. 2023 Jul 21;6(7):e2324630. doi: 10.1001/jamanetworkopen.2023.24630

Table 2. Hazard Ratios of ASD in Offspring Associated With LEA and/or Oxytocin Exposures at Labor and Delivery.

Variable	No. with ASD/total	HR (95% CI)
Variable	No. with ASD/total	Model A^a	Model B^b	Model C^c
Single exposure
Epidural
No	979/52 114	1 [Reference]	1 [Reference]	1 [Reference]
Yes	4167/153 880	1.41 (1.31-1.51)	1.30 (1.21-1.40)	1.30 (1.20-1.39)
Oxytocin
No	1927/88 186	1 [Reference]	1 [Reference]	1 [Reference]
Yes	3219/117 808	1.25 (1.18-1.32)	1.12 (1.06-1.19)	1.11 (1.05-1.18)
Mutually adjusted
Epidural
No	979/52 114	1 [Reference]	1 [Reference]	1 [Reference]
Yes	4167/153 880	1.33 (1.24-1.44)	1.28 (1.18-1.38)	1.27 (1.18-1.38)
Oxytocin
No	1927/88 186	1 [Reference]	1 [Reference]	1 [Reference]
Yes	3219/117 808	1.15 (1.08-1.22)	1.05 (0.99-1.12)	1.05 (0.98-1.11)
Stratified^d
Unexposed to LEA and oxytocin	729/38 507	1 [Reference]	1 [Reference]	1 [Reference]
Exposed to oxytocin only	250/13 607	0.98 (0.85-1.14)	0.90 (0.78-1.04)	0.90 (0.78-1.04)
Exposed to LEA only	1198/49 679	1.25 (1.14-1.37)	1.20 (1.09-1.32)	1.19 (1.09-1.31)
Exposed to LEA and oxytocin	2969/104 201	1.48 (1.36-1.61)	1.30 (1.20-1.42)	1.29 (1.19-1.41)

Abbreviations: ASD, autism spectrum disorders; HR, hazard ratio; LEA, labor epidural analgesia.

^{^a}

Adjusted for birth year only; birth year was modeled as a spline function with 4 df.

^{^b}

Adjusted for birth year, maternal age at delivery, race and ethnicity, educational level, household income, marital status, parity, history of comorbidity, prepregnancy body mass index, gestational weight gain, diabetes, chronic hypertension, gestational hypertension or preeclampsia, hypothyroidism, infection, seizures, mental health issues, smoking, alcohol, drug use during pregnancy, antepartum hemorrhage, premature rupture of membranes, birth weight, preterm status, child sex, and medical center. Other than birth year, all other continuous variables were modeled as linear function and categorical variables were modeled as categorical variables.

^{^c}

Adjusted for covariates listed in note b along with birth defect, fetal distress, and dystocia.

^{^d}

Exposure stratification generated 1 variable with 4 levels: (1) unexposed, (2) exposed to oxytocin only, (3) exposed to LEA only, and (4) exposed to both LEA and oxytocin.