Participants
The present research was a cross-sectional analytic study. The study sample included married women who were residing in Saveh and Zarandieh cities in Iran in 2015–2016. The study’s inclusion criteria were being Iranian, being married for the first time, and having been married for a year or more, with no child or only one child. Women who had medical reasons for their subfertility or infertility, or were unwilling to take part in the study, were excluded.
Procedure
After obtaining the required approval from Saveh University of Medical Sciences (UMS) and preparing a list of all healthcare centers under the jurisdiction of the faculty, research units were selected through a multi-stage sampling method. In the first stage, based on the 2013 census statistics, data were obtained regarding the population of four districts (two Nobaran central districts of Saveh and central and Kharghan district of Zarandieh) which were under the coverage of Saveh UMS. Then, from all healthcare centers of Saveh and Zarandieh, one urban and one rural center were selected via random sampling. Eventually, four urban and four rural centers were selected. In the next stage, the sample size for each center was determined based on the population covered by the center and through quota sampling. In the final stage, the required sample from each center was selected by systematic sampling method and based on the number of households in the family file. The data were available from an earlier descriptive research project.
Sample size
Cochran’s formula was used to estimate the sample size. This formula does not estimate sample size using power analysis. By using Cochran formula, 5% margin of error, and 95% significance level, the sample size was decided to be 400 women. To increase the accuracy, 490 questionnaires were administered, of which 17 were excluded due to incompleteness, and finally, 483 questionnaires were collected (97% return rate).
Data collection
Data were collected using a multi-section self-report questionnaire: The first part covered personal information including age, age at marriage, duration marriage, monthly household income, literacy, residential area, and employment status of women and their husbands. The other parts of the questionnaires included scales that have been widely used in the previous studies [4, 8, 9] as follows:
Attitudes toward childbearing and fertility [8, 10,11,12]
Attitudes of women toward childbearing and fertility were assessed using 15 items on a Likert type scale ranging from 1 (completely agree) to 5 (completely disagree), (e.g.: In my opinion/belief, life without having any children is dull and spiritless). The total range of scores for this section was from 15 to 75 with the higher values indicating better attitudes respectively. The reliability of the attitude scale yielded a satisfactory level of Cronbach’s alpha (0.81).
Subjective norms (SN) [12,13,14]
SN, which refer to the perceived pressure of important others to perform or not to perform a behavior, were assessed using 6 items, (e.g.: My husband thinks that one child is enough). A scale from completely correct (1) to completely incorrect (5) was used to assess these SN. The total possible range of scores in this section was 6 to 30, with the higher values indicating better SN. Internal consistency of the scale was measured by Cronbach’s alpha, and the results revealed a good level of reliability (0.77).
Behavioral intention of childbearing [8, 12,13,14]
The behavioral intention was defined as a woman’s perceived likelihood that she would engage in childbearing. It was evaluated through four 5-point items, including “I will definitely do this (5), I most probably will do this (4), I may do this (3), I possibly will not do this (2), and I will not do this at all (1)” (e.g., “At any time during the next 2 years do you intend to get pregnant?”). The scores of this part ranged from 4 to 20, and its reliability was tested with Cronbach’s alpha (0.85).
The ENRICH Marital Satisfaction Scale [15]
The ENRICH Marital Satisfaction Scale included 35 items ranked based on a 5-point Likert scale, namely, the style responses of “absolutely agree,” “agree,” “neither agree nor disagree,” “disagree,” and “totally disagree”; these items scored from 1 to 5. In this questionnaire, the evaluated satisfaction aspects are as follows: personal issues, leisure activities, sexual relationships, family and friend’s religious orientation, and parenting. The scores of this part ranged from 35 to 175. In Iran, the scale content validity and reliability were calculated and confirmed [16]. In our study, good reliability was confirmed by a Cronbach’s alpha level of 0.81.
The Snyder Hopes Scale [17]
The Snyder Hopes Scale included 8 items ranked based on an 8-point scale from completely wrong (1) to completely right (8), (e.g., “I can find many ways to achieve the things that are important for me”). The minimum and maximum scores were 8 and 64, respectively. A higher score in the scale showed a higher level of hope. The questionnaire has two sub-scales called hope agency and hope pathways. In Iran, psychometric properties of the scale has been satisfactory [18]. In our study, good reliability was confirmed with a Cronbach’s alpha of 0.78.
Social support (SS) [19]
The multidimensional scale of perceived SS, which is a 12-item questionnaire developed by Zimet et al., 2013 measures the perceived SS from family, friends and significant others. This instrument provides response options ranging from 0 to 6 (very strongly disagree to very strongly agree). The scores of this part ranged from 0 to 72. A higher score reflects more support. The reliability and validity of the Farsi version of the perceived SS have been evaluated [20]. In the present study, Cronbach’s alpha for the scale was 0.89.
Validity
To ensure the selected items were of the best quality, quantitative and qualitative content validity ratio (CVR) and content validity index (CVI) were used. This process included asking 10 experts in the areas of health education, social medicine, public health, midwifery, and obstetrics to divide the items into three categories of “necessary,” “beneficial but not necessary,” and “not necessary.” Based on the Lawche’s table, the items with CVR > 0.62 were considered as significant and therefore; they all remained in the questionnaire (P < 5%). For the purpose of CVI estimation, experts were asked to rate scales for relevancy and clarity based on a 4-point Likert type scale. Items were regarded as clear and relevant if they obtained values equal to or greater than 0.79. Consequently, all items remained within the questionnaire. To check the qualitative content validity, 10 experienced university professors were asked to assess the quality of included items and consider the grammatical features, wording, item placement, and grades assigned to each item.
Data analyses
The Kolmogorov-Smirnov test was used to determine the normal distribution of the obtained data. Data were analyzed by SPSS 18 (SPSS, Chicago, IL, USA, acquired by IBM) using Chi-square, independent sample t tests, Pearson correlation, and regression tests. P < 0.05 was considered as statistically significant. To assess factors associated with childbearing intent, multiple logistic regression analyses were conducted to generate odds ratios (OR) and 95% confidence intervals (CI) for the associations of interest. Only the independent variables that showed significant associations with childbearing (P ≤ 0.05) in bivariate analyses were included in the multiple logistic regression model.
To determine the dependent variable in logistic regression models, data regarding fertility intention status within 2 years were collected using one question: “During the next 2 years do you have an intention to have a child?” with yes/no responses. Participants who indicated that they did not have any intention to have a child in the next 2 years were coded 0, and the others as code 1.