Cohort of 500 children Non-participants (N=483) Sex (male / female) 267 / 233 (53.4% / 46.6%) 254 / 229   (52.6% / 47.4%) N.s. Birth weight (g) 3743 / SD 473 3686 / SD 478 N.s. Length (cm) 53.4 / SD 2.1 (N=499) 53.2 / SD 2.2 (N=481) N.s. Gestational age (weeks) 40.1 / SD 1.2 40.1 / SD 1.3 N.s. Apgar at 1 min. 9.2 / SD 1.0 9.1 / SD 1.1 (N=482) N.s. Apgar at 5 min. 9.9 / SD 0.5 9.9 / SD 0.4 (N=482) N.s. Pediatrician present at delivery (no / yes) 93.2% / 6.8% 93.6% / 6.4% N.s. Transfer to intensive care or observation (no/ yes) 97.6% / 2.4% (N=497) 94.6% / 5.4% (N=482) 0.016 Maternal age (years) 29.0 / SD 5.2 28.3 / SD 5.7 0.038 Parity (including this one) 2.3 / SD 1.1 2.1 / SD 1.1 (N=482) 0.018 Civil status of mother (married or living together with father of child / other) 92.4% / 7.6% (N=397) 91.6% / 8.4 (N=370) N.s. Smoking of mother   (no / yes) 75.4% / 24.6% (N=491) 69.5% / 30.5% (N=469) 0.043 Complications during pregnancy (no / yes) 89.6% / 10.4% 85.5% / 14.5% N.s. Induction of labor (no / yes) 73.2% / 26.8% 71.2% / 28.8% N.s. Presentation at birth   (vertex / other) 87.4% / 12.6% 86.3% / 13.7% N.s. Instrumental delivery   (no / yes) 87.4% / 12.6% 85.1% / 14.9% N.s. Analgesia during delivery (none, acupuncture / more) 48.2% / 51.8% 46.0% / 54.0% N.s. Complications during delivery (no / yes) 88.4% / 11.6% 84.5% / 15.5% N.s. Color of amniotic fluid (clear / not clear) 88.6% / 11.4% (N=491) 88.2% / 11.8% (N=473) N.s. N.s.: Not significant (2-tailed P >0.05) If information was not available for all children, the number of cases is given in parenthesis. For ordinal parameters mean and standard deviation (SD) are given.   ce Significan-