. Author manuscript; available in PMC: 2016 May 1.

Published in final edited form as: Am J Obstet Gynecol. 2015 Jan 7;212(5):669.e1–669.e6. doi: 10.1016/j.ajog.2015.01.004

Table 2.

Risk of Placenta Previa in Second Pregnancy According to Prior Delivery Mode

	First Pregnancy Delivery Mode
	Vaginal	Prelabor CD	Intrapartum CD
	(n=22,142)	(n=914)	(n=3,931)
	OR (95% CI)	OR (95% CI)	OR (95% CI)
Unadjusted	1.00 (Reference)	4.07 (2.00–8.26)	1.57 (0.88–2.78)
Model A^a	1.00 (Reference)	3.13 (1.49–6.56)	1.37 (0.77–2.45)
Model B^b	1.00 (Reference)	2.62 (1.24–5.56)	1.22 (0.68–2.19)

Abbreviations: CD, cesarean delivery; CI, confidence interval; OR, odds ratio.

Model A adjusted for maternal age, pregnancy loss, history of previa, insurance, and smoking

Model B adjusted for all variables from model A and anemia, pregestational diabetes, and thyroid disease.