Rates of preterm delivery (PTD) and very low birth weight (VLBW) among women born in Mexico delivering in California (immigrants) and Mexico (WIMX) including women in Mexican immigrant sending states in 2009: relative risks (RR) and 95% CI
| PTD* (in weeks) and VLBW | Immigrants | WIMX | MX sending states | RR immigrant: WIMX 95% CI | RR immigrant: MX sending states 95% CI | |||
|---|---|---|---|---|---|---|---|---|
| N | Per cent | N | Per cent | N | Per cent | |||
| Any PTD | 2239 | 6.73 | 40 254 | 5.76 | 8303 | 5.47 | 1.17 (1.12 to 1.22) | 1.23 (1.17 to 1.29) |
| Early PTD (<32) | 386 | 1.23 | 5456 | 0.82 | 1104 | 0.73 | 1.50 (1.35 to 1.66) | 1.60 (1.42 to 1.79) |
| Moderate PTD (32–33) | 233 | 0.75 | 4823 | 0.73 | 1000 | 0.66 | 1.03(0.90 to 1.17) | 1.06 (0.92 to 1.23) |
| Late PTD (34–36) | 1620 | 4.87 | 29 975 | 4.29 | 6199 | 4.09 | 1.14 (1.08 to 1.19) | 1.19 (1.13 to 1.26) |
| Term (37–42) | 30 988 | 93.19 | 658 561 | 94.20 | 143 360 | 94.48 | 0.99 (0.99 to 0.99) | 0.99 (0.98 to 0.99) |
| Post-term (43–44) | 24 | 0.07 | 314 | 0.04 | 66 | Not calculated | Not calculated | |
| VLBW | 335 | 1.01 | 5503 | 0.79 | 1146 | 0.76 | 1.27(1.14 to 1.42) | 1.33 (1.18 to 1.50) |
Denominator for any PTD, term deliveries and VLBW is all deliveries.
*Denominator for early, moderate and late PTD is the outcome of interest and term deliveries only. The results that are bolded denote statistical significance at p<=0.05.