Table 2.
Event rates and relative risk for pregnancy outcomes among recipients of HepB-CpG and HepB-alum.
| HepB-CpG |
HepB-alum |
|||||||
|---|---|---|---|---|---|---|---|---|
| Number of pregnancies/infants included | Number of events n (%) | Event rate (95% CI) | Number of pregnancies/infants included | Number of events n (%) |
Event rate (95% CI) | Unadjusted RR (95% CI) |
Adjusted RR (95% CI)* |
|
| Non-live birth outcomes | ||||||||
| Spontaneous abortion (involuntary loss <20 weeks) | 81 | 6 (7.4) | 0.07 (0.03-0.16) | 125 | 21 (16.8) | 0.17 (0.11-0.26) | 0.44 (0.19-1.05) | 0.40 (0.16,1.00)† |
| Induced abortion | 81 | 1 (1.2) | 0.01 (0.00-0.09) | 125 | 4 (3.2) | 0.03 (0.01-0.09) | 0.39 (0.04-3.39) | N/A |
| Stillbirth | 81 | 1 (1.2) | 0.01 (0.00-0.09) | 125 | 1 (0.8) | 0.01 (0.00-0.06) | 1.54 (0.10-24.33) | N/A |
| Live birth | ||||||||
| Low birth weight (<2500 grams) | 67 | 5 (7.5) | 0.07 (0.03-0.18) | 89 | 9 (10.1) | 0.10 (0.05-0.19) | 0.74 (0.26-2.10) | N/A |
| Preterm birth (gestational age <37 weeks) | 68 | 10 (14.7) | 0.15 (0.08-0.27) | 94 | 13 (13.8) | 0.14 (0.08-0.24) | 1.06 (0.50-2.28) | 0.97 (0.47-1.99)‡ |
| Small for gestational age (below 10th percentile) | 67 | 3 (4.5) | 0.04 (0.01-0.14) | 85 | 3 (3.5) | 0.04 (0.01-0.11) | 1.27 (0.26-6.09) | N/A |
| Major birth defects among infants born in KPSC | ||||||||
| Central nervous system defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Eye defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Ear defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Cardiovascular defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Orofacial defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Gastrointestinal defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Genitourinary defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Musculoskeletal defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Chromosomal defects | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
| Any major birth defect listed above | 66 | 0 | N/A | 67 | 0 | N/A | N/A | N/A |
Abbreviations: N/A, not applicable; KPSC, Kaiser Permanente Southern California.
*Per protocol, adjusted robust Poisson regression models were used to compare event rates when there were sufficient events to provide at least 80% power to detect a relative risk of 5.
†Adjusted for mother’s age at vaccination, pre-pregnancy body mass index, history of diabetes in the year prior to conception, income, and timing of vaccination ≤28 d prior to conception or during pregnancy. Start of prenatal care removed due to lack of convergence.
‡Adjusted for mother’s age at vaccination, pre-pregnancy body mass index, history of diabetes in the year prior to conception, income, timing of vaccination ≤28 d prior to conception or during pregnancy and start of prenatal care.