Table 2.
Cohort or case series studies from China
| Author | Number of women | Number of eligible neonates | GA at onset of Sx or diagnosis (range) | Mode of delivery | RT-PCR for SARS-CoV-2 |
Neonatal serology | Placental histology | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Neonatal NP swab | Placenta | Cord blood | Amniotic fluid | Other fetal sites or tests | |||||||
| Cao et al59 | 10 | 5 | GA at admission: 33 wk 6 d–40 wk 5 d | VD 2; CD 8 | 0/5 | None | None | None | None | None | None |
| Chen et al10 | 9 | 6 | GA at admission: 36 wk–39 wk 4 d | CD 9 | 0/6 | None | 0/6 | 0/6 | None | None | None |
| Hu et al60 | 7 | 7 | 37–40 wk | VD 1; CD 6 | 1/7 (subsequent swabs were negative for that positive neonate) | None | None | 0/7 positive | Fetal blood (0/7), feces (0/7), urine (0/7) | None | None |
| Khan et al61 | 17 | 17 | Date of admission: 35–41 wk | CD 17 | 2/17 | None | None | None | None | None | None |
| Liu et al62 | 19 | 19 | 36 wk 3 d–41 wk 2 d | CD 19 | 0/19 | None | 0/10 | 0/10 | Urine (0/10), anal swabs (0/10) | None | None |
| Nie et al63 | 33 | 28 | 3 women in the second trimester (17–26 wk), rest in the third trimester | VD 5, CD 22 | 1/28 | 0/1 | 0/1 | None | None | 1/28 | None |
| Qiancheng et al64 | 28 | 23 | Median GA on admission=38 wk (IQR, 36.5–39) | VD 5, CD 17 | 0/23 | None | None | None | None | None | None |
| Yan et al11 | 116 | 100 | 37 wk 3 d–39 wk 4 d | CD 85, VD 14 | 0/86 | None | 0/10 | 0/10 | None | None | None |
| Yang et al65 | 7 | 7 | 36–38 wk | CD 7 | 0/5 | None | 0/5 | 0/5 | None | None | None |
| Yin et al66 | 31 | 17 | N/A | VD 4, CD 13, TAB 3 | 0/17 | 0/2 | None | 0/2 | Rectal swab (0/5) | None | None |
| Yu et al56 | 7 | 7 | 37 wk–41 wk 5 d | CD 7 | 1/3 | None | None | None | None | None | None |
| Zeng et al26 | 6 | 6 | N/A | CD 6 | 0/6 | None | None | None | Fetal blood | Elevated IgM (2/6), elevated IgG (3/6) | None |
| Zeng et al67 | 33 | 33 | 31 wk 2 d–41 wk 4 d | VD 7, CD 26 | 3/33 | None | None | None | Anal swab (3/33) | None | None |
| Zhu et al9 | 9 | 10 | 33 wk 6 d–39 wk | VD 2, CD 7 | 0/9 | None | None | None | None | None | None |
| Chen et al68 | 5 | 5 | 38–41 wk | VD 3, CD 2 | 0/5 | None | None | None | None | None | No placental infarction and chorionic amniotic inflammation |
| Chen et al69 | 17 | 17 | 3<37 wk, 14>37 wk | CD 17 | 0/17 | None | None | None | None | None | None |
| Liao et al70 | 88 | 10 | 36–40 wk | VD 10 | 0/7 | None | None | None | None | None | None |
| Liu et al71 | 51 | 51 | GA at delivery: 35 wk 1 d–41 wk 2 d | VD 3, CD 48 | 0/51 (5 were considered false positive) | None | None | None | None | IgM and IgG (0/51) | None |
| Wu et al72 | 13 | 5 | 5–38 wk | VD 1, CD 4 | 0/5 | None | None | None | Anal (0/4) | None | None |
| Wu et al73 | 23 | 21 (1 case of twins) | First trimester (6–12 wk), third trimester (31 wk 5 d–40 wk) | VD 2, CD 18 | 0/5 (5 negative by RT-PCR, 17 negative by clinical criteria) | None | None | None | None | None | None |
| Yang et al74 | 55 | 57 (2 cases of twins) | Average GA: 38 wk | VD 16, CD 39 | 0/20 | None | None | None | None | None | None |
| Yang et al75 | 27 | 24 (1 case of twins) | 3 women in the first trimester, rest in the third trimester (30–40 wk) | VD 5, CD 18 | 0/23 | None | None | None | None | IgM and IgG (1/1), other 23 not tested | None |
All papers are identified by author, country (unless otherwise specified), and citation number within the main text.
BAL, bronchoalveolar lavage; CD, cesarean delivery; EM, electron microscopy; GA, gestational age; IgG, immunoglobulin G; IgM, immunoglobulin G; IQR, interquartile range; N/A, not available; NP, nasopharyngeal; RT-PCR, reverse transcription–polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; Sx, symptoms; TAB, therapeutic abortion; VD, vaginal delivery.
Kotlyar. Vertical transmission of COVID-19: a systematic review and meta-analysis. Am J Obstet Gynecol 2021.