609 The association between toxicology-confirmed marijuana use close to delivery and neonatal outcomes and placental pathology

Abstract

Marijuana use is increasing in women of reproductive age. Prior studies on marijuana's association with obstetric and neonatal outcomes were mainly based on self-reported use remote from delivery. We aim to evaluate the association between toxicology-confirmed marijuana use, within 72 hours of delivery and adverse neonatal outcomes. We also aim to examine placental pathology in women exposed to marijuana during pregnancy. This is a retrospective study of patients delivered between January 2016 and December 2019. Singleton pregnancies with urine drug screen performed within 72 hours of delivery and placenta sent to pathology at the time of delivery were included. Women who tested positive for polysubstance use and current tobacco and alcohol users were excluded. Neonatal outcomes and placental pathology (PP) findings were compared between the women that tested negative for drugs (NDS) and positive for marijuana use (MU). PP findings were categorized into vascular malperfusion and inflammatory findings. 466 patients (NDS) and 32 (MU) were identified. MU are likely to be younger (p=0.002), black and non- Hispanic (p=0.005) and have a psychiatric history (p= 0.01). There is no difference in BMI, parity and preexisting conditions among the groups. Gestational age at delivery and antepartum complications were similar among the groups except for gestational diabetes, which was higher in NDS group (p=0.01). The mean birth weight (BW) is lower in MU group. However, low BW, defined as <2500 grams, is similar among the groups (Table-1). NICU admissions and length of stay did not differ among the groups (Table 1). MU are likely to have higher composite neonatal morbidity (p=0.09). PP did not differ among the groups (Table 2). In contrast to prior studies, MU is not associated with increased risk of low BW, when smoking is excluded. This is also demonstrated in PP, as placental vascular insufficiency is similar in both the groups. Our study also showed increased risk of composite neonatal morbidity which has not been previously reported.View Large Image Figure ViewerDownload Hi-res image Download (PPT)