Introduction

Preconception care targets women's health care before pregnancy (1). This care aimed at the identifications of the risk factors associated with fertility and reduction of these risks through appropriate training, prevention, and treatment (2). Preconception care as a supplement to prenatal care can improve the outcome and health status of women by the implementation of a long-term approach (3). Nearly half of the pregnancies are unplanned in the United States (4). The review of 49 studies indicated that the prevalence of unplanned pregnancy in Iran is 30.6% (5). Moreover, one-third of all pregnancies in Mashhad are unintended (6).

Despite the integration of preconception care in maternal care program of all medical universities of the country since 2006 (7), the preconception care rate is still low in Iran. In a study conducted in Iran during 2013, more than 50% of women performed no preconception care (8). According to the current review, the majority of studies in the field of preconception care have reported that the level of knowledge, attitude, or performance is below the expected levels of preconception care behavior. The lack of knowledge about preconception care has also been reported among women in Italy (9), Ethiopia (10), Jordan (11), England (12), Denmark (13), and Egypt (14).

In a study performed by Barchloo et al. (2013), it was reported that 59.9% and18.5% of women had moderate and weak knowledge about folic acid consumption and knowledge, respectively. In addition, 37.6% of the subjects had a false attitude toward the effects of folic acid, whereas 34.5% of the participants were unaware of the effects of folic acid (15). In a recent study, Firouzi and Ebrahimi (2017) declared that knowledge and attitude regarding preconception care had not been investigated previously. Accordingly, they suggested to implement further studies in this field and evaluate performance and effective factors in this regard (16). Moreover, Bayrami et al. concluded that before pregnancy, women require to be educated on issues related to prenatal care to prevent potential health problems (8). On the other hand, ShamshiriMilani et al. (2016) indicated that limited knowledge and community's unawareness about preconception care and services in healthcare centers were considered as the most perceived barriers posed by participants (17). In health education, two variables of knowledge and attitude are important behavioral determinants. Knowledge is considered as the base in the study of the perception of risk and beliefs while attitude plays a role as a predisposing an individual factor in affecting behaviors (18).

The use of models of health education will help researchers recognize the factors affecting health behaviors. Among health education models, the health belief model is one of the most effective models in the cognitive psychology to determine health behaviors that shows the relationship between health beliefs and health behaviors and emphasizes on the intrinsic factors of individuals, such as knowledge, attitudes, beliefs and behavior (19, 20). The health belief model was the first theory, exclusively used for "health-related behaviors", in particular for designing programs to prevent inappropriate health behaviors that are based on people's attitudes and beliefs. This model encompasses four main concepts, including sensitivity, severity, benefits and perceived barriers (20).

 Today, it is believed that individuals must feel threatened by their current behavioral patterns to succeed in behavioral change, as desired in the health belief model. In addition, they must believe that a particular type of behavior leads to a valuable outcome with an acceptable outcome (21). Therefore, in order to conduct a healthy behavior (e.g., preconception care), one must believe that s/he is susceptible to the disease (perceived susceptibility), fully understand the depth of the risk and the seriousness of its various complications in his/her life (perceived severity), and consider the proposed behaviors, such as preconception care, useful to reduce the risk or severity of the disease (perceived benefits) to overcome the inhibiting factors (perceived barriers) (22).

Preconception care is considered a preventive measure in the provision of maternal and neonatal health. Therefore, it is important to employ a health belief model in studies related to preventive health behaviors and investigate the role of knowledge and attitude as well as health belief model on intra-individual factors (e.g., knowledge and attitude). Given the above-mentioned issues and the lack of research on the use of the health belief model in assessing women's knowledge and attitudes regarding preconception care, this st