Population-based estimate of sibling risk for preterm birth, preterm premature rupture of membranes, placental abruption and pre-eclampsia

Table 4 λ_S and sib-sib OR (with 95% CI) for pre-eclampsia.

	All races	White	Black
Population: pre-eclampsia	8600	6749	1736
Population: N	267840	220505	42861
Population risk	0.032 (0.031–0.033)	0.031 (0.031–0.031)	0.041 (0.039–0.043)
Siblings: sibpairs with both siblings affected	1070	821	233
Siblings: sibpairs with first sibling affected	7384	5869	1400
Sibling risk	0.145 (0.137–0.153)	0.140 (0.131–0.149)	0.166 (0.146–0.186)
λ_S	4.5 (4.2–4.8)	4.5 (4.2–4.8)	4.1 (3.6–4.6)
Sib-sib unadjusted OR (95% CI)	9.2 (8.5–9.9)	10.0 (9.1–10.9)	6.7 (5.7–7.9)
Sib-sib adjusted OR (95% CI)#	8.1 (7.5–8.8)	9.0 (8.2–9.8)	5.8 (4.9–7.0)

#Adjusted for mother < 20 or > 35 years old, mother < 12 education, Medicaid (index of low SES), no prenatal care, mother BMI < 20 kg/m², cigarette smoking, insulin-dependent diabetes mellitus, chronic hypertension

ISSN: 2730-6844