Predictors of receiving care and folic acid supplementation prior to pregnancy: a large cross-sectional study in Shiraz, Iran
Preconceptional care (PCC) includes a set of preventive and therapeutic interventions  designed with the aim of maintaining health during pregnancy and childbirth . PCC increases the probability of a healthy child being born , and should be available to all who are planning a pregnancy . Due to its benefits, including increased folic acid supplementation, PCC also reduces the risk of miscarriage, neural tube defects, premature birth and low birth weight and adverse perinatal outcomes . Nevertheless, the frequency of receiving PCC varies between countries. For example, the frequency of delivering PCC is 40% in China , 33% in the United States of America  and 47.7% in Isfahan, Iran . In other areas of Iran such as Mashhad, it is 34.2%  and in Golestan, the frequency of PCC has been reported as 31%, 63.9% in both urban and rural areas, respectively . In order to increase such frequencies, it will be important to determine the predictors of receiving PCC. In Iran, the comprehensive Pre-Pregnancy Care program is integrated into health care services  and includes risk assessment, screening tests, control of underlying diseases, drug assessments, and other risk factors prior to pregnancy. The program promotes healthy lifestyles, enables the prescribing of supplements and vaccinations as necessary, and offers training and counseling to all, increasing readiness for pregnancy. This aligns with the main purpose of PCC, which is to identify and modify risk factors or diseases that threaten perinatal health and outcomes . Other PCC intervention components may include diet, health and lifestyle assessments, genetic counselling, sexual health screening along with chronic disease management. Yet it is not clear which factors in particular predict engagement with PCC in the context of Iran. Various factors influence the receipt of PCC, the components of which can be reported in the three distinct categories of 1) environmental and organizational, 2) interpersonal and 3) individual factors. Environmental and organizational factors are often related to the availability of and access to public and private health care centers ). Poor engagement with services may be related to referral system problems, service costs, high workload of health personnel and lack of communication and knowledge relating to guidelines . Interpersonal and communication factors include the provision of appropriate information, adequate and appropriate counseling, positive treatment of health workers , family support , lack of awareness of the importance of PCC , trusting the advice of people around you and distrust of health centers . Individual factors influencing engagement with PCC include demographic variables such as age, education level, socio-economic status , perceptions of one’s own health , history of chronic disease , number of previous births  and health literacy . Although it has been almost a decade since the start of Pre-Pregnancy Care services in Iran, there has been a lack of evidence to support its impact. Only one study in the city of Mashhad has been conducted with government health care centers, and private services have yet to be included in research at all . In identifying predictive factors of receiving PCC, services may be improved. As such, the present study aimed to determine the predictors of receiving PCC, as well as folic acid supplementation prior to pregnancy in Iran. 

Study design and setting This cross-sectional study was conducted with participants referring to health centers and gynecology offices in Shiraz, Iran. The selection of urban health centers was done using a multi-stage method. In the first stage, health centers were divided into 5 clusters based on the socio-economic level of potential participants in the Shiraz Municipality. The first cluster was classified as ‘high level’ (6 centers), the second cluster consisted of ‘upper middle level’ (5 centers), the third cluster consisted of ‘normal level’ (11 centers), the fourth cluster was classified as ‘average downward’ (7 centers) and the fifth cluster was classified as ‘weak’ (6 centers), from which 50% of the centers were selected via a simple random method. From all private gynecology offices in Shiraz (n = 165), 20 were selected via a simple random method (Table ). Sampling occurred between May 2021 and February 2022 in both health centers and gynecology offices continuously until the sample size was reached. Participants who met the inclusion criteria were pregnant (≤ 14 weeks' gestation), aged between 18–45 years, and Iranian residents of Shiraz city with the ability to complete the questionnaire. Informed consent was obtained by the research team from participants after providing information about the purpose of the research and the process of what was required. Participants’ confidentiality was assured at all times. Participants were excluded if they did not complete their questionnaire. Study sample To determine the minimum sample size required to estimate the receipt of PCC at a 95% confidence level and with the accuracy of estimation d = 0.03 and considering that the receipt of PCC in Shiraz city is 20% , after quantification in the following formula, the minimum required sample size was estimated to be n = 685. [12pt]{minimal}
				
				 
				 
				 
				
				
				
				
				$$n=_{1-{}^{ }\!/ \!{}_{2}.}^{2} pq}{{d}^{2}}=^{2} 0.2 0.8}{{0.03}^{2}}=685$$ n = z 1 - ∝ 2 2 p q d 2 = 1.96 2 × 0.2 × 0.8 0.03 2 = 685 Outcome measures and measurements Data collection tools included three questionnaires measuring: individual and fertility characteristics, PCC information (designed based on national guidelines and the Health Literacy of Iranian Adults (HELIA) aged 18 to 65 years (Supplementary file 1). Questionnaire of individual and fertility characteristics included: Age, level of education, occupational status, economic status, insurance status, previous pregnancy history, pregnancy planning status, gestational age (< 14 weeks gestation), history of adverse obstetric outcomes (e.g., abortion, PTB, IUFD, LBW or congenital anomaly) and length of marriage. PCC information questionnaire included: PCC engagement and folic acid supplement consumption prior to pregnancy (based on national guidelines . Health Literacy of Iranian adults (HELIA) aged 18 to 65 years questionnaire : HELIA was designed and psychometrically evaluated by Montazeri et al. (2013). The questionnaire has 33 items in 5 domains, including access to information (6 items), reading skill (4 items), understanding (7 items), appraisal (4 items) and the decision-making/behavioral intention dimension with 12 items. Scores obtained from this questionnaire for each person range between 33 and 165. The literacy level score for each person ranges between 0 and 100, whereby a higher score is indicative of a higher level of health literacy. A score between 0–50 is interpreted as ‘inadequate’, a score between 50.1–66 is ‘problematic’, 66.1–84 is ‘sufficient’ and 84.1–100 is ‘excellent’. HELIA is a reliable and valid instrument for measuring health literacy in Iran, and it’s internal consistency is satisfactory, with Cronbach’s alpha coefficients ranging from 0.72 to 0.89 . Data analysis Data analysis was completed utilizing SPSS version 23 software. For descriptive statistics, frequency distributions were used for the qualitative variables and numerical indicators of minimum, maximum, mean along with standard deviation were used for the quantitative variables. To compare the means, independent sample t-test and one-way analysis of variance were used, and if significant, Tukey's post hoc test was also used. To determine the relationship of each one of the independent variables (individual and fertility variables) on the dependent variable (PCC and Folic Acid supplementation separately), those variables that confirmed significance in the bivariate test ( p < 0.2) were then entered into a Binary Logistic Regression model using an enter strategy. Results from the Binary Logistic Regression analysis are presented as Odds Ratio (OR) with associated 95% CIs. The level of statistical significance was set at P < 0.1 . 

This cross-sectional study was conducted with participants referring to health centers and gynecology offices in Shiraz, Iran. The selection of urban health centers was done using a multi-stage method. In the first stage, health centers were divided into 5 clusters based on the socio-economic level of potential participants in the Shiraz Municipality. The first cluster was classified as ‘high level’ (6 centers), the second cluster consisted of ‘upper middle level’ (5 centers), the third cluster consisted of ‘normal level’ (11 centers), the fourth cluster was classified as ‘average downward’ (7 centers) and the fifth cluster was classified as ‘weak’ (6 centers), from which 50% of the centers were selected via a simple random method. From all private gynecology offices in Shiraz (n = 165), 20 were selected via a simple random method (Table ). Sampling occurred between May 2021 and February 2022 in both health centers and gynecology offices continuously until the sample size was reached. Participants who met the inclusion criteria were pregnant (≤ 14 weeks' gestation), aged between 18–45 years, and Iranian residents of Shiraz city with the ability to complete the questionnaire. Informed consent was obtained by the research team from participants after providing information about the purpose of the research and the process of what was required. Participants’ confidentiality was assured at all times. Participants were excluded if they did not complete their questionnaire. 

To determine the minimum sample size required to estimate the receipt of PCC at a 95% confidence level and with the accuracy of estimation d = 0.03 and considering that the receipt of PCC in Shiraz city is 20% , after quantification in the following formula, the minimum required sample size was estimated to be n = 685. [12pt]{minimal}
				
				 
				 
				 
				
				
				
				
				$$n=_{1-{}^{ }\!/ \!{}_{2}.}^{2} pq}{{d}^{2}}=^{2} 0.2 0.8}{{0.03}^{2}}=685$$ n = z 1 - ∝ 2 2 p q d 2 = 1.96 2 × 0.2 × 0.8 0.03 2 = 685 

Data collection tools included three questionnaires measuring: individual and fertility characteristics, PCC information (designed based on national guidelines and the Health Literacy of Iranian Adults (HELIA) aged 18 to 65 years (Supplementary file 1). Questionnaire of individual and fertility characteristics included: Age, level of education, occupational status, economic status, insurance status, previous pregnancy history, pregnancy planning status, gestational age (< 14 weeks gestation), history of adverse obstetric outcomes (e.g., abortion, PTB, IUFD, LBW or congenital anomaly) and length of marriage. PCC information questionnaire included: PCC engagement and folic acid supplement consumption prior to pregnancy (based on national guidelines . Health Literacy of Iranian adults (HELIA) aged 18 to 65 years questionnaire : HELIA was designed and psychometrically evaluated by Montazeri et al. (2013). The questionnaire has 33 items in 5 domains, including access to information (6 items), reading skill (4 items), understanding (7 items), appraisal (4 items) and the decision-making/behavioral intention dimension with 12 items. Scores obtained from this questionnaire for each person range between 33 and 165. The literacy level score for each person ranges between 0 and 100, whereby a higher score is indicative of a higher level of health literacy. A score between 0–50 is interpreted as ‘inadequate’, a score between 50.1–66 is ‘problematic’, 66.1–84 is ‘sufficient’ and 84.1–100 is ‘excellent’. HELIA is a reliable and valid instrument for measuring health literacy in Iran, and it’s internal consistency is satisfactory, with Cronbach’s alpha coefficients ranging from 0.72 to 0.89 . 

Data analysis was completed utilizing SPSS version 23 software. For descriptive statistics, frequency distributions were used for the qualitative variables and numerical indicators of minimum, maximum, mean along with standard deviation were used for the quantitative variables. To compare the means, independent sample t-test and one-way analysis of variance were used, and if significant, Tukey's post hoc test was also used. To determine the relationship of each one of the independent variables (individual and fertility variables) on the dependent variable (PCC and Folic Acid supplementation separately), those variables that confirmed significance in the bivariate test ( p < 0.2) were then entered into a Binary Logistic Regression model using an enter strategy. Results from the Binary Logistic Regression analysis are presented as Odds Ratio (OR) with associated 95% CIs. The level of statistical significance was set at P < 0.1 . 

According to statistical calculations, the minimum sample size was estimated to be 685. Out of a total of 977 people who met the conditions for entering the study, 237 (24.25%) were unwilling and 740 people were willing to participate. Out of the total number of participants recruited (n = 740), 693 filled out their questionnaires completely and the rest (n = 47) incompletely. The reasons for not completing the forms were recorded as: declining to answer some of the questions (n = 19), lack of time (n = 11), spousal opposition (n = 4), length of questionnaire too long (n = 9), and lack of suitable space (n = 4). Examining the frequency of variables relating to individual characteristics showed that the mean age of participants was 30.32 with a standard deviation of 5.29 years and more than half (59.3%) had university education. Most of them (80.7%) were unemployed, 58% considered their family's financial situation to be relatively favorable, and 80.7% were covered by insurance. Examining the frequency of fertility characteristics showed that 37.1% of pregnancies were first time pregnancies. More than half (56.7%) were pregnant from 7 to 12 weeks and 57.3% used contraception, of which the natural method was reported most frequently (57.4%). Overall, 82.3% declared that their current pregnancy was planned, and 69.8% had no history of abortion. The majority of participants (96.4%) had no history of stillbirth, 94.2% had no history of premature birth, and 95.8% had no history of having a baby born with congenital and genetic defects. Also, the majority (96.2%) had no history of low-birth-weight babies. The length of marriage of 47.9% of participants was between 4 and 10 years, and in terms of health literacy, only 49.4% of participants had adequate health literacy (Table ). Results demonstrated that PCC has a statistically significant relationship with a number of variables such as level of education ( P = 0.01). Here, only 60.3% of those with less than diploma level education and 60.3% with diploma level education engaged in PCC, while 71.3% of those who were university educated engaged in PCC. Employment status also had a statistically significant relationship with PCC ( P = 0.002), as 64% of unemployed and 78.4% of working participants engaged in PCC. Also, length of marriage had a statistically significant relationship with PCC ( P = 0.008), whereby the mean length of marriage was significantly higher in those who had PCC The number of pregnancies was also significant ( P = 0.03), in that 72.8% of those who had their first pregnancy had PCC, those who had second and third children received preconceptional care 63.6% and 62.4%, respectively while only 59.7% of those who had their fourth pregnancy or more had received PCC. Pregnancy gestation was significant ( p = 0.003) in that 57.8% of those whose pregnancy was 6 weeks or less, 63.4% of those whose pregnancies were between 7 to 12 weeks and 75% of those with a pregnancy up to 14 weeks gestation had received PCC. Another significant variable was that of pregnancy status ( P < 0.001), as 73.7% of participants who had planned a pregnancy had PCC, while only 29.3% with an unplanned pregnancy had PCC. Health literacy had a statistically significant relationship with PCC ( P < 0.001), as the mean score of health literacy was higher in those who had PCC (Table ). Results highlight how variables such as length of marriage, health literacy, education level, occupational status, economic status, number of pregnancies, week of pregnancy, and current pregnancy status have a significant relationship with PCC. Length of marriage, health literacy, occupational status, and pregnancy planning status variables entered the logistic regression model remained in the model following analysis (Table ). Having an unplanned pregnancy in comparison to having a planned pregnancy, being unemployed compared to being employed and having only an adequate level of health compared to an excellent level of health reduced the chance of participants receiving PCC by 86%, 40% and 85%, respectively (Table ). Results demonstrate that folic acid supplementation also has a statistically significant relationship with a number of variables including level of education ( P = 0.001), whereby only 41.3% of participants with undergraduate level education and 47% of those with diploma level education used folic acid supplements prior to pregnancy, while 59.4% of university level educated participants used folic acid supplements prior to pregnancy. The financial status of the family was also significant ( P = 0.045) in that only 45.7% of participants with unfavorable financial status and 54.2% with relatively favorable status used folic acid supplements, while 60.1% with favorable financial status used folic acid supplements. Also of significance was participants’ length of marriage ( P = 0.002), as the mean length of marriage was significantly lower in those who used folic acid supplements. The number of pregnancies was also significant ( P = 0.02) in that 61.5% of participants who were pregnant for the first time had taken folic acid supplements. This was more frequent than others who were multiparous. Participants’ pregnancy status was also significant ( P < 0.001), as 58.2% who had a planned pregnancy had taken folic acid supplements, while only 33.3% with an unplanned pregnancy had taken folic acid prenatally. Health literacy ( P < 0.001) also had a statistically significant relationship with folic acid supplementation in that the mean score obtained from participants who used the supplement was higher than scores obtained from others (Table ). Variables such as length of marriage, health literacy, education level, occupational status, economic status, number of pregnancies, week of pregnancy, and current pregnancy status have a significant relationship with folic acid supplementation. Length of marriage, health literacy, occupational, and pregnancy planning status variables entered the logistic regression model and remained in the model following analysis. Evidently, unplanned pregnancy compared to planned pregnancy, being unemployed compared to being employed, and having a problematic level of health compared to an adequate level of health reduced the chance of prenatal folic acid consumption by 61%, 49%, and 54%, respectively (Table ). 

This research aimed to determine the predictors of receiving PCC, as well as folic acid supplementation prior to pregnancy in Iran. The prevalence reported here (66.8%) is based on information obtained from clients visiting health centers and even more from private gynecology offices. This is in stark contrast to the prevalence of 20% reported from the Sib system hosted by the Ministry of Health regarding the city of Shiraz in 2021 from data collected via health centers. It is also important to consider that sampling in the present study occurred during the COVID-19 pandemic, and thus the number of visitors to the health centers was greatly reduced. Nevertheless, prior to the COVID-19 pandemic the numbers visiting health centers to receive PCC were still small, and so we must consider that the majority attend private centers to receive PCC, and that for this reason, their information is not recorded in the Sib system. Given the above, this research provides important foundational evidence on the predictors of receiving PCC, as well as folic acid supplementation prior to pregnancy in Iran. Participants’ level of education, employment status, length of marriage, number of pregnancies, weeks of pregnancy and current pregnancy status (planned or unplanned) had a statistically significant relationship with PCC. Contrariwise, age, insurance coverage, financial status, pregnancy prevention, history of abortion, history of stillbirth, history of premature birth, history of birthing a baby with congenital and genetic defects and history of birthing a baby with low birth weight did not have a statistically significant relationship with PCC. Elsewhere, participants over 35 years of age were more aware of PCC compared to their younger counterparts . The reason for this higher awareness among older participants may be due to the risk of pregnancy at an older age, more awareness and greater expectations also means that those pregnant at an older age will have increased knowledge about PCC . In Adeyemo et al.'s study (2021), there was a statistically significant relationship between age, occupation, age at first pregnancy, number of previous pregnancies and the receipt of PCC. Yet regarding the variables of marital status, education level, number of births and history of receiving family planning methods, this relationship was not statistically significant . Such differences call for further qualitative research to understand these relationships in more detail with regards to context. In the present study, a statistically significant relationship between participants’ occupation and PCC was identified. PCC was received by more unemployed participants than those working. This may be due to working hours being incompatible with the opening hours of health care centers. Such findings point to the need to increase accessibility to PCC for those working. Similar to the results of the present study, Temel et al. also showed that those working participate in less PCC . Yet conversely, Mkandawire et al. (2019) identified that a higher percentage of people who refer to receive PCC services are employed . This may be linked to one’s level of education, or indeed be unrelated. Further qualitative work is again required to understand such differences in context. In the present study, a statistically significant relationship was identified between a person's education and them receiving PCC. This relationship has also been confirmed in separate studies, where those who had a higher level of education were more likely to have a higher income and access more PCC . Nevertheless, in other studies conducted elsewhere (e.g., Nigeria), this relationship was not statistically significant . The reason for this difference may be that in Mashhad, more than 80% of the population has only diploma level education or less. Nevertheless, these diversities of results add to the need for larger mixed-methods studies in this area to better understand the nuances between various contexts and populations. In the present study, there was no statistically significant relationship identified between the individual's income and the receipt of PCC. Elsewhere, PCC has been received more by those with very low socio-economic status  Yet those with a lower socioeconomic status and with the highest risk of complications during and after pregnancy have also been found to have the least PCC . Contrariwise, in France those with a high socio-economic class have been found to have a higher probability of seeking PCC with an odds ratio of 2.32 . Equally, in the present study, a statistically significant relationship was seen between the number of pregnancies and referrals for PCC. PCC delivery was the highest in those pregnant for the first time, and the lowest in those with 4 or more pregnancies. In the study by Paradis et al. (2017) conducted in France, primiparous participants when compared to multiparous participants similarly received significantly more PCC (54.8% vs. 35.1%). Indeed, primiparous participants with an odds ratio of 2.47 had a higher probability of seeking PCC overall . This may be due to primiparous participants’ inexperience with pregnancy and childbearing, and lack of obstetric histories. In the current study, there was no statistically significant relationship identified between the history of adverse pregnancy outcomes such as history of miscarriage, history of stillbirth, history of premature birth, history of birthing a baby with congenital and genetic defects, history of low birth weight and PCC. Similarly, there was no relationship identified between receiving PCC and the history of premature birth, abortion, and medical problems found elsewhere . In a separate study, in those who had an adverse pregnancy history, the probability of engaging in PCC showed a fivefold increase compared to those who had no history . These results are consistent with research conducted in Los Angeles . Yet those presented by Connor et al.'s (2014) found no association between PCC and preterm birth or gestational diabetes . The lack of association in this study may be due to the small number of participants with an adverse pregnancy history (preterm birth, miscarriage, and medical problems). Thus, larger studies are required to understand this relationship in more depth. In the present study, a statistically significant relationship was found between pregnancy status (unplanned and planned) and PCC. Results presented by Shadab et al. (2017) are in line with these. Here, among the causes of not receiving PCC, unplanned pregnancy (64.6%), lack of awareness of the importance of PCC (40.3%) and lack of awareness of PCC provided in health centers (15.8%) were the most important reasons cited for lack of engagement with PCC . The results of Pourheydari et al.'s study again showed that 21.8% of those with planned pregnancy and 8.3% with unplanned pregnancy received PCC . Thus, we can be confident that this significant relationship may be more generalizable and applicable in other populations. Regarding the relationship between health literacy and PCC, those who referred to receive PPC had a higher health literacy score. The difference between the two groups (receiving and not receiving PCC) was statistically significant. These results are in line with those presented by Ghanbari et al. (2020), where those who had a higher average health literacy score were also found to be more likely to receive preventive measures and health care . Sodergren et al. (2017) also reported that those with low health literacy are less likely to receive PCC including folic acid supplementation and support with smoking cessation . This same finding is present with regards to pre-pregnancy counseling, and vaccination . Consequently, health literacy will be important to enable more engagement with PCC, and thus greater perinatal health outcomes. Level of education, economic status of the family, length of marriage, number of pregnancies, week of pregnancy and current pregnancy status had a statistically significant relationship with the intake of folic acid. Age, employment, insurance coverage, economic status of the family, pregnancy status, history of abortion, history of stillbirth, history of premature birth, history of birthing a baby with congenital and genetic defects and history of birth of a baby with low birth weight did not have statistically significant relationship with receiving folic acid. Other studies have also confirmed no statistically significant relationship between age and receiving folic acid supplements  Yet another has reported no statistically significant relationship between education and receiving folic acid supplements . The reason for this difference in particular may be because in the present study, approximately three-fifths of the population had a university education, whereas in the study by Alsammani et al. (2017), less than one-tenth of the studied population had a university level of education. Moreover, more than half of participants (53.8%) engaged in folic acid supplementation prior to pregnancy overall, this finding along with the varying rates across Iran warrant further investigation and suggest a need for more co-ordinated and national approaches to increase folic acid supplementation prior to pregnancy. In line with the results presented here, Ezzeddin et al. (2019) also reported a statistically significant relationship between level of education, employment, whether pregnancy was planned or not, and the number of pregnancies with folic acid supplementation prior to pregnancy. Participants in the study reported by Ezzeddin et al. who received folic acid supplements prior to pregnancy were both employed (68.2%) and unemployed (52.3%). Being employed increased the probability of folic acid consumption . In the present study, the consumption of folic acid in employed participants was also more frequent than in unemployed participants (60.44% and 50.23%, respectively), yet this difference was not statistically significant. Employment in this context may therefore be a protective factor against folic acid deficiency. In both this study and another reported by Tort et al., 2013, primiparous participants compared to multiparous participants and those with favorable financial status compared to unfavorable status had higher folic acid intake .In several studies, there has also been a statistically significant relationship between the number of pregnancies and the intake of folic acid prior to pregnancy . The consumption of folic acid during pregnancy had a significant relationship with the number of pregnancies and abortions in an earlier study . Yet in line with the present study, Alsammani et al. (2017) reported no statistically significant relationship between abortion history and folic acid supplementation , as did researchers in Australia with regards to premature birth and folic acid intake . These discrepancies indicate a need to conduct further research in this area with larger sample sizes and qualitative elements. The mean score of health literacy in participants who took folic acid supplements was statistically significantly higher than the mean score for health literacy in the group that did not. The results of Roudsari et al.'s study similarly showed that a statistically significant but weak relationship between people's knowledge and folic acid consumption . Further research is again required to strengthen the evidence in this regard. In terms of implications and recommendations, the comprehensive Pre-Pregnancy Care program , which is integrated into health care services in Iran must focus its efforts on improving health literacy and family planning among those with lower levels of education, those who have been married for longer, and those with subsequent pregnancies. Wider agencies must invest in employment and improvements in the financial status of Iranian families, whilst also investing in education. Targeted health promotion through media may be useful in these tasks. Strengths and limitations and suggestions for future research A key strength of the present study is that it has employed multi-stage sampling techniques and has achieved a high sample size. Nevertheless, there have been some non-completions of the questionnaire by participants living in more rural areas of Shiraz city. The results presented therefore cannot be wholly generalizable to other populations or settings. Moreover, the limitations of cross-sectional designs lie in their inherent inability to infer causality. This suggests a need for future research to use longitudinal designs to examine statistically significant causal relationships. With regards to our demographic and fertility variables, it is important to consider that the unplanned pregnancy measurements may have been affected by both recall and social desirability bias. The characteristics of non-responders were also available to assess and compare with the characteristics of those who participated. This may mean that the results have been affected by potential selection bias. The components of PCC were measured using ‘yes’ or ‘no’ responses and could have been better measured via more nuanced ways. Lastly, due to the COVID-19 pandemic being active at the time of sampling, the majority of participants were referred to private gynecology offices. Consequently, it was not possible to include larger numbers of participants from health centers for comparison. Future research could usefully include participants from rural areas and more health centers to examine such relationships further, including those between health literacy and regular consumption of folic acid prior to pregnancy. 

A key strength of the present study is that it has employed multi-stage sampling techniques and has achieved a high sample size. Nevertheless, there have been some non-completions of the questionnaire by participants living in more rural areas of Shiraz city. The results presented therefore cannot be wholly generalizable to other populations or settings. Moreover, the limitations of cross-sectional designs lie in their inherent inability to infer causality. This suggests a need for future research to use longitudinal designs to examine statistically significant causal relationships. With regards to our demographic and fertility variables, it is important to consider that the unplanned pregnancy measurements may have been affected by both recall and social desirability bias. The characteristics of non-responders were also available to assess and compare with the characteristics of those who participated. This may mean that the results have been affected by potential selection bias. The components of PCC were measured using ‘yes’ or ‘no’ responses and could have been better measured via more nuanced ways. Lastly, due to the COVID-19 pandemic being active at the time of sampling, the majority of participants were referred to private gynecology offices. Consequently, it was not possible to include larger numbers of participants from health centers for comparison. Future research could usefully include participants from rural areas and more health centers to examine such relationships further, including those between health literacy and regular consumption of folic acid prior to pregnancy. 

Higher levels of education, being married for a shorter length of time, being pregnant for the first time, having a planned pregnancy and higher health literacy are effective factors in receiving PCC and acid folic consumption prior to pregnancy. Moreover, being employed and having favorable financial status are also effective for increased folic acid consumption prior to pregnancy. In order to improve the status of PCC and folic acid supplementation, special attention must be afforded to improving the status of health literacy and levels of education along with reducing unplanned pregnancies. 

Supplementary Material 1 

