Pregnancy is not a risk factor for gallstone disease: Results of a randomly selected population sample

Table 5 Review of published studies addressing the effect of the factor “pregnancy” on the prevalence of gallbladder stones

Factor by which the prevalence of gallstone diseasein women with prior pregnancy is increased	1.0–1.5 times	1.6–2.5 times	2.6–10 times	11 – 50 times
Studies showing a quantitative relation between cholecystolithiasis and pregnancy	1966 Framingham[42] 1988 Sirmione[21] 1985 San Antonio[45] 1985 Maastricht[46]	1982 Oxford[47] 1982 Kopenhagen[44]	1979 Stockholm[48] 1982 Rom[32] 1986 Schwedt[41] 1986 Chianciano[22] 1991 Santiago[49]	1988 Srinagar[15]
Studies not showing a quantitative relation between cholecystolithiasis and pregnancy	1956 Birmingham[50] 1970 Pima reservation[51] 1980 Boston[52] 1982 Oberpfuss[53] 1983 Oxford[54] 1984 Adelaide[55] 1989 Soweto[12] 1990 Dublin[43] 1995 Ulm[19] 1996 Römerstein[20] 2002 Leutkirch