The target population of this experimental study was primiparous pregnant women referring to 8 comprehensive health centers in Rafsanjan in 2021. The code of ethics for this study was obtained from the Ethics Committee of Rafsanjan University of Medical Sciences (IR.RUMS.REC.1399.205).
Inclusion criteria were age 15–45 years with a gestational age of 20–36 weeks, living with husband, having a smart phone, no history of serious psychiatric disorders (schizophrenia or other psychotic or mood disorders), and no use of psychiatric drugs before or during pregnancy by the couple. Exclusion criteria were an unwillingness to continue participation at any stage of the study, the presence of the husband in less than 3 prenatal care visits in the intervention group, and the occurrence of a traumatic event in a recent month (death of a close relative, divorce, separation, or marital dispute).
Considering a 95% confidence level, 80% power, the standard deviation of 2.84 for the depression score according to Rabieipoor et al. (9), 2.5 units difference in the mean score of postpartum blues in the two groups, and an attrition rate of 20%, the minimum sample size was estimated to be 30 subjects in each group. To increase the study power, 72 primiparous pregnant women were ultimately selected.
By computerized randomization, 36 samples each were assigned to the intervention and control groups. The researcher invited participants to the study by making a telephone call and introducing herself. Groups were created on the social network WhatsApp for each study group, and invitation letters were sent to them. The invitation was repeated by the staff of the health centers who gave a paper invitation and written informed consent form to prospective participants in either group.
The husbands in the intervention group were invited to participate in 3 out of 6 prenatal care sessions for their wives in the second half of pregnancy. In these three sessions, only routine prenatal care was performed in the presence of the husband. All face-to face education plans for husbands were suspended because of the COVID-19 pandemic. Instead, the planned content regarding couples' intimacy and postpartum blues was sent to the intervention group through WhatsApp.
Educational content included a training program to increase the intimacy of couples based on Iranian indigenous culture according to a study by Kalantari et al. (21) and a training program to reduce and control postpartum blues. Samples in the control group received routine prenatal care without the presence of their husbands. Due to the study method, it was not possible to blind the main researcher, health center staffs, or participants.
Data collection tools in this study comprised a demographic characteristics checklist, the Unidimensional Relationship Closeness Scale (URCS), and the postpartum blues Stein questionnaire. The URCS is a 12-item self-report scale that assesses the closeness of individuals and social relationships (22). Pakpour et al. translated the URCS into Persian according to international standard guidelines (23). Accordingly, the reliability of the test-retest assay of the Persian URCS at 2-week intervals was 0.91 and Cronbach's correlation coefficient was 0.88. In addition, the one-dimensional structure of the URCS was confirmed.
The postpartum blues Stein questionnaire (24) was confirmed by the content validity method in Kariman et al.'s study. The reliability of this questionnaire in Kariman’s study was 0.90% (25). The postpartum blues questionnaire consists of 13 questions; the first 8 questions are scored from 0–4, and in the last 5 questions, yes and no answers are scored 1 and 0 points, respectively. On a general scale with a score of 0–26, a score of 8 or higher usually indicates that significant mood swings have occurred (24).
In this study, the URCS was completed twice through interviews with participants, once during the first telephone call and then two weeks postpartum. The Stein questionnaire was completed just one week postpartum. Both questionnaires were completed by participants in the control and intervention groups by phone calls. Data were analyzed using SPSS software version 25 with the T-test, Chi-square, and Fisher exact tests.