Background: Suction pressure has been reported to be a key driving force of lactation. An infant's sucking at its mother's breasts is the major stimulus to post-natal prolactin (PRL) secretion, and PRL is the essential hormone for lactation and milk production. It is unknown what role suction pressure has in PRL secretion and milk supply postnatally. Objectives: To explore the relationship between the suction pressure, PRL level, lactation, and milk supply in breastfeeding mother-infant dyads. Methods: Healthy women with normal full-term infants were enrolled (n = 122). Data collection included suction pressure, PRL level, and the mother's perception of both the onset of her lactation and her milk supply at 1 month. Suction pressure was measured with a pressure sensor connected to a tube placed alongside the nipple. The chemiluminescence method was used to quantify maternal serum PRL level both before and after a breastfeed to explore the effect of suckling on PRL increment. The mother's perception of the onset of her lactation was evaluated by the mother's sense of fullness in her breast. The mother's perception of milk supply was evaluated by using the H&H Lactation Scale. Results: Data from 117 participants were included in this analysis. Low suction pressure, a shorter gestational age, a high pre-gestational body mass index (BMI), and high infant birth weight were associated with a smaller than average PRL increment. High suction pressure, longer sucking duration, and a low gestational weight gain were related to a mother's perception of an earlier onset of her lactation. However, low suction pressure, a high frequency of giving formula, a small PRL increment, and the mother's perception of a later onset of her lactation were correlated with her perception of an insufficient milk supply. Conclusions: Suction pressure varied directly with the post-natal PRL increment. Suction pressure was associated with the timing of the mother's perception of her lactation. Strong suction pressure by the infant is likely to enhance the mother's confidence in her lactation. Additionally, sucking duration, frequency of giving formula, maternal BMI, and infant birth weight played a role in early breastfeeding success.

Background: Pre-pregnancy overweight and obesity are negatively associated with delayed onset of lactogenesis II (OL), but the mechanisms by which these conditions affect OL are still unclear. Objectives: To identify biological factors related to pre-pregnancy overweight/obesity and determine whether these biological factors were associated with delayed OL in this population. Methods: In this prospective observational study, we assigned 72 primipara to a pre-pregnancy overweight/obese group ( n = 36) and a normal-weight group ( n = 36). Blood samples were collected at 37 w of gestation and 48 h postpartum and assayed for levels of the following hormones: leptin, insulin, estradiol, prolactin (PRL), progesterone, and oxytocin. The primary outcome was timing of OL, estimated by maternal perception of breast fullness. We used linear-regression analysis to determine associations between hormones and delayed OL. Results: Sixty-three participants (87.5%) had complete data. OL occurred later in overweight/obese than in normal-weight women ( p < .001). Compared with the normal-weight group, the overweight/obese group showed higher leptin levels at both times of observation and exhibited a slower drop in estrogen concentrations from 37 w of gestation to 48 h postpartum (all p < .05). After adjusting for confounding factors, leptin concentrations in late pregnancy and the magnitudes of decline in estrogen concentrations at 48 h postpartum were correlated with OL. Conclusion: Women who were overweight/obese before pregnancy had elevated leptin levels in late pregnancy and a delayed decline in estrogen concentrations at 48 h postpartum. Both of these phenomena were related to delayed OL in this population.

Background: Adherence to secondary prevention measures among patients with coronary artery disease (CAD) affects patient prognosis, whereas patients' adherence behaviors change over time. Objectives: The aims of this study were to identify adherence trajectories to secondary prevention measures including medication-taking and a heart-healthy lifestyle and to estimate predictors of adherence trajectories among patients with CAD. Methods: This longitudinal study enrolled 698 patients with CAD who received a percutaneous coronary intervention in China. Demographics, clinical characteristics, adherence to secondary prevention measures, and patient-related factors including disease knowledge, self-efficacy, and health literacy were measured during hospitalization. Adherence behaviors were followed at 1, 3, and 6 months, and 1 year after discharge. Group-based trajectory models estimated adherence trajectories, and multinomial logistic regression identified trajectory group predictors. Results: Four trajectory groups were identified for medication-taking adherence: sustained adherence (39.9%), increasing and then decreasing adherence (23.1%), increasing adherence (23.4%), and nonadherence (13.6%). The 3 adherence trajectory groups for a heart-healthy lifestyle were sustained adherence (59.7%), increasing adherence (28.3%), and nonadherence (12.0%). Married patients were more likely (odds ratio [OR], 3.42; 95% confidence interval [CI], 1.56–7.52) to have sustained adherence to medication-taking. However, patients with higher disease knowledge were less likely (OR, 0.93; 95% CI, 0.87–0.99) to be adherent. Patients who were not working (OR, 2.25; 95% CI, 1.03–4.92) had higher self-efficacy (OR, 1.21; 95% CI, 1.08–1.37). Those with higher health literacy (OR, 1.18; 95% CI, 1.01–1.38) were more likely to have sustained adherence to a heart-healthy lifestyle. However, patients having no coronary stents (OR, 0.36; 95% CI, 0.19–0.70) were less likely to have done so. Conclusions: Trajectories of adherence to secondary prevention measures among mainland Chinese patients with CAD are multipatterned. Healthcare providers should formulate targeted adherence support, which considers the influence of disease knowledge, self-efficacy, and health literacy.