Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality. Previous studies have suggested that the maternal vaginal microbiota contributes to the pathophysiology of PTB, but conflicting results in recent years have raised doubts. We conducted a study of PTB compared with term birth in two cohorts of pregnant women: one predominantly Caucasian (n = 39) at low risk for PTB, the second predominantly African American and at high-risk (n = 96). We profiled the taxonomic composition of 2,179 vaginal swabs collected prospectively and weekly during gestation using 16S rRNA gene sequencing. Previously proposed associations between PTB and lower Lactobacillus and higher Gardnerella abundances replicated in the low-risk cohort, but not in the high-risk cohort. High-resolution bioinformatics enabled taxonomic assignment to the species and subspecies levels, revealing that Lactobacillus crispatus was associated with low risk of PTB in both cohorts, while Lactobacillus iners was not, and that a subspecies clade of Gardnerella vaginalis explained the genus association with PTB. Patterns of cooccurrence between L. crispatus and Gardnerella were highly exclusive, while Gardnerella and L. iners often coexisted at high frequencies. We argue that the vaginal microbiota is better represented by the quantitative frequencies of these key taxa than by classifying communities into five community state types. Our findings extend and corroborate the association between the vaginal microbiota and PTB, demonstrate the benefits of high-resolution statistical bioinformatics in clinical microbiome studies, and suggest that previous conflicting results may reflect the different risk profile of women of black race.pregnancy | prematurity | vaginal microbiota | Lactobacillus | Gardnerella P reterm birth (PTB; delivery at <37 gestational wk) affects ≈12% of US births and is the leading cause of neonatal death and morbidity worldwide. Multiple lines of evidence support a role for the indigenous microbial communities of the mother (the maternal microbiota) in the pathophysiology of PTB. Microbial invasion of the amniotic cavity is one of the most frequent causes of spontaneous PTB (1), and the most common invading taxa are consistent with maternal origin (2-4). Bacterial vaginosis (BV), a condition involving an altered vaginal microbiota, has been consistently identified as a risk factor for PTB (5, 6). Multiple studies have also found chronic periodontitis, another condition associated with an altered microbiota, to be a risk factor for PTB (7,8).High-throughput sequencing methods have facilitated new lines of investigation into the microbial etiology of PTB (9, 10). Amplification and high-throughput sequencing of the 16S rRNA gene (metabarcoding) simultaneously measures the presence and relative abundance of thousands of bacterial taxa (composition), and resolves differences to the level of genus and sometimes species or subspecies. To date, metabarcoding studies of the relationship between the vaginal microbiota and PTB have y...
The obesity epidemic is a global issue and shows no signs of abating, while the cause of this epidemic remains unclear. Marketing practices of energy-dense foods and institutionally-driven declines in physical activity are the alleged perpetrators for the epidemic, despite a lack of solid evidence to demonstrate their causal role. While both may contribute to obesity, we call attention to their unquestioned dominance in program funding and public efforts to reduce obesity, and propose several alternative putative contributors that would benefit from equal consideration and attention. Evidence for microorganisms, epigenetics, increasing maternal age, greater fecundity among people with higher adiposity, assortative mating, sleep debt, endocrine disruptors, pharmaceutical iatrogenesis, reduction in variability of ambient temperatures, and intrauterine and intergenerational effects, as contributing factors to the obesity epidemic are reviewed herein. While the evidence is strong for some contributors such as pharmaceutical-induced weight gain, it is still emerging for other reviewed
OBJECTIVETo evaluate whether treatment of mild gestational diabetes mellitus (GDM) confers sustained offspring health benefits, including a lower frequency of obesity.RESEARCH DESIGN AND METHODSFollow-up study of children (ages 5–10) of women enrolled in a multicenter trial of treatment versus no treatment of mild GDM. Height, weight, blood pressure, waist circumference, fasting glucose, fasting insulin, triglycerides, and HDL cholesterol were measured.RESULTSFive hundred of 905 eligible offspring (55%) were enrolled. Maternal baseline characteristics were similar between the follow-up treated and untreated groups. The frequencies of BMI ≥95th (20.8% and 22.9%) and 85th (32.6% and 38.6%) percentiles were not significantly different in treated versus untreated offspring (P = 0.69 and P = 0.26). No associations were observed for BMI z score, log waist circumference, log triglycerides, HDL cholesterol, blood pressure, or log HOMA-estimated insulin resistance (HOMA-IR). The effect of treatment was different by sex for fasting glucose and log HOMA-IR (P for interaction = 0.002 and 0.02, respectively) but not by age-group (5–6 and 7–10 years) for any outcomes. Female offspring of treated women had significantly lower fasting glucose levels.CONCLUSIONSAlthough treatment for mild GDM has been associated with neonatal benefits, no reduction in childhood obesity or metabolic dysfunction in the offspring of treated women was found. However, only female offspring of women treated for mild GDM had lower fasting glucose.
Objective To identify risk factors for uterine atony or hemorrhage. Study Design Secondary analysis of a 3-arm double-blind randomized trial of different dose-regimens of oxytocin to prevent uterine atony after vaginal delivery. The primary outcome was uterine atony or hemorrhage requiring treatment. Twenty-one potential risk factors were evaluated. Logistic regression was used to identify independent risk factors using 2 complementary pre-defined model selection strategies. Results Among 1798 women randomized to 10, 40 or 80U prophylactic oxytocin after vaginal delivery, treated uterine atony occurred in 7%. Hispanic (OR 2.1; 95% CI 1.3–3.4) and non-Hispanic whites (OR 1.6; 95% CI 1.0–2.5), preeclampsia (OR 3.2; 95% CI 2.0–4.9) and chorioamnionitis (OR 2.8; 95% CI 1.6–5.0) were consistent independent risk factors. Other risk factors based on the specified selection strategies were obesity, induction/augmentation of labor, twins, hydramnios, anemia, and arrest of descent. Amnioinfusion appeared to be protective against uterine atony (OR 0.53; 95% CI 0.29–0.98). Conclusion Independent risk factors for uterine atony requiring treatment include Hispanic and non-Hispanic white ethnicity, preeclampsia and chorioamnionitis.
Objective Spontaneous preterm birth (SPTB) is a complex condition that is likely a final common pathway with multiple possible etiologies. We hypothesized that a comprehensive classification system could appropriately group women with similar STPB etiologies, and provide an explanation, at least in part, for the disparities in SPTB associated with race and gestational age at delivery. Study Design Planned analysis of a multicenter, prospective study of singleton SPTB. Women with SPTB < 34 weeks were included. We defined 9 potential SPTB phenotypes based on clinical data, including infection/inflammation, maternal stress, decidual hemorrhage, uterine distention, cervical insufficiency, placental dysfunction, premature rupture of the membranes, maternal comorbidities, and familial factors. Each woman was evaluated for each phenotype. Delivery gestational age was compared between those with and without each phenotype. Phenotype profiles were also compared between women with very early (20.0–27.9 weeks) SPTB vs. those with early SPTB (28.0–34.0 weeks), and between African-American and Caucasian women. Statistical analysis was by t-test and chi-square as appropriate. Results The phenotyping tool was applied to 1025 women with SPTB who delivered at a mean 30.0 (+/− 3.2) weeks gestation. Of these, 800 (78%) had ≥2 phenotypes. Only 43 (4.2%) had no phenotypes. The 281 women with early SPTB were more likely to have infection/inflammation, decidual hemorrhage, and cervical insufficiency phenotypes (all p≤0.001). African-American women had more maternal stress and cervical insufficiency but less decidual hemorrhage and placental dysfunction compared to Caucasian women (all p<0.05). Gestational age at delivery decreased as the number of phenotypes present increased. Conclusions Precise SPTB phenotyping classifies women with SPTB and identifies specific differences between very early and early SPTB and between African-Americans and Caucasians.
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