Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada.
Division of Maternal Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
Acta Obstet Gynecol Scand. 2021 Oct;100(10):1756-1770. doi: 10.1111/aogs.14206. Epub 2021 Jun 28.
Conflicting reports of increases and decreases in rates of preterm birth (PTB) and stillbirth in the general population during the COVID-19 pandemic have surfaced. The objective of our study was to conduct a living systematic review and meta-analyses of studies reporting pregnancy and neonatal outcomes by comparing the pandemic and pre-pandemic periods.
We searched PubMed and Embase databases, reference lists of articles published up until 14 May 2021 and included English language studies that compared outcomes between the COVID-19 pandemic time period and pre-pandemic time periods. Risk of bias was assessed using the Newcastle-Ottawa scale. We conducted random-effects meta-analysis using the inverse variance method.
Thirty-seven studies with low-to-moderate risk of bias, reporting on 1 677 858 pregnancies during the pandemic period and 21 028 650 pregnancies during the pre-pandemic period, were included. There was a significant reduction in unadjusted estimates of PTB (28 studies, unadjusted odds ratio [uaOR] 0.94, 95% confidence [CI] 0.91-0.98) but not in adjusted estimates (six studies, adjusted OR [aOR] 0.95, 95% CI 0.80-1.13). The reduction was noted in studies from single centers/health areas (uaOR 0.90, 95% CI 0.86-0.94) but not in regional/national studies (uaOR 0.99, 95% CI 0.95-1.03). There was reduction in spontaneous PTB (five studies, uaOR 0.89, 95% CI 0.82-0.98) and induced PTB (four studies, uaOR 0.90, 95% CI 0.81-1.00). There was no reduction in PTB when stratified by gestational age <34, <32 or <28 weeks. There was no difference in stillbirths between the pandemic and pre-pandemic time periods (21 studies, uaOR 1.08, 95% CI 0.94-1.23; four studies, aOR 1.06, 95% CI 0.81-1.38). There was an increase in birthweight (six studies, mean difference 17 g, 95% CI 7-28 g) during the pandemic period. There was an increase in maternal mortality (four studies, uaOR 1.15, 95% CI 1.05-1.26), which was mostly influenced by one study from Mexico. There was significant publication bias for the outcome of PTB.
The COVID-19 pandemic time period may be associated with a reduction in PTB; however, referral bias cannot be excluded. There was no difference in stillbirth between the pandemic and pre-pandemic period.
在 COVID-19 大流行期间，有关早产 (PTB) 和死产率增加和减少的相互矛盾的报告已经出现。我们研究的目的是通过比较大流行时期和大流行前时期来进行妊娠和新生儿结局的实时系统评价和荟萃分析。
我们检索了 PubMed 和 Embase 数据库，以及截至 2021 年 5 月 14 日发表的文章的参考文献列表，并纳入了比较 COVID-19 大流行时期和大流行前时期结果的英语研究。使用纽卡斯尔-渥太华量表评估偏倚风险。我们使用逆方差法进行随机效应荟萃分析。
纳入了 37 项具有低至中度偏倚风险的研究，这些研究报告了大流行期间的 1677858 例妊娠和大流行前期间的 21028650 例妊娠。未调整的早产估计值显著降低（28 项研究，未调整的优势比 [uaOR] 0.94，95%置信区间 [CI] 0.91-0.98），但调整后的估计值没有降低（6 项研究，调整后的 OR [aOR] 0.95，95% CI 0.80-1.13）。这种降低在单中心/卫生区域的研究中观察到（uaOR 0.90，95% CI 0.86-0.94），但在区域/国家研究中没有观察到（uaOR 0.99，95% CI 0.95-1.03）。自发性早产（5 项研究，uaOR 0.89，95% CI 0.82-0.98）和诱导性早产（4 项研究，uaOR 0.90，95% CI 0.81-1.00）均有所降低。按孕龄 <34 周、<32 周或 <28 周分层时，早产率没有降低。大流行期间和大流行前时期的死产率没有差异（21 项研究，uaOR 1.08，95% CI 0.94-1.23；4 项研究，aOR 1.06，95% CI 0.81-1.38）。在大流行期间，出生体重增加（6 项研究，平均差异 17 克，95% CI 7-28 克）。孕产妇死亡率增加（4 项研究，uaOR 1.15，95% CI 1.05-1.26），这主要受墨西哥的一项研究影响。PTB 结局存在显著的发表偏倚。
COVID-19 大流行期间可能与早产率降低有关；但是，不能排除转诊偏倚。大流行期间和大流行前时期的死产率没有差异。
