Household crowding index: a correlate of socioeconomic status and inter-pregnancy spacing in an urban setting

Household density has long been viewed as both an indicator of low socioeconomic status and as a stressful situation associated with high morbidity and mortality risks. Several decades of research have correlated a high household crowding index, denoted by the number of co-residents per room, with socioeconomically deprived urban communities and a wide range of pathological health outcomes. ^{1- 11} Previous studies have shown a cumulative effect of household crowding through an increased incidence of chronic conditions ^{12, 13} as well as higher perinatal ¹⁴ and old age ¹⁵ mortality rates. Domestic crowding was shown to impact on psychological wellbeing, ^{3, 16} violent behaviour, ^{1, 17} and injuries. ¹⁸ Patterson suggested a protective effect of crowding on the incidence of insulin dependent diabetes mellitus. ¹⁹ Others found no effect of household density on morbid behaviour ¹ or adverse birth outcome. ²⁰

Studies relating household crowding and reproduction ^{21- 24} are comparatively scarce. Ethological research using experimental animals suggested that crowded environments promote aberrant forms of sexual behaviour ranging from complete abstinence to hypersexuality accompanied by a decline in successful reproduction. ^{1, 2, 25} Correlational studies in various sociocultural settings, including North America and the Far East, have associated household crowding with psychological stress among co-residents. ²⁵ The latter was associated with a decreased sense of privacy thereby affecting most aspects of daily life, including sexual activity, reproduction, and the use of contraceptive methods. ²⁵ Nevertheless, the impact of household crowding on fertility in human populations is still controversial. Johnson and Booth reported no influence of neighbourhood or household crowding on the probability of pregnancy and infant survival. ²² Edwards found only modest and selective effects of objective and subjective crowding on sexual and reproductive behaviour among Bangkok city dwellers. ²⁴ A community based study by Fikree and Berendes reported a higher risk for intrauterine growth retardation in the context of poor housing conditions in Pakistan, ²⁶ while another by Kieffer found no association between objective crowding and the prevalence of low birth weight in Hawaii. ²⁰

Another measure of reproductive health and behaviour with many policy implications is inter-pregnancy spacing. Previous studies found that short as well as long inter-pregnancy spacing increase the risk of adverse pregnancy outcomes, affecting child survival and wellbeing. ^{27- 30}