Long-Term Effect of Lactation on Maternal Cardiovascular Function and Adiposity in a Murine Model.

OBJECTIVE: Epidemiological studies suggest that lactation is associated with long-term maternal health benefits. To avoid confounders in human studies, we used a previously characterized murine model to investigate the long-term effect of lactation on both cardiovascular function and adiposity. STUDY DESIGN: After the delivery of the pups, CD-1 female mice were randomly divided into two groups: lactated and nonlactated (NL). Before pregnancy and at 9 months postdelivery, blood pressure was measured using a tail cuff, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by computed tomography (CT), echocardiography was performed using microultrasound, and cholesterol panels and fasting blood glucose were measured. The data were analyzed using Student's t-test (significance at p < 0.05). RESULTS: There were no differences in baseline parameters between the two groups. At 9 months postdelivery, the NL group weighed significantly more (p = 0.03) and demonstrated a significantly lower cardiac output (p = 0.05) and ejection fraction (p = 0.03). The mice in the NL group also had higher VAT (p < 0.01) and SAT percentiles (p = 0.03). Fasting glucose (p = 0.01) and low-density lipoprotein (p = 0.01) were significantly higher in the NL group at 9 months. CONCLUSION: Our results show the benefit of lactation is not just limited to the immediate postpartum period but it also extends into midlife in a murine model.

Perceived susceptibility to pregnancy and its association with safer sex, contraceptive adherence and subsequent pregnancy among adolescent and young adult women.

BACKGROUND: The study was conducted to examine the hypotheses that adolescent and young adult women who perceived they are susceptible to pregnancy when birth control is not used are less likely to practice unsafe sex, discontinue oral contraception (OC) and become pregnant during a 12-month follow-up period. STUDY DESIGN: We conducted secondary analyses using data collected for a randomized controlled trial on OC adherence among 1155 low-income women 16-24 years of age. Demographics, lifestyle variables, perceived susceptibility to pregnancy assessed at baseline, and data on OC and condom use and pregnancy status collected during 12 months of follow-up were used for the analyses. RESULTS: Overall, 62.3% of women accurately understood the risks of pregnancy without using any birth control method. However, perceived susceptibility was not associated with OC continuation [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.79-1.11], condom use at last sexual intercourse (OR 1.02, 95% CI 0.84-1.24), dual method use (OR 1.17, 95% CI 0.92-1.48) and subsequent pregnancy (hazards ratio 1.08, 95% CI 0.77-1.49) during the 12-month follow-up period. CONCLUSIONS: Perceived susceptibility to pregnancy, an important component of the health belief model, does not seem to have any impact on use of birth control methods, safer sex or rate of subsequent pregnancy among low-income adolescent and young adult women.