Objective To explore the factors affecting neurobehavioral development of 18-month-old infants with low birth weight （LBW）， and to provide scientific basis for early identification of neurobehavioral abnormalities.

Methods The information of LBW infants who required follow-up in maternal and child health care institutions of 16 districts in Shanghai from January to October 2018 was collected. The subjects who met the inclusion and exclusion criteria were investigated by questionnaire， physical growth measurement and Gesell development diagnosis evaluation.

Results A total of 885 qualified subjects were included in this study， including 400 boys （45.2%）， 485 girls （54.8%）， 32 cases with birth weight <1 500 g （3.6%）， and 853 cases with birth weight ranging from 1 500 g to 2 500 g （96.4%）. The percentage of abnormalities in the LBW infants at 18 months was 3.3% for gross-motor， 10.3% for fine-motor， 15.7% for adaptive behaviors， 22.1% and 14% for language and personal-social behaviors （DQ≤85）， respectively. Multivariate analysis， with gender， birth weight and gestational age adjusted as confounding factors， showed the following risk factors： male for LBW fine-motor dysplasia （OR=1.86， 95%CI： 1.19‒2.90） and personal-social behavior dysplasia （OR=1.69， 95%CI： 1.14‒2.50）； gestational age less than 32 weeks for personal-social behavior dysplasia （OR=4.95， 95%CI： 2.08‒11.79）； stress during pregnancy for gross- motor dysplasia （OR=3.3， 95%CI： 1.33‒8.21）， language dysplasia （OR=1.72， 95%CI： 1.03‒2.88） and personal-social behavior dysplasia （OR=2.72， 95%CI： 1.56‒4.72）； cigarette smoke exposure during pregnancy for fine-motor dysplasia （OR=5.52， 95%CI： 2.07‒14.70） and adaptive behavior dysplasia （OR=2.88， 95%CI： 1.12‒7.43）； gestational diabetes for language dysplasia （OR=2.22， 95%CI： 1.12‒4.42）； pregnancy induced hypertension （PIH） for abnormal personal-social behavior development （OR=3.57， 95%CI： 1.86‒6.83）； and small head circumference （HCZ<-2） for gross-motor dysplasia （OR=16.15， 95%CI： 3.05‒85.69）， fine-motor dysplasia （OR=11.17， 95%CI： 1.15‒108.83） and language dysplasia （OR=7.86， 95%CI： 1.45‒42.57）.

Conclusion The neurobehavioral development of LBW infants is related to gender， gestational age， mood during pregnancy， cigarette smoke exposure during pregnancy， diseases during pregnancy and head circumference development. Thus， avoiding adverse environmental exposure during pregnancy， actively preventing complications during pregnancy， paying attention to head circumference follow-up and prevention of preterm delivery are of protective significance to the neurobehavioral development of low birth weight infants.