Table 2 Crude gestational age (days) with 95% confidence intervals (CI) among referred women potentially exposed to endocrine disrupting chemicals (EDC), and among the internal and the external reference group
n | Median | Mean | 95% CI | Mean difference (95% CI) | ||
|---|---|---|---|---|---|---|
Exposed versus internal reference | Exposed versus external reference | |||||
Exposed to EDC | 582 | 280 | 277.5 | 276.4 – 278.7 | −1.21 (−2.82 – 0.39) | −0.27 (−1.4 – 0.90) |
Internal references | 620 | 280 | 278.7 | 277.7 – 279.9 | . | . |
External references | 346,544 | 280 | 277.8 | 277.8 – 277.8 | . | . |