Table 2.
Potential predictors from the Copenhagen Perinatal Cohort and associations with the Overall mean of milestones
| N | Mean (SD) | Range | ra | |
|---|---|---|---|---|
| FAMILY BACKGROUND | ||||
| Parental social status (1 to 8 point scale) | 3421 | 4.5 (1.8) | 1–8 | −0.04 |
| Parity (first child, Yes %) | 4001 | 48.9% | First/not first | 0.02 |
| Maternal age | 3988 | 26.6 (6.5) | 14–48 | 0.003 |
| Paternal age | 3886 | 30.2 (7.6) | 16–71 | 0.02 |
| Single mother, prenatally (yes %) | 3998 | 23.2% | Yes/No | −0.002 |
| PREGNANCY AND DELIVERY | ||||
| Sex (female %) | 4009 | 48.9% | Female/male | −0.18*** |
| Gestational age (weeks) | 3340 | 39.1 (2.4) | 27–46.5 | −0.11*** |
| Birth weight (grams) | 3992 | 3247 (586) | 850–5450 | −0.09*** |
| Birth length (cm) | 3989 | 51.0 (2.7) | 24–60 | −0.07*** |
| Head circumference at birth (cm) | 3734 | 34.5 (1.7) | 25.1–39.7 | −0.07*** |
| BMI at birth | 3988 | 12.4 (1.4) | 7.2–17.5 | −0.09*** |
| Mother’s smoking in last trimester (yes %) | 3954 | 45.8% | Yes/no | 0.02 |
| Mother’s attitude towards pregnancy (unwanted %) | 3894 | 45.1% | Wanted/unwanted | 0.03 |
| POSTNATAL FACTORS | ||||
| Breastfeeding (months) | 3432 | 3.4 (2.8) | 0.3–12 | − 0.06*** |
| Mother’s employment (not employed at 1-year) | 2750 | 88.9% | Yes/no | 0.02 |
| Lived in full-time institution at some point in first year (yes %) | 3945 | 7.3% | Yes/no | 0.04* |
| Daycare institution at some point in the first year (yes %) | 3932 | 10.7% | Yes/no | −0.0004 |
| POSTNATAL GROWTH AND DEVELOPMENT | ||||
| Weight increase, first year (kg) | 3425 | 7.1 (1.3) | 3–20.6 | 0.00 |
| Length increase, first year (cm) | 3374 | 25.1 (3.6) | 14–46.5 | 0.05** |
| Head increase, first year (cm) | 3193 | 12.8 (1.7) | 5.5–21.3 | 0.08*** |
| BMI increase, first year | 3359 | 5.5 (2.0) | −2.7-22.4 | 0.02 |
| Weight increase, age 1–3 | 2849 | 4.5 (1.4) | −4.1-11.4 | 0.004 |
| Length increase, age 1–3 | 2871 | 20.4 (3.7) | 0–40 | −0.03 |
| Head increase, age 1–3 | 2880 | 3.4 (1.2) | 0–13.5 | 0.004 |
| Overall mean of 1-year milestones | 4008 | 0.05 (0.7) | −2.17-2.99 | 0.34*** |
a Pearson correlations were used to evaluate bivariate associations between each predictor and Overall mean of milestones (point-biserial correlation for binary predictors)
*p < 0.05; ** p < 0.01; *** p < 0.001