Early-onset preeclampsia/gestational hypertension may be associated with a low incidence of cerebral palsy at 3 years old in singleton very low-birth-weight infants born at 28-31 weeks of gestation (EOPE-DQ study): a multi-center retrospective cohort study in 2013-2016

Our aim was to evaluate the effects of any types of hypertensive disorders of pregnancy (HDP) on the development of either cerebral palsy (CP) or developmental delay (DD) at 3 years old in singleton very low-birth-weight (VLBW) infants born at 24-31 weeks of gestation. This was a retrospective cohort study of VLBW infants born at 24-31 weeks in 2013-2016 in Japan, using a nationwide obstetrical database, and Neonatal Research Network Japan (NRNJ) Database, accompanied by a secondary survey of women complicated with HDP (EOPE-DQ study). In 529 candidates for long-term follow-up in 7 tertiary centers, the percentage undergoing follow-up for CP at 3 years old was 56.1%, and the percentage receiving follow-up for DD at 3 years old was 54.1%. The percentage of PE/SPE/GH was significantly lower in infants with CP than in controls (1/22 [4.5%] vs. 66/274 [24.1%], p = 0.034); especially, in infants born at 28-31 weeks, the percentage of PE/SPE/GH was significantly lower in infants with CP than in controls (0/13 [0%] vs. 44/151 [29.1%], p = 0.021). The percentage of PE/SPE/GH was not different between infants with DD and controls (9/49 [18.4%] vs. 54/237 [22.8%], p = 0.574). The percentage of composite risk factors (either bronchopulmonary dysplasia at a postmenstrual age of 36 weeks, intraventricular hemorrhage, hypoxic ischemic encephalopathy, sepsis, necrotizing enterocolitis, or periventricular leukomalacia) was significantly higher in infants with DD than in controls. In conclusion, PE/SPE/GH around 30 weeks may be associated with a low incidence of CP.