Department of Obstetrics and Gynecology, William Beaumont Hospital - Royal Oak, Royal Oak, MI, USA.
Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA.
J Matern Fetal Neonatal Med. 2023 Dec;36(1):2199343. doi: 10.1080/14767058.2023.2199343.
COVID-19 has been reported to increase the risk of prematurity, however, due to the frequent absence of unaffected controls as well as inadequate accounting for confounders in many studies, the question requires further investigation. We sought to determine the impact of COVID-19 disease on preterm birth (PTB) overall, as well as related subcategories such as early prematurity, spontaneous, medically indicated preterm birth, and preterm labor (PTL). We assessed the impact of confounders such as COVID-19 risk factors, a-priori risk factors for PTB, symptomatology, and disease severity on rates of prematurity.
This was a retrospective cohort study of pregnant women from March 2020 till October 1st, 2020. The study included patients from 14 obstetric centers in Michigan, USA. Cases were defined as women diagnosed with COVID-19 at any point during their pregnancy. Cases were matched with uninfected women who delivered in the same unit, within 30 d of the delivery of the index case. Outcomes of interest were frequencies of prematurity overall and subcategories of preterm birth (early, spontaneous/medically indicated, preterm labor, and premature preterm rupture of membranes) in cases compared to controls. The impact of modifiers of these outcomes was documented with extensive control for potential confounders. A value <.05 was used to infer significance.
The rate of prematurity was 8.9% in controls, 9.4% in asymptomatic cases, 26.5% in symptomatic COVID-19 cases, and 58.8% among cases admitted to the ICU. Gestational age at delivery was noted to decrease with disease severity. Cases were at an increased risk of prematurity overall [adjusted relative risk (aRR) = 1.62 (1.2-2.18)] and of early prematurity (<34 weeks) [aRR = 1.8 (1.02-3.16)] when compared to controls. Medically indicated prematurity related to preeclampsia [aRR = 2.46 (1.47-4.12)] or other indications [aRR = 2.32 (1.12-4.79)], were the primary drivers of overall prematurity risk. Symptomatic cases were at an increased risk of preterm labor [aRR = 1.74 (1.04-2.8)] and spontaneous preterm birth due to premature preterm rupture of membranes [aRR = 2.2(1.05-4.55)] when compared to controls and asymptomatic cases combined. The gestational age at delivery followed a dose-response relation with disease severity, as more severe cases tended to deliver earlier (Wilcoxon < .05).
COVID-19 is an independent risk factor for preterm birth. The increased preterm birth rate in COVID-19 was primarily driven by medically indicated delivery, with preeclampsia as the principal risk factor. Symptomatic status and disease severity were significant drivers of preterm birth.
有报道称，COVID-19 会增加早产的风险，然而，由于许多研究中经常缺乏未受影响的对照组，并且对混杂因素的处理不充分，因此这个问题需要进一步研究。我们旨在确定 COVID-19 疾病对早产（PTB）的总体影响，以及相关的亚类，如早期早产、自发性、医学上需要的早产和早产临产（PTL）。我们评估了 COVID-19 风险因素、早产的预先存在的风险因素、症状和疾病严重程度等混杂因素对早产率的影响。
这是一项对 2020 年 3 月至 2020 年 10 月 1 日期间孕妇的回顾性队列研究。该研究包括来自美国密歇根州 14 个产科中心的患者。病例定义为在妊娠期间任何时候被诊断为 COVID-19 的妇女。病例与在指数病例分娩后 30 天内在同一单位分娩的未感染妇女相匹配。感兴趣的结局是病例与对照组相比，早产的总体发生率和早产的亚类（早期、自发性/医学上需要的、早产临产和早产胎膜早破）。记录了这些结局的修饰因素的影响，并对潜在混杂因素进行了广泛的控制。 <.05 用于推断显著性。
对照组的早产率为 8.9%，无症状病例为 9.4%，有症状 COVID-19 病例为 26.5%，重症监护病房（ICU）病例为 58.8%。分娩时的胎龄随着疾病严重程度的增加而降低。与对照组相比，病例总体上早产的风险增加（调整后的相对风险[aRR] = 1.62（1.2-2.18]），早期早产（<34 周）的风险增加[aRR = 1.8（1.02-3.16]）。与子痫前期相关的医学上需要的早产[aRR = 2.46（1.47-4.12）]或其他指征[aRR = 2.32（1.12-4.79）]是总体早产风险的主要驱动因素。与对照组和无症状病例相比，有症状病例早产临产的风险增加[aRR = 1.74（1.04-2.8）]，自发性早产由于早产胎膜早破的风险增加[aRR = 2.2（1.05-4.55）]。随着疾病严重程度的增加，分娩时的胎龄呈剂量-反应关系，病情较重的病例往往更早分娩（Wilcoxon <.05）。
COVID-19 是早产的一个独立危险因素。COVID-19 中早产率的增加主要是由医学上需要的分娩引起的，子痫前期是主要的风险因素。症状和疾病严重程度是早产的重要驱动因素。
