Participants
From August to October 2022, we
conducted this cross-sectional study among infertile couples in an
artificial endometrial preparation from the Center for Reproductive
Medicine, First Affiliated Hospital of Anhui Medical University (Hefei,
Anhui, China). Those patients who met the diagnostic criteria for
infertility and were actively seeking treatment were included. Subjects
with a history of psychiatric disease, no embryo transfer, comorbidities
such as hypertension, diabetes, or kidney disease, or voluntarily
withdrew were excluded (n = 152). In this study, baseline data were
collected on the day of the ovulation injection through a questionnaire
that the subjects scanned a QR code using a mobile application to access
the questionnaire and completed it under the constant supervision of
highly trained research staff. The content of the questionnaire included
general demographic characteristics (age, sex, ethnicity, education
level, income, occupation, and marital status), behavioral lifestyle
(smoking or passive smoking, alcohol and coffee consumption, Sleep,
psychological state, physical activity, and dietary habits), family and
social relationships (social capital, family power and reproductive
quality of life) and fertility treatment history (parity, gravidity,
history of preterm birth and abortion, infertility treatment timing and
causes). Ultimately, after subjects with missing data were excluded (n =
44), a total of 1,022 infertile patients were included in the final
analysis. The study protocol was approved by the Ethics Committee of
Anhui Medical University (No. 20200961) in accordance with the
guidelines of the Declaration of Helsinki and international ethical
standards. All invited participants have obtained a written informed
consent form to participate in the study (Figure S1 ).
Chronotype assessment
At present, the most widely used
circadian rhythm scale is the Morning and Evening Questionnaire, of
which the Morning and Evening Questionnaire-19 Items (MEQ-19) was first
proposed by Horne and Ostberg 31. In order to quickly
screen the chronotypes, we used the Morning and Evening Questionnaire-5
Items (MEQ-5), which was extracted from the MEQ-19 by Adan and Almiralli
through statistical modeling 32. It is proved to have
promising psychometric properties, reliability and validity, where the
Cronbach’s alpha coefficient for our study was 0.703. Due to the limited
number of individuals within the lowest or highest chronotype score
group, the chronotype of subjects were divided into evening chronotype
(4-11 score), neutral chronotype (12-17 score), and morning chronotype
(18-25 score) in current study based on the MEQ-5 score.
Depressive symptoms
assessment
The
participants were also asked to report their psychological status over
the past week through the Patient Health Questionnaire-9 (PHQ-9). It is
a simple and effective self-rating scale for the depressive disorder
based on the diagnostic criteria of the American Psychological
Association 33, which has been demonstrated to have
good reliability and validity by previous studies 34,
with Cronbach’s alpha coefficient being 0.910 in the present study. It
contains 9 items with an overall score ranging from 0 to 27, higher
scores indicate more severe depressive symptoms. In the present study,
the total score was divided into a dichotomous variable, score >4
points indicate mild and above depressive symptoms, and conversely no
depressive symptoms.