Table 3.
Maternal and infant outcomes by Tdap vaccination status (N = 1,759).
| Outcomes | Did not receive Tdap vaccine (n = 650) | Received Tdap vaccine (n = 1109) | AOR (95% CI)a | p |
|---|---|---|---|---|
| Maternal outcomesb | n (%) | n (%) | ||
| Chorioamnionitisc | 14 (2.2) | 39 (3.5) | 1.53 (0.80–2.90) | 0.19 |
| Postpartum endometritisd | 5 (0.8) | 9 (0.8) | 1.67 (0.51–5.50)e | 0.41 |
| Preterm premature rupture of membranes | 19 (2.9) | 36 (3.2) | 1.05 (0.57–1.95) | 0.87 |
| Preterm delivery | 59 (9.1) | 58 (5.2) | 0.68 (0.45–1.03) | 0.07 |
| Any above maternal outcome | 89 (13.7) | 152 (13.7) | 1.09 (0.81–1.48) | 0.56 |
| Induced labor | 338 (52.0) | 656 (59.2) | 0.82 (0.66–1.51) | 0.06 |
| Mode of deliveryf | ||||
| Vaginal | 405 (62.3) | 759 (68.4) | ||
| Cesarean | 245 (37.7) | 350 (31.6) | 0.78 (0.63–0.98) | 0.03 |
| Infant outcomes | n (%) | n (%) | ||
| Low birth weight (<2500g) | 59 (9.1) | 61 (5.5) | 0.76 (0.51–1.14) | 0.19 |
| Very low birth weight (<1500g) | 12 (1.8) | 2 (0.2) | 0.24 (0.05–1.20)e | 0.08 |
| Small for gestational age (<10th percentile) | 31 (4.8) | 46 (4.2) | 0.89 (0.55–1.46) | 0.65 |
| Apgar score at 5 min of life <8 | 10 (1.5) | 14 (1.3) | 0.87 (0.22–3.52) | 0.85 |
| Birth defectg | 15 (2.3) | 18 (1.6) | 0.80 (0.38–1.67)e | 0.55 |
| NICU admission | 86 (13.2) | 103 (9.3) | 0.78 (0.56–1.08) | 0.14 |
| Any infant outcomeh | 123 (18.9) | 159 (14.3) | 0.80 (0.61–1.06) | 0.12 |
Boldface indicates statistical significance (p<0.05).
All odds ratios were adjusted by mother's age, race, number of prenatal visits, influenza vaccination status during pregnancy, number of infants born prematurely, and whether the first prenatal visit occurred before 12 weeks gestation.
Outcomes occurring anytime during pregnancy were included. Only two patients in the Tdap group experienced one of these adverse outcomes prior to vaccination (both preterm premature rupture of membranes).
Included in analyses only if patient's chart included a physician's diagnosis for chorioamnionitis, fever >100.4°F, and 2 of the following clinical findings: uterine tenderness, maternal tachycardia, fetal tachycardia, maternal leukocytosis, or foul vaginal discharge.24
Included in analyses only if a patient's chart included a physician's diagnosis for endometritis, fever ≥100.4 °F, and at least one of the following: uterine tenderness, foul-smelling vaginal discharge, or maternal leukocytosis.25
Model not adjusted by race/ethnicity due to small cell sizes.
Vaginal compared to cesarean delivery. Tdap vaccinated women were less likely to deliver by cesarean.
Includes: spina bifida, transposition of great arteries, tetralogy of Fallot, atrioventricular septal defect, cleft palate, cleft lip, rectal and large intestinal atresia/stenosis, reduction deformity of upper limbs, gastroschisis, and/or diaphragmatic hernia.
Very low birthweight not included.
NICU, Neonatal intensive care unit; AOR = adjusted odds ratio.