OBJECTIVES:

Smoking during pregnancy is linked to diminished offspring birthweight. Related research using Electronic Health Record (EHR) data is limited. This research evaluates the association between pregnant smoking and infant weight at time of birth using EHR data.

METHODS:

This study uses retrospective, deidentified EHR data from Oracle EHR Real-Word Data (OERWD) and is non-interventional in nature. OERWD is extracted from 139 health systems which have consented to the use of their respective EHR data. Records for mothers aged 18-45 with a valid indication of timestamped infant birthweight between January 1^st 2013 and July 31^st 2023 were extracted for analysis. Further inclusion criteria included the presence of a valid maternal smoking status indicated within 9 months of birth and a valid state of residence on the mother’s record. The association between smoking status and infant birthweight was examined using generalized linear models, controlling for year of infant birth, maternal state of residence, age, race, ethnicity, marital status, insurance type, and Charlson Comorbidity Index.

RESULTS:

Of the 107,902 maternal records extracted, 10,235 (9.5%) indicated cigarette smoking during pregnancy. Mean age was 29.02 (SD=5.83), 75.2% were white, 54.4% were married/living with a domestic partner, 57.8% had commercial insurance, and average time from smoking indication to birth was 1.32 (SD=2.30) months. Mothers who reported smoking within 9 months of giving birth were associated with a 198.53g decrease (p<0.001) in offspring birthweight. Additionally, mothers who smoked were 1.77 times (p<0.001) as likely to have a low birthweight (<2,500g) offspring.

CONCLUSIONS:

The results of this study indicate a correlation between pregnant maternal smoking and negative birthweight outcomes. This demonstrates the need for prenatal counseling and public health policy to reduce the incidence of pregnant smoking. Due to the retrospective, non-interventional nature of this study, causal relationships cannot be established.