Table 3.

A sensitivity analysis

	Resolved low-lying placenta (n = 191) n (%)	Unexposed (n = 225) n (%)	p-Value	Unadjusted OR [95% CI]	Adjusted OR [95% CI]
Postpartum hemorrhage (PPH)a	17 (8.9)	10 (4.4)	0.07	2.10 [0.94–4.70]	2.34 [1.02–5.37]b
Triage visit for bleeding	28 (15.7)	18 (8.0)	0.03	1.98 [1.06–3.70]	1.99 [1.06–3.73]c
Antenatal corticosteroid use	18 (9.4)	7 (3.1)	0.007	3.24 [1.32–7.93]	3.33 [1.35–8.20]c
Induction of labor for bleeding	10 (5.2)	3 (1.3)	0.03	4.09 [1.11–15.08]	4.12 [1.11–15.33]c
Preterm birth (<37 weeks’ gestation)	19 (10.0)	18 (8.0)	0.49	1.27 [0.65–2.50]	1.28 [0.65–2.53]c
Gestational age at deliveryd	39 [38–39]	39 [38–39]	0.38	NA	NA
Mode of delivery			0.36	NA	NA
Spontaneous vaginal	131 (68.6)	154 (68.4)
Operative vaginal	10 (5.2)	6 (2.7)
Cesarean	50 (26.2)	65 (28.9)
EBLd	400 [300–700]	400 [250–700]	0.26	NA	NA
Unanticipated uterotonic use	40 (20.9)	34 (15.1)	0.12	1.49 [0.90–2.46]	1.51 [0.90–2.52]b
Blood transfusion intrapartum and postpartum	14 (7.3)	13 (5.8)	0.52	1.29 [0.59–2.82]	1.40 [0.63–3.11]b
Intravenous iron transfusion postpartum	11 (5.8)	7 (3.1)	0.19	1.90 [0.72–5.01]	2.01 [0.75–5.37]b
Intra-amniotic infection	12 (6.3)	21 (9.3)	0.25	NA	NA

Abbreviations: CI, confidence interval; EBL, estimated blood loss; IQR, interquartile range; OR, odds ratio.

^aDefined as estimated blood loss (EBL) ≥ 1,000 mL.

^bAdjusted for parity, prior cesarean, and delivery mode.

^cAdjusted for parity and prior cesarean.

^dMedian [interquartile range].