Design and sampling
This randomized controlled trial study with parallel groups was conducted on pregnant women referred to Urmia health centers in 2018–2019. The study was executed for the last 12 months, from April 2018 to May 2019. This trial was registered in the Iranian Registry of Clinical Trials (IRCT) in 05/06/2020 with IRCT20151004024340N15 identifying number. Also this study was verified by the Urmia Ethics Committee with IR.UMSU.REC.1397.162 code.
Sample size and sampling method
The sample size was calculated according to Michele Bisson  The study, because of the similarity in the targeted primary and secondary outcomes, where the moderate and vigorous physical activity (MVPA) index was 11.7 ± 9.5 min / day in their control group and 25.4 ± 20.4 min / day in their treatment group after the intervention. General Chat Chat Lounge With the 90% of study power (Z)1 β β= 1.28), and the two-sided alpha level at 0.05 (Z1/2/2= 1.96), and a 10% chance of dropout, the sample size was determined for 45 subjects for each group. Therefore, ninety subjects were included in the study. The flow diagram of the participants is shown in Fig. 1.
Inclusion criteria were the study: the tendency to choose in the study, having an ability to read and write, under 20 weeks gestational age, lack of chronic diseases (ie, diabetes, hypertension, kidney disease), lack of any medical. Limiting for physical activity by the mother, no mental illness and no history of hospitalization (based on the participant’s self-report), lack of cerclage and prenatal care, having a smartphone, access to the internet, and residence in Urmia. The exclusion criteria were: having any problems or special diseases in current pregnancy such as preeclampsia, diabetes, anemia, high-risk pregnancy and cerclage surgery, frequent bleeding during the intervention, premature contractions, reduction of fetal movements, amniotic fluid leakage, diet for a specific disease, and migration from Urmia.
We used stratified sampling method for subjects including different socioeconomic strata of Urmia. There were three levels of health centers; 1, 2, and 3 according to their social and economic status. Then, two centers from each category were selected randomly by lottery. Also the participants for each group were randomly assigned to a block allocation ratio with the block randomization method. First, the blocks were created with the combination of AAABBB by computer and all possible statuses were identified and an exclusive code was assigned for each. Next, considering the sample size (N = 90) and block sizes (S = 6), 15 blocks were selected by a simple randomization method by the researcher. Selected subjects were allocated to the control or intervention group consistently by the study manager. All these stages were performed under the provision of a consultant epidemiologist and using Random Allocation Software version 1.0.0.
Data collection tools
In this study, demographic, Pregnancy Physical Activity Questionnaire (PPAQ) questionnaires were used and completed. Height measured with a stadiometer and weight by a Seca scale. Demographic information questionnaire had questions such as age, weight, height, education level, employment status, economic status, BMI, pregnancy age, number of fetuses, number of pregnancies, history of underlying disease, infertility of history, cerclage, ectopic pregnancy, and specific disease in the current pregnancy.
The standard PPAQ, which is related to physical activity in pregnancy, includes two parts: Part I consisted of information about individual characteristics and Part II included 32 questions on physical activity. The questionnaire of pregnancy consists of 4 groups of questions related to activities: at home (16 questions), community (3 questions), and activity in the workplace (5 questions), and sports and entertainment (8 questions). Within the manual the PPAQ’s classification and classification of daily physical activities based on their intensity and duration of time they have been explained well. Based on that manual sum of the values multiplied intensity and duration of some activities within the questionnaire can predict the amount of MET / Min for each category of activities as sedentary, light, moderate and sever that has been detailed in the data analysis section. General Chat Chat Lounge
After selecting the subjects in the first meeting, the researcher introduced himself to the mothers and explained the purpose of the study. Informed written consent was then obtained. Later the questionnaires related to personal information and physical activity were filled in. Body mass index (BMI) was calculated and assessed. The mother’s weight was checked with minimal clothing and without shoes, using a digital scale with a precision of 100 g. People’s height was measured using a wall gauge with an accuracy of 1 cm while standing barefoot by the wall, as the shoulders were in a normal position. BMI was calculated by dividing weight by height squared.
Based on weight status (ie, normal, overweight, and obese) and through the permuted block randomization, all pregnant women were randomly assigned to the control and treatment group by Random Allocation Software version 1.0.0. Both groups received individual diets according to BMI, a nutritionist who also provided the necessary explanations. All educational content in the format of text, audio, and video files was delivered and provided through what app as a social media platform. All intervention and control subjects received their specific educational contents according to the prepared study protocol for each group.
The control group subjects were quiet match and more similar with the intervention one. They received a routine pregnancy care that was provided by the health care centers and were followed together with the intervention group in the same time period. Subjects joined a virtual group in a social network (What’s App) that was accessible via both mobile, laptop or PC devices to all subjects in each centers control group. They received prepared individually about diets and materials that track how their effect on their weight gain during pregnancy. In parallel, the treatment group also joined a virtual training group in a social network (What’s App), which was similarly accessible through mobile, laptop or PC devices for all subjects from each intervention center. The only difference was that for this group, they received special and prepared educational content as written, audio or video materials to improve their physical activity along with an individually designed diet during 16 weeks in 8 weeks. The content is delivered to the virtual group twice a week and in a specified time period. Each session was about 90 minutes that all educational programs were delivered by an educated and specialized midwife. During the different session subjects performed appropriate exercises and physical activities during pregnancy, introducing appropriate exercises for pregnant women and the manner in which their execution was educated. Also in some sessions topics related to the necessary precautions and perhaps some risks with health risks were discussed. Reminder massages were sent twice a week regarding the importance of doing exercises and activities truly, the importance of good adhering to the diet, and the announcement about the time of the next session and its contents. All women’s questions were answered both within the group and in private chat based on the type of question. The respondent rate for both groups was% 87.8 in average. Mothers’ weights were recorded after a face-to-face meeting in the fourth week. All delivered massages are deposited in the virtual group by the end of the intervention. Our primary outcome was measuring the amount of changes in mean daily total physical activity level, while secondary outcomes were measuring the level of changes in daily subgroups of daily physical activity along with the level of weight gain during pregnancy.
At the end of the intervention, both groups of pregnant mothers filled the PPAQ questionnaires for the second time. The data acquired in this phase were compared with the first one.
Quantitative data were reported as mean ± standard deviation and qualitative data were expressed in the form’s frequencies and percentages. Activity intensity was measured based on the amount of Metabolic Equivalent of Task (MET). To calculate the total MET / Min of activities, the intensity of activities regarding the MET level was multiplied by the amount of time spent per day. The level of daily activity is determined based on the amount of MET / Min obtained for the activities and their average per day. The categorization for the level of physical activity was done according to the PPAQ specific manual. An activity with MET / Min less than 1.5 was considered as inactivity or sedentary, with MET / Min 1.5–3 as light activity, with MET / Min 3–6 as moderate activity, and with MET / Min more than 6 as a sever activity. General Chat Chat Lounge An independent t-test was used to compare the data about the groups comparing them at the beginning and at the end of the intervention. A paired t-test was used for comparing changes within groups and comparing before and after data. Also, the chi-square test was used to compare data regarding qualitative variables between the two groups at the start of the study. To control for possible confounding factors and better determination of the treatment effect, multivariate analysis was done. The statistical significance for all statistical tests was less than 0.05. We used per protocol analysis for comparing the extracted results between study groups. All analyses were performed using SPSS-21 software.