Resistance to PRMT5-targeted therapy in mantle cell lymphoma.

ABSTRACT: Mantle cell lymphoma (MCL) is an incurable B-cell non-Hodgkin lymphoma, and patients who relapse on targeted therapies have poor prognosis. Protein arginine methyltransferase 5 (PRMT5), an enzyme essential for B-cell transformation, drives multiple oncogenic pathways and is overexpressed in MCL. Despite the antitumor activity of PRMT5 inhibition (PRT-382/PRT-808), drug resistance was observed in a patient-derived xenograft (PDX) MCL model. Decreased survival of mice engrafted with these PRMT5 inhibitor-resistant cells vs treatment-naive cells was observed (P = .005). MCL cell lines showed variable sensitivity to PRMT5 inhibition. Using PRT-382, cell lines were classified as sensitive (n = 4; 50% inhibitory concentration [IC50], 20-140 nM) or primary resistant (n = 4; 340-1650 nM). Prolonged culture of sensitive MCL lines with drug escalation produced PRMT5 inhibitor-resistant cell lines (n = 4; 200-500 nM). This resistant phenotype persisted after prolonged culture in the absence of drug and was observed with PRT-808. In the resistant PDX and cell line models, symmetric dimethylarginine reduction was achieved at the original PRMT5 inhibitor IC50, suggesting activation of alternative resistance pathways. Bulk RNA sequencing of resistant cell lines and PDX relative to sensitive or short-term-treated cells, respectively, highlighted shared upregulation of multiple pathways including mechanistic target of rapamycin kinase [mTOR] signaling (P < 10-5 and z score > 0.3 or < 0.3). Single-cell RNA sequencing analysis demonstrated a strong shift in global gene expression, with upregulation of mTOR signaling in resistant PDX MCL samples. Targeted blockade of mTORC1 with temsirolimus overcame the PRMT5 inhibitor-resistant phenotype, displayed therapeutic synergy in resistant MCL cell lines, and improved survival of a resistant PDX.

Extinction of austral diatoms in response to large-scale climate dynamics in Antarctica.

Despite evidence for microbial endemism, an understanding of the impact of geological and paleoclimate events on the evolution of regional protist communities remains elusive. Here, we provide insights into the biogeographical history of Antarctic freshwater diatoms, using lacustrine fossils from mid-Miocene and Quaternary Antarctica, and dovetail this dataset with a global inventory of modern freshwater diatom communities. We reveal the existence of a diverse mid-Miocene diatom flora bearing similarities with several former Gondwanan landmasses. Miocene cooling and Plio-Pleistocene glaciations triggered multiple extinction waves, resulting in the selective depauperation of this flora. Although extinction dominated, in situ speciation and new colonizations ultimately shaped the species-poor, yet highly adapted and largely endemic, modern Antarctic diatom flora. Our results provide a more holistic view on the scale of biodiversity turnover in Neogene and Pleistocene Antarctica than the fragmentary perspective offered by macrofossils and underscore the sensitivity of lacustrine microbiota to large-scale climate perturbations.

Adverse Maternal and Neonatal Outcomes in Indicated Compared with Spontaneous Preterm Birth in Healthy Nulliparas: A Secondary Analysis of a Randomized Trial.

OBJECTIVE: To compare the risks of adverse maternal and neonatal outcomes associated with spontaneous (SPTB) versus indicated preterm births (IPTB). METHODS: A secondary analysis of a multicenter trial of vitamin C and E supplementation in healthy low-risk nulliparous women. Outcomes were compared between women with SPTB (due to spontaneous membrane rupture or labor) and those with IPTB (due to medical or obstetric complications). A primary maternal composite outcome included: death, pulmonary edema, blood transfusion, adult respiratory distress syndrome (RDS), cerebrovascular accident, acute tubular necrosis, disseminated intravascular coagulopathy, or liver rupture. A neonatal composite outcome included: neonatal death, RDS, grades III or IV intraventricular hemorrhage (IVH), sepsis, necrotizing enterocolitis (NEC), or retinopathy of prematurity. RESULTS: Of 9,867 women, 10.4% (N = 1,038) were PTBs; 32.7% (n = 340) IPTBs and 67.3% (n = 698) SPTBs. Compared with SPTB, the composite maternal outcome was more frequent in IPTB-4.4% versus 0.9% (adjusted odds ratio [aOR], 4.0; 95% confidence interval [CI], 1.4-11.8), as were blood transfusion and prolonged hospital stay (3.2 and 3.7 times, respectively). The frequency of composite neonatal outcome was higher in IPTBs (aOR, 1.8; 95% CI, 1.1-3.0), as were RDS (1.7 times), small for gestational age (SGA) < 5th percentile (7.9 times), and neonatal intensive care unit (NICU) admission (1.8 times). CONCLUSION: Adverse maternal and neonatal outcomes were significantly more likely with IPTB than with SPTB.

Carpenter-Coustan Compared With National Diabetes Data Group Criteria for Diagnosing Gestational Diabetes.

OBJECTIVE: Use of Carpenter-Coustan compared with National Diabetes Data Group criteria increases the number of women diagnosed with gestational diabetes mellitus (GDM) by 30-50%, but whether treatment of this milder GDM reduces adverse outcomes is unknown. We explored the effects of the diagnostic criteria used on the benefits of GDM treatment. METHODS: This was a secondary analysis of a randomized trial for treatment of mild GDM diagnosed using Carpenter-Coustan criteria. We evaluated the effect of treatment within two mutually exclusive diagnostic groups: 1) women who met the stricter National Diabetes Data Group as well as Carpenter-Coustan criteria (National Diabetes Data Group), and 2) those diagnosed by Carpenter-Coustan but not meeting National Diabetes Data Group criteria (Carpenter-Coustan only). Maternal outcomes examined were pregnancy-induced hypertension, shoulder dystocia, maternal weight gain, and cesarean delivery. Neonatal outcomes were large for gestational age, macrosomia (greater than 4,000 g), fat mass, small for gestational age, and a composite outcome of perinatal death, birth injury, hypoglycemia, hyperbilirubinemia, and hyperinsulinemia. Analysis of variance or the Breslow-Day test, as appropriate, was used to test for the interaction between diagnostic criteria and GDM treatment on the outcomes of interest. RESULTS: Of 958 patients, 560 (58.5%) met National Diabetes Data Group criteria and 398 (41.5%) met Carpenter-Coustan only. Compared with untreated women, the direction of treatment effect did not differ by diagnostic criteria used and was consistent with the original trial. The P value for interaction between diagnostic criteria and treatment status was not significant for any outcome. CONCLUSION: The overall beneficial treatment effect on pregnancy-induced hypertension, shoulder dystocia, cesarean delivery, and macrosomia was seen in patients diagnosed by the higher National Diabetes Data Group and by the lower thresholds of the Carpenter-Coustan criteria.

Are manic symptoms that 'dip' into depression the essence of mixed features?

BACKGROUND: Three symptoms of (hypo)mania that clinically represent mood disorders mixed states have been omitted from the DSM-5 mixed features specifier because 'they fail to discriminate between manic and depressive syndromes'. Therefore, the present study examined the role of distractibility, irritability and psychomotor agitation (DIP) in characterising mixed depressive states. METHODS: Fifty in-patients at a specialist mood disorders unit underwent a detailed longitudinal clinical evaluation (3-6 weeks) and were assessed on a range of standardized measures to characterise their illness according to depression subtype, duration of illness and clinical features-including specifically depressive and manic symptoms and the context in which these occur. RESULTS: 49 patients met criteria for major depressive episode, and of these, 34 experienced at least one dip symptom. Patients who endorsed distractibility were more likely to be diagnosed with Bipolar Disorder than Major Depressive Disorder; patients who endorsed irritable mood were more likely to have non-melancholic depression (admixture of depressive and anxiety symptoms), and patients who reported psychomotor agitation experienced a significantly greater number of distinct periods of (hypo)manic symptoms compared with those who did not. LIMITATIONS: The present study used a modest sample size and did not control for medication or comorbid illness. Although this is inevitable when examining real-world patients in a naturalistic setting, future research needs to allow for comorbidity and its impact, specifically anxiety. CONCLUSIONS: The present findings suggest that all 3 symptoms that have been excluded from DSM-5 may be cardinal features of mixed states, as they 'dip' into depressive symptoms to create a mixed state.

Reinforcing cerclage for a short cervix at follow-up after the primary cerclage procedure.

OBJECTIVE: To determine whether a reinforcing cerclage (RC) for a short cervix measured after the primary cerclage procedure prolonged pregnancy. METHODS: We conducted a retrospective cohort study of 157 women with singleton gestations who underwent cerclage for standard indications. Women were grouped according to cervical length (CL) at the time of follow-up 1-2 weeks after the initial cerclage placement: ≥25 mm (106 women) and <25 mm with (20 women) or without RC (31 women). Gestational age (GA) at delivery was compared by ANOVA. Survival risk analysis was applied to model GA at delivery adjusted for indication and CL before and after the first cerclage. RESULTS: Women with CL ≥25mm delivered later than women with CL < 25mm after the first cerclage (p < 0.01). RC did not delay delivery for women with CL < 25 mm (p = 0.17) after the primary procedure. Indication for the primary cerclage (p < 0.01) and CL (p < 0.01) after the primary cerclage were the best predictors for GA at delivery. CONCLUSION: Placement of RC for short cervix did not prolong duration of pregnancy, GA at delivery or modify the probability of preterm birth.

Does maternal body mass index influence treatment effect in women with mild gestational diabetes?

OBJECTIVE: The aim of the article is to determine whether maternal body mass index (BMI) influences the beneficial effects of diabetes treatment in women with gestational diabetes mellitus (GDM). STUDY DESIGN: Secondary analysis of a multicenter randomized treatment trial of women with GDM. Outcomes of interest were elevated umbilical cord c-peptide levels (> 90th percentile 1.77 ng/mL), large for gestational age (LGA) birth weight (> 90th percentile), and neonatal fat mass (g). Women were grouped into five BMI categories adapted from the World Health Organization International Classification of normal, overweight, and obese adults. Outcomes were analyzed according to treatment group assignment. RESULTS: A total of 958 women were enrolled (485 treated and 473 controls). Maternal BMI at enrollment was not related to umbilical cord c-peptide levels. However, treatment of women in the overweight, Class I, and Class II obese categories was associated with a reduction in both LGA birth weight and neonatal fat mass. Neither measure of excess fetal growth was reduced with treatment in normal weight (BMI < 25 kg/m(2)) or Class III (BMI ≥ 40 kg/m(2)) obese women. CONCLUSION: There was a beneficial effect of treatment on fetal growth in women with mild GDM who were overweight or Class I and Class II obese. These effects were not apparent for normal weight and very obese women.

Accuracy of sonographic chorionicity classification in twin gestations.

OBJECTIVES: To evaluate the accuracy of sonographic classification of chorionicity in a large cohort of twins and investigate which factors may be associated with sonographic accuracy. METHODS: We conducted a secondary analysis of a randomized trial of preterm birth prevention in twins. Sonographic classification of chorionicity was compared with pathologic examination of the placenta. Maternal (age, body mass index, diabetes, and hypertension), obstetric (prior cesarean delivery, gestational age at the first sonographic examination, and antepartum bleeding), and sonographic (oligohydramnios, polyhydramnios, and twin-twin transfusion syndrome) factors were assessed for their possible association with accuracy. RESULTS: A total of 545 twin sets in which chorionicity was classified by sonography before 20 weeks' gestation were included; 455 were dichorionic and 90 were monochorionic based on pathologic examination. Sonography misclassified 35 of 545 twin pregnancies (6.4%): 18 of 455 dichorionic twins (4.0%) and 17 of 90 monochorionic twins (19.0%). The sensitivity and specificity of sonographic diagnosis of monochorionicity were 81.1% and 96.0%, respectively. In a multivariable analysis, pregnancies with initial sonographic examinations before 14 weeks' gestation were less likely to have misclassified chorionicity than those with sonographic examinations at 15 to 20 weeks (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.23-0.96). For each week increase in gestational age, the odds of misclassification rose by 10% (OR, 1.10; 95% CI, 1.01-1.2). In the multivariable analysis, maternal age, body mass index, parity, and prior cesarean delivery were not associated with sonographic accuracy. CONCLUSIONS: Sonography before 20 weeks incorrectly classified chorionicity in 6.4% of twin gestations. Those with first sonographic examinations performed at earlier gestational ages had improved chorionicity diagnosis.

Standardized severe maternal morbidity review: rationale and process.

Severe maternal morbidity and mortality have been rising in the United States. To begin a national effort to reduce morbidity, a specific call to identify all pregnant and postpartum women experiencing admission to an intensive care unit or receipt of four or more units of blood for routine review has been made. While advocating for review of these cases, no specific guidance for the review process was provided. Therefore, the aim of this expert opinion is to present guidelines for a standardized severe maternal morbidity interdisciplinary review process to identify systems, professional, and facility factors that can be ameliorated, with the overall goal of improving institutional obstetric safety and reducing severe morbidity and mortality among pregnant and recently pregnant women. This opinion was developed by a multidisciplinary working group that included general obstetrician­gynecologists, maternal­fetal medicine subspecialists, certified nurse­midwives, and registered nurses all with experience in maternal mortality reviews. A process for standardized review of severe maternal morbidity addressing committee organization, review process, medical record abstraction and assessment, review culture, data management, review timing, and review confidentiality is presented. Reference is made to a sample severe maternal morbidity abstraction and assessment form.

Standardized severe maternal morbidity review: rationale and process.

Severe maternal morbidity and mortality have been rising in the United States. To begin a national effort to reduce morbidity, a specific call to identify all pregnant and postpartum women experiencing admission to an intensive care unit or receipt of 4 or more units of blood for routine review has been made. While advocating for review of these cases, no specific guidance for the review process was provided. Therefore, the aim of this expert opinion is to present guidelines for a standardized severe maternal morbidity interdisciplinary review process to identify systems, professional, and facility factors that can be ameliorated, with the overall goal of improving institutional obstetric safety and reducing severe morbidity and mortality among pregnant and recently pregnant women. This opinion was developed by a multidisciplinary working group that included general obstetrician-gynecologists, maternal-fetal medicine subspecialists, certified nurse-midwives, and registered nurses all with experience in maternal mortality reviews. A process for standardized review of severe maternal morbidity addressing committee organization, review process, medical record abstraction and assessment, review culture, data management, review timing, and review confidentiality is presented. Reference is made to a sample severe maternal morbidity abstraction and assessment form.

Delivery timing and cesarean delivery risk in women with mild gestational diabetes mellitus.

OBJECTIVE: The purpose of this study was to evaluate the relationship between gestational age (GA) and induction of labor (IOL) and the rate of cesarean delivery in women with mild gestational diabetes mellitus. STUDY DESIGN: We conducted a secondary analysis of data from a multicenter randomized controlled trial of mild gestational diabetes mellitus treatment. Cesarean delivery rate of women delivering at term (≥37 weeks' gestation) was evaluated by 2 complementary approaches: (1) IOL vs spontaneous labor: women who were induced at each GA compared with those who spontaneously labored at the same GA and (2) IOL vs expectant management: women who delivered after IOL at each GA compared with those who delivered after spontaneous labor at the same GA or subsequently after spontaneous or induced labor (outcome at each week compared with expectant management at that week). Logistic regression adjusted for potential confounders. RESULTS: The overall cesarean delivery rate was 13%. When compared with 39 weeks' gestation (either IOL or spontaneous labor) as the referent, there was no significant difference in the cesarean delivery rate in women who delivered at 37, 38, or 40 weeks' gestation. However, IOL was associated with a 3-fold increase in cesarean delivery rate at 41 weeks' gestation and beyond, as compared with IOL at 39 weeks' gestation. Similarly, there was a 3-fold increase in the cesarean delivery rate in women who were induced when compared with those who were treated expectantly at 40 completed weeks' gestation. CONCLUSION: Induction of labor in women with mild gestational diabetes mellitus does not increase the rate of cesarean delivery at <40 weeks' gestation.

Haptoglobin phenotype and abnormal uterine artery Doppler in a racially diverse cohort.

OBJECTIVE: The anti-oxidant and proangiogenic protein haptoglobin (Hp) is believed to be important for implantation and pregnancy, although its specific role is not known. The three phenotypes (1-1, 2-1 and 2-2) differ in structure and function. Hp 2-2 is associated with increased vascular stiffness in other populations. We examined whether Hp phenotype is associated with abnormal uterine artery Doppler (UAD) in pregnancy. METHODS: We conducted a secondary analysis of a preeclampsia prediction cohort nested within a larger placebo-controlled randomized clinical trial of antioxidants for prevention of preeclampsia. We determined Hp phenotype in 2184 women who completed UAD assessments at 17 weeks gestation. Women with notching were re-evaluated for persistent notching at 24 weeks' gestation. Logistic regression was used to assess differences in UAD indices between phenotype groups. RESULTS: Hp phenotype did not significantly influence the odds of having any notch (p = 0.32), bilateral notches (p = 0.72), or a resistance index (p = 0.28) or pulsatility index (p = 0.67) above the 90th percentile at 17 weeks' gestation. Hp phenotype also did not influence the odds of persistent notching at 24 weeks (p = 0.25). CONCLUSIONS: Hp phenotype is not associated with abnormal UAD at 17 weeks' gestation or with persistent notching at 24 weeks.

Umbilical cord serum interleukin-6, C-reactive protein, and myeloperoxidase concentrations at birth and association with neonatal morbidities and long-term neurodevelopmental outcomes.

OBJECTIVE: The aim of the study is to determine if umbilical cord serum concentrations of interleukin-6 (IL-6), C-reactive protein (CRP), and myeloperoxidase (MPO), in pregnancies at risk for preterm birth (PTB), are associated with neonatal morbidities and/or altered neurodevelopmental outcomes in the children. STUDY DESIGN: Umbilical cord serum samples were collected at birth from 400 newborns delivered within a multicenter randomized controlled trial of repeated versus single course of antenatal corticosteroids (ACs), in women at increased risk for PTB. Newborns were followed through discharge and were evaluated between 36 and 42 months corrected age with neurological examination and Bayley Scales of Infant Development. Umbilical cord serum concentrations of IL-6, CRP, and MPO were determined using enzyme-linked immunoassays. Multivariate logistic regression analyses explored the relationship between umbilical cord serum IL-6, CRP, and MPO levels, adverse newborn outcomes, and PTB < 32 weeks of gestational age (GA). RESULTS: Univariate analysis revealed that umbilical cord IL-6 above the 75th percentile was associated with increased respiratory distress syndrome (RDS) and chronic lung disease (CLD), but not with necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), or neonatal sepsis; however, this association was not significant after adjusting for GA at delivery and treatment group. No significant associations between CRP or MPO and RDS, CLD, NEC, sepsis, or IVH were evident. Regression analysis revealed that CRP above the 75th percentile was associated with a decreased risk of CLD (odds ratio, 0.10; 95% confidence interval, 0.02-0.41). No associations between umbilical cord IL-6, CRP, or MPO and MDI < 70 or PDI < 70 were evident. Umbilical cord serum concentrations of IL-6, CRP, and MPO, above the 75th percentile, were associated with more frequent PTB < 32 weeks of GA. CONCLUSION: Elevated umbilical cord serum concentration of CRP is associated with reduced risk for CLD even after adjusting for GA at delivery. Occurrence of levels > 75th percentile of IL-6, CRP, and MPO in umbilical cord serum was associated with PTB < 32 weeks of GA. Elevated umbilical cord serum concentrations of IL-6, CRP, and MPO at birth were not associated with poor neurodevelopmental outcomes.

Relationship between 17-alpha hydroxyprogesterone caproate concentration and spontaneous preterm birth.

OBJECTIVE: 17-alpha hydroxyprogesterone caproate 250 mg weekly reduces recurrent spontaneous preterm birth in women with a prior spontaneous preterm birth by 33%. The dose is not based on pharmacologic considerations. A therapeutic concentration has not been determined hampering any attempt to optimize treatment. This study evaluated the relationship between 17-alpha hydroxyprogesterone caproate plasma concentrations and the rate of spontaneous preterm birth in women with singleton gestation. STUDY DESIGN: A single blood sample was obtained between 25 and 28 weeks' gestation from 315 women with a spontaneous preterm birth who participated in a placebo-controlled, prospective, randomized clinical trial evaluating the benefit of omega-3 supplementation in reducing preterm birth. All women in the parent study received 17-alpha hydroxyprogesterone caproate and 434 received omega-3 supplementation and 418 received a placebo. Plasma from 315 consenting women was analyzed for 17-alpha hydroxyprogesterone caproate concentration. RESULTS: There were no differences between placebo and omega-3 supplemented groups in demographic variables, outcomes or in mean 17-alpha hydroxyprogesterone caproate concentration. Plasma concentrations of 17-alpha hydroxyprogesterone caproate ranged from 3.7-56 ng/mL. Women with plasma concentrations of 17-alpha hydroxyprogesterone caproate in the lowest quartile had a significantly higher risk of spontaneous preterm birth (P = .03) and delivered at significantly earlier gestational ages (P = .002) than did women in the second to fourth quartiles. The lowest preterm birth rates were seen when median 17-alpha hydroxyprogesterone caproate concentrations exceeded 6.4 ng/mL. CONCLUSION: Low plasma 17-alpha hydroxyprogesterone caproate concentration is associated with an increased risk of spontaneous preterm birth. This finding validates efficacy of this treatment but suggests that additional studies are needed to determine the optimal dosage.

Relationship between 1-hour glucose challenge test results and perinatal outcomes.

OBJECTIVE: To estimate the relationship between 1-hour 50 g glucose challenge test values and perinatal outcomes. METHODS: This was a secondary analysis of data from a multicenter treatment trial of mild gestational diabetes mellitus. Women with glucose challenge test values of 135-199 mg/dL completed a 3-hour oral glucose tolerance test. Mild gestational diabetes mellitus was defined as fasting glucose less than 95 mg/dL and two or more abnormal oral glucose tolerance test values: 1-hour 180 mg/dL or more; 2-hour 155 mg/dL or more; and 3-hour 140 mg/dL or more. Our study included untreated women with glucose challenge test values of 135-139 mg/dL and 140-199 mg/dL and a comparison group with values less than 120 mg/dL. Primary outcomes included a perinatal composite (stillbirth, neonatal death, hypoglycemia, hyperbilirubinemia, neonatal hyperinsulinemia, and birth trauma), large for gestational age (LGA, birth weight above the 90 percentile based on sex-specific and race-specific norms), and macrosomia (greater than 4,000 g). RESULTS: There were 436 women with glucose challenge test values less than 120 mg/dL and 1,403 with values of 135 mg/dL or more (135-139, n=135; 140-199, n=1,268). The composite perinatal outcome occurred in 25.6% of those with glucose challenge test values less than 120 mg/dL compared with 21.1% for values of 135-139 mg/dL and 35.3% for values of 140-199 mg/dL. Rates of LGA by group were 6.6%, 6.8%, and 12.4%, respectively. Rates of macrosomia by group were 7.8%, 6.1%, and 12.1%, respectively. Compared with glucose challenge test values less than 120 mg/dL, the adjusted odds ratios (ORs) (95% confidence intervals [CIs]) for values of 140-199 mg/dL were 1.48 (1.14-1.93) for the composite outcome, 1.97 (1.29-3.11) for LGA, and 1.61 (1.07-2.49) for macrosomia. For glucose challenge test values of 135-139 mg/dL, adjusted ORs and 95% CIs were 0.75 (0.45-1.21), 1.04 (0.44-2.24), and 0.75 (0.30-1.66), respectively. The subcategories with glucose challenge test values of 140-144 mg/dL and 145-149 mg/dL also were associated with an increase in selected outcomes when compared with those with values less than 120 mg/dL. CONCLUSIONS: Glucose challenge test values of 135-139 mg/dL were not associated with adverse outcomes compared with values less than 120 mg/dL; however, glucose challenge test values of 140 mg/dL or more were associated with an increase in odds of the composite perinatal outcome, LGA, and macrosomia.

Maternal 25-hydroxyvitamin d and preterm birth in twin gestations.

OBJECTIVE: To assess whether there was an independent association between maternal 25-hydroxyvitamin D concentrations at 24-28 weeks of gestation and preterm birth in a multicenter U.S. cohort of twin pregnancies. METHODS: Serum samples from women who participated in a clinical trial of 17 α-hydroxyprogesterone caproate for the prevention of preterm birth in twin gestations (2004-2006) were assayed for 25-hydroxyvitamin D concentrations using liquid chromatography tandem mass spectrometry (n=211). Gestational age was determined early in pregnancy using a rigorous algorithm. Preterm birth was defined as delivery of the first twin or death of either twin at less than 35 weeks of gestation. RESULTS: The mean serum 25-hydroxyvitamin D concentration was 82.7 nmol/L (standard deviation 31.5); 40.3% of women had concentrations less than 75 nmol/L. Preterm birth at less than 35 weeks of gestation occurred in 49.4% of women with 25-hydroxyvitamin D concentrations less than 75 nmol/L compared with 26.2% among those with concentrations of 75 nmol/L or more (P<.001). After adjustment for maternal race and ethnicity, study site, parity, prepregnancy body mass index, season, marital status, education, gestational age at blood sampling, smoking status, and 17 α-hydroxyprogesterone caproate treatment, maternal 25-hydroxyvitamin D concentration of 75 nmol/L or more was associated with a 60% reduction in the odds of preterm birth compared with concentrations less than 75 nmol/L (adjusted odds ratio [OR] 0.4, 95% confidence interval [CI] 0.2-0.8). A similar protective association was observed when studying preterm birth at less than 32 weeks of gestation (OR 0.2, 95% CI 0.1-0.6) and after confounder adjustment. CONCLUSIONS: Late second-trimester maternal 25-hydroxyvitamin D concentrations less than 75 nmol/L are associated with an increase in the risk of preterm birth in this cohort of twin pregnancies. LEVEL OF EVIDENCE: II.

Advanced lipoprotein measures and recurrent preterm birth.

OBJECTIVE: Lipoproteins are associated with atherogenic and inflammatory processes, and these processes may be related to adverse pregnancy outcomes. We therefore examined whether variations in lipoprotein particle size and concentration are associated with preterm birth (PTB) <35 weeks' gestation. STUDY DESIGN: This is a case-control ancillary study to a randomized trial of omega-3 fatty acid supplementation to prevent recurrent PTB. We measured standard lipids and used nuclear magnetic resonance (NMR) spectroscopy to characterize 17 lipoprotein particles from plasma collected at the baseline randomization visit (16-21 weeks' gestation) in 128 cases (PTB <35 weeks' gestation) and 132 term controls. Logistic regression models controlled for study center, race/ethnicity, number of prior PTB, smoking, and treatment group, as well as total low-density lipoprotein (LDL), high-density lipoprotein, and triglyceride concentrations when examining LDLNMR, high-density lipoproteinNMR, and very LDL (VLDL)NMR, respectively. RESULTS: Only 1 of the 17 NMR lipoproteins was associated with recurrent PTB. We observed an increased odds of recurrent PTB of 1.04 (95% confidence interval, 1.01-1.08; P = .02) per nanometer increase in VLDLNMR particle size and an odds ratio of 3.00 (confidence interval, 1.40-6.43; P = .005) for the third tertile of VLDLNMR particle size compared with the first tertile. CONCLUSION: In women with prior PTB, variations in midpregnancy lipoproteins were not associated with recurrent PTB overall, however the association observed with VLDLNMR particle size is suggestive that PTB may be amenable to lifestyle, nutritional, or pharmacologic interventions.

Gestational age-specific risks vs benefits of multicourse antenatal corticosteroids for preterm labor.

OBJECTIVE: The purpose of this study was to estimate a gestational age threshold at which the benefits of treatment with weekly courses of antenatal corticosteroids (ACS) during preterm labor outweigh the risks. STUDY DESIGN: Risk-benefit ratios by gestational age were determined with the use of a Markov microsimulation decision-analysis model with a 1-week cycle length. Single course and multiple (weekly to a maximum of 4) courses of ACS by gestational age of entry (23 weeks to 31 weeks 6 days' gestation) were compared. Benefits were composite events (respiratory distress syndrome, chronic lung disease, severe intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia, or stillbirth) averted. Risks were small head circumference and small for gestational age. RESULTS: More composite events are averted (benefits) than risks acquired (ratio, 6:1) when multiple courses of ACS are initiated at 26 weeks' gestation. When multiple courses of ACS are initiated at 29 weeks' gestation, the risk-benefit ratio is 1. Beyond 29 weeks, there is a suggestion of more risk than benefit. CONCLUSION: The model suggests that multiple courses of ACS that are initiated at <29 weeks' gestation may have increased benefit compared with risks. Further analyses are needed to determine the long-term clinical significance of these findings.