BMJ Glob Health. 2018 Jan 13;3(1):e000304. doi: 10.1136/bmjgh-2017-000304. eCollection 2018.

Intimate partner violence and pregnancy spacing: results from a meta-analysis of individual participant time-to-event data from 29 low-and-middle-income countries

Maxwell L¹, Nandi A^1,2, Benedetti A¹, Devries K³, Wagman J⁴, García-Moreno C⁵.

Author information

1 Epidemiology, Biostatistics, and Occupational Health, McGill University, Montréal, Quebec, Canada.

2 Institute for Health and Social Policy, McGill University, Montréal, Quebec, Canada.

3 Department of Global Health and Development, Social and Mathematical Epidemiology Group and Gender Violence and Health Centre, London School of Hygiene & Tropical Medicine, London, UK.

4 Division of Global Public Health, Department of Medicine Central Research Services Facility (CRSF), University of California, San Diego, California, USA.

5 Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.

Abstract

INTRODUCTION:

Inadequately spaced pregnancies, defined as pregnancies fewer than 18 months apart, are linked to maternal, infant, and child morbidity and mortality, and adverse social, educational and economic outcomes in later life for women and children. Quantifying the relation between intimate partner violence (IPV) and womens ability to space and time their pregnancies is an important part of understanding the burden of disease related to IPV.

METHODS:

We applied Cox proportional hazards models to monthly data from the Demographic and Health Surveys Reproductive Health Calendar to compare interpregnancy intervals for women who experienced physical, sexual and/or emotional IPV in 29 countries. We conducted a one-stage meta-analysis to identify the periods when women who experienced IPV were at the highest risk of unintended and incident pregnancy, and a two-stage meta-analysis to explore cross-country variations in the magnitude of the relation between womens experience of IPV and pregnancy spacing.

RESULTS:

For the one-stage analysis, considering 52 959 incident pregnancies from 90 446 women, which represented 232 394 person-years at risk, womens experience of IPV was associated with a 51% increase in the risk of pregnancy (95% CI 1.38 to 1.66), although this association decreased over time. When limiting our inference to unintended pregnancies that resulted in live births, womens experience of IPV was associated with a 30% increase in the risk of unintended pregnancy (95% CI 1.25 to 1.34; n=13 541 pregnancies, 92 848 women, 310 319 person-years at risk). In the two-stage meta-analyses, womens experience of IPV was associated with a 13% increase in the probability of incident pregnancy (95% CI 1.07 to 1.20) and a 28% increase in the likelihood of unintended pregnancy (95% CI 1.19 to 1.38).

CONCLUSIONS:

Across countries, womens experience of IPV is associated with a reduction in time between pregnancies and an increase in the risk of unintended pregnancy; the magnitude of this effect varied by country and over time.