Location

Year published

Number of Patients Enrolled

Risk Factors Identified

Maiduguri, Northern Nigeria [4]

1990

241 cases, 148 controls

Younger age at marriage, shorter height

Northern Nigeria [6]

1999

50 cases, 50 controls

Younger age at marriage, fewer parities, husband lower status occupation, husband fewer years of education

North-Eastern Nigeria [7]

2007

80 cases, 80 controls

Younger age at marriage, shorter height, illiteracy, lower social class, lack of employment, village rather than town residence, further distance from health facility