Post-Acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) After Infection During Pregnancy.

OBJECTIVE: To estimate the prevalence of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) after infection with SARS-CoV-2 during pregnancy and to characterize associated risk factors. METHODS: In a multicenter cohort study (NIH RECOVER [Researching COVID to Enhance Recovery]-Pregnancy Cohort), individuals who were pregnant during their first SARS-CoV-2 infection were enrolled across the United States from December 2021 to September 2023, either within 30 days of their infection or at differential time points thereafter. The primary outcome was PASC, defined as score of 12 or higher based on symptoms and severity as previously published by the NIH RECOVER-Adult Cohort, at the first study visit at least 6 months after the participant's first SARS-CoV-2 infection. Risk factors for PASC were evaluated, including sociodemographic characteristics, clinical characteristics before SARS-CoV-2 infection (baseline comorbidities, trimester of infection, vaccination status), and acute infection severity (classified by need for oxygen therapy). Multivariable logistic regression models were fitted to estimate associations between these characteristics and presence of PASC. RESULTS: Of the 1,502 participants, 61.1% had their first SARS-CoV-2 infection on or after December 1, 2021 (ie, during Omicron variant dominance); 51.4% were fully vaccinated before infection; and 182 (12.1%) were enrolled within 30 days of their acute infection. The prevalence of PASC was 9.3% (95% CI, 7.9-10.9%) measured at a median of 10.3 months (interquartile range 6.1-21.5) after first infection. The most common symptoms among individuals with PASC were postexertional malaise (77.7%), fatigue (76.3%), and gastrointestinal symptoms (61.2%). In a multivariable model, the proportion PASC positive with vs without history of obesity (14.9% vs 7.5%, adjusted odds ratio [aOR] 1.65, 95% CI, 1.12-2.43), depression or anxiety disorder (14.4% vs 6.1%, aOR 2.64, 95% CI, 1.79-3.88) before first infection, economic hardship (self-reported difficulty covering expenses) (12.5% vs 6.9%, aOR 1.57, 95% CI, 1.05-2.34), and treatment with oxygen during acute SARS-CoV-2 infection (18.1% vs 8.7%, aOR 1.86, 95% CI, 1.00-3.44) were associated with increased prevalence of PASC. CONCLUSION: The prevalence of PASC at a median time of 10.3 months after SARS-CoV-2 infection during pregnancy was 9.3% in the NIH RECOVER-Pregnancy Cohort. The predominant symptoms were postexertional malaise, fatigue, and gastrointestinal symptoms. Several socioeconomic and clinical characteristics were associated with PASC after infection during pregnancy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT05172024.

Phthalate and phthalate replacement concentrations in relationship to adiposity in a multi-racial cohort of children.

BACKGROUND/OBJECTIVE: Phthalates and phthalate replacements are used in multiple everyday products, making many of them bioavailable to children. Experimental studies suggest that phthalates and their replacements may be obesogenic, however, epidemiologic studies remain inconsistent. Therefore, our objective was to examine the association between phthalates, phthalate replacements and childhood adiposity/obesity markers in children. SUBJECTS/METHODS: A cross-sectional study was conducted in 630 racial/ethnically diverse children ages 4-8 years. Urinary oxidative metabolites of DINCH and DEHTP, three low molecular weight (LMW) phthalates, and eleven high molecular weight (HMW) phthalates were measured. Weight, height, waist circumference and % body fat were measured. Composite molar sum groups (nmol/ml) were natural log-transformed. Linear regression models adjusted for urine specific gravity, sex, age, race-ethnicity, birthweight, breastfeeding, reported activity level, mother's education and pre-pregnancy BMI. RESULTS: All children had LMW and HMW phthalate metabolites and 88% had DINCH levels above the limit of detection. One unit higher in the log of DINCH was associated with 0.106 units lower BMI z-score [ß = -0.106 (95% CI: -0.181, -0.031)], 0.119 units lower waist circumference z-score [ß = -0.119 (95% CI: -0.189, -0.050)], and 0.012 units lower percent body fat [ß = -0.012 (95% CI: -0.019, -0.005)]. LMW and HMW group values were not associated with adiposity/obesity. CONCLUSIONS: We report an inverse association between child urinary DINCH levels, a non-phthalate plasticizer that has replaced DEHP in several applications, and BMI z-score, waist circumference z-score and % body fat in children. Few prior studies of phthalates and their replacements in children have been conducted in diverse populations. Moreover, DINCH has not received a great deal of attention or regulation, but it is a common exposure. In summary, understanding the ubiquitous nature of these chemical exposures and ultimately their sources will contribute to our understanding of their relationship with obesity.

Researching COVID to enhance recovery (RECOVER) pregnancy study: Rationale, objectives and design.

IMPORTANCE: Pregnancy induces unique physiologic changes to the immune response and hormonal changes leading to plausible differences in the risk of developing post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID. Exposure to SARS-CoV-2 during pregnancy may also have long-term ramifications for exposed offspring, and it is critical to evaluate the health outcomes of exposed children. The National Institutes of Health (NIH) Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC aims to evaluate the long-term sequelae of SARS-CoV-2 infection in various populations. RECOVER-Pregnancy was designed specifically to address long-term outcomes in maternal-child dyads. METHODS: RECOVER-Pregnancy cohort is a combined prospective and retrospective cohort that proposes to enroll 2,300 individuals with a pregnancy during the COVID-19 pandemic and their offspring exposed and unexposed in utero, including single and multiple gestations. Enrollment will occur both in person at 27 sites through the Eunice Kennedy Shriver National Institutes of Health Maternal-Fetal Medicine Units Network and remotely through national recruitment by the study team at the University of California San Francisco (UCSF). Adults with and without SARS-CoV-2 infection during pregnancy are eligible for enrollment in the pregnancy cohort and will follow the protocol for RECOVER-Adult including validated screening tools, laboratory analyses and symptom questionnaires followed by more in-depth phenotyping of PASC on a subset of the overall cohort. Offspring exposed and unexposed in utero to SARS-CoV-2 maternal infection will undergo screening tests for neurodevelopment and other health outcomes at 12, 18, 24, 36 and 48 months of age. Blood specimens will be collected at 24 months of age for SARS-CoV-2 antibody testing, storage and anticipated later analyses proposed by RECOVER and other investigators. DISCUSSION: RECOVER-Pregnancy will address whether having SARS-CoV-2 during pregnancy modifies the risk factors, prevalence, and phenotype of PASC. The pregnancy cohort will also establish whether there are increased risks of adverse long-term outcomes among children exposed in utero. CLINICAL TRIALS.GOV IDENTIFIER: Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT05172011.

Researching COVID to enhance recovery (RECOVER) pregnancy study: Rationale, objectives and design.

Importance: Pregnancy induces unique physiologic changes to the immune response and hormonal changes leading to plausible differences in the risk of developing post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID. Exposure to SARS-CoV-2 during pregnancy may also have long-term ramifications for exposed offspring, and it is critical to evaluate the health outcomes of exposed children. The National Institutes of Health (NIH) Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC aims to evaluate the long-term sequelae of SARS-CoV-2 infection in various populations. RECOVER- Pregnancy was designed specifically to address long-term outcomes in maternal-child dyads. Methods: RECOVER-Pregnancy cohort is a combined prospective and retrospective cohort that proposes to enroll 2,300 individuals with a pregnancy during the COVID-19 pandemic and their offspring exposed and unexposed in utero, including single and multiple gestations. Enrollment will occur both in person at 27 sites through the Eunice Kennedy Shriver National Institutes of Health Maternal-Fetal Medicine Units Network and remotely through national recruitment by the study team at the University of California San Francisco (UCSF). Adults with and without SARS-CoV-2 infection during pregnancy are eligible for enrollment in the pregnancy cohort and will follow the protocol for RECOVER-Adult including validated screening tools, laboratory analyses and symptom questionnaires followed by more in-depth phenotyping of PASC on a subset of the overall cohort. Offspring exposed and unexposed in utero to SARS-CoV-2 maternal infection will undergo screening tests for neurodevelopment and other health outcomes at 12, 18, 24, 36 and 48 months of age. Blood specimens will be collected at 24 months of age for SARS-CoV-2 antibody testing, storage and anticipated later analyses proposed by RECOVER and other investigators. Discussion: RECOVER-Pregnancy will address whether having SARS-CoV-2 during pregnancy modifies the risk factors, prevalence, and phenotype of PASC. The pregnancy cohort will also establish whether there are increased risks of adverse long-term outcomes among children exposed in utero. Registration: NCT05172024.

Associations of Maternal Prenatal Stress and Depressive Symptoms With Childhood Neurobehavioral Outcomes in the ECHO Cohort of the NICHD Fetal Growth Studies: Fetal Growth Velocity as a Potential Mediator.

OBJECTIVE: Maternal prenatal stress and mood symptoms are associated with risk for child psychopathology. Within the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies (ECHO-FGS), a racially and ethnically diverse cohort, we studied associations between prenatal stress and depressive symptoms with child neurobehavior, and potential mediation by fetal growth velocity (FGV) in low-risk pregnancies. METHOD: For 730 mother-child pairs, we had serial ultrasound measurements, self-reports of prenatal stress and depression, observations of child executive functions and motor skills from 4 to 8 years, and maternal reports of child psychiatric problems. We tested associations between prenatal stress and depressive symptoms with child neurobehavior in regression analyses, and associations with FGV in mixed effect models. Post hoc we tested severity of prenatal symptoms; FGV at 25th, 50th, and 75th percentiles; and moderation by biological sex and by race and ethnicity. RESULTS: Prenatal stress and depressive symptoms were associated with child psychiatric problems, and prenatal depressive symptoms with decrements in executive functions and motor skills, especially in biological male children. Neither prenatal stress nor depressive symptoms were associated with FGV. CONCLUSION: In one of the largest cohorts with observed child outcomes, and the first with broad representation of race and ethnicity in the United States, we found that prenatal stress and depressive symptoms were associated with greater reports of child psychiatric symptoms. Only prenatal depressive symptoms were associated with observed decrements in cognitive abilities, most significantly in biological male children. Stress during low-risk pregnancies may be less detrimental than theorized. There was no mediation by FGV. These findings support the need to attend to even small changes in prenatal distress, as these may have long-lasting implications.

The association between maternal pre-pregnancy BMI, gestational weight gain and child adiposity: A racial-ethnically diverse cohort of children.

BACKGROUND: The prevalence of obesity in US children has more than tripled in the past 40 years; hence, it is critical to identify potentially modifiable factors that may mitigate the risk. OBJECTIVES: To examine the association between maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG) and child adiposity as measured by BMI, waist circumference and percent body fat in a racial-ethnically diverse cohort. METHODS: In a prospective cohort study of healthy women without chronic disease, we examined the association between pre-pregnancy BMI, GWG and child adiposity. Children ages 4-8 years (n = 816) in the Environmental Influences on Child Health Outcomes-NICHD Fetal Growth Studies were assessed. Trained study staff ascertained maternal pre-pregnancy BMI, GWG and child adiposity. RESULTS: The odds of child obesity (≥95th BMI percentile) increased independently for each unit increase in maternal pre-pregnancy BMI [OR = 1.12 (95% CI: 1.08, 1.17)] and for each 5-kg increase in GWG [OR = 1.25 (95% CI: 1.07, 1.47)]. The odds of child waist circumference (≥85th percentile) also increased independently for pre-pregnancy BMI [OR = 1.09 (95% CI: 1.05, 1.12)] and GWG [OR = 1.18 (95% CI: 1.04, 1.34)]. CONCLUSIONS: Maternal pre-pregnancy BMI and GWG were each independently and positively associated with child obesity and high child waist circumference.

Early Exposure to Animals and Childhood Body Mass Index Percentile and Percentage Fat Mass.

INTRODUCTION: A few studies have identified childhood animal exposure as associated with adiposity, but results are inconsistent and differ in timing. METHODS: We conducted an observational cohort study of children ages 4-8 in the Environmental Influences on Child Health Outcomes [ECHO] study. The main exposure was having a dog in the home and/or regular contact with farm animals during the first year of life. Outcomes of interest were child BMI percentile (adjusted for gender and age) categorized as normal/underweight (<85th percentile), overweight (85th to <95th), and obese (≥95th), and percent fat mass (continuous). Associations were analyzed using multinomial logistic regression and multivariable linear regression, respectively, with and without multiple imputation. RESULTS: First year animal exposure occurred in 245 of 770 (31.8%) children. Children with early animal exposure had 0.53 (95% CI: 0.28, 0.997) times the odds of being in the obese BMI category compared to those exposed to animals after controlling for covariates: maternal pre-pregnancy BMI, race/ethnicity, reported child activity level, receiving food assistance, age child began daycare (<1 year vs 1+), exclusively breastfed x6 months, and NICU admission (n=721). Children with early animal exposure had, on average, 1.5% (95% CI: -3.0, -0.1) less fat mass than exposed children after adjustment for maternal BMI, race/ethnicity, activity, food assistance, breastfeeding, and maternal education (n=548). Multiple imputation did not alter either result. CONCLUSION: These results provide evidence that exposure to dogs or farm animals in the first year of life is associated with lower odds of obesity and lower percent fat mass in childhood.

Association between gestational PFAS exposure and Children's adiposity in a diverse population.

Perfluoroalkyl substances (PFAS) are widely distributed suspected obesogens that cross the placenta. However, few data are available to assess potential fetal effects of PFAS exposure on children's adiposity in diverse populations. To address the data gap, we estimated associations between gestational PFAS concentrations and childhood adiposity in a diverse mother-child cohort. We considered 6 PFAS in first trimester blood plasma, measured using ultra-high-performance liquid chromatography with tandem mass spectrometry, collected from non-smoking women with low-risk singleton pregnancies (n = 803). Body mass index (BMI), waist circumference (WC), fat mass, fat-free mass, and % body fat were ascertained in 4-8 year old children as measures of adiposity. We estimated associations of individual gestational PFAS with children's adiposity and overweight/obesity, adjusted for confounders. There were more non-Hispanic Black (31.7 %) and Hispanic (42.6 %) children with overweight/obesity, than non-Hispanic white (18.2 %) and Asian/Pacific Islander (16.4 %) children (p < 0.0001). Perfluorooctane sulfonate (PFOS; 5.3 ng/mL) and perfluorooctanoic acid (2.0 ng/mL) had the highest median concentrations in maternal blood. Among women without obesity (n = 667), greater perfluoroundecanoic acid (PFUnDA) was associated with their children having higher WC z-score (ß = 0.08, 95%CI: 0.01, 0.14; p = 0.02), fat mass (ß = 0.55 kg, 95%CI: 0.21, 0.90; p = 0.002), and % body fat (ß = 0.01 %; 95%CI: 0.003, 0.01; p = 0.004), although the association of PFUnDA with fat mass attenuated at the highest concentrations. Among women without obesity, the associations of PFAS and their children's adiposity varied significantly by self-reported race-ethnicity, although the direction of the associations was inconsistent. In contrast, among the children of women with obesity, greater, PFOS, perfluorononanoic acid, and perfluorodecanoic acid concentrations were associated with less adiposity (n = 136). Our results suggest that specific PFAS may be developmental obesogens, and that maternal race-ethnicity may be an important modifier of the associations among women without obesity.

Breastfeeding Associations with Childhood Obesity and Body Composition: Findings from a Racially Diverse Maternal-Child Cohort.

Background: Studies suggest breastfeeding lowers obesity risk in childhood, but generalizability of existing evidence is limited. We examined associations of breastfeeding with childhood overweight, obesity, and percentage body fat, in a racially diverse maternal-child cohort. Methods: This cross-sectional study included 823 children, ages 4-8 years, enrolled in the Environmental Exposures and Child Health Outcomes (ECHO) cohort, a subset of the National Institute of Child Health and Human Development Fetal Growth Studies cohort. Logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for overweight [BMI (kg/m2) 85th to <95th percentile] and obesity (BMI ≥95th percentile) in relation to breastfeeding including duration of exclusive and total breastfeeding. Linear regression was used to evaluate association between breastfeeding and percentage body fat measured by bioelectrical impedance analysis. Results: Fifty-two percent of children were male, 32% non-Hispanic Black, 29% Hispanic, 27% non-Hispanic White, and 13% Asian; 16% were overweight and 13% obese. Six months of exclusive breastfeeding, compared with no breastfeeding, was associated with 60% lower odds of obesity (95% CI 0.18-0.91) adjusting for age, gender, race, socioeconomic status, maternal BMI, and child's activity. Percentage body fat was inversely associated with breastfeeding duration. For none, <6, and ≥6 months of exclusive breastfeeding, adjusted mean percentage body fat was 16.8, 14.5, and 13.4, respectively. Results did not differ by gender, race/ethnicity, or maternal BMI status. Conclusions: Exclusive breastfeeding for the first 6 months of life is inversely and significantly associated with obesity and percentage body fat at ages 4-8 years. These findings support current breastfeeding guidelines.

Fetal Exosomal Platelet-activating Factor Triggers Functional Progesterone Withdrawal in Human Placenta.

In most mammals, labor is heralded by the withdrawal of progesterone. In humans, circulating progesterone levels increase as gestation advances while placental expression of progesterone receptor A (PR-A) declines. As a result of PR-A downregulation, the non-canonical NF-κB pathway is activated, an event implicated in triggering labor. Here, we sought to identify fetal-derived mediator(s) that represses placental PR-A in human placenta leading to activation of pro-labor signaling. Lipidomic profiling demonstrated enrichment of platelet-activating factor (PAF) in exosomes originating from the human fetus. Exposure of primary cytotrophoblasts to fetal exosomes from term pregnancies reduced PR-A expression by > 50%, and PAF also reduced PR-A message levels in a dose-dependent manner. Notably, fetal exosomes from preterm pregnancies had lower PAF levels and no effect on PR-A expression. Synthetic PAF-induced DNA methylation increases by 20% at the PR-A promoter, leading to recruitment of corepressors and downregulation of PR-A in cytotrophoblast. Furthermore, suppression of PR-A by PAF-stimulated expression of the pro-labor genes, corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2), which was reversed by disruption of the DNA methyltransferases 3B and 3L. Taken together, PAF represents a novel fetal-derived candidate for initiation of labor by stimulating methylation and repression of PR-A and activating pro-labor signaling in trophoblast.

Reported Neighborhood Traffic and the Odds of Asthma/Asthma-Like Symptoms: A Cross-Sectional Analysis of a Multi-Racial Cohort of Children.

Asthma in children poses a significant clinical and public health burden. We examined the association between reported neighborhood traffic (a proxy for traffic-related air pollution) and asthma among 855 multi-racial children aged 4-8 years old who participated in the Environmental Influences on Child Health Outcomes (ECHO) cohort. We hypothesized that high neighborhood traffic density would be associated with the prevalence of asthma. Asthma/asthma-like symptoms (defined as current and/or past physician diagnosed asthma, past wheezing, or nighttime cough or wheezing in the past 12 months) was assessed by parental report. The relationship between neighborhood traffic and asthma/asthma-like symptoms was assessed using logistic regression. The prevalence of asthma/asthma-like symptoms among study participants was 23%, and 15% had high neighborhood traffic. Children with significant neighborhood traffic had a higher odds of having asthma/asthma-like symptoms than children without neighborhood traffic [adjusted OR = 2.01 (95% CI: 1.12, 3.62)] after controlling for child's race-ethnicity, age, sex, maternal education, family history of asthma, play equipment in the home environment, public parks, obesity and prescribed asthma medication. Further characterization of neighborhood traffic is needed since many children live near high traffic zones and significant racial/ethnic disparities exist.

Trends in invasive prenatal diagnostic testing at a single institution.

OBJECTIVE: As diagnostic methodologies evolve, we sought to determine whether invasive testing rates would decline, whether there would be a shift in indications for invasive testing, and whether the diagnostic yield would increase. METHODS: We conducted a retrospective, observational study from 2006 through 2015. We quantified the number of invasive procedures per year and examined what percentage of these procedures yielded abnormal results. We also examined the indications for testing and determined the trend of these indications during the study period. RESULTS: The number of amniocenteses showed a steady decline (P < .05). The number of CVS procedures has increased and was recently equivalent to amniocentesis. The percentage of abnormal results steadily increased from 11.4% to 27.0% (P < .001). The abnormal aneuploidy screening indication remained constant over time. Advanced maternal age (AMA) as the sole indication substantially declined from 42.3% to 15.52% (P < .001). Testing for a known single gene disorder steadily increased from 3.0% to 9.20% (P = .018). CONCLUSION: Our study showed a significant decline in the number of amniocenteses, a steady increase in the percentage of abnormal results from invasive testing, and a decline in AMA as the sole indication for invasive testing.

Association of histological chorioamnionitis and magnesium sulfate treatment in singleton and dichorionic twin pregnancies with preterm premature rupture of membranes: preliminary observations.

Objective To evaluate the possible association between antenatal magnesium sulfate treatment with histological chorioamnionitis in patients with singleton or dichorionic twins that had preterm premature rupture of the membranes. Methods This was an observational study performed in patients admitted to the hospital with rupture of membranes before 34 weeks' gestation. The primary outcome was histological chorioamnionitis and the primary predictor was antenatal magnesium sulfate treatment. A logistic regression model was used without consideration of other antenatal medical treatments. Results Among 107 patients with preterm deliveries, 57 were admitted to the hospital before 34 weeks' gestation with preterm premature rupture of membranes. Fifty-cases were excluded from the analysis because they were admitted after 34 weeks' gestation, delivered before 24 weeks' gestation or had intrauterine fetal demise or monochorionic twins. The logistic regression analysis adjusting for maternal age, gravidity, parity, multiple gestation, gestational age at delivery, and birthweight, indicated that patients with singleton pregnancies and histological chorioamnionitis had received magnesium sulfate antenatally more frequently (χ2=6.46; P=0.01). The association between histological chorioamnionitis and magnesium sulfate treatment was not found among patients with dichorionic twin pregnancies with one intact gestational sac. Conclusions In this cohort of patients with preterm premature rupture of membranes admitted to the hospital before 34 week's gestation, those with singleton pregnancies treated antenatally with magnesium sulfate for neonatal neuroprotection had a greater rate of histological chorioamnionitis.

Vein of Galen malformation in a neonate: A case report and review of endovascular management.

Vein of Galen malformation (VOGM) is a rare congenital vascular malformation caused by the maldevelopment of its embryonic precursor, the median prosencephalic vein of Markowski. VOGM results in neonatal morbidity and mortality, and premature delivery does not improve the outcome. We report a term female neonate in whom a vein of Galen malformation was diagnosed prenatally at 37 wk of gestation during a growth ultrasound and confirmed by fetal magnetic resonance imaging. Signs of cardiac decompensation were evident in the fetus. Multiple interventional radiology embolizations of the feeding vessels were performed successfully on days 7, 10, 12, 14 and 19. A review of the literature on the endovascular management of neonates with these malformations is presented herein.

Cerclage in twin pregnancy with dilated cervix between 16 to 24 weeks of gestation: retrospective cohort study.

BACKGROUND: Cervical dilation in the second trimester is associated with a greater than 90% rate of spontaneous preterm birth and a poor perinatal prognosis. OBJECTIVE: To compare the perinatal outcomes of twin pregnancies with dilated cervix in women who underwent either cerclage or expectant management. STUDY DESIGN: Retrospective cohort study of asymptomatic twin pregnancies identified with cervical dilation of ≥1 cm at 16-24 weeks (1997-2014) at 7 institutions. Exclusion criteria were genetic or major fetal anomaly, multifetal reduction at >14 weeks, prior cerclage placement, monochorionic-monoamniotic placentation, active vaginal bleeding, labor, chorioamnionitis, elective termination of pregnancy, or medically indicated preterm birth. The primary outcome was incidence of spontaneous preterm birth at <34 weeks. Secondary outcomes were incidence of spontaneous preterm birth at <32 weeks, <28 weeks, and <24 weeks; perinatal mortality; and composite adverse neonatal outcome (respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and sepsis). RESULTS: A total of 76 women with twin pregnancy with dilated cervix of 1.0-4.5 cm were managed with either cerclage (n = 38) or expectant management (n = 38). Demographic characteristics were not significantly different. Analysis was adjusted for amniocentesis and vaginal progesterone use. In the cerclage group, 29 women (76%) received prophylactic indomethacin and 36 (94%) received prophylactic antibiotics, whereas the expectant management group did not. Interval from time at diagnosis of open cervix to delivery in the cerclage group was 10.46 ± 5.6 weeks vs 3.7 ± 3.2 weeks in the expectant management group, with a mean difference of 6.76 weeks (95% confidence interval [CI], 4.71-8.81). There were significant decreases in spontaneous preterm birth at <34 weeks (52.6% vs 94.7%; adjusted odds ratio [aOR], 0.06; 95% CI, 0.03-0.34), at <32 weeks (44.7% vs 89.4%; aOR, 0.08; 95% CI, 0.03-0.34); at <28 weeks (31.6% vs 89.4%; aOR, 0.05; 95% CI, 0.01-0.2); and at <24 weeks (13.1% vs 47.3%; aOR, 0.17; 95% CI, 0.05-0.54). There were also significant reductions in perinatal mortality (27.6% vs 59.2%; aOR, 0.24; 95% CI, 0.11-0.5), neonatal intensive care unit admission (75.9% vs 97.6%; aOR, 0.07; 95% CI, 0.01-0.66), and composite adverse neonatal outcome (33.9% vs 90.5%; aOR, 0.05; 95% CI, 0.01-0.21). CONCLUSION: Cerclage, indomethacin, and antibiotics in twin pregnancies with dilated cervix ≥1 cm before 24 weeks were associated with significant longer latency period from diagnosis to delivery (6.7 weeks), decreased incidence of spontaneous preterm birth at any given gestational age, and improved perinatal outcome when compared with expectant management.

Glucocorticoid receptor signaling contributes to constitutive activation of the noncanonical NF-κB pathway in term human placenta.

Our recent study demonstrated that constitutively activated RelB/NF-κB2 positively regulates the CRH in the human placenta. In the current study, we explored the role of the glucocorticoid receptor (GR) signaling in constitutive activation of the noncanonical NF-κB pathway. A glucocorticoid response element (GRE) motif search suggests that both NF-κB inducing kinase (NIK) and RelB genes, which are key regulators of the noncanonical NF-κB pathway, have a putative GRE within their promoter, approximately 1 kb upstream from the transcription start site. By using chromatin immunoprecipitation assay we identified that the GR and phosphorylated GR at Ser211 were associated with the GREs of both NIK and RelB. Dexamethasone stimulated expression of NIK, RelB, NF-κB2 as well as CRH and cyclooxygenase-2 (COX-2). Repression of GR by short interfering RNA resulted in inhibition of NIK, RelB, NF-κB2, CRH, and COX-2. In addition, depletion of GR attenuated glucocorticoid-mediated up-regulation of NIK, RelB, NF-κB2, CRH, and COX-2. Furthermore, siRNA specifically targeting NIK down-regulated CRH and COX-2. Taken together, these results suggest that constitutive activation of the noncanonical NF-κB pathway in term human placenta is driven by the GR signaling, which in turn up-regulates placental CRH and other NF-κB-responsive genes.

Correlations between local strains and tissue phenotypes in an experimental model of skeletal healing.

Defining how mechanical cues regulate tissue differentiation during skeletal healing can benefit treatment of orthopaedic injuries and may also provide insight into the influence of the mechanical environment on skeletal development. Different global (i.e., organ-level) mechanical loads applied to bone fractures or osteotomies are known to result in different healing outcomes. However, the local stimuli that promote formation of different skeletal tissues have yet to be established. Finite element analyses can estimate local stresses and strains but require many assumptions regarding tissue material properties and boundary conditions. This study used an experimental approach to investigate relationships between the strains experienced by tissues in a mechanically stimulated osteotomy gap and the patterns of tissue differentiation that occur during healing. Strains induced by the applied, global mechanical loads were quantified on the mid-sagittal plane of the callus using digital image correlation. Strain fields were then compared to the distribution of tissue phenotypes, as quantified by histomorphometry, using logistic regression. Significant and consistent associations were found between the strains experienced by a region of the callus and the tissue type present in that region. Specifically, the probability of encountering cartilage increased, and that of encountering woven bone decreased, with increasing octahedral shear strain and, to a lesser extent, maximum principal strain. Volumetric strain was the least consistent predictor of tissue type, although towards the end of the four-week stimulation timecourse, cartilage was associated with increasingly negative volumetric strains. These results indicate that shear strain may be an important regulator of tissue fate during skeletal healing.

Transcriptional profiling and biochemical analysis of mechanically induced cartilaginous tissues in a rat model.

OBJECTIVE: To characterize patterns of molecular expression that lead to cartilage formation in vivo in a postnatal setting, by profiling messenger RNA expression across the time course of mechanically induced chondrogenesis. METHODS: Retired breeder Sprague-Dawley rats underwent a noncritical-sized transverse femoral osteotomy. Experimental animals (n = 45) were subjected to bending stimulation (60 degrees cyclic motion in the sagittal plane for 15 minutes/day) of the osteotomy gap beginning on day 10 after the operation. Control animals (n = 32) experienced continuous rigid fixation. Messenger RNA isolated on days 10, 17, 24, and 38 after surgery was analyzed using a microarray containing 608 genes involved in skeletal development, tissue differentiation, fracture healing, and mechanotransduction. The glycosaminoglycan (GAG) content in the stimulated tissues was compared with that in native articular cartilage as a means of assessing the progression of chondrogenic development of the tissues. RESULTS: The majority of the 100 genes that were differentially expressed were up-regulated in response to mechanical stimulation. Many of these genes are associated with articular cartilage development and maintenance, diarthrodial joint development, cell adhesion, extracellular matrix synthesis, signal transduction, and skeletal development. Quantitative real-time polymerase chain reaction results were consistent with the microarray findings. The GAG content of the stimulated tissues increased over time and was no different from that of articular cartilage on day 38 after surgery. CONCLUSION: Our findings indicate that mechanical stimulation causes up-regulation of genes that are principally involved in joint cavity morphogenesis and critical to articular cartilage function. Further study of this type of stimulation may identify key signaling events required for postnatal hyaline cartilage formation.

Mechanical stimulation alters tissue differentiation and molecular expression during bone healing.

Further understanding of how mechanical cues modulate skeletal tissue differentiation can identify potential means of enhancing repair following injury or disease. Prior studies examined the effects of mechanical loading on osteogenesis, chondrogenesis, and fibrogenesis in an effort to enhance bony union. However, exploring how mechanical stimuli can divert the bone healing process towards formation of other mesenchymal tissues, as an endpoint, may elucidate new avenues for repair and regeneration of tissues such as cartilage and fibrous tissue. This study investigated the use of mechanical stimulation to promote cartilage rather than bone formation within an osteotomy. Our overall goal was to define skeletal tissue distribution and molecular expression patterns induced by the stimulation. Retired breeder Sprague-Dawley rats (n = 85) underwent production of a mid-diaphyseal, transverse femoral osteotomy followed by external fixation. Beginning on postoperative day 10 and continuing for 1, 2, or 4 weeks, a cyclic bending motion (+35 degrees/-25 degrees at 1 Hz) was applied in the sagittal plane for 15 min/day for 5 consecutive days/week. Control animals experienced continuous rigid fixation. Histological and molecular analyses indicated that stimulation substantially altered normal bone healing. Stimulated specimens exhibited an increase in cartilage volume over time, while control specimens demonstrated bony bridging. Stimulation induced upregulation of cartilage-related genes (COL2A1 and COL10A1) and downregulation of bone morphogenetic proteins (BMPs) -4, -6 and -7. However, BMP-3 was upregulated with stimulation. These findings illustrate that mechanical cues can selectively modulate osteogenesis and chondrogenesis in vivo, and suggest a potential basis for treatment regimens for injured or diseased cartilaginous tissues.

Mechanotransduction and fracture repair.

Fracture-healing is regulated in part by mechanical factors. Study of the processes by which the mechanical environment of a fracture modulates healing can yield new strategies for the treatment of bone injuries. This article focuses on several key unanswered questions in the study of mechanotransduction and fracture repair. These questions concern identifying the mechanical stimuli that promote bone-healing, defining the mechanisms that are involved in this process, and examining the potential for cross-talk between investigations of mechanotransduction in bone-healing and in healing of other mesenchymally derived tissues. Several approaches to obtain accurate estimates of the mechanical stimuli present within a fracture callus are proposed, and our current understanding of the mechanotransduction processes involved in bone-healing is reviewed. Further study of mechanotransduction mechanisms is needed in order to identify those that are most critical and active during the various phases of fracture repair. A better understanding of the effect of mechanical factors on bone-healing will also benefit the study of healing, regeneration, and engineering of other skeletal tissues.