[Indicadores de salud perinatal en una región española entre los años 2015 y 2020.]

Objective: The availability in the literature of data related to perinatal variables in the Spanish population is very scarce. The aim of this study was to know the evolution of perinatal health indicators according to the risk groups of prematurity and birth weight, the proportion of multiple births, caesarean section and stillbirths.

Methods: We conducted a population-based cross-sectional study of births in eleven hospitals in Castilla y León (January 2015 to June 2020). There were 70,024 newborns from 68,769 deliveries. Jointpoint regression analysis was used to identify changes in trend over the years, and binomial logistic regression was used to adjust for the potential interaction of hospital type, sex, type of delivery and multiple births on the frequencies of prematurity and death.

Results: There was a 19.9% decrease in deliveries and a 42% decrease in multiple births, with no change in preterm (7.7%) and stillbirths (0.44%). The percentage of caesarean sections was 21.5% with a slight downward trend over time. Death (stillbirth) was associated with preterm multiple birth; especially with the male-male combination (p<0.05). Late preterm and early term newborns showed higher risk of death compared to term newborns: OR 7.7 (95%CI 5.6-10.7) and 2.4 (95%CI 1.6-3.6), respectively; as well as the low birth weight group (OR 17.6; 95%CI 13.9-22.2) and small for gestational age (OR 3.4; 95%CI 1.9-5.8), compared to those of adequate weight.

Conclusions: Prior to the development of the COVID-19 pandemic there is a decline in births, including multiple births, with no change in stillbirths or prematurity. Late preterm and early term newborns are at increased risk of intrauterine death.