Introduction

As an important type of diabetes, Gestational Diabetes Mellitus (GDM) is a condition of glucose intolerance develo** during pregnancy. According to International Diabetes Federation (IDF), 17% of the maternal population (aged 21–49 years old) suffered from GDM worldwide in 2021, affecting 21 million newborns [1]. The prevalence of the maternal population suffering from GDM during 2012–2015 in China was 17.5%, which showed an increasing trend in recent years [2].

Although GDM resolves after delivery for the majority of women, it is not uncommon for mothers and their offspring to suffer from multiple long-term health outcomes [3,4,5,8]. In addition, breastfeeding has been reported to be associated with a reduced risk of obesity and diabetes mellitus in GDM mothers’ offspring [9, 10]. Thus, GDM mothers are supposed to insist on breastfeeding to mitigate the health risks for themselves and their offspring.

However, the prevalence of breastfeeding among GDM mothers was far from optimal around the world, with 34.8% of GDM mothers exclusively breastfeeding (EBF) their infants which was far less than the target of 50% of the recommended criteria from the World Health Organization [11, 12]. The prevalence of exclusive breastfeeding (EBF) in infants under 6 months was 29.2% according to a national survey in China and the prevalence was lower in GDM mothers [13].

However, GDM mothers’ formation and decision-making process regarding their feeding behavior was still unclear. Existing studies concentrated on healthy mothers and found that pathological factors [14], psychological factors [13], knowledge of breastfeeding [15], perceived barriers to breastfeeding [16], self-efficacy [17], social support [16] and personal characteristics [12, 15] was associated with maternal breastfeeding intention and actual behavior. However, this is not the situation for GDM mothers [18,19,20]. It was shown that GDM mothers were at greater risk of delayed lactation initiation [21] and higher risk of adverse outcomes from GDM (such as neonatal hypoglycemia, macrosomia and cesarean section) [22], which put more burden and barriers compared with healthy mothers. Studies also found that mothers with GDM required more social support from professionals and their families and more self-efficacy in breastfeeding to insist on breastfeeding compared with mothers without GDM [16, 3).

Regarding the perceived value of breastfeeding, respondents commonly reported perceived the benefits of breastfeeding (3.35 ± 0.46) (Table 3), agreeing that breastfeeding is nutritious and safe and can enhance the parent–child bond and improve the child’s immunity (Mean score > 3.24, SD: 0.49–0.73). However, maternal awareness of the benefits of breastfeeding to reduce the future diabetes of themselves (3.06 ± 0.75) and their child (3.04 ± 0.76) was insufficient (Supplementary S3). On the other hand, respondents reported a high level of perceived barriers to breastfeeding (2.20 ± 0.47). Insufficient breast milk supply, believing that formula milk could provide the same nutrition as breast milk, and the impact of breastfeeding on daily life were considered important barriers to breastfeeding (Mean score > 2.3, SD: 0.78–0.93). In contrast, neonatal jaundice and breast distension engorgement were not major obstacles to breastfeeding (Mean score < 2.3, SD: 0.63–0.67).

Generally, respondents showed a high level of self-efficacy in breastfeeding (3.43 ± 0.97) (Table 3) and received a high level of social support from families, friends and society (3.74 ± 0.74). The details of responses could be found in supplementary S3.

Formation of breastfeeding behavior based on HBM

The SEM confirmed the theoretical framework for the breastfeeding behavior of GDM based on HBM (Fig. 3) with an excellent model fit index (RMESA = 0.033, CFI = 0.969, TLI = 0.965, WRME≈1 (1.087)).

Fig. 3
figure 3

Formation of feeding behaviors of GDM mothers based on HBM. Legends: Results based on SEM and only significant pathways (p < 0.05) were reported with standardized path coefficients

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Higher knowledge scores were found to be linked with fewer perceived barriers (β = -0.154, p = 0.034) and more perceived benefits (β = 0.375, p < 0.0001) of breastfeeding. It was also associated with a higher level of perceived severity (β = 0.253, p = 0.010), but not significantly related to higher perceived susceptibility (p = 0.697) of GDM long-term consequences. Moreover, a higher level of social support was associated with higher perceived benefits (β = 0.331, p < 0.0001) and fewer perceived barriers (β = -0.370, p < 0.0001).

Furthermore, higher perceived barriers (β = -0.636, p < 0.0001), higher perceived susceptibility (β = -0.157, p = 0.005) and less level of social support (β = 0.127, p = 0.006) were associated with GDM mothers’ less self-efficacy of breastfeeding. Respondents who showed higher self-efficacy (β = 0.661, p < 0.0001) and perceived less benefit of breastfeeding (β = -0.329, p < 0.0001) were more likely to breastfeed the newborns.

To explore whether the relationship of breastfeeding behavior based on HBM varied between subgroups of mothers. Respondents’ characteristics (such as age, mode of delivery, and history of smoking) were further included as covariates. Age, genetic history of diabetes, drinking history, education level, parity, working status, age of neonatal, and occupation were found to be significantly associated with GDM mothers’ perceived health belief towards breastfeeding. (Details see Supplementary S4).

In sum, knowledge of GDM had indirect effects on breastfeeding via changing mothers’ perceived benefits and barriers of breastfeeding and the total effect is negative (total effect: -0.030). GDM mothers’ perceived barriers to breastfeeding (total effect: -0.303), perceived susceptibility of GDM long-term consequences (total effect: -0.104), and reception of social support (total effect: 0.137) were able to influence their breastfeeding behaviors via changing self-efficacy. However, only an increase in social support can result in a higher likelihood of GDM mothers’ breastfeeding. Finally, mothers’ self-efficacy (total effect: 0.596) and perceived benefits of breastfeeding (total effect: -0.372) directly influenced their feeding behaviors.

Discussion

Main findings

The study adopted HBM to explore how GDM mothers form their feeding behaviors as well as its potential determinants. It seemed that GDM mothers showed a relatively low rate of breastfeeding and they commonly did not recognize the long-term effect of GDM and the protective effect of breastfeeding on themselves and their offspring. Although GDM mothers showed high self-efficacy and a high level of social support for breastfeeding, the various barriers hindered their success in the such feeding patterns. Based on the well-fitting SEM results, it was shown that knowledge of GDM can shape one’s perceived benefits and barriers of EBF and the perceived severity of GDM. Perceived barriers to breastfeeding and perceived susceptibility and social support may alter feeding behaviors by changing GDM mothers’ self-efficacy. Perceived benefits and self-efficacy of breastfeeding were identified as two main significant predictors of EBF.

Comparison to existing studies

Breastfeeding behavior

Despite the well-known importance of breastfeeding for mothers with GDM and their offspring, few studies had reported the rate of EBF among GDM mothers in China. The prevalence of EBF in this study among mothers with GDM was 33.95%, which was consistent with results from western China, in which a prevalence of EBF of 36.9% in mothers with GDM was identified (at 6 months postpartum) [

Conclusion

Mothers with GDM showed a low rate of breastfeeding and they commonly did not recognize the long-term effect of GDM and the protective effect of breastfeeding on themselves and their offspring. Although GDM mothers showed high self-efficacy and a high level of social support for breastfeeding, the various barriers hindered their success in the such feeding pattern. During the formation of feeding behaviors, GDM mothers’ self-efficacy, perceived benefits and barriers of breastfeeding, perceived severity of GDM long-term consequence, knowledge of GDM and social support played roles. To improve EBF for GDM mothers, physicians’ education, emphasizing the protecting effect of breastfeeding and how to correct breastfeeding, is highly recommended. In addition, social support for GDM mothers is also important to reduce their barriers to breastfeeding and help enhance self-efficacy in breastfeeding.