Induction of labor and cerebral palsy: a population-based study in Norway

Abstract

Objective: To investigate the association between labor induction and later development of cerebral palsy (CP).

Design: Registry-based cohort study.

Setting: Perinatal data on all children born in Norway 1996-1998 were obtained from the Medical Birth Registry of Norway (MBRN). Neurodevelopmental data were collected from the Norwegian Cerebral Palsy Registry (CPRN).

Population: A total of 176,591 children surviving the neonatal period. Of 373 children with CP, detailed data were available on 241.

Methods: Unadjusted and adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated as estimates of the relative risk that a child with CP was born after labor induction.

Main outcome measures: Total CP and spastic CP subtypes.

Results: Bilateral cerebral palsy was more frequently observed after induced labor (OR: 3.1; 95% CI 2.1-4.5). For children born at term the association between bilateral CP and labor induction was stronger (OR: 4.4; 95% CI 2.3-8.6). The association persisted after adjustment for maternal disease, gestational age, standard deviation score for birthweight (z-score) and prelabor rupture of membranes (PROM) (adjusted OR: 3.7; 95%CI 1.8-7.5). Among children with CP born at term, four-limb involvement (quadriplegia) was significantly more frequent after induced (45.5%) compared with non-induced labor (8.0%). There was no significant association between labor induction and unilateral CP subtype or CP in preterm born children.

Conclusions: In this study population, we found that labor induction at term was associated with excess risk of bilateral spastic CP and in particular CP with four-limb involvement.