Stillbirth rates in Peruvian populations at high altitude

Objective: To compare the stillbirth rates in 4 cities at different altitudes in Peru. Methods: The stillbirth rates from a sample of 22,662 births recorded in the Perinatal Information System database were analyzed between 2005 and 2006 for the cities of Lima (150 m), Huancayo (3280 m), Cuzco (3430 m), and Puno (3850 m). Results: Stillbirths were higher at high altitude (> 3000 m) (OR 4.82; CI, 3.05-7.72) compared with low altitude. The effect of altitude was observed after controlling for socioeconomic (OR 4.29; CI, 2.61-6.93), demographic and biological (OR 4.18; CI, 2.65-6.77), maternal health care (OR 4.72; CI, 2.96-7.61), and fetal factors (OR 3.96; CI, 2.48-6.45). Inhabitants from the southern Andes demonstrated a protective effect on stillbirth rate compared with the central Andes, which may be due to an ancestry effect with longer multigenerational residence in the southern Andes population. Conclusion: Stillbirth rate is higher at high altitude compared with low altitude.