Metformin in pregnancy and childhood neurodevelopmental outcomes: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to examine the impact of maternal metformin use during pregnancy on offspring neurodevelopmental outcomes. DATA SOURCES: MEDLINE, Embase, and Web of Science (Core Collection) were searched from inception until July 1, 2023. STUDY ELIGIBILITY CRITERIA: Studies of women who received treatment with metformin at any stage of pregnancy for any indication with neurodevelopmental data available for their offspring were included. Studies without a control group were excluded. Randomized controlled trials, case-control, cohort, and cross-sectional studies were included in the review. METHODS: Studies were screened for inclusion and data were extracted independently by 2 reviewers. Risk of bias was assessed using a modified version of the Newcastle-Ottawa Scale for nonrandomized studies, and the Risk of Bias 2 tool for randomized trials. RESULTS: A total of 7 studies met the inclusion criteria, including a combined cohort of 14,042 children with 7641 children who were exposed and followed for up to 14 years of age. Metformin use during pregnancy was not associated with neurodevelopmental delay in infancy (relative risk, 1.09; 95% confidence interval, 0.54-2.17; 3 studies; 9668 children) or at ages 3 to 5 years (relative risk, 0.90; 95% confidence interval, 0.56-1.45; 2 studies; 6118 children). When compared with unexposed peers, metformin use during pregnancy was not associated with altered motor scores (mean difference, 0.30; 95% confidence interval, -1.15 to 1.74; 3 studies; 714 children) or cognitive scores (mean difference, -0.45; 95% confidence interval, -1.45 to 0.55; 4 studies; 734 children). Studies that were included were of high quality and deemed to be at low risk of bias. CONCLUSION: In utero exposure to metformin does not seem to be associated with adverse neurodevelopmental outcomes in children up to the age of 14 years. These findings provide reassurance to clinicians and pregnant women considering metformin use during pregnancy.

Unravelling the complex interplay between antibiotic consumption and adaptive changes in methicillin-resistant Staphylococcus aureus.

OBJECTIVES: This study aims to elucidate the genomic dynamics driving the emergence of antimicrobial resistance (AMR), with a specific focus on the interplay between AMR and antimicrobial usage. METHODS: We conducted a comprehensive analysis using a ST239 methicillin-resistant Staphylococcus aureus (MRSA) dataset over a continuous 12-year period from a single hospital. Genomic analyses were performed tracking the changes in MRSA populations, particularly the emergence of reduced vancomycin susceptibility, and assessing the impact of glycopeptide use on these emergence events. RESULTS: Our findings reveal a significant correlation between hospital glycopeptide usage and the selection of MRSA strains with reduced vancomycin susceptibility. Genomic analyses provided insights into the molecular mechanisms driving resistance emergence, including the slowing of the molecular clock rate in response to heightened antimicrobial consumption. CONCLUSIONS: In conclusion, this study the highlights the complex dynamics between AMR and antimicrobial use at the hospital level. The observed correlation between antimicrobial consumption and the development of less susceptible MRSA strains underscores the importance of antimicrobial stewardship programmes and the establishment of optimal consumption thresholds for mitigating AMR effectively.

Educational Outcomes for Children at 7 to 9 Years of Age After Birth at 39 vs 40 to 42 Weeks' Gestation.

Importance: Birth at 39 weeks' gestation is common and thought to be safe for mother and neonate. However, findings of long-term outcomes for children born at this gestational age have been conflicting. Objective: To evaluate the association of birth at 39 weeks' gestation with childhood numeracy and literacy scores at ages 7 to 9 years compared with birth at 40 to 42 weeks' gestation. Design, Setting, and Participants: In this Australian statewide, population-based cohort study using a causal inference framework based on target trial emulation, perinatal data on births between January 1, 2005, and December 31, 2011, were linked to educational outcomes at 7 to 9 years of age. Statistical analyses were performed from December 2022 to June 2023. Exposure: Birth at 39 weeks' gestation compared with birth at 40 to 42 weeks' gestation. Main Outcomes and Measures: Numeracy and literacy outcomes were assessed at 7 to 9 years of age using Australian National Assessment Program-Literacy and Numeracy data and defined by overall z score across 5 domains (grammar and punctuation, reading, writing, spelling, and numeracy). Multiple imputation and doubly robust inverse probability weighted regression adjustment were used to estimate population average causal effects. Results: The study population included 155 575 children. Of these children, 49 456 (31.8%; 24 952 boys [50.5%]) were born at 39 weeks' gestation and were compared with 106 119 (68.2%; 52 083 boys [49.1%]) born at 40 to 42 weeks' gestation. Birth at 39 weeks' gestation was not associated with altered educational outcomes for children aged 7 to 9 years compared with their peers born at 40 to 42 weeks' gestation (mean [SE] z score, 0.0008 [0.0019] vs -0.0031 [0.0038]; adjusted risk difference, -0.004 [95% CI, -0.015 to 0.007]). Each educational domain was investigated, and no significant difference was found in grammar and punctuation (risk difference [RD], -0.006 [95% CI, -0.016 to 0.005]), numeracy (RD, -0.009 [95% CI, -0.020 to 0.001]), spelling (RD, 0.001 [95% CI, -0.011 to 0.0013]), reading (RD, -0.008 [95% CI, -0.019 to 0.003]), or writing (RD, 0.006 [95% CI, -0.005 to 0.016]) scores for children born at 39 weeks' gestation compared with those born at 40 to 42 weeks' gestation. Birth at 39 weeks' gestation also did not increase the risk of scoring below national minimum standards in any of the 5 tested domains. Conclusions and Relevance: Using data from a statewide linkage study to emulate the results of a target randomized clinical trial, this study suggests that there is no evidence of an association of birth at 39 weeks' gestation with numeracy and literacy outcomes for children aged 7 to 9 years.

Prevalence of Perinatal Anxiety and Related Disorders in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.

Importance: Anxiety disorders are associated with poor maternal and neonatal outcomes. Women in low- and middle-income countries (LMICs) are thought to be disproportionally burdened by these disorders, yet their prevalence is unclear. Objective: To conduct a systematic review and meta-analysis to determine the prevalence of 6 anxiety and related disorders among perinatal women in LMICs. Data Sources: Embase, MEDLINE, PsycINFO, Cochrane Library, CINAHL, and Web of Science databases were searched from inception until September 7, 2023. Study Selection: Studies conducted in World Bank-defined LMICs and reporting prevalence of generalized anxiety disorder, obsessive-compulsive disorder, social anxiety disorder, posttraumatic stress disorder, panic disorder, or adjustment disorder during the perinatal period (conception to 12 months post partum) using a validated method were included. Data Extraction and Synthesis: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. Study eligibility, extracted data, and risk of bias of included studies were assessed by 2 independent reviewers. Random-effects meta-analysis was used to estimate pooled point prevalence. Subgroup analyses were performed by specific anxiety disorder. Main Outcomes and Measures: Main outcomes were prevalence estimates of each anxiety disorder, measured as percentage point estimates and corresponding 95% CIs. Results: At total of 10 617 studies were identified, 203 of which met the inclusion criteria and reported the outcomes of 212 318 women from 33 LMICs. Generalized anxiety disorder was the most reported (184 studies [90.6%]) and most prevalent disorder at 22.2% (95% CI, 19.4%-25.0%; n = 173 553). Posttraumatic stress disorder was the second most prevalent (8.3%; 95% CI, 5.0%-12.2%; 33 studies; n = 22 452). Adjustment disorder was least prevalent (2.9%; 95% CI, 0.0%-14.1%; 2 studies; n = 475). The prevalence of generalized anxiety varied by country income status, with the highest prevalence among lower-middle-income countries (27.6%; 95% CI, 21.6%-33.9%; 59 studies; n = 25 109), followed by low-income (24.0%; 95% CI, 15.3%-33.8%; 11 studies; n = 4961) and upper-middle-income (19.1%; 95% CI, 16.0%-22.4%; 110 studies; n = 138 496) countries. Conclusions and Relevance: These findings suggest that 1 in 5 women living in LMICs experience anxiety disorders during pregnancy and post partum. Targeted action is needed to reduce this high burden.

The long-term risk of cardiovascular disease among women with a history of hypertensive disorders of pregnancy: a systematic review of clinical practice guidelines.

BACKGROUND: The lifelong risks of cardiovascular disease following preeclampsia and gestational hypertension are well-established. However, it is unclear whether this evidence has been translated into clinical practice guidelines. Thus, this review aimed to assess the quality and content of Australian clinical practice guidelines regarding the risk of cardiovascular disease following gestational hypertension and preeclampsia. METHODS: We conducted a systematic search of MEDLINE (Ovid), EMBASE (Ovid), and CINAHL databases, as well as hospital, obstetric society, and medical college websites. Publications were included if: they were a clinical practice guideline; were published in the previous ten years; and included recommendations for the management of future cardiovascular disease risk following hypertensive disorders of pregnancy. Quality assessment was performed using Appraisal of Guidelines for Research and Evaluation Instrument Version Two (AGREE-II) and AGREE Recommendations Excellence Instrument (AGREE-REX). RESULTS: Eighteen guidelines were identified, and of these, less than half (n = 8) included recommendations for managing future cardiovascular risk following hypertensive disorders of pregnancy. Across these eight, four main counselling recommendations were found regarding (1) risk of future cardiovascular disease; (2) risk factor screening; (3) lifestyle interventions; and (4) prenatal counselling for future pregnancies. The quality and content of these recommendations varied significantly, and the majority of guidelines (87.5%) were assessed as low to moderate quality. CONCLUSIONS: There are limited Australian clinical practice guidelines providing appropriate advice regarding future risk of cardiovascular disease following hypertensive disorders of pregnancy. The quality and content of these guidelines varied significantly. These findings highlight the need for improved translation from evidence-based research to enhance clinical care and guidance.

Cell surface associated protein mucin 15 (MUC15) is elevated in preeclampsia.

BACKGROUND: Mucins are a family of proteins that protect the epithelium. A particular type of mucin, MUC15 is highly expressed in the placenta. This study aimed to characterise MUC15 in preeclampsia and investigate its role in placental stem cell biology. METHODS: MUC15 mRNA and protein were measured in placentas from patients with early onset (<34 weeks' gestation) preeclampsia. Circulating serum MUC15 was measured via ELISA. MUC15 was localised in the placenta using in situ hybridisation. MUC15 mRNA expression was measured across differentiation of human trophoblast stem cells (hTSCs) to syncytiotrophoblast and extravillous trophoblasts. MUC15 was measured after syncytialised hTSCs were cultured in hypoxic (1% O2) and proinflammatory (TNF α, IL-6) conditions. MUC15 secretion was assessed when syncytialised hTSCs were treated with brefeldin A (impairs protein trafficking) and batimastat (inhibits matrix metalloproteinases). RESULTS: MUC15 protein was significantly increased in the placenta (P = 0.0003, n = 32 vs n = 20 controls) and serum (P = 0.016, n = 32 vs n = 22 controls) of patients with preeclampsia, whilst MUC15 mRNA remained unchanged (n = 61 vs n = 18 controls). MUC15 mRNA (P = 0.005) and protein secretion (P = 0.006) increased following differentiation to syncytiotrophoblast cells. In situ hybridisation confirmed MUC15 localised to the syncytiotrophoblast cell within the placenta. Neither hypoxic or inflammatory conditions changed MUC15 mRNA expression or secretion. Brefeldin A treated hTSCs did not alter MUC15 secretion, whilst batimastat reduced MUC15 secretion (P = 0.044). CONCLUSIONS: MUC15 is increased in early onset preeclampsia and is cleaved by matrix metalloproteinases. Increased MUC15 may reflect a protective mechanism associated with placental dysfunction. Further research will aid in confirming this.

Can single-cell and spatial omics unravel the pathophysiology of pre-eclampsia?

Pre-eclampsia is a leading cause of maternal and fetal morbidity and mortality. Characterised by the onset of hypertension and proteinuria in the second half of pregnancy, it can lead to maternal end-organ injury such as cerebral ischemia and oedema, pulmonary oedema and renal failure, and potentially fatal outcomes for both mother and fetus. The causes of the different maternal end-organ phenotypes of pre-eclampsia and why some women develop pre-eclampsia condition early in pregnancy have yet to be elucidated. Omics methods include proteomics, genomics, metabolomics, transcriptomics. These omics techniques, previously mostly used on bulk tissue and individually, are increasingly available at a single cellular level and can be combined with each other. Multi-omics techniques on a single-cell or spatial level provide us with a powerful tool to understand the pathophysiology of pre-eclampsia. This review will explore the status of omics methods and how they can and could contribute to understanding the pathophysiology of pre-eclampsia.

Telehealth in antenatal care: recent insights and advances.

BACKGROUND: For decades, antenatal care in high-resource settings has involved 12-14 face-to-face visits across pregnancy. The COVID-19 pandemic forced many care providers to rapidly embrace telehealth to reduce face-to-face visits. Here we review recent advances in telehealth used to provide antenatal care. MAIN BODY: We conducted a narrative review examining the impact of telehealth on obstetric care. Two broad types of telehealth are used in antenatal care. The first is real-time telehealth, where consultations are done virtually instead of face-to-face. The second is remote monitoring, where in-clinic physical examinations are replaced with at-home alternatives. These can include blood pressure monitoring, fetal heart rate monitoring, and emerging technologies such as tele-ultrasound. Large cohort studies conducted during the pandemic era have shown that telehealth appears not to have increased adverse clinical outcomes for mothers or babies. However, further studies may be required to confidently conclude rare outcomes are unchanged, such as maternal mortality, serious morbidity, or stillbirth. Health economic studies suggest telehealth has the potential to reduce the financial cost of care provision. Telehealth in antenatal care seems to be acceptable to both pregnant women and healthcare providers. CONCLUSION: Adoption of telehealth technologies may improve the antenatal care experience for women and reduce healthcare expenditure without adversely impacting health outcomes for the mother or baby. More studies are warranted to confirm telehealth does not alter the risk of rare outcomes such as maternal or neonatal mortality.

Plasma lipids are dysregulated preceding diagnosis of preeclampsia or delivery of a growth restricted infant.

BACKGROUND: Lipids serve as multifunctional metabolites that have important implications for the pregnant mother and developing fetus. Abnormalities in lipids have emerged as potential risk factors for pregnancy diseases, such as preeclampsia and fetal growth restriction. The aim of this study was to assess the potential of lipid metabolites for detection of late-onset preeclampsia and fetal growth restriction. METHODS: We used a case-cohort of 144 maternal plasma samples at 36 weeks' gestation from patients before the diagnosis of late-onset preeclampsia (n = 22), delivery of a fetal growth restricted infant (n = 55, defined as <5th birthweight centile), gestation-matched controls (n = 72). We performed liquid chromatography-tandem mass spectrometry (LC-QQQ) -based targeted lipidomics to identify 421 lipids, and fitted logistic regression models for each lipid, correcting for maternal age, BMI, smoking, and gestational diabetes. FINDINGS: Phosphatidylinositol 32:1 (AUC = 0.81) and cholesterol ester 17:1 (AUC = 0.71) best predicted the risk of developing preeclampsia or delivering a fetal growth restricted infant, respectively. Five times repeated five-fold cross validation demonstrated the lipids alone did not out-perform existing protein biomarkers, soluble tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) for the prediction of preeclampsia or fetal growth restriction. However, lipids combined with sFlt-1 and PlGF measurements improved disease prediction. INTERPRETATION: This study successfully identified 421 lipids in maternal plasma collected at 36 weeks' gestation from participants who later developed preeclampsia or delivered a fetal growth restricted infant. Our results suggest the predictive capacity of lipid measurements for gestational disorders holds the potential to improve non-invasive assessment of maternal and fetal health. FUNDING: This study was funded by a grant from National Health and Medical Research Council.

Paternal Expressed Gene 10 (PEG10) is decreased in early-onset preeclampsia.

BACKGROUND: Preeclampsia is a severe complication of pregnancy which is attributed to placental dysfunction. The retrotransposon, Paternal Expressed Gene 10 (PEG10) harbours critical placental functions pertaining to placental trophoblast cells. Limited evidence exists on whether PEG10 is involved in preeclampsia pathogenesis. This study characterised the expression and regulation of PEG10 in placentas from patients with early-onset preeclampsia compared to gestation-matched controls. METHODS: PEG10 expression was measured in plasma and placentas collected from patients with early-onset preeclampsia (< 34 weeks') and gestation-matched controls using ELISA (protein) and RT-qPCR (mRNA). First-trimester human trophoblast stem cells (hTSCs) were used for in vitro studies. PEG10 expression was measured during hTSC differentiation and hTSC exposure to hypoxia (1% O2) and inflammatory cytokines (IL-6 and TNFα) using RT-qPCR. Functional studies used PEG10 siRNA to measure the effect of reduced PEG10 on canonical TGF-[Formula: see text] signalling and proliferation using luciferase and xCELLigence assays, respectively. RESULTS: PEG10 mRNA expression was significantly reduced in placentas from patients with early-onset preeclampsia (< 34 weeks' gestation) relative to controls (p = 0.04, n = 78 vs n = 18 controls). PEG10 protein expression was also reduced in preeclamptic placentas (p = 0.03, n = 5 vs n = 5 controls, blinded assessment of immunohistochemical staining), but neither PEG10 mRNA nor protein could be detected in maternal circulation. PEG10 was most highly expressed in hTSCs, and its expression was reduced as hTSCs differentiated into syncytiotrophoblasts (p < 0.0001) and extravillous trophoblasts (p < 0.001). Trophoblast differentiation was not altered when hTSCs were treated with PEG10 siRNA (n = 5 vs n = 5 controls). PEG10 was significantly reduced in hTSCs exposed to hypoxia (p < 0.01). PEG10 was also reduced in hTSCs treated with the inflammatory cytokine TNF [Formula: see text] (p < 0.01), but not IL-6. PEG10 knocked down (siRNA) in hTSCs showed reduced activation of the canonical TGF-ß signalling effector, the SMAD binding element (p < 0.05) relative to controls. PEG10 knockdown in hTSCs however was not associated with any significant alterations in proliferation. CONCLUSIONS: Placental PEG10 is reduced in patients with early-onset preeclampsia. In vitro studies suggest that hypoxia and inflammation may contribute to PEG10 downregulation. Reduced PEG10 alters canonical TGF-[Formula: see text] signalling, and thus may be involved in trophoblast dysfunction associated with this pathway.

Comparison of Maternal Labor-Related Complications and Neonatal Outcomes Following Elective Induction of Labor at 39 Weeks of Gestation vs Expectant Management: A Systematic Review and Meta-analysis.

Importance: Elective induction of labor at 39 weeks of gestation is common. Thus, there is a need to assess maternal labor-related complications and neonatal outcomes associated with elective induction of labor. Objective: To examine maternal labor-related complications and neonatal outcomes following elective induction of labor at 39 weeks compared with expectant management. Data Sources: A systematic review of the literature was conducted using the MEDLINE (Ovid), Embase (Ovid), Cochrane Central Library, World Health Organization, and ClinicalTrials.gov databases and registries to search for articles published between database inception and December 8, 2022. Study Selection: This systematic review and meta-analysis included randomized clinical trials, cohort studies, and cross-sectional studies reporting perinatal outcomes following induction of labor at 39 weeks vs expectant management. Data Extraction and Synthesis: Two reviewers independently assessed study eligibility, extracted data, and assessed studies for bias. Pooled odds ratios (ORs) and 95% CIs were calculated using a random-effects model. This study is reported per the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guideline, and the protocol was prospectively registered with PROSPERO. Main Outcomes and Measures: Maternal outcomes of interest included emergency cesarean section, perineal injury, postpartum hemorrhage, and operative vaginal birth. Neonatal outcomes of interest included admission to the neonatal intensive care unit, low 5-minute Apgar score (<7) after birth, macrosomia, and shoulder dystocia. Results: Of the 5827 records identified in the search, 14 studies were eligible for inclusion in this review. These studies reported outcomes for 1 625 899 women birthing a singleton pregnancy. Induction of labor at 39 weeks of gestation was associated with a 37% reduced likelihood of third- or fourth-degree perineal injury (OR, 0.63 [95% CI, 0.49-0.81]), in addition to reductions in operative vaginal birth (OR, 0.87 [95% CI, 0.79-0.97]), macrosomia (OR, 0.66 [95% CI, 0.48-0.91]), and low 5-minute Apgar score (OR, 0.62 [95% CI, 0.40-0.96]). Results were similar when confined to multiparous women only, with the addition of a substantial reduction in the likelihood of emergency cesarean section (OR, 0.61 [95% CI, 0.38-0.98]) and no difference in operative vaginal birth (OR, 1.01 [95% CI, 0.84-1.21]). However, among nulliparous women only, induction of labor was associated with an increased likelihood of shoulder dystocia (OR, 1.22 [95% CI, 1.02-1.46]) compared with expectant management. Conclusions and Relevance: In this study, induction of labor at 39 weeks was associated with improved maternal labor-related and neonatal outcomes. However, among nulliparous women, induction of labor was associated with shoulder dystocia. These results suggest that elective induction of labor at 39 weeks may be safe and beneficial for some women; however, potential risks should be discussed with nulliparous women.

Subsequent pregnancy outcomes among women with tubal ectopic pregnancy treated with methotrexate.

Lay summary: An ectopic pregnancy occurs when an embryo implants outside of the uterus, usually in a fallopian tube. When detected early, treatment is often with a medication called methotrexate. When methotrexate does not work, surgery is required. A recent clinical trial of ectopic pregnancy treatment (called GEM3) found that adding a drug called gefitinib to methotrexate did not reduce the need for surgery. We have used data from the GEM3 trial, combined with data collected 12 months after the trial finished, to investigate post-methotrexate pregnancy outcomes. We found no difference in pregnancy rates, pregnancy loss rates and recurrent ectopic pregnancy rates between those treated medically only and those who subsequently also needed surgery. The surgical technique used also did not affect pregnancy rates. This research provides reassurance that women with ectopic pregnancies treated medically who need surgery have similar post-treatment pregnancy outcomes to those treated successfully medically.

Early (Days 1-4) post-treatment serum hCG level changes predict single-dose methotrexate treatment success in tubal ectopic pregnancy.

STUDY QUESTION: What is the capacity of the change between Day 1 and Day 4 post-treatment serum human chorionic gonadotropin (hCG) levels for predicting single-dose methotrexate treatment success in tubal ectopic pregnancy? SUMMARY ANSWER: Any fall in Days 1-4 serum hCG signified an 85% (95% CI 76.8-90.6) likelihood of treatment success for women with tubal ectopic pregnancy (initial hCG of ≥1000 and ≤5000 IU/l) managed with single-dose methotrexate. WHAT IS KNOWN ALREADY: For those with tubal ectopic pregnancy managed by single-dose methotrexate, current guidelines advocate intervention if Days 4-7 hCG fails to fall by >15%. The trajectory of hCG over Days 1-4 has been proposed as an early indicator that predicts treatment success, allowing early reassurance for women. However, almost all prior studies of Days 1-4 hCG changes have been retrospective. STUDY DESIGN, SIZE, DURATION: This was a prospective cohort study of women with tubal ectopic pregnancy (pre-treatment hCG of ≥1000 and ≤5000 IU/l) managed with single-dose methotrexate. The data were derived from a UK multicentre randomized controlled trial of methotrexate and gefitinib versus methotrexate and placebo for treatment of tubal ectopic pregnancy (GEM3). For this analysis, we include data from both treatment arms. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were categorized according to single-dose methotrexate treatment success or failure. Treatment success for this analysis was defined as complete and uneventful resolution of tubal ectopic pregnancy to serum hCG <30 IU/l following single-dose methotrexate treatment without additional treatment. Patient characteristics of the treatment success and failure groups were compared. Changes in Days 1-4, 1-7, and 4-7 serum hCG were evaluated as predictors of treatment success through receiver operating characteristic curve analysis. Test performance characteristics were calculated for percentage change ranges and thresholds including optimal classification thresholds. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 322 women with tubal ectopic pregnancy were treated with single-dose methotrexate. The overall single-dose methotrexate treatment success rate was 59% (n = 189/322). For any fall in serum hCG on Days 1-4, likelihood ratios were >3, while for any fall of serum hCG >20% on Days 1-7, likelihood ratios reached 5. Any rise of serum hCG on Days 1-7 and 4-7 strongly reduced the chance of success. Any fall in Days 1-4 hCG predicted single-dose methotrexate treatment success with a sensitivity of 58% and specificity 84%, resulting in positive and negative predictive values of 85% and 57%, respectively. Any rise in Days 1-4 serum hCG <18% was identified as an optimal test threshold that predicted treatment success with 79% sensitivity and 74% specificity, resulting in 82% positive predictive value and 69% negative predictive value. LIMITATIONS, REASONS FOR CAUTION: Our findings may be limited by intervention bias resulting from existing guidelines which influences evaluation of hCG changes reliant on Day 7 serum hCG levels. WIDER IMPLICATIONS OF THE FINDINGS: Examining a large prospective cohort, we show the value of Days 1-4 serum hCG changes in predicting single-dose methotrexate treatment success in tubal ectopic pregnancy. We recommend that clinicians provide early reassurance to women who have a fall or only a modest (<18%) rise in Days 1-4 serum hCG levels, that their treatment will likely be effective. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by funding from the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership (grant reference number 14/150/03). A.W.H. has received honoraria for consultancy for Ferring, Roche, Nordic Pharma and AbbVie. W.C.D. has received honoraria from Merck and Guerbet and research funding from Galvani Biosciences. L.H.R.W. has received research funding from Roche Diagnostics. B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.M. also reports consultancy for ObsEva and Merck and travel support from Merck. The other authors declare no competing interests. TRIAL REGISTRATION NUMBER: This study is a secondary analysis of the GEM3 trial (ISRCTN Registry ISRCTN67795930).

Assessment of the tocolytic nifedipine in preclinical primary models of preterm birth.

Spontaneous preterm birth is the leading cause of perinatal morbidity and mortality. Tocolytics are drugs used in cases of imminent preterm birth to inhibit uterine contractions. Nifedipine is a calcium channel blocking agent used to delay threatened spontaneous preterm birth, however, has limited efficacy and lacks preclinical data regarding mechanisms of action. It is unknown if nifedipine affects the pro-inflammatory environment associated with preterm labour pathophysiology and we hypothesise nifedipine only targets myometrial contraction rather than also mitigating inflammation. We assessed anti-inflammatory and anti-contractile effects of nifedipine on human myometrium using in vitro and ex vivo techniques, and a mouse model of preterm birth. We show that nifedipine treatment inhibited contractions in myometrial in vitro contraction assays (P = 0.004 vs. vehicle control) and potently blocked spontaneous and oxytocin-induced contractions in ex vivo myometrial tissue in muscle myography studies (P = 0.01 vs. baseline). Nifedipine treatment did not reduce gene expression or protein secretion of pro-inflammatory cytokines in either cultured myometrial cells or ex vivo tissues. Although nifedipine could delay preterm birth in some mice, this was not consistent in all dams and was overall not statistically significant. Our data suggests nifedipine does not modulate preterm birth via inflammatory pathways in the myometrium, and this may account for its limited clinical efficacy.