[Association of antenatal anxiety with preterm birth and low birth weight: evidence from a birth cohort study].

Objective: To investigate the impacts of antenatal anxiety on preterm birth and low birth weight. Methods: Women in early pregnancy were recruited for follow-up, antenatal anxiety in three trimesters was screened using Self-Rating Anxiety Scale and the score ≥50 was regarded as anxiety. Logistic regression analysis was conducted to evaluate the associations of the anxiety in three trimesters, new onset anxiety in the second and third trimesters with infant birth outcomes, such as preterm birth and low birth weight. Results: The rates of anxiety in the first, second and third trimesters of pregnancy were 12.5%, 3.7%, and 7.4% respectively. We found that there was no statistical association between anxiety in the first and second trimester and preterm birth. The anxiety in the third trimester was associated with increased odds for preterm birth (OR=3.55, 95%CI: 1.62-7.82). Associations between anxiety in all three trimesters and low birth weight were not significant. New onset anxiety in the third trimester was associated with significant increased risk of premature delivery (OR=5.20, 95%CI: 1.84-14.70) and low birth weight (OR=6.93, 95%CI: 2.42-19.88). Conclusions: Our study showed that anxiety in the third trimester is an important risk factor for premature delivery, new onset anxiety symptoms in the third trimester can significantly increase the incidence of premature birth and low birth weight of infant.