Pregnancy characteristics in the Pregnancy Cohort and the Child Cohort of the PPRN
| PHARMO Perinatal Research Network (PPRN) 1999–2017 | Perined 1999–2017 (reference) | ||
| Pregnancy Cohort | Child Cohort | Total population | |
| Pregnancies (n) | ~542 900 | ~126 200 | ~3 200 000 |
| Mothers (n) | ~387 100 | ~101 400 | – |
| Maternal characteristics | |||
| Age at delivery (mean±SD; years) | 31.0±4.8 | 30.8±4.7 | 31.0±4.9 |
| Nulliparous (%) | 46 | 57 | 47 |
| Dutch ethnicity (%) | 79 | 84 | 79 |
| Database history before delivery (mean±SD; years) | 6.0±4.3 | 6.1±4.3 | – |
| Database follow-up after delivery (mean±SD; years)* | 7.9±5.0 | 7.7±4.7 | – |
| Infant characteristics | |||
| Male sex (%) | 51 | 53 | 51 |
| Gestational age at birth (mean±SD; weeks) | 39.1±3.5 | 39.2±2.7 | 39.3±2.3 |
| Preterm birth (%) | 8 | 7 | 8 |
| Multiple birth (%) | 2 | <0.5 | 4 |
| Database follow-up after birth (mean±SD; years)* | 7.8±4.7 | 7.8±4.7 | – |
*Current censoring: 31 December 2018.