Multiple health implications of women's early marriage go beyond early childbearing

"We find that under-age marriage is a marker of multiple vulnerabilities, all of which reflect women's continuing low status in society, relative to men," says the study's lead author, Dr. Akanksha Marphatia from the University of Cambridge, UK.

She continues, "Increased education, the primary approach for delaying girls' marriage, has had some effect, but less than we expected. Women's education may be used to gain better marriage matches, without necessarily widening life opportunities."

The study reviews research from Bangladesh, India, Nepal and Pakistan -- where the extent of under-age marriage, below 18 years, for girls is among the highest in the world. While some progress has been made in reducing the prevalence of child marriages (under 15 years) in this South Asian region and in late adolescence (16-17 years) in Pakistan, the proportion of 16-17-year-old girls marrying in India, Nepal and Bangladesh has increased.

Until now, little attention has been paid by public health researchers to marriage itself. Instead, early childbearing, which has been shown to put the health of mothers and their children at risk, has been the focus of concern.

"Some of the negative health consequences of early marriage, for both mothers and their children, are related to the fact these women are so young -- they are more likely to be having their first births and these are always riskier. Others are related to their physiology, for example, pregnancy complications associated with young, biologically-immature mothers," explains Dr. Alice Reid, co-author of this research. "However, our study reveals that other factors, such as lack of autonomy and subordinate household position among those marrying young, also lead to poor health outcomes."

Those marrying early may be more susceptible to domestic violence, poor mental health, and malnutrition. They are also more likely to have limited access to contraception and healthcare. These negative effects may then impact their children, with daughters potentially also marrying young.

"Families can get stuck in cycles of negative consequences," explains Dr. Reid. "Reversal of these cycles is unlikely to happen simply through economic development, and may require concerted effort from a number of different policy areas."

Dr. Marphatia and her colleagues were prompted to highlight under-age marriage as a public health concern after their comprehensive review of demographic, public health and social scientific research and policy documents from international organizations on this subject. They also looked at predictive factors, to see if patterns of under-age marriage emerged.

"Our unique approach of geographically mapping women's marriage age and their educational attainment allowed us to highlight differences, such as between rural and urban areas, and between different countries," says Dr. Gabriel Amable, also a co-author.

These maps show that marriage age in these South Asian countries is shaped by more than socio-cultural dynamics.

"Marriage is more than simply a decision reflecting cultural norms and practices. Age at marriage is also linked to factors such as a family's socio-economic status, nutritional experience in early life, and differences in life opportunities available in rural and urban areas," explains Dr. Reid.

Dr. Amable describes where they hope the research to go next.

"Further mapping will help identify potential 'pockets of vulnerability', where women marry and drop-out of school at a younger age. We can also identify areas where, despite completing more education, girls still marry early. This information can help to target future policies and interventions."