared with other causes of preterm birth may be related to the perinatal therapies associated with preterm premature rupture of the membranes (such as corticosteroids, antibiotics, maternal-fetal surveillance), which may have an inhibitory effect on the development of retinopathy of prematurity. We suggest that the physiologic events that predispose infants to type 1 or type 2 retinopathy of prematurity begin before delivery.
早产儿视网膜病变是早产的不良后果，是儿童失明的主要原因。早产亚型与早产儿视网膜病变之间的关系研究较少。
探讨因自发性早产、早产的医学指征或胎膜早破导致早产的婴儿中，1型或2型早产儿视网膜病变的发生率是否存在差异。
对在科罗拉多州一家三级医疗中心分娩的827例接受早产儿视网膜病变筛查的婴儿进行回顾性队列研究。所有婴儿均符合美国儿科学会2013年早产儿视网膜病变筛查标准，即“出生体重≤1500g或胎龄30周及以下（由主治新生儿科医生定义）的婴儿，以及出生体重在1500至2000g之间或胎龄>30周且临床病程不稳定的特定婴儿，包括那些需要心肺支持且其主治儿科医生或新生儿科医生认为有早产儿视网膜病变高风险的婴儿”。两名独立的审阅者在不知道早产儿视网膜病变结果的情况下，确定早产是由自发性早产、早产的医学指征还是胎膜早破引起的。如有分歧，由第三位审阅者解决。数据采用单变量和多变量逻辑回归分析。
在我们的队列中，因自发性早产、早产的医学指征或胎膜早破导致早产的频率分别为34%、40%和26%。队列中以及各早产亚型的平均胎龄（周、天）±标准差（范围）如下：整个队列，28周6天±2周3天（23周3天 - 36周4天）；自发性早产，28周1天±2周3天（23周3天 - 33周4天）；早产的医学指征，29周1天±2周2天（24 - 36周4天）；胎膜早破，28周4天±2周1天（24 - 33周1天）。在患有1型、2型或无早产儿视网膜病变的婴儿中，因自发性早产、早产的医学指征和胎膜早破出生的婴儿中1型或2型早产儿视网膜病变的发生率分别为218例中的37例（17%）、272例中的27例（10%）和164例中的10例（6%）。在调整了胎龄、出生体重和多胎妊娠因素后，与胎膜早破组相比，自发性早产和早产的医学指征导致1型或2型早产儿视网膜病变的比值比分别为6.1（95%置信区间，1.8至20，P = .003）和5.5（95%置信区间，1.4至21，P = .01）。在胎膜早破后出生的新生儿中，胎膜破裂持续时间长达24小时的婴儿发生1型或2型早产儿视网膜病变的可能性最大。24小时后，发生1型或2型早产儿视网膜病变的可能性下降。与胎膜早破>24小时的婴儿相比，胎膜早破≤24小时的婴儿发生1型或2型早产儿视网膜病变的比值比为9.0（95%置信区间2.3至34，P = .002）。
1型或2型早产儿视网膜病变是不良的眼部结局，不仅与分娩时较低的胎龄和出生体重有关，还与触发早产的宫内环境事件有关。与其他早产原因相比，胎膜早破组中1型或2型早产儿视网膜病变的发生率降低可能与胎膜早破相关的围产期治疗（如皮质类固醇、抗生素、母婴监测）有关，这些治疗可能对早产儿视网膜病变的发展有抑制作用。我们认为，使婴儿易患1型或2型早产儿视网膜病变的生理事件在分娩前就已开始。
