Investigation procedure
The principal investigator explained the purpose of the study to the older primiparous wives who participated in a regular maternity class at the hospital. The husbands' cooperation was secured through their wives. The survey was conducted three times in total, that is during pregnancy, and at 1 and at 3 months after childbirth. The researchers distributed questionnaires and reply envelopes to each couple. The wives and husbands placed completed questionnaires in their respective envelopes following which the completed questionnaires were collected from each couple.The data collection period was from April 2018 to December 2019.