Substance use in pregnancy: do we care?

Area of Science:

• Obstetrics and Gynecology
• Perinatology
• Addiction Medicine

Background:

• Substance use during pregnancy poses significant risks to both mother and fetus, including high perinatal mortality and adverse birth outcomes.
• Historical data from 1969-1979 indicated a very high perinatal mortality rate (9.8%) and poor fetal outcomes among polydrug-using pregnant women.

Purpose of the Study:

• To evaluate the impact of a strict surveillance system implemented in 1980-1989 on perinatal outcomes in substance-using women.
• To identify factors associated with adverse birth outcomes, such as preterm delivery and low birth weight, within substance-using populations.

Main Methods:

• Retrospective comparison of two cohorts of substance-using women: 1969-1979 (n=92) and 1980-1989 (n=240).
• Inclusion of control groups for comparison of outcomes.
• Multivariate analysis to determine relationships between substance use, prenatal care, lifestyle factors, and fetal outcomes.

Main Results:

• The perinatal mortality rate (PMR) in substance-using women decreased from 9.8% (1969-1979) to 0.4% (1980-1989), approaching control levels.
• Despite improvements, 22% of deliveries were preterm and 27% resulted in infants below the 10th percentile for birth weight in the second cohort.
• Neonatal abstinence syndrome was linked to lower birth weight, and poor engagement with prenatal care correlated with shorter pregnancy length. Substance use was associated with a 345g lower birth weight and 0.8 cm smaller head circumference.

Conclusions:

• Strict surveillance and improved prenatal care significantly reduce perinatal mortality in pregnant substance users.
• Lifestyle factors, including smoking and inconsistent prenatal care, remain critical determinants of pregnancy length and fetal growth.
• While opiate use is implicated in lower birth weight, the relationship is not strictly dose-dependent, highlighting the complexity of substance use impacts on pregnancy.