Maternal Opioid Drug Use during Pregnancy and Its Impact on Perinatal Morbidity, Mortality, and the Costs of Medical Care in the United States

Table 2

Rates^a  of selected clinical outcomes by opioid use status and odds ratios and 95% confidence intervals for the association between opioid use and each outcome among pregnancy-related discharges, NIS, 1998–2009.

Outcomes	Rate^a  of outcome		OR (95% CI)
	Opioid users	Nonopioid users	Model 1^b	Model 2^c	Model 3^d
Maternal
Threatened preterm labor	30.1	22.3	1.36 (1.24–1.49)	1.34 (1.22–1.47)	1.32 (1.19–1.45)
Early onset delivery	124.0	65.2	2.03 (1.88–2.20)	1.92 (1.77–2.07)	1.72 (1.59–1.85)
PROM	38.5	35.4	1.10 (1.00–1.20)	1.12 (1.03–1.23)	1.06 (0.98–1.16)
Wound infection	7.0	5.0	1.41 (1.18–1.68)	1.19 (1.00–1.42)	1.17 (0.98–1.40)
Acute renal failure	2.1	0.5	4.10 (3.11–5.41)	2.78 (2.09–3.72)	2.84 (2.11–3.84)
Postpartum depression^f	24.7	2.1	12.04 (10.83–13.40)	2.09 (1.79–2.44)	1.75 (1.49–2.05)
Hospital stay >5 days^e	133.4	29.9	5.00 (4.16–6.02)	4.83 (4.10–5.69)	4.02 (3.41–4.74)
In-hospital maternal mortality	0.8	0.1	5.89 (3.74–9.28)	3.63 (2.32–5.68)	3.69 (2.32–5.87)
Fetal
Poor fetal growth	35.9	15.9	2.31 (2.10–2.55)	2.21 (2.00–2.44)	1.61 (1.46–1.77)
Stillbirth	10.0	6.3	1.60 (1.39–1.83)	1.41 (1.23–1.62)	1.32 (1.15–1.51)

CI = confidence interval, NIS = Nationwide Inpatient Sample, OR = odds ratio, PROM = premature rupture of membranes.
^aPer 1,000 pregnancy-related discharges.
^bCrude model with maternal opioid use as the only independent variable.
^cModel 1 + adjustment for maternal age, household income, multiple birth, primary payer, and rural/urban status.
^dModel 2 + adjustment for tobacco, alcohol, maternal obesity, chronic renal failure, diabetes mellitus, and existing hypertension.
^eModel also adjusts for disposition at discharge.
^fModel also adjusts for history of depression.