Table 1.
Main characteristics of studies included in the systematic review
| First author, y (country) | Design (sample size) | Group with SARS-CoV-2 infection | Timing of the diagnosis of SARS-CoV-2 infection | Group without SARS-CoV-2 infection | Adjustment for confounders or matching of variables | Outcome |
|---|---|---|---|---|---|---|
| Ahlberg,88 2020 (Sweden) | Retrospective cohort (759) | n=155; women with a positive RT-PCR test result (98%) or positive for antibodies against SARS-CoV-2 (2%); 65% asymptomatic and 35% symptomatic | Admission for delivery (91%) and antepartum period (9%); ∼90% during the third trimester | n=604; women in labor with a negative RT-PCR test result (100%) | Maternal age, parity, body mass index, country of birth, living with partner, and prepregnancy comorbidity | Preeclampsia |
| Yang,89 2020 (China) | Retrospective cohort (11,078) | n=65; women with a positive RT-PCR test result (100%) | “During late pregnancy” | n=11,013; women with a negative RT-PCR test result (57%) or without signs or symptoms of COVID-19 (43%) | Maternal age, occupation, education, gravidity, parity, gestational hypertension, preeclampsia, gestational diabetes mellitus, and premature rupture of membranes | Preeclampsia |
| Prabhu,90 2020 (United States) | Prospective cohort (675) | n=70; women with a positive RT-PCR test result (100%); 79% asymptomatic and 21% symptomatic | Admission for delivery (100%); median gestational age, 39.0 wk | n=605; women admitted for delivery with a negative RT-PCR test result (100%) | No | Preeclampsia |
| Grechukhina,91 2020 (United States) | Retrospective cohort (8768) | n=77; women with a positive RT-PCR test result (100%); 53% asymptomatic and 47% symptomatic | Admission for delivery (67%), antepartum period (24%), and postpartum period (9%); most during the third trimester | n=8691; prepandemic (2018–2019) control group of pregnant women | No | Preeclampsia |
| Adhikari,92 2020 (United States) | Retrospective cohort (3280) | n=245; women with a positive RT-PCR test result (100%); 39% asymptomatic, 56% with mild or moderate illness and 5% with severe or critical illness | Admission for delivery (68%), antepartum period (30%), and unclear (2%); 93% during the third trimester and 7% during the second trimester | n=3035; women with a negative RT-PCR test result (100%) | No | Preeclampsia with severe features |
| Pirjani,93 2020 (Iran) | Prospective cohort (199) | n=66; women with a positive RT-PCR test result, or signs or symptoms of COVID-19 plus a chest CT scan suggestive of the disease; 100% symptomatic | During the second (24%) and third (74%) trimester; mean gestational age, 32.6 wk | n=133; healthy women without signs or symptoms of COVID-19 (100%) | Maternal age, body mass index, previous delivery type, gestational age, previous pregnancy problems, and preexisting medical problems | Preeclampsia |
| Wang,94 2020 (United States) | Retrospective cohort (813) | n=53; women with a positive RT-PCR or antigen test result (100%); 85% with asymptomatic or mild illness and 15% with moderate, severe, or critical illness | Admission to the hospital (100%); mean gestational age, 38.1 wk | n=760; women with a negative RT-PCR or antigen test result, or without signs or symptoms of COVID-19 | No | Preeclampsia with severe features |
| Egerup,95 2021 (Denmark) | Prospective cohort (1313) | n=28; women with a positive result for anti–SARS-CoV-2 IgM or IgG antibodies in serum (100%); no woman had a positive RT-PCR test result; 50% asymptomatic and 50% symptomatic | Admission for delivery (100%); median gestational age, 40.1 wk | n=1285; women with a negative result for anti–SARS-CoV-2 IgM and IgG antibodies in serum (100%); one woman had a positive RT-PCR test result | No | Preeclampsia |
| Hcini,96 2021 (French Guiana) | Prospective cohort (507) | n=137; women with a positive RT-PCR test result (100%); 63% asymptomatic, 33% with mild illness, and 4% with severe illness | Admission for delivery (100%); most during the third trimester | n=370; women admitted for delivery with a negative RT-PCR test result (100%) | “Unbalanced maternal characteristics” | Preeclampsia |
| Mahajan,97 2021 (India) | Retrospective cohort (73) | n=10; women with multiple gestation and a positive RT-PCR test result (100%); 80% asymptomatic and 20% symptomatic | During the second (25%) and third (75%) trimesters; median gestational age, 34.5 wk | n=63; prepandemic (2019–2020) control group of pregnant women with multiple gestation | No | Preeclampsia and eclampsia |
| Madden,98 2021 (United States) | Retrospective cohort (1715) | n=167; women with a positive RT-PCR test result (100%) | Admission to the hospital (100%) | n=1548; women with a negative RT-PCR test result (100%) | No | Preeclampsia, preeclampsia with severe features, and preeclampsia without severe features |
| Colon-Aponte,99 2021 (United States) | Prospective cohort (24) | n=12; women with a positive RT-PCR test result (100%) | Admission for delivery (100%); mean gestational age, 39.0 wk | n=12; women with a negative RT-PCR test result (100%) | No | Preeclampsia |
| Yazihan,100 2021 (Turkey) | Prospective cohort (187) | n=95; women with a positive RT-PCR test result (100%); 74% with mild illness, 24% with moderate illness, and 2% with severe illness | During the first (34%), second (34%) and third (33%) trimesters | n=92; healthy women without signs or symptoms of COVID-19 | No | Preeclampsia |
| Brandt,101 2021 (United States) | Prospective cohort (183) | n=61; women with a positive RT-PCR test result (100%); 89% with asymptomatic or mild illness, and 11% with severe or critical illness | Mean gestational age, 38.8 wk for women with asymptomatic or mild illness and 33.6 wk for those with severe or critical illness | n=122; women with a negative RT-PCR test result or those without signs or symptoms of COVID-19 | Maternal age, obesity, maternal race, and comorbid medical problems (chronic hypertension, diabetes mellitus, renal disease, asthma, immunocompromised state, and anemia) | Preeclampsia |
| Cardona-Pérez,102 2021 (Mexico) | Retrospective cohort (231) | n=67; women with a positive RT-PCR test result (100%); 86% asymptomatic and 14% symptomatic | Admission for delivery (100%); <28 wk, 10%; 28–36 wk, 24%, ≥37 wk, 66% | n=164; women with a negative RT-PCR test result (100%) | Maternal age, body mass index, preexisting comorbidities, and gestational age at admission | Preeclampsia |
| Steffen,103 2021 (United States) | Prospective cohort (1000) | n=61; women with a positive result for anti–SARS-CoV-2 IgG antibodies in serum (84%) or RT-PCR test (5%) or both tests (11%); 51% asymptomatic and 49% symptomatic | Admission for delivery (100%); median gestational age, 39.0 wk | n=939; women with a negative result for anti–SARS-CoV-2 IgG antibodies in serum or RT-PCR test (100%) | No | Preeclampsia, preeclampsia with severe features, preeclampsia without severe features, and eclampsia |
| Jering,104 2021 (United States) | Cross-sectional (406,446) | n=6380; women giving birth with a diagnosis of COVID-19 at discharge (ICD-10 code U07.1). Diagnostic criteria for SARS-CoV-2 infection were not reported | At birth; 98% in the third trimester | n=400,066; women giving birth without a diagnosis of COVID-19 at discharge (ICD-10 code U07.1) | Adjusted for propensity score, which included the following covariates: maternal age, race and ethnicity, geographic region, urban population, teaching hospital, discharge month, trimester of pregnancy, obesity, smoking, hypertension, gestational hypertension, diabetes, gestational diabetes, kidney disease, pulmonary disease | Preeclampsia, eclampsia, and HELLP syndrome |
| Vousden,105 2021 (United Kingdom) | Prospective cohort (1842) | n=1148; women with a positive RT-PCR test result within 7 days of admission to hospital (99%) or chest imaging suggestive of COVID-19 (1%); 37% asymptomatic and 63% symptomatic | <22 wk, 7%; 22–27 wk, 7%; ≥28 wk, 86% | n=694; prepandemic (2017–2018) control group of pregnant women | Maternal age, ethnicity, body mass index, any relevant previous medical problem, cigarette smoking | Preeclampsia |
| Abedzadeh-Kalahroudi,106 2021 (Iran) | Prospective cohort (149) | n=55; women with a positive RT-PCR test result, signs or symptoms of COVID-19, or laboratory tests and a chest CT scan suggestive of the disease; >90% symptomatic | During the first (7%), second (14%), and third (79%) trimesters; mean gestational age, 31.9 wk | n=94; healthy women without clinical signs or symptoms of COVID-19 (100%) | No | Preeclampsia |
| Crovetto,107 2021 (Spain) | Prospective cohort (1304) | n=176; women with a positive result for anti–SARS-CoV-2 IgG or IgM or IgA antibodies in serum (∼99%) and/or RT-PCR test; 60% asymptomatic and 40% symptomatic | Admission for delivery (100%); 24–42 wk | n=1128; women with a negative result for anti–SARS-CoV-2 IgG and IgM or IgA antibodies in serum or negative RT-PCR test (100%) | No | Preeclampsia |
| Rosenbloom,108 2021 (United States) | Retrospective cohort (249) | n=83; women with a positive RT-PCR or antigen test result (100%); 58% asymptomatic and 42% symptomatic | Any time during pregnancy | n=166; women with a negative RT-PCR test result (100%) | Race, parity | Preeclampsia, preeclampsia with severe features, and preeclampsia without severe features |
| Trahan,109 2021 (Canada) | Retrospective cohort (270) | n=45; women with a positive RT-PCR test result (100%); 27% asymptomatic and 73% symptomatic | Any time during pregnancy; 98% in the third trimester | n=225; women with a negative RT-PCR test result (100%) | No | Preeclampsia |
| Soto-Torres,110 2021 (United States) | Retrospective cohort (209) | n=106; women with a positive RT-PCR or antigen test result (100%); 54% asymptomatic and 46% symptomatic (28% with mild illness and 18% with severe illness) | Any time during pregnancy; median gestational age, 32.9 wk (range, 10.9–40.4 wk); | n=103; women with a negative RT-PCR or antigen test result (100%) | Maternal age, body mass index, parity, gestational age | Preeclampsia |
| Katz,111 2021 (United States) | Prospective cohort (1454) | n=490; women with a positive RT-PCR test result within 14 d of delivery (100%); 64% asymptomatic and 36% symptomatic | Within 14 d of delivery; most in the third trimester | n=964; women with a negative RT-PCR test result (84%) or without signs or symptoms of COVID-19 (16%) | Maternal age, race, ethnicity, body mass index, and maternal comorbidities (including diabetes, preexisting hypertension, cardiac, pulmonary, or autoimmune disease) | Preeclampsia |
| Chornock,112 2021 (United States) | Retrospective cohort (1008) | n=73; women with a positive RT-PCR test result (100%); 84% asymptomatic and 16% symptomatic | Admission for delivery (99.2%) and antepartum period (0.8%); mean gestational age, 40.1 wk | n=935; women with a negative RT-PCR test result at admission for delivery (100%) | Race, body mass index, aspirin use, and chronic hypertension | Preeclampsia, preeclampsia with severe features, and preeclampsia without severe features |
| Cruz Melguizo,113 2021 (Spain) | Prospective cohort (2954) | n=1347; women with a positive RT-PCR test result (100%); 51% asymptomatic and 49% symptomatic (35% with mild or moderate illness and 14% with severe or critical illness) | Any time during pregnancy; most in the third trimester | n=1607; women with a negative RT-PCR test result at admission for delivery (100%) | No | Preeclampsia, preeclampsia with severe features, and preeclampsia without severe features |
| Gurol-Urganci,114 2021 (United Kingdom) | Cross-sectional (342,080) | n=3527; women with a positive RT-PCR test result (100%) | At the time of birth (100%) | n=338,553; women without laboratory-confirmed SARS-CoV-2 infection (ICD-10 code U07.1) | Maternal age, ethnicity, parity, preexisting diabetes, preexisting hypertension, and socioeconomic deprivation | Preeclampsia |
| Papageorghiou,115 2021 (Multicountry)a | Prospective cohort (2184) | n=725; women with a positive RT-PCR test result (92.7%), clinical signs or symptoms of COVID-19 (6.8%), or chest imaging suggestive of COVID-19 (0.6%); 40% asymptomatic and 60% symptomatic | ≤26 wk, 5%; >26 wk, 95%; median gestational age, 37.6 wk (IQR 34.3–39.1); 71% of women were diagnosed <10 d before giving birth | n=1459; women with a negative RT-PCR or antigen test result (50%) or women without signs or symptoms of COVID-19 (50%) | Maternal age, parity, cigarette smoking, overweight or obesity, history of diabetes, cardiac disease, hypertension, or renal disease, and history of adverse pregnancy outcomes | Preeclampsia |
CT, computed tomography; HELLP, hemolysis, elevated liver enzymes, low platelet count; ICD, International Classification of Diseases; IgM, immunoglobulin M; IQR, interquartile range; RT-PCR, reverse transcription polymerase chain reaction.
Conde-Agudelo. Association between SARS-CoV-2 infection during pregnancy and preeclampsia. Am J Obstet Gynecol 2022.
a
Includes cases from Argentina, Brazil, Egypt, France, Ghana, India, Indonesia, Italy, Japan, Mexico, Nigeria, North Macedonia, Pakistan, Russia, Spain, Switzerland, the United Kingdom, and the United States.