Table 1. Characteristics of reports following 2009 H1N1 vaccines among pregnant women, November 1, 2009–August 31, 2010, by vaccine type.
| Characteristic | Vaccine type | |
| Unadjuvanted vaccine | MF59®-adjuvanted vaccine | |
| (n = 28) | (n = 7) | |
| Serious reportsa, n (%) | 14 (50) | 3 (43) |
| Maternal deaths, n (%) | 0 (0) | 0 (0) |
| Median maternal age (range), y | 34 (18–42) | 31 (21–36) |
| Median onset interval (range), d | 19.5 (0–70) | 32 (7–46) |
| Median gestational age at time of onset (range), w | 16.5 (6–40) | 20 (15–37) |
| Gestational ageb at time of vaccination, n (%) | ||
| First trimester | 10 (36) | 4 (57) |
| Second trimester | 13 (46) | 1 (14) |
| Third trimester | 5 (18) | 2 (29) |
a
Reports were categorized as serious if they resulted in death, life-threatening illness, hospitalization, prolongation of an existing hospitalization, permanent disability, or congenital anomaly.
b
First trimester, 0–13 weeks; second trimester, 14–27 weeks; third trimester, ≥28 weeks of pregnancy.