[Epidemiological features of spontaneous abortion among reproductive Tibetan women living at high altitudes areas].

OBJECTIVE

To study the status of spontaneous abortion among reproductive Tibetan women aged 15 - 49 years.

METHODS

A cross-sectional survey was conducted on reproductive history of Tibetan women and the sample was chosen under the stratified multistage cluster random sampling technique.

RESULTS

A total number of 3741 women were studied with a total number of 10,245 pregnancies. There were 386 spontaneous abortions reported with an incidence rate of 3.9%. Women living in the urban area had a higher rate than living in the rural areas. Women living in area where altitudes were above 4500 m, had a 2-time risk of having spontaneous abortion than those living in areas below 3500 m. The risk of having spontaneous abortion increased among women aged > or = 35 and those with more than 3 pregnancies.

CONCLUSIONS

High altitude could contribute to the increase of spontaneous abortions incidence, suggesting that improvement of maternal care and nutrition and reduction of the frequency of pregnancy had important roles to play in reducing the incidence of spontaneous abortion among Tibetan women. Despite the fact that retrospective study on reproductive history could underestimate the incidence of spontaneous abortion, the incidence rate among Tibetan women might not be much higher than women living in the lowland areas.