Study design and data collection
We conducted a multisite cross-sectional study with the Edinburgh Postnatal Depression Scale (EPDS) to assess the mental health effect of the emergence of the COVID-19 Delta variant on pregnant women. For each survey instrument used in our study, e.g. the Edinburgh Postnatal Depression Scale, licenses were obtained in order to use each survey.This study was conducted between June 14, 2021 and July 5, 2021. The data were collected from the Perinatal and Postpartum Depression Information Collection System that we created [3, 8]. Ethical approval was provided by the institutional review board of The Third Affiliated Hospital of Guangzhou Medical University (Guangzhou, Guangdong, China). Informed consent was provided by all of the participants.
The participants originated from 25 public hospitals within Guangdong Province, China. During their regular antenatal care visit, the pregnant women were asked to complete a study questionnaire from a trained research assistant. All data were collected using an online survey tool made in China (https://www.wjx.cn/). The women completed the questionnaires using a mobile phone to scan the WeChat (Tencent, China) QR code.
An informational leaflet was sent to each woman waiting for a routine antenatal visit or obstetric ultrasound examination in the participating hospitals. It included a brief introduction to the study, instructions regarding the completion of the questionnaire, and the online survey's QR code.
The survey included three sections. The first section was comprised of socio-demographic information and obstetric history. The variables included maternal age, height, body weight, gestational age, past obstetric history, current obstetric complications, educational level, occupation, family monthly income, family address, hospital attended for antenatal care, medium used to obtain information (TV, newspaper, and internet), and history of mental disorders.
The second section was designed to capture the women's understandings of the COVID-19 Delta variant and vaccines. There were eight subjective questions and four objective questions, including three subjective questions and two objective questions about the Delta variant as well as five subjective questions and two objective questions about the vaccines. There also were eight subjective questions about their understanding of epidemic prevention policies. There was no correct answer to the subjective questions. The women’s understandings about the Delta variant and vaccines were assessed using a five-point Likert scale with scores for each correct answer.
The third section was devoted to the EPDS. The EPDS was used to measure depression and anxiety. The scale has been successfully used for both postpartum depression and perinatal depression . The scale consists of 10 items scored on a 3-point scale; a score of greater than 13 would be clinically relevant . The scale was used to identify feelings during the past seven days to detect possible depression . In addition to depression, we used the EPDS to evaluate anxiety symptoms [10, 14, 15]. The accumulative score of EPDS items 3 to 5 (EPDS-3A) were employed to assess anxiety. When more than two items were left unanswered, the completed questionnaire was deemed invalid and thus not scored. The scale included the following four classes: (0) Almost never, (1) Occasionally, (2) Often, and (3) All the time. Answers with a score of 3 indicated a high level of anxiety/depression .
Statistical analysis was conducted using IBM SPSS Statistics 26 (SPSS, Inc., Chicago, IL, USA). We calculated the frequency (n) and percentage (%) of categorical variables. In addition, mean (X) and standard deviation (SD) of the numerical variables were calculated.
In our study, the correlation among scale scores was analyzed using Pearson correlation coefficient. Furthermore, the relationship of numerical variables, area, and pregnancy risk was analyzed using an independent samples t-test as well as a one-way ANOVA test. The correlation among various discrete variables, pregnancy risk, and area was assessed using the chi-square test or Fisher’s exact test. We also analyzed depression level using a repeated measures ANOVA test. Differences with P < 0.05 were considered statistically significant.