Risk of preterm and early term birth by maternal drug use

Objective Examine the risk of preterm birth (PTB, < 37 weeks) and early term birth (37-38 weeks) for women with reported drug abuse/dependence. Study Design The population was drawn from singleton livebirths in California from 2007 to 2012. Drug abuse/dependence was determined from maternal diagnostic codes (opioid, cocaine, cannabis, amphetamine, other, or polysubstance). Relative risks, adjusted for maternal factors were calculated for PTB and early term birth. Result Of the 2,890,555 women in the sample, 1.7% (n = 48 ,133) had a diagnostic code for drug abuse/dependence. The percentage of PTBs varied from 11.6% (cannabis) to 24.3% (cocaine), compared with 6.7% of women without reported drug abuse/dependence. Conclusion Women with reported drug abuse/dependence during pregnancy were at increased risk of having a PTB and all but those using cannabis were at risk of having an early term birth. Women using cocaine and polysubstance were at the highest risk of birth < 32 weeks.