Supplementary Material for: ABO Incongruency Increases Risk for Necrotizing Enterocolitis in Preterm Neonates

Introduction: Preterm neonates are at high risk for complications, and inflammation has been implicated in many of these pathologies. ABO incongruency occurs when the maternal and neonatal blood types are different and may cause complications when the mother creates antibodies against neonatal blood type antigens. In this study, we investigated whether preterm neonates with type A or B blood born to mothers with type O blood (ABO incongruent) had higher rates of neonatal complications than neonates with type O blood born to mothers with type O blood (ABO congruent). We hypothesized that preterm neonates who were ABO incongruent would have a higher incidence of neonatal morbidity. Methods: This was a population-based single-center retrospective cohort study of 371 preterm neonates whose mothers had O blood type, were born between 21 0/7 and 32 6/7 weeks gestation, and admitted to University of Iowa Health Care Neonatal Intensive Care Unit between January 2018 and December 2022. Neonates were grouped by ABO incongruent versus congruent as well as by gestational age (GA) (22-26 and 27-32 weeks GA). Demographics data were collected. Outcomes included bronchopulmonary dysplasia (BPD), pulmonary hypertension, patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC), packed red blood cell (pRBC) transfusions, intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and survival to discharge. Results: ABO incongruent neonates between 27-32 weeks GA were more likely to have NEC and had a trend towards an increased incidence of early pulmonary hypertension. There were trends towards more heart dysfunction and severity of IVH in neonates between 22-26 weeks GA. Conclusion: ABO incongruency is associated with neonatal complications in the preterm population. This study is underpowered to adequately evaluate all neonatal morbidities. More studies are required to evaluate the effects of ABO incongruency on neonatal outcomes, particularly on NEC and pulmonary hypertension.

引言：早产新生儿发生并发症的风险极高，炎症与其中多种病理过程密切相关。ABO血型不合（ABO incongruency）指母婴血型不符，当母体产生针对新生儿血型抗原的抗体时，可能引发并发症。本研究旨在探讨：母亲为O型血的A型或B型血早产新生儿（ABO不合组），其新生儿并发症发生率是否高于母婴均为O型血的早产新生儿（ABO相合组）。本研究提出假设：ABO不合的早产新生儿的新生儿不良事件发生率更高。
方法：本研究为基于人群的单中心回顾性队列研究，纳入2018年1月至2022年12月期间于爱荷华大学医疗保健系统新生儿重症监护病房（Neonatal Intensive Care Unit, NICU）收治的371例早产新生儿，其母亲均为O型血，新生儿胎龄为21⁰/₇~32⁶/₇周。研究对象按ABO血型相合/不合情况，以及胎龄（GA）分为22~26周与27~32周两个亚组。收集研究对象的人口学资料，观察结局包括：支气管肺发育不良（bronchopulmonary dysplasia, BPD）、肺动脉高压（pulmonary hypertension）、动脉导管未闭（patent ductus arteriosus, PDA）、坏死性小肠结肠炎（necrotizing enterocolitis, NEC）、悬浮红细胞（packed red blood cell, pRBC）输注、脑室内出血（intraventricular hemorrhage, IVH）、脑室周围白质软化（periventricular leukomalacia, PVL）以及出院存活率。
结果：胎龄27~32周的ABO不合新生儿更易发生坏死性小肠结肠炎，且早期肺动脉高压的发生率呈升高趋势；胎龄22~26周的ABO不合新生儿则呈现出更高的心脏功能异常发生率与更严重的脑室内出血程度趋势。
结论：ABO血型不合与早产新生儿的并发症发生相关。本研究的检验效能不足以全面评估所有新生儿不良结局。未来需开展更多研究以明确ABO血型不合对新生儿结局的影响，尤其是针对坏死性小肠结肠炎与肺动脉高压。