According to the forecasting analysis of the Global Burden of Disease Study, by 2050, a total of 151 countries are projected to have below-replacement fertility, meaning a total fertility rate (TFR) below 2.1 births per woman [1]. The declining trend of TFR is not only limited to developed countries; in a recent review, a declining trend was reported in the Middle East and North Africa (MENA) [2]. Lebanon, the Islamic Republic of Iran, Tunisia, and Turkey have already experienced a belowreplacement TFRs [2].

Iran, the second-largest country in the Middle East, reached replacement fertility levels at the beginning of the 21st century. By 2011, 21 of the country’s 31 provinces had a TFR below the replacement level [3]. According to a United Nations’ report, Iran is projected to see substantial growth in the percentage of the older population by 2050, making it the only country in the MENA region where more than 30% of its population will be elderly [4]. Furthermore, between 2015 and 2050, Iran is the second-fastest aging country in the world after South Korea in terms of the growth of the older population percentage [5]. Indeed, some have referred to the population crisis in Iran as an “emerging demographic tsunami.” [6] Accordingly, low fertility has garnered considerable attention from policy-makers and researchers in Iran, as well as those in many other below-replacement TFR countries. As Iranian society moves towards modernity, people’s values are changing [7]. Cultural factors, such as changes in women’s dispositions towards marriage and childbearing, the weakening of traditional values, and a tendency toward individualistic norms and lifestyles, all negatively impact fertility intentions [8].

There are several approaches to explaining the reasons underlining the declining fertility trend in countries with a low TFR [9]. One perspective analyzes the determinants of fertility at three levels: micro (individual), meso (group), and macro (policy) [10]. At the micro level, the emphasis is on individuals’ fertility behavior and how it is formed [10]. Interest in micro level research has increased in recent decades, and psychology and behavioral sciences are major disciplines that fuel this paradigm shift [9]. In this regard, the theory of planned behavior (TPB), “one of the most applied theories in the social and behavioral sciences,” [11] continues to offer an empirical framework in the field of fertility research [9]. Proposed by Ajzen [12], the TPB depicts how a person’s thoughts affect their behavior and explains how our behavioral intentions and behaviors are shaped by a combination of three core components: attitudes toward a certain behavior, subjective norms, and perceived behavioral control. Attitude toward fertility is the degree to which an individual has a favorable or unfavorable evaluation with respect to having a/another child [13]. Subjective norm refers to a person’s perception of significant others’ expectations of them having a/another child [13]. Finally, perceived behavioral control means an individual’s subjective perception of the ease or difficulty of having a/another child [13].

Many empirical studies on childbearing intentions have employed TPB to determine the determinants of fertility behaviors. However, most have evaluated the role of each of the three aforementioned constructs (i.e., attitudes, subjective norms, and perceived behavioral control) as a whole rather than item by item [14,15]. Thus, policy-makers and researchers require more accurate and detailed information about beliefs that influence fertility intentions.

In our study, we used a simple TPB model to elicit the antecedent beliefs that underlie the formation of fertility intentions among Iranian women.

Understanding the proximate psychological mechanisms underlying childbearing intention helps us understand what is going on in people’s minds regarding having children [24]. In this way, our path for designing interventions and developing evidence-based population policies will become clearer. In this study, we restricted our use of the TPB to the three immediate psychological antecedents of the fertility intention of married Iranian women [25]. The study findings revealed that, in Iranian culture, all three constructs of the TPB (i.e., attitude, subjective norms, and perceived behavioral control) have a detrimental role in the childbearing intention of married women. Our findings also showed that a higher percentage of Iranian women intended to have children in the future than women in European countries, including Russia (14.1), Italy (22.6), Germany (30.4), France (47.9), and Hungary (48.9) [13].

Among the attitude items, the highest mean values belonged to “blessings come to my life” and “hope and excitement are added to my life.” According to Islamic beliefs, children bring their own “blessing” with them. The word equivalent to blessing in Islam is barakah, “an invisible blessing that manifests itself as an increase that cannot be calculated in material terms encompassing the whole human affairs.” [26] This belief gives Muslims an inherent positive attitude toward having children, which is unfamiliar in the modern era [26]. On the other hand, the lowest mean score of the attitude items was related to the phrase “I have to give up many of my hobbies.” Although the individualistic thinking of Western culture has penetrated Eastern countries, this finding shows that Eastern mothers still do not consider having children an obstacle to their enjoyment of leisure activities [2].

The scores of the subjective norms items showed that parents have a greater influence on the mentality of married women than do friends and relatives. Therefore, parents can be a driving force in strengthening their intention to have children in the younger generation. Findings from a German longitudinal study similarly showed that parents are key normative referents influencing the fertility intentions of adult children [27].

The greatest perceived barrier to the decision to have a child was the individual’s general physical and mental health. In the Generations and Gender Survey conducted in European countries, which have a better economic situation than most of them, the financial situation was the most important control factor [25]. According to Ciritel et al. [28], financial status is not the issue; what matters is the conviction of believe that one has the financial resources to raise a child.

The SEM showed that attitudes, subjective norms, and perceived behavioral control were consistently and significantly associated with childbearing intention. Attitude was the most important determinant of fertility intention, followed by perceived behavioral control and subjective norms. Among the attitude items, “increase joy and satisfaction in my life” was the strongest determining manifest variable. Although Iranian women’s tendencies toward the norms of Western cultures are slowly emerging [7,15], Iran remains a traditional society where childbearing and family values are important [29]. According to the SEM model, siblings and relatives are the most important influential subjective norm in women’s reproductive decision-making processes, and the strongest control beliefs were related to working and educational conditions. However, the importance of the three immediate antecedents of fertility decisions varies by country, and pro-natalistic policies may not be applicable to other countries [25]. For example, in Bulgaria, the strongest determining factor was perceived behavioral control [30], in China, the domain of attitudes played the most important role [31], while in Germany and Italy, perceived behavioral control had no statistically significant effect on the intention to have a child in the future [13]. On the other hand, subjective norms work as a double-edged sword. In countries with low fertility rates, close friends and relatives may encourage couples not to have children [30] and in traditional societies such as Iran, the reverse is still true [15]. According to Nauck and Klaus [32], the overall value assigned to children is lower in more affluent low-fertility countries. Normative pressure does not develop overnight and is the result of years of ideological changes that are less influenced by policies; meanwhile, the attitude that represents the internal evaluations of individuals toward childbearing is more prone to be affected by general policy settings [30]. Therefore, in a situation where traditional culture has been overshadowed by individualism and modernity, policy-makers should pay close attention to cultural factors and ideological issues (e.g., value orientations and religion) in their planning to promote childbearing.

In conclusion, attitude was the strongest proximate predictor of fertility intentions among married women. The TPB model showed that, in Iran, pro-natalistic policies should consider the psychological mechanisms underlying childbearing intentions.