The Effect of Breastfeeding on Prevention of Maternal Hypertension: Systematic Review

PURPOSE: The purpose of this study is to clarify the relevance of breastfeeding and its preventive effect on maternal hypertension as well as to evaluate the theoretical mechanism behind of it through systematic evaluation of existing articles. METHODS: For systematic evaluation of literatures in recent 5 years, 5 most suitable articles were selected with the key words, (breastfeeding or breastfeed or lactation) AND (hypertension or high blood pressure or hypertensive disorders) from PubMed, EMBASE, and Cochran Library, and carefully reviewed by 2 researchers. RESULTS: Breastfeeding women have less frequently developed hypertension in their later life. Depending on the duration of breastfeeding, compared to nonbreastfeeding women, breastfeeding women's odds ratio for developing hypertension are 0.87 (95% confidence interval [CI], 0.76–0.99), 0.83 (95% CI, 0.68–1.00), and 0.79 (95% CI, 0.65–0.97) each for 0–6 months, 6–12 months, and greater than 12 months of breastfeeding. As the number of breastfeeding children increases, the incidence of maternal hypertension decreases. In addition, both partial and exclusive breastfeeding lower the risk of developing maternal hypertension. Though the mechanism of prophylactic effect of breastfeeding on hypertension is not conclusive, reset hypothesis, oxytocin release, the increase of ghrelin and protein peptide YY, as well as epigenetic programming are considered to be relevant to the etiology of the condition. CONCLUSION: Breastfeeding prevents maternal hypertension later in life. Studies show dose-response relationship of breastfeeding as the duration matters. In addition, both partial and exclusive breastfeeding have preventive effect on maternal hypertension. Numerous mechanisms are continuously being reported and further studies are needed for clarification.

Women with Endometriosis, Especially Those Who Conceived with Assisted Reproductive Technology, Have Increased Risk of Placenta Previa: Meta-analyses

BACKGROUND: Many women with endometriosis have become pregnant through assisted reproductive technology (ART), and have often experienced placenta previa (PP) during pregnancy. The objective of this study was to assess the association between women with endometriosis, especially those who conceived with ART, and the risk of PP. METHODS: Two reviewers independently determined studies that were considered suitable for meta-analyses published in various medicine-related databases from March 1, 2004 through July 31, 2017 without language restrictions. Eight studies met the inclusion criteria, with a combined sample size of 21,930 women. Of these 21,930 pregnancies, 6,256 had endometriosis (endometriosis) and 15,674 had no endometriosis. Four of these studies included 8,161 women who conceived with ART, 1,640 of whom had endometriosis (endometriosis + ART), and 6,521 of whom did not have endometriosis. Meta-analyses were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using random effect analysis according to heterogeneity of studies. RESULTS: These meta-analyses showed women with endometriosis (endometriosis) have an increased risk of PP (OR, 4.038; 95% CI, 2.291–7.116; P = 0.000). These results showed women who conceived with ART (endometriosis + ART), have a substantially increased risk of PP (OR, 5.543; 95% CI, 1.659–18.523; P = 0.005). CONCLUSION: These meta-analyses demonstrate women with endometriosis have an increased risk of PP.

MiR-9 Controls Chemotactic Activity of Cord Blood CD34⁺ Cells by Repressing CXCR4 Expression

Improved approaches for promoting umbilical cord blood (CB) hematopoietic stem cell (HSC) homing are clinically important to enhance engraftment of CB-HSCs. Clinical transplantation of CB-HSCs is used to treat a wide range of disorders. However, an improved understanding of HSC chemotaxis is needed for facilitation of the engraftment process. We found that ectopic overexpression of miR-9 and antisense-miR-9 respectively down- and up-regulated C-X-C chemokine receptor type 4 (CXCR4) expression in CB-CD34⁺ cells as well as in 293T and TF-1 cell lines. Since CXCR4 is a specific receptor for the stromal cell derived factor-1 (SDF-1) chemotactic factor, we investigated whether sense miR-9 and antisense miR-9 influenced CXCR4-mediated chemotactic mobility of primary CB CD34⁺ cells and TF-1 cells. Ectopic overexpression of sense miR-9 and antisense miR-9 respectively down- and up-regulated SDF-1-mediated chemotactic cell mobility. To our knowledge, this study is the first to report that miR-9 may play a role in regulating CXCR4 expression and SDF-1-mediated chemotactic activity of CB CD34⁺ cells.