Background and purpose: The anxiety and birth-related biological stresses lead to delayed onset of lactogenesis stage II and early termination of breastfeeding. This study aimed to determine the effect of continuous support during labor on the onset of lactogenesis stage II in primiparas.

Materials and methods This randomized clinical trial study included 80 primigravida women attending Mashahd Omlbanin Hospital who were  randomly allocated in to two groups ( n= 40 per group). The intervention group and the control group received supportive care and routine care, respectively. In both groups the onset of lactogenesis II were measured after delivery. Data was collected through a questionnaire, a checklist and Spielberger State-Trait Anxiety Inventory (STAI). Data was then analyzed using descriptive statistics, student’s t-test, Mann- Whitney U and Chi-Square test.

Results: The mean onset of lactogenesis II was 2.6± 0.96 days in supportive care group and 3.0± 1.1 days in routine care group indicating no significant difference between the two groups (P=0.870). The first duration of breastfeeding postpartum in supportive care group was significantly higher than that in the routine care group. (P= 0.007).

Conclusion: Supporting the mother during labor dose not effect the onset of lactogenesis stage II, but increases the first duration of breastfeeding postpartum.