Table 3.

Main experimental concerns and potential solutions involving the detection of HPA axis hormones.

Categories	Concerns	Potential solutions
Nature of the tools	Sensitivity, specificity, and reliability of the scoring system; cutoff time	Analyze the correlation according to different cutoff values (i.e., EPDS scores of 10–13), or address the correlation according to scores.
	Selection of different biomarkers	Consider the detection technique in clinical settings.
Experimental setting	Different sampling timing (antepartum and postpartum)	Combine the sampling points with regular antepartum and postpartum inspections according to local medical instructions.
	Variation in sample types	In addition to invasiveness and noninvasiveness, consider sample treatment procedure and availability of commercial tests.
	Variation in collection timing for periodic hormone	Consider the time of cortisol and ACTH sampling to eliminate the variation in levels caused by normal fluctuation caused by circadian rhythm.
Techniques	Preparation of different samples	Screening tool should be simple and easy to handle.
	Usage of an in vitro diagnostic technique	A safe, easily operated, commercialized method might help increase the reliability. Determine a reference range from a healthy population obtained with the selected method.
Target population	Exclusion criteria and background of participants	Historical health data and basic health status of patients should be specified in studies and analyzed together with the stress hormones.
	Socioeconomic and cultural differences	Verify whether questionnaires written in the local language are easy for target population to complete. For parallel comparison, results of other local studies can be used as references to establish cutoff values.

ACTH, adrenocorticotropic hormone; EPDS, Edinburgh Postnatal Depression Scale; HPA, hypothalamus–pituitary–adrenal.