TABLE 6.
Estimated Number of Well-Appearing Infants Born to Women With Chorioamnionitis Potentially Treated for Each Initially Asymptomatic Infant With Culture-Confirmed, Early-Onset Infection
| Number of Live Birthsa | Estimated Chorioamnionitis Prevalence, % | Estimated Number of Infants Whose Mothers Had Chorioamnionitis | Estimated Number Of Chorioamnionitis-Exposed Infants Without Symptoms of Early-Onset Infection at Birthb | Estimated Number of Well-Appearing Chorioamnionitis-Exposed Infants Evaluated and Treated for Each Initially Asymptomatic Infant With Early-Onset Infectionc |
|---|---|---|---|---|
| Overall (N = 396 586) | 0.5 | 1983 | 1783 | 60 |
| 1 | 3966 | 3766 | 130 | |
| 3 | 11 898 | 11 698 | 400 | |
| 10 | 39 659 | 39 459 | 1400 | |
| Term (n = 348 996) | 0.5 | 1745 | 1687 | 70 |
| 1 | 3490 | 3432 | 150 | |
| 3 | 10 470 | 10 412 | 450 | |
| 10 | 34 900 | 34 842 | 1500 | |
| Preterm (n = 47 590) | 6 | 2856 | 2714 | 450 |
| 20 | 9518 | 9376 | 1600 | |
| 40 | 19 036 | 18 894 | 3100 | |
| 70 | 33 313 | 33 171 | 5500 |
For these calculations, we assumed 88% of births were term and 12% were preterm.
The number of infants with culture-confirmed, early-onset infections in the cohort who were symptomatic within 6 hours of birth was subtracted from the total estimated number of infants born to mothers with chorioamnionitis. Thus, overall estimates exclude 200 symptomatic infants with culture-confirmed, early-onset infections; estimates for term infants exclude 58 symptomatic term infants; and estimates for preterm infants exclude 142 symptomatic preterm infants. The totals are likely to overestimate the number of asymptomatic chorioamnionitis-exposed infants in the cohort, because we had no data for infants who may have had symptoms but negative cultures.
Estimates were derived as the number of infants without symptoms of early-onset infection within 6 hours of birth (previous column) divided by the number of initially asymptomatic infants with culture-confirmed, early-onset infections in the cohort, namely the following: 29 infants overall, 23 term infants, and 6 preterm infants. Estimates were rounded to 1 significant digit (if <100) or 2 significant digits.