TABLE 3.

Odds and adjusted odds for CB with induction of labor compared with expectant management (inclusive or exclusive) in two midwifery practices in the United States

	OR (95% CI) for CB if IOL versus inclusive EM			OR (95% CI) for CB if IOL versus exclusive EM
	OR (95% CI) for CB with IOL vs EM	(1) aOR (95% CI)	(2) aOR (95% CI)	OR (95% CI) for CB with IOL vs EM	(1) aOR (95% CI)	(2) aOR (95% CI)
37th week	0.98 (0.53–1.80)	1.49 (0.75–2.94)	1.05 (0.49–2.25)	0.96 (0.53–1.78)	1.45 (0.73–2.87)	1.04 (0.49 –2.22)
38th week	1.39 (0.91–2.14)	1.67 (1.01–2.78)*	1.63 (0.91–2.90)	1.31 (0.85–2.01)	1.59 (0.96–2.64)	1.54 (0.86–2.76)
39th week	1.17 (0.83–1.67)	1.05 (0.68–1.63)	0.98 (0.61–1.58)	1.00 (0.70–1.43)	0.98 (0.63–1.53)	0.93 (0.58–1.51)
40th week	0.93 (0.66–1.30)	0.82 (0.55–1.22)	0.70 (0.44–1.09)	0.66 (0.46–0.93)*	0.65 (0.43–0.98)*	0.57 (0.36 –0.90)*
41st week	1.39 (1.08–1.80)**	1.53 (1.14–2.05)**	1.55 (1.11–2.15)**	0.81 (0.57–1.14)	1.00 (0.67–1.51)	1.06 (0.68–1.64)
42nd week +	n/a			n/a

Note: (1) Adjusted for age, pre pregnancy BMI, HTN/preeclampsia, gestational weight gain, neonatal weight at birth.

(2) Adjusted for same covariates as first model plus neuraxial analgesia

Abbreviations: confidence interval; expectant management, OR; induction of labor, EM; IOL; odds ratio, CI.

Definitions: Inclusive EM includes all labors within and beyond the week when IOL was performed. Exclusive EM excludes spontaneous labors during the index week and counts all labors after the week IOL was performed.

^*P-value <0.05 (IOL vs EM).

^**P-value <0.01 (IOL vs EM).