The impact of the Wenchuan earthquake on birth outcomes

Earthquakes and other catastrophic events frequently occurring worldwide can be considered as outliers and cause a growing and urgent need to improve our understanding of the negative effects imposed by such disasters. Earthquakes can intensively impact the birth outcomes upon psychological and morphological development of the unborn children, albeit detailed characteristics remain obscure.

We utilized the birth records at Du Jiang Yan and Peng Zhou counties to investigate the birth outcomes as a consequence of a major earthquake occurred in Wenchuan, China on May 12, 2008. Totally 13,003 of neonates were recorded, with 6638 and 6365 for pre- and post- earthquake, respectively. Significant low birthweight, high ratio of low birthweight, and low Apgar scores of post-earthquake group were observed. In contrast, the sex ratio at birth, birth length and length of gestation did not show statistical differences. The overall ratio of birth-defect in the post-earthquake (1.18%) is statistically high than that of pre-earthquake (0.99%), especially for those in the first trimester on earthquake day (1.47%). The birth-defect spectrum was dramatically altered after earthquake, with the markedly increased occurrences of ear malformations. The ratio of preterm birth post-earthquake (7.41%) is significant increased than that of pre-earthquake (5.63%). For the birth outcomes of twins, significant differences of the ratio of twins, birth weight, ratio of low birthweight and birth-defect rate were observed after earthquake.

A hospital-based study of birth outcomes impacted by the Wenchuan earthquake shows that the earthquake was associated with significant effects on birth outcomes, indicating it is a major monitor for long-term pregnant outcomes.