TABLE 4.
Pregnancy and infant outcomes by trimester of infection during delta variant predominance
| Total N (%) | First/second trimester, n (%) | Third trimester, n (%) | Unadjusted PR (95% CI) | Adjusted PRa (95% CI) | ||
|---|---|---|---|---|---|---|
| Totalb | 18,222 (100.0) | 11,031 (60.5) | 7191 (39.5) | |||
| Outcome | Live birth | 18,067 (99.1) | 10,920 (99.0) | 7147 (99.4) | ref | ref |
| Stillbirth | 133 (0.7) | 89 (0.8) | 44 (0.6) | 0.76 (0.52–1.08) | 0.69 (0.41–1.14) | |
| Spontaneous abortion | 22 (0.1) | 22 (0.2) | N/A | |||
| Gestational agec | Term | 13,692 (87.2) | 9680 (88.6) | 4012 (83.9) | ref | ref |
| Preterm | 2012 (12.8) | 1240 (11.4) | 772 (16.1) | 1.42 (1.30–1.55)d | 1.41 (1.28–1.56)d | |
| Late preterm (34–37 wk) | 1484 (9.4) | 893 (8.2) | 591 (12.4) | |||
| Moderate preterm (32–34 wk) | 277 (1.8) | 153 (1.4) | 124 (2.6) | |||
| Early preterm (28–32 wk) | 167 (1.1) | 110 (1.0) | 57 (1.2) | |||
| Very preterm (20–28 wk) | 84 (0.5) | 84 (0.8) | N/A | |||
| Unknown | 0 (0.0) | 0 (0.0) | 0 (0.0) | |||
| Preterm birth indicatione | Spontaneous | 375 (18.6) | 221 (17.8) | 154 (19.9) | N/A | N/A |
| Indicated | 563 (28.0) | 338 (27.3) | 225 (29.1) | N/A | N/A | |
| Unknown | 1074 (53.4) | 681 (54.9) | 393 (50.9) | |||
| Small for gestational age | Yes | 1024 (5.7) | 596 (5.5) | 428 (6.0) | 1.10 (0.97–1.25) | 1.10 (0.96–1.27) |
| No | 16,960 (93.9) | 10,294 (94.3) | 6666 (93.3) | ref | ref | |
| Unknown | 83 (0.5) | 30 (0.3) | 53 (0.7) | |||
| Neonatal intensive caref | NICU admission | 667 (4.2) | 367 (3.8) | 300 (4.7) | 1.29 (1.11–1.50)d | 1.21 (1.01–1.45)d |
| None | 15,031 (93.6) | 9239 (95.4) | 5792 (90.9) | ref | ref | |
| Unknown | 355 (2.2) | 74 (0.8) | 281 (4.4) |
CI, confidence interval; NICU, neonatal intensive care unit; PCR, polymerase chain reaction.
Adjusted for continuous maternal age, race/ethnicity, and insurance at delivery.;
Row percent for total; remaining table includes column percent.;
Among live-born infants with maternal infection occurring at <37 weeks of gestation.;
Indicates statistical significance.;
Among live-born infants with maternal infection occurring at <37 weeks of gestation. Spontaneous preterm birth was reported if evidence existed of premature rupture of membranes, vaginal delivery, or labor was not induced and there was evidence of attempted use of forceps, vacuum, prolonged labor, precipitous labor, fetal intolerance to labor, or augmentation of labor. Indicated preterm birth was defined as no evidence of premature rupture of membranes, labor was induced, or evidence of cesarean delivery. Methodology adapted from Klebanoff, et al20.;
Among term, live-born infants.