Increased Breastfeeding Frequency Enhances Milk Production and Infant Weight Gain: Correlation with the Basal...

Breastfeeding is an important health concern for postpartum women. This study aimed to investigate the effect of breastfeeding frequency on the level of serum prolactin (PRL), milk intake, and infant weight gain. The time and duration of each breastfeeding episode were recorded by participants from day 1 to 28 postpartum. According to their diaries, we divided participants into the low-frequency breastfeeding group (Group I; <10 breastfeeding episodes/day) and high-frequency breastfeeding group (Group II; >/ = 10 breastfeeding episodes/day). A total of 23 mother-infant pairs were enrolled; blood samples were drawn between 1600 and 1800 hours. The PRL levels were examined using the DPC Immulite system. Overall, 71.8% (23) of the enrolled mother-infant pairs completed the follow-up. Infant birth weight was higher in Group II than in Group I (3275.6 ± 93.3 g versus 2918 ± 82.1 g). On day 28 postpartum, infants in Group II ingested significantly more milk per feeding (71.6 ± 4.0 mL versus 54.1 ± 5.2 mL) and gained more weight from birth (142.9% ± 4.5% versus 130.2% ± 2.4%) compared with those in Group I. The mothers of Group II had significantly higher basal serum PRL levels (116.4 ± 11.8 ng/mL versus 72.7 ± 7.77 ng/mL), but a significantly lower increase in PRL postsuckling (168.5% ± 23.1% versus 291.6% ± 37.6% of basal PRL). The frequency of suckling was positively correlated (r = 0.5) with the basal PRL level. Moreover, infant weight gain was significantly higher in male (144.7% ± 4.7%) than in female (132.3% ± 2.9%) infants. Increase in frequency of breastfeeding of over 10/day is associated with baseline PRL levels and increased milk production and weight gain. These results provide useful information for breastfeeding women.