A comparison of migrants to, and women born in, urban Mongolia: demographic, reproductive, anthropometric and lifestyle characteristics.

Background: Mongolia has experienced vast migration from rural to urban areas since the 1950s. We hypothesized that women migrating to Ulaanbaatar, the capital, would differ in factors related to future chronic disease risk compared with women who were born in Ulaanbaatar.

Methods: Premenopausal mothers (aged <44 years) of children attending two schools (one in the city centre and one in the outskirts) in Ulaanbaatar were recruited for the study. During April and May 2009, 420 women were interviewed about migration, reproductive history and lifestyle factors and anthropometric measurements were taken.

Results: Women born in (n=178) and outside (n=242) Ulaanbaatar were similar in education and marital status, but the latter appeared to have a more traditional lifestyle including being more likely to have lived as a nomadic herder (22.3% vs 5.6%; p<0.001) and to currently live in a traditional yurt or ger (40.1% vs 29.2%). Ever-use of hormonal contraception was more common in women born outside Ulaanbaatar (52.1% vs 38.2%; p=0.005) and their age at first live birth was older (26.0% vs 20.8% for ≥ 25 vs <25 years). Although the number of pregnancies was similar, the number of live births was greater for those born outside Ulaanbaatar (p=0.002). Women born in Ulaanbaatar were more likely to have smoked cigarettes (24.7% vs 11.2%; p<0.001). Women born outside Ulaanbaatar were more likely to consume the traditional meat and dairy diet.

Conclusion: Rural migrants to Mongolia's capital have retained a traditional lifestyle in some, but not all, respects. Internal migrant populations may provide the opportunity to assess the effect of changes in isolated risk factors for subsequent chronic disease.