The present double-blind randomized clinical trial was carried out among 60 pregnant women, who referred to the health care centers of Shahrekord City (capital city of Charmahal o Bakhtiyari province) from April 2018 to November 2018. Available sampling method was administered to select the participants. In this regard, six health centers were randomly selected from high (n=2), medium (n=2), and low (n=2) socio-economical areas in Shahrekord. The centers were far apart, so that members of the study groups could not communicate with each other. Followed by applying random sampling, one health center, selected from each socio-economical area, was assigned into the intervention and control groups and participants were randomly selected from these centers.
The following inclusion criteria were considered for selecting the participants: healthy pregnant women with no background diseases, no partial or absolute exercise contradictions during pregnancy (such as vaginal bleeding, preterm labor, twin pregnancies, BMI<12, etc.), no pain during pregnancy, and no previous history of back and pelvic pain, no medicine intake, willingness to participate in the research, and literacy education. The exclusion criteria included maternal complications, such as kidney disease (low back pain due to kidney disorder), pre-eclampsia, bone disorders, and etc. after starting the study, lack of participation in Pilates exercises for more than one session, lack of willingness to stay in the study, and lack of completing the questionnaire.
Of 135 women who met the inclusion criteria, 75 individuals quitted the study because they were concerned about the safety issues and were not ensure about the research efficiency. Upon obtaining approval from the Ethics Committee of Shahrekord University of Medical Sciences, Iran, the researcher referred to the research contexts, introduced herself to the health center’s authorities, explained the research procedure and purpose, and made the required coordination to implement the study. Later, written informed consent forms were obtained from all participants, they were provided with the required information on the study goals and features, and were asked to complete the demographic questionnaire and the exercise checklist. The researcher’s cellphone number was also available to the participants, so that they could contact her in case of facing any problem while performing the exercises.
Pilates exercises started at 20th week of gestation for the intervention group (1). Exercises were performed in the gym under supervision of an instructor with a Pilates exercise coaching certificate and based on safe Pilates exercises during pregnancy (2). The intervention was conducted two sessions per week for 12 weeks and each session lasted 30 minutes with moderate intensity and 8 to 10 strength exercises were performed in each session (3). Gestational age was diagnosed at the beginning of study using ultrasound. The trainer was asked to date and sign an attendance list after each session to ensure that the participants performed the exercises regularly. During the intervention, the participants were followed up by making phone calls and reviewing the exercise checklist weekly. The control group received routine care during pregnancy. In the case that members of the control group attended Pilates exercises during pregnancy, they were excluded from the study and replaced.
To meet the participants after their delivery, researcher assistant attended the health centers, where sampling was performed near the probable dates of delivery of the intervention and control groups. Until the pregnant woman (both control and intervention groups) visits the health center for the latest pregnancy care, they should complete a checklist of pain during pregnancy.
Assessment of pain
Pain assessment was carried out using a visual analog scale (VAS) according to Bourbanis, and completed by making a checklist (√) or circling (O) numbers on a pain scale corresponding to the level of pain felt. We included a brief interview guide equipped with images corresponding to specific pain scale ratings. A pain assessment was performed after
completion of the entire period of exercise(6).
The two study groups were matched in terms of their demographic information, such as the participants' age, period after the last pregnancy (month), having previous pregnancies, intake of supplements during pregnancy, BMI before intervention, exercising before pregnancy, nutritional status in pregnancy, job, and income.
Finally, data obtained from the control and intervention groups were analyzed using descriptive and analytical statistics in SPSS software version 23. Independent t-test was run to compare the baseline variables between the two groups. The level of significance in all tests was considered to be 0.05.