RESUMEN
Objective: To investigate the second or third trimester pregnancy-related anxiety on small-for-gestational-age infants. Methods: This study was based on Ma'anshan Birth Cohort Study (MABC), with 3 040 maternal-singleton pairs finally selected for data analysis, from May 2013 to September 2014. The psychological state of pregnancy was evaluated according to a self-developed 'anxiety scale for gestation'. Small-for-gestational-age was defined as 'having birth weight below the 10(th) percentile at a particular gestational week', while large-for-gestational-age infants was defined as 'having birth weight above the 90(th) percentile'. Birth weight between the 10(th) and 90(th) percentile was classified as appropriate-for-gestational age infants. χ(2) test was used to compare the distribution of characteristics in pregnancy among three groups with different birth weights. Multivariate logistic regression models were conducted to evaluate the associations between third trimester pregnancy- related anxiety and birth weight. Results: The incidence rates of small- and large-gestational-age infants were 9.6% and 16.6%, respectively. Difference between women with only one of the second or third trimester pregnancy-related anxiety syndromes and small-for-gestational-age infants showed no statistical significance. Women with both second and third trimester pregnancy-related anxieties might increase the risk of small-for-gestational-age infants (OR=1.39, 95%CI: 1.04-1.87). However, there was no significant difference between pregnancy-related anxiety and large-for- gestational-age infants (OR=1.05, 95%CI: 0.81-1.35) noticed. Conclusion: Women with second and third trimester pregnancy-related anxiety appeared a risk factor for small-for-gestational-age infants.