Table 1. Socio-demographic and reproductive characteristics and infant outcomes in the study sample, Lima, Peru.

Maternal Characteristics	Placental Abruption
	Cases	Controls
	(n = 280)	(n = 244)	p-value**
Maternal age at delivery, years *	27.03 (6.5)	27.3 (6.6)	0.517
<35	239 (85%)	200 (82%)	0.337
≥35	40 (14%)	43 (18%)
Nulliparous	115 (41%)	95 (39%)	0.655
Less than High school education	220 (79%)	186 (76%)	0.598
Employed during pregnancy	126 (45%)	108 (44%)	0.935
Planned pregnancy	114 (41%)	99 (.41%)	0.929
No prenatal vitamin	82 (29%)	65 (27%)	0.559
Smoked during pregnancy	12 (4%)	5 (2%)	0.216
Alcohol use during pregnancy	9 (3%)	0 (0)	0.004
Pre-pregnancy BMI, kg/m2 *	23.5 (3.5)	23.9 (3.9)	0.228
<18.5	14 (5%)	8 (3%)
18.5–24.9	179 (64%)	149 (61%)
25.0–29.9	57 (2%)	56 (23%)
≥30.0	13 (5%)	18 (7%)
Chronic hypertension	8 (3%)	4 (2%)	0.391
Preeclampsia or Eclampsia	58 (21%)	29 (12%)	0.005
History of placental abruption	2 (7%)	0 (0)	0.498
Infant birthweight, grams *	2357 (888)	3058 (825)	2.20E-16
Gestational age at delivery, weeks *	35 (4.3)	37.8 (3.5)	2.68E-15

*Mean (standard deviation), otherwise count (%).

**t-test and chi-square test respectively used for continuous and categorical variables.