Table 3 Trend test in spontaneous preterm birth incidence rates in multiparous women
From: The association between parity and spontaneous preterm birth: a population based study
P1 | P2 | P3 | P4 | P-value* | |
|---|---|---|---|---|---|
Spontaneous PTB | |||||
< 37 weeks | 8065 (2.8%) | 2761 (2.6%) | 893 (2.9%) | 347 (3.7%) | 0.0178 |
< 32 weeks | 873 (0.3%) | 349 (0.3%) | 121 (0.4%) | 58 (0.6%) | <.0001 |
< 28 weeks | 367 (0.1%) | 142 (0.1%) | 64 (0.2%) | 37 (0.4%) | <.0001 |
34–37 weeks | 6406 (2.2%) | 2118 2.0%) | 675 (2.2%) | 251 (2.7%) | NS |