Short stature, smoking habits and birth outcome in international adoptees in Sweden.

Objective. To investigate short stature and smoking habits as risk factors for birth outcome in international adoptees in comparison with non-adopted mothers. Design. Prospective cohort study. Setting. Nationwide study in Sweden. Population. Two study groups were identified from mothers who were born 1968-1979 and gave birth during 1982-2001 - 3,610 mother-child dyads with a mother adopted from a non-European country and 336,992 mother-child dyads with a mother born in Sweden. Method. Register study. Outcome measures. Pre-eclampsia, instrumental delivery, preterm delivery, small for gestational age (SGA), Apgar score, cephalhematoma and perinatal mortality and birth weight. Results. Short stature and smoking were more common in international adoptees compared with non-adopted, odds ratios (ORs) 29.07 (95% C.I.: 25.29-33.42) and 1.39 (1.27-1.52), respectively. International adoptees had a slightly increased risk for instrumental delivery (OR: 1.42; 1.32-1.54) and preterm delivery (<37 weeks) (OR: 1.39; 1.24-1.56) and there was a slightly increased risk for SGA (OR: 1.24; 1.01-1.52) in their offspring. However, when we adjusted for maternal height, preterm delivery was the only outcome that remained statistically significant. Adjustment for smoking habits had marginal effects on all outcomes. Conclusion. The short stature of international adoptees increased their risk for delivery and birth complications in a predictable manner, but otherwise outcomes were very similar to the general population. No special obstetric monitoring is indicated by adoption status in itself. [ABSTRACT FROM AUTHOR]