Objective  To explore the mediating effect of childbirth self-efficacy on the impact pathway of intolerance of uncertainty on the fear of childbirth in primiparas in the second and third trimesters and the potential moderating effect of perceived partner responsiveness.

  Methods  A total of 429 primiparas in their second and third trimesters completed the survey, which included general information questionnaire, Intolerance of Uncertainty Scale, Childbirth Self-Efficacy Inventory, Perceived Partner Responsiveness Scale, and Childbirth Attitudes Questionnaire. Rank sum test was used to compare the scores for the fear of childbirth among different groups and Spearman's correlation was used to analyze the scores for all the scales. In addition, the data were centrally processed by using PROCESS V3.4.1 Model 4 (a simple mediation model), Model 5 (the direct path of the mediation model was regulated), and non-parametric Bootstrap method to test the mediation effect and moderation effect.

  Results  The study showed that 54.31% of the participants experienced fear of childbirth. Their scores for intolerance of uncertainty, childbirth self-efficacy, and perceived partner responsiveness were 15.00 (8.00), 240.00 (75.00), and 72.00 (19.00), respectively. There were significant differences in the scores for the fear of childbirth scale among pregnant women of different age groups, gestational weeks, employment statuses, and average per capita monthly income of the family (P<0.05). According to our findings, intolerance of uncertainty directly and positively impacted on fear of childbirth (β=0.76, P<0.001), with childbirth self-efficacy playing partial mediation role between them, its indirect effect being 0.05 and the contribution rate being 6.17%. In addition, after the scores of Perceived Partner Responsiveness Scale were added to the model, perceived partner responsiveness had no significant predictive effect for fear of childbirth, but the product term of the scores for Perceived Partner Responsiveness Scale and Intolerability Uncertainty Scale had significant predictive effect for fear of childbirth (β=0.01, P<0.05), which suggested that perceived partner responsiveness also played a moderating role between intolerance of uncertainty and fear of childbirth.

  Conclusion  Health care providers can help primiparas reduce fear of childbirth and improve their childbirth experience by reducing perceived intolerance of uncertainty, improving family support, and teaching coping strategies.