Table I:

Model inputs

Probabilities
	Gestational Age (weeks)						Source
	34	35	36	37	38	39
Emergent Bleed	0.0000	0.0469	0.1504	0.2987	0.5855	0.8723	Calculated, see text Zlatnik 2007(6)
Intrauterine fetal demise	0.0000	0.0004	0.0007	0.0012	0.0017	0.0022	Smith 2000(7)
Neonatal death	0.0130	0.0080	0.0050	0.0044	0.0029	0.0020	Copper 1993 (8), see text
Respiratory distress syndrome	0.1350	0.0640	0.0330	0.0040	0.0040	0.0030	Robertson 1992(9)
Cerebral palsy	0.0088	0.0051	0.0031	0.0025	0.0013	0.0009	Surman 2004(10)
			No emergent bleed		Emergent bleed		Kohi P, Zlatnik M, Little S, Caughey A. Bleeding previa: what are the risks? [abstract] Am J Obstet Gynecol 2006;195S113.
Postpartum hemorrhage			0.124		0.2488
Blood transfusion			0.0849		0.2615
Hysterectomy			0.0165		0.0547
			No placenta accreta		Placenta accreta
Maternal death, if hysterectomy			0.01		0.091		Gielchinsky (11), Clark 1984(12)
Placenta accreta			0.05				Usta 2005(13), Miller 1997(14)
Amniocentesis rupture of membranes			0.01				Gordon 2002(15)
Reduction in respiratory distress syndrome from steroid administration			0.34				Roberts 2006(16), Stutchfield 2005 (17)
% of cerebral palsy that is severe			0.29				Surman 2004(10)
% of cerebral palsy that is moderate			0.15
Sensitivity fetal lung maturity testing			0.851				Herbert 1986(18)
Specificity fetal lung maturity testing			0.843
Life expectancies
Maternal			56				CDC(19)
Neonatal			77.9
Neonate with severe cerebral palsy			28.7				Life Expectancy Project 2005(20)
Neonate with moderate cerebral palsy			62
Utilities
Infertility			0.82				Hu 2004(21)
Having a child with cerebral palsy			0.81				Kuppermann 2000(22)
Fetal/Neonatal death			0.92
Having severe cerebral palsy			0.3				Saigal 1999(23)
Having moderate cerebral palsy			0.9
Having a child with respiratory distress			0.98 (one year duration)				Assumed