Externally validated prediction models for pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the performance of existing externally validated prediction models for pre-eclampsia (PE) (specifically, any-onset, early-onset, late-onset and preterm PE).

METHODS

A systematic search was conducted in five databases (MEDLINE, EMBASE, Emcare, CINAHL and Maternity & Infant Care Database) and using Google Scholar/reference search to identify studies based on the Population, Index prediction model, Comparator, Outcome, Timing and Setting (PICOTS) approach until 20 May 2023. We extracted data using the CHARMS checklist and appraised the risk of bias using the PROBAST tool. A meta-analysis of discrimination and calibration performance was conducted when appropriate.

RESULTS

Twenty-three studies reported 52 externally validated prediction models for PE (one preterm, 20 any-onset, 17 early-onset and 14 late-onset PE models). No model had the same set of predictors. Fifteen any-onset PE models were validated externally once, two were validated twice and three were validated three times, while the Fetal Medicine Foundation (FMF) competing-risks model for preterm PE prediction was validated widely in 16 different settings. The most common predictors were maternal characteristics (prepregnancy body mass index, prior PE, family history of PE, chronic medical conditions and ethnicity) and biomarkers (uterine artery pulsatility index and pregnancy-associated plasma protein-A). The FMF model for preterm PE (triple test plus maternal factors) had the best performance, with a pooled area under the receiver-operating-characteristics curve (AUC) of 0.90 (95% prediction interval (PI), 0.76-0.96), and was well calibrated. The other models generally had poor-to-good discrimination performance (median AUC, 0.66 (range, 0.53-0.77)) and were overfitted on external validation. Apart from the FMF model, only two models that were validated multiple times for any-onset PE prediction, which were based on maternal characteristics only, produced reasonable pooled AUCs of 0.71 (95% PI, 0.66-0.76) and 0.73 (95% PI, 0.55-0.86).

CONCLUSIONS

Existing externally validated prediction models for any-, early- and late-onset PE have limited discrimination and calibration performance, and include inconsistent input variables. The triple-test FMF model had outstanding discrimination performance in predicting preterm PE in numerous settings, but the inclusion of specialized biomarkers may limit feasibility and implementation outside of high-resource settings. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

Associations Between Late-Onset Preeclampsia and the Use of Calcium-Based Antacids and Proton Pump Inhibitors During Pregnancy: A Prospective Cohort Study

Purpose

Preeclampsia is a leading cause of maternal morbidity and mortality. Calcium-based antacids and proton pump inhibitors (PPIs) are commonly used during pregnancy to treat symptoms of gastroesophageal reflux disease. Both have been hypothesized to reduce the risk of preeclampsia. We determined associations of calcium-based antacid and PPI use during pregnancy with late-onset preeclampsia (≥34 weeks of gestation), taking into account dosage and timing of use.

Patients and Methods

We included 9058 pregnant women participating in the PRIDE Study (2012–2019) or The Dutch Pregnancy Drug Register (2014–2019), two prospective cohorts in The Netherlands. Data were collected through web-based questionnaires and obstetric records. We estimated risk ratios (RRs) for late-onset preeclampsia for any use and trajectories of calcium-based antacid and PPI use before gestational day 238, and hazard ratios (HRs) for time-varying exposures after gestational day 237.

Results

Late-onset preeclampsia was diagnosed in 2.6% of pregnancies. Any use of calcium-based antacids (RR 1.2 [95% CI 0.9–1.6]) or PPIs (RR 1.4 [95% CI 0.8–2.4]) before gestational day 238 was not associated with late-onset preeclampsia. Use of low-dose calcium-based antacids in gestational weeks 0–16 (<1 g/day; RR 1.8 [95% CI 1.1–2.9]) and any use of PPIs in gestational weeks 17–33 (RR 1.6 [95% CI 1.0–2.8]) seemed to increase risks of late-onset preeclampsia. We did not observe associations between late-onset preeclampsia and use of calcium-based antacids (HR 1.0 [95% CI 0.6–1.5]) and PPIs (HR 1.4 [95% CI 0.7–2.9]) after gestational day 237.

Conclusion

In this prospective cohort study, use of calcium-based antacids and PPIs during pregnancy was not found to reduce the risk of late-onset preeclampsia.

Placental Growth Factor in First Trimester of Pregnancy for Prediction of Maternal and Perinatal Adverse Outcomes

Purpose of the study

Placental growth factor (PLGF) is an angiogenic factor in pregnancy. To find out correlation of plasma levels of placental growth factor in first trimester of pregnancy in Indian women who develop maternal and perinatal adverse outcomes was the aim of the study.

Methods

A prospective longitudinal noninterventional study was done in the department of Obstetrics and Gynecology after obtaining ethics approval. After enrolling patients in the first trimester (11 weeks to 13 weeks 6 days), a questionnaire was filled for demographic characteristics. Uterine artery doppler was done for every patient and blood sample (5 ml) was taken by venu puncture of median cubital vein. Serum levels of PLGF were measured by enzyme linked immunosorbent assay using Thermo Scientific Pierce Human PLGF kit (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Patients were followed for their whole antenatal period and delivery outcomes.

Results

Incidence of preeclampsia in our study was 9.3% (15/161) and fetal growth restriction (FGR) was 19.8% (32/161). Neither BMI nor nulliparity was found to have statistically significant correlation with development of preeclampsia. However, history of preeclampsia was found to be significant risk factor for prediction of preeclampsia (p value < 0.04). Plasma levels of PLGF were significantly lower in preeclampsia and FGR group and this difference was statistically significant (p value < 0.04). 7.5% still born occurred in complicated group and 10% needed NNU/NICU admission in this group.

Conclusion

Measuring PLGF levels in first trimester of pregnancy can help in prediction of preeclampsia and FGR.

Maternal metabolic factors and the association with gestational diabetes: A systematic review and meta-analysis

Gestational diabetes (GDM) is associated with several adverse outcomes for the mother and child. Higher levels of individual lipids are associated with risk of GDM and metabolic syndrome (MetS), a clustering of risk factors also increases risk for GDM. Metabolic factors can be modified by diet and lifestyle. This review comprehensively evaluates the association between MetS and its components, measured in early pregnancy, and risk for GDM. Databases (Cumulative Index to Nursing and Allied Health Literature, PubMed, Embase, and Cochrane Library) were searched from inception to 5 May 2021. Eligible studies included ≥1 metabolic factor (waist circumference, blood pressure, fasting plasma glucose (FPG), triglycerides, and high-density lipoprotein cholesterol), measured at <16 weeks' gestation. At least two authors independently screened potentially eligible studies. Heterogeneity was quantified using I² . Data were pooled by random-effects models and expressed as odds ratio and 95% confidence intervals (CIs). Of 7213 articles identified, 40 unique articles were included in meta-analysis. In analyses adjusting for maternal age and body mass index, GDM was increased with increasing FPG (odds ratios [OR] 1.92; 95% CI 1.39-2.64, k = 7 studies) or having MetS (OR 2.52; 1.65, 3.84, k = 3). Women with overweight (OR 2.17; 95% CI 1.89, 2.50, k = 12) or obesity (OR 4.34; 95% CI 2.79-6.74, k = 9) also were at increased risk for GDM. Early pregnancy assessment of glucose or the MetS, offers a potential opportunity to detect and treat individual risk factors as an approach towards GDM prevention; weight loss for pregnant women with overweight or obesity is not recommended. Systematic review registration: PROSPERO CRD42020199225.

First trimester preeclampsia screening and prediction

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. Early-onset disease requiring preterm delivery is associated with a higher risk of complications in both mothers and babies. Evidence suggests that the administration of low-dose aspirin initiated before 16 weeks' gestation significantly reduces the rate of preterm preeclampsia. Therefore, it is important to identify pregnant women at risk of developing preeclampsia during the first trimester of pregnancy, thus allowing timely therapeutic intervention. Several professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) and National Institute for Health and Care Excellence (NICE) have proposed screening for preeclampsia based on maternal risk factors. The approach recommended by ACOG and NICE essentially treats each risk factor as a separate screening test with additive detection rate and screen-positive rate. Evidence has shown that preeclampsia screening based on the NICE and ACOG approach has suboptimal performance, as the NICE recommendation only achieves detection rates of 41% and 34%, with a 10% false-positive rate, for preterm and term preeclampsia, respectively. Screening based on the 2013 ACOG recommendation can only achieve detection rates of 5% and 2% for preterm and term preeclampsia, respectively, with a 0.2% false-positive rate. Various first trimester prediction models have been developed. Most of them have not undergone or failed external validation. However, it is worthy of note that the Fetal Medicine Foundation (FMF) first trimester prediction model (namely the triple test), which consists of a combination of maternal factors and measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has undergone successful internal and external validation. The FMF triple test has detection rates of 90% and 75% for the prediction of early and preterm preeclampsia, respectively, with a 10% false-positive rate. Such performance of screening is superior to that of the traditional method by maternal risk factors alone. The use of the FMF prediction model, followed by the administration of low-dose aspirin, has been shown to reduce the rate of preterm preeclampsia by 62%. The number needed to screen to prevent 1 case of preterm preeclampsia by the FMF triple test is 250. The key to maintaining optimal screening performance is to establish standardized protocols for biomarker measurements and regular biomarker quality assessment, as inaccurate measurement can affect screening performance. Tools frequently used to assess quality control include the cumulative sum and target plot. Cumulative sum is a sensitive method to detect small shifts over time, and point of shift can be easily identified. Target plot is a tool to evaluate deviation from the expected multiple of median and the expected median of standard deviation. Target plot is easy to interpret and visualize. However, it is insensitive to detecting small deviations. Adherence to well-defined protocols for the measurements of mean arterial pressure, uterine artery pulsatility index, and placental growth factor is required. This article summarizes the existing literature on the different methods, recommendations by professional organizations, quality assessment of different components of risk assessment, and clinical implementation of the first trimester screening for preeclampsia.

Impact of maternal pre-pregnancy body mass index on maternal, fetal and neonatal adverse outcomes in the worldwide populations: A systematic review and meta-analysis

OBJECTIVE

Systematic review and meta-analysis conducted to investigate the effect of stratified pre-pregnancy maternal body mass index on twenty maternal and fetal/neonatal adverse outcomes.

METHODS

PubMed, Google Scholar, Medline, Embase, Web of Science databases were searched from inception till July 11, 2020. Cohort studies were included. The pooled odds ratio with 95% confidence interval was reported considering the random effect and the quality effect model. The sub-group analysis and meta-regression were conducted for BMI cut-offs, geographical region, source of BMI, and sample size.

RESULTS

Overall, 86 studies representing 20,328,777 pregnant women were included in this meta-analysis. Our study reveals that overweight and obese mothers are at increased odds of cesarean delivery, elective cesarean delivery, emergency cesarean delivery, gestational diabetes, gestational hypertension, induction of labor, postpartum hemorrhage, pre-eclampsia, pre-term premature rupture of membrane, and the fetuses/neonates of overweight and obese mothers are at increased risk of admission in the newborn intensive care unit, APGAR scores less than 7 at 5 min, large for gestational age, macrosomia, extreme pre-term birth in pregnant mothers compared with standard BMI mothers. However, the underweight mothers showed increased odds for small for gestational age infant and pre-term birth, whereas obese mothers were at higher risk for post-term birth and stillbirths. The subgroup and meta-regression analyses have shown the impact of BMI cut-offs, geographical region, source of BMI, and sample size on several maternal, fetal/neonatal adverse outcomes.

CONCLUSION

The meta-analysis confirmed the association of elevated pre-pregnancy maternal BMI with higher odds of adverse maternal and fetal/neonatal outcomes.

A prospective population-based multicentre study on the impact of maternal body mass index on adverse pregnancy outcomes: Focus on normal weight

Background

Maternal body mass index (BMI) below or above the reference interval (18.5–24.9 kg/m²) is associated with adverse pregnancy outcomes. Whether BMI exerts an effect within the reference interval is unclear. Therefore, we assessed the association between adverse pregnancy outcomes and BMI, in particular within the reference interval, in a general unselected pregnant population.

Methods

Data was extracted from a prospective population-based multicentre cohort (Risk Estimation for PrEgnancy Complications to provide Tailored care (RESPECT) study) conducted between December 2012 to January 2014. BMI was studied in categories (I: <18.5, II: 18.5–19.9, III: 20.0–22.9, IV: 23.0–24.9, V: 25.0–27.4, VI: 27.5–29.9, VII: >30.0 kg/m²) and as a continuous variable within the reference interval. Adverse pregnancy outcomes were defined as composite endpoints for maternal, neonatal or any pregnancy complication, and for adverse pregnancy outcomes individually. Linear trends were assessed using linear-by-linear association analysis and (adjusted) relative risks by regression analysis.

Results

The median BMI of the 3671 included women was 23.2 kg/m² (IQR 21.1–26.2). Adverse pregnancy outcomes were reported in 1256 (34.2%). Linear associations were observed between BMI categories and all three composite endpoints, and individually for pregnancy-induced hypertension (PIH), preeclampsia, gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates; but not for small-for-gestational-age neonates and preterm birth. Within the reference interval, BMI was associated with the composite maternal endpoint, PIH, GDM and LGA, with adjusted relative risks of 1.15 (95%CI 1.06–1.26), 1.12 (95%CI 1.00–1.26), 1.31 (95%CI 1.11–1.55) and 1.09 (95%CI 1.01–1.17).

Conclusions

Graded increase in maternal BMI appears to be an indicator of risk for adverse pregnancy outcomes even among women with a BMI within the reference interval. The extent to which BMI directly contributes to the increased risk in this group should be evaluated in order to determine strategies most valuable for promoting safety and long-term health for mothers and their offspring.

External validation and clinical utility of prognostic prediction models for gestational diabetes mellitus: A prospective cohort study

Introduction

We performed an independent validation study of all published first trimester prediction models, containing non‐invasive predictors, for the risk of gestational diabetes mellitus. Furthermore, the clinical potential of the best performing models was evaluated.

Material and methods

Systemically selected prediction models from the literature were validated in a Dutch prospective cohort using data from Expect Study I and PRIDE Study. The predictive performance of the models was evaluated by discrimination and calibration. Clinical utility was assessed using decision curve analysis. Screening performance measures were calculated at different risk thresholds for the best model and compared with current selective screening strategies.

Results

The validation cohort included 5260 women. Gestational diabetes mellitus was diagnosed in 127 women (2.4%). The discriminative performance of the 12 included models ranged from 68% to 75%. Nearly all models overestimated the risk. After recalibration, agreement between the observed outcomes and predicted probabilities improved for most models.

Conclusions

The best performing prediction models showed acceptable performance measures and may enable more personalized medicine‐based antenatal care for women at risk of developing gestational diabetes mellitus compared with current applied strategies.

Low-dose-aspirin usage among women with an increased preeclampsia risk: A prospective cohort study

INTRODUCTION

Low-dose aspirin (LDA) prophylaxis has been shown to reduce women's preeclampsia risk. Evidence regarding LDA adherence rates of pregnant women is based almost exclusively on clinical trials, giving a potentially biased picture. Moreover, these studies do not report on determinants of adherence. Since 2017, obstetric healthcare professionals in a Dutch region have assessed women's preeclampsia risk by means of a prediction tool and counseled those with an above-population average risk on LDA as a prophylactic measure.

MATERIAL AND METHODS

From 2017 to 2018, 865 women were recruited in multiple centers and prospectively followed using web-based surveys (Expect Study II). Rates and determinants of LDA usage among women with an increased preeclampsia risk in daily practice were assessed. Results were compared with findings in a similar cohort from a care-as-usual setting lacking risk-based counseling (Expect Study I, n = 2614). Netherlands Trial Register NTR4143.

RESULTS

In total, 306 women had a predicted increased preeclampsia risk. LDA usage was higher for women receiving risk-based care than care-as-usual (29.4% vs 1.5%, odds ratio 19.1, 95% confidence interval 11.2-32.5). Daily LDA usage was positively correlated with both predicted risk and women's concerns regarding preeclampsia. Most reported reasons for non- or incomplete use were unawareness of LDA as a preventive intervention, concerns about potential adverse effects and doubts regarding the benefits.

CONCLUSIONS

Risk-based counseling was associated with a higher prevalence of LDA usage, but general usage rates were low. Future research regarding potential factors improving the usage of LDA during pregnancy is necessary.

Implementing a Preeclampsia Prediction Model in Obstetrics: Cutoff Determination and Health Care Professionals' Adherence

Background. Despite improved management, preeclampsia remains an important cause of maternal and neonatal mortality and morbidity. Low-dose aspirin (LDA) lowers the risk of preeclampsia. Although several guidelines recommend LDA prophylaxis in women at increased risk, they disagree about the definition of high risk. Recently, an externally validated prediction model for preeclampsia was implemented in a Dutch region combined with risk-based obstetric care paths. Objectives. To demonstrate the selection of a risk threshold and to evaluate the adherence of obstetric health care professionals to the prediction tool. Study Design. Using a survey (n = 136) and structured meetings among health care professionals, possible cutoff values at which LDA should be discussed were proposed. The prediction model, with chosen cutoff and corresponding risk-based care paths, was embedded in an online tool. Subsequently, a prospective multicenter cohort study (n = 850) was performed to analyze the adherence of health care professionals. Patient questionnaires, linked to the individual risk profiles calculated by the online tool, were used to evaluate adherence. Results. Health care professionals agreed upon employing a tool with a high detection rate (cutoff: 3.0%; sensitivity 75%, specificity 64%) followed by shared decision between patients and health care professionals on LDA prophylaxis. Of the 850 enrolled women, 364 women had an increased risk of preeclampsia. LDA was discussed with 273 of these women, resulting in an 81% adherence rate. Conclusion. Consensus regarding a suitable risk cutoff threshold was reached. The adherence to this recommendation was 81%, indicating adequate implementation.

The International Federation of Gynecology and Obstetrics (FIGO) initiative on pre-eclampsia: A pragmatic guide for first-trimester screening and prevention

Pre‐eclampsia (PE) is a multisystem disorder that typically affects 2%–5% of pregnant women and is one of the leading causes of maternal and perinatal morbidity and mortality, especially when the condition is of early onset. Globally, 76 000 women and 500 000 babies die each year from this disorder. Furthermore, women in low‐resource countries are at a higher risk of developing PE compared with those in high‐resource countries. Although a complete understanding of the pathogenesis of PE remains unclear, the current theory suggests a two‐stage process. The first stage is caused by shallow invasion of the trophoblast, resulting in inadequate remodeling of the spiral arteries. This is presumed to lead to the second stage, which involves the maternal response to endothelial dysfunction and imbalance between angiogenic and antiangiogenic factors, resulting in the clinical features of the disorder. Accurate prediction and uniform prevention continue to elude us. The quest to effectively predict PE in the first trimester of pregnancy is fueled by the desire to identify women who are at high risk of developing PE, so that necessary measures can be initiated early enough to improve placentation and thus prevent or at least reduce the frequency of its occurrence. Furthermore, identification of an “at risk” group will allow tailored prenatal surveillance to anticipate and recognize the onset of the clinical syndrome and manage it promptly. PE has been previously defined as the onset of hypertension accompanied by significant proteinuria after 20 weeks of gestation. Recently, the definition of PE has been broadened. Now the internationally agreed definition of PE is the one proposed by the International Society for the Study of Hypertension in Pregnancy (ISSHP). According to the ISSHP, PE is defined as systolic blood pressure at ≥140 mm Hg and/or diastolic blood pressure at ≥90 mm Hg on at least two occasions measured 4 hours apart in previously normotensive women and is accompanied by one or more of the following new‐onset conditions at or after 20 weeks of gestation: 1.Proteinuria (i.e. ≥30 mg/mol protein:creatinine ratio; ≥300 mg/24 hour; or ≥2 + dipstick); 2.Evidence of other maternal organ dysfunction, including: acute kidney injury (creatinine ≥90 μmol/L; 1 mg/dL); liver involvement (elevated transaminases, e.g. alanine aminotransferase or aspartate aminotransferase >40 IU/L) with or without right upper quadrant or epigastric abdominal pain; neurological complications (e.g. eclampsia, altered mental status, blindness, stroke, clonus, severe headaches, and persistent visual scotomata); or hematological complications (thrombocytopenia–platelet count <150 000/μL, disseminated intravascular coagulation, hemolysis); or 3.Uteroplacental dysfunction (such as fetal growth restriction, abnormal umbilical artery Doppler waveform analysis, or stillbirth). It is well established that a number of maternal risk factors are associated with the development of PE: advanced maternal age; nulliparity; previous history of PE; short and long interpregnancy interval; use of assisted reproductive technologies; family history of PE; obesity; Afro‐Caribbean and South Asian racial origin; co‐morbid medical conditions including hyperglycemia in pregnancy; pre‐existing chronic hypertension; renal disease; and autoimmune diseases, such as systemic lupus erythematosus and antiphospholipid syndrome. These risk factors have been described by various professional organizations for the identification of women at risk of PE; however, this approach to screening is inadequate for effective prediction of PE. PE can be subclassified into: 1.Early‐onset PE (with delivery at <34+0 weeks of gestation); 2.Preterm PE (with delivery at <37+0 weeks of gestation); 3.Late‐onset PE (with delivery at ≥34+0 weeks of gestation); 4.Term PE (with delivery at ≥37+0 weeks of gestation). These subclassifications are not mutually exclusive. Early‐onset PE is associated with a much higher risk of short‐ and long‐term maternal and perinatal morbidity and mortality. Obstetricians managing women with preterm PE are faced with the challenge of balancing the need to achieve fetal maturation in utero with the risks to the mother and fetus of continuing the pregnancy longer. These risks include progression to eclampsia, development of placental abruption and HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome. On the other hand, preterm delivery is associated with higher infant mortality rates and increased morbidity resulting from small for gestational age (SGA), thrombocytopenia, bronchopulmonary dysplasia, cerebral palsy, and an increased risk of various chronic diseases in adult life, particularly type 2 diabetes, cardiovascular disease, and obesity. Women who have experienced PE may also face additional health problems in later life, as the condition is associated with an increased risk of death from future cardiovascular disease, hypertension, stroke, renal impairment, metabolic syndrome, and diabetes. The life expectancy of women who developed preterm PE is reduced on average by 10 years. There is also significant impact on the infants in the long term, such as increased risks of insulin resistance, diabetes mellitus, coronary artery disease, and hypertension in infants born to pre‐eclamptic women. The International Federation of Gynecology and Obstetrics (FIGO) brought together international experts to discuss and evaluate current knowledge on PE and develop a document to frame the issues and suggest key actions to address the health burden posed by PE. FIGO's objectives, as outlined in this document, are: (1) To raise awareness of the links between PE and poor maternal and perinatal outcomes, as well as to the future health risks to mother and offspring, and demand a clearly defined global health agenda to tackle this issue; and (2) To create a consensus document that provides guidance for the first‐trimester screening and prevention of preterm PE, and to disseminate and encourage its use. Based on high‐quality evidence, the document outlines current global standards for the first‐trimester screening and prevention of preterm PE, which is in line with FIGO good clinical practice advice on first trimester screening and prevention of pre‐eclampsia in singleton pregnancy.1 It provides both the best and the most pragmatic recommendations according to the level of acceptability, feasibility, and ease of implementation that have the potential to produce the most significant impact in different resource settings. Suggestions are provided for a variety of different regional and resource settings based on their financial, human, and infrastructure resources, as well as for research priorities to bridge the current knowledge and evidence gap. To deal with the issue of PE, FIGO recommends the following: Public health focus: There should be greater international attention given to PE and to the links between maternal health and noncommunicable diseases (NCDs) on the Sustainable Developmental Goals agenda. Public health measures to increase awareness, access, affordability, and acceptance of preconception counselling, and prenatal and postnatal services for women of reproductive age should be prioritized. Greater efforts are required to raise awareness of the benefits of early prenatal visits targeted at reproductive‐aged women, particularly in low‐resource countries. Universal screening: All pregnant women should be screened for preterm PE during early pregnancy by the first‐trimester combined test with maternal risk factors and biomarkers as a one‐step procedure. The risk calculator is available free of charge at https://fetalmedicine.org/research/assess/preeclampsia. FIGO encourages all countries and its member associations to adopt and promote strategies to ensure this. The best combined test is one that includes maternal risk factors, measurements of mean arterial pressure (MAP), serum placental growth factor (PLGF), and uterine artery pulsatility index (UTPI). Where it is not possible to measure PLGF and/or UTPI, the baseline screening test should be a combination of maternal risk factors with MAP, and not maternal risk factors alone. If maternal serum pregnancy‐associated plasma protein A (PAPP‐A) is measured for routine first‐trimester screening for fetal aneuploidies, the result can be included for PE risk assessment. Variations to the full combined test would lead to a reduction in the performance screening. A woman is considered high risk when the risk is 1 in 100 or more based on the first‐trimester combined test with maternal risk factors, MAP, PLGF, and UTPI. Contingent screening: Where resources are limited, routine screening for preterm PE by maternal factors and MAP in all pregnancies and reserving measurements of PLGF and UTPI for a subgroup of the population (selected on the basis of the risk derived from screening by maternal factors and MAP) can be considered. Prophylactic measures: Following first‐trimester screening for preterm PE, women identified at high risk should receive aspirin prophylaxis commencing at 11–14+6 weeks of gestation at a dose of ~150 mg to be taken every night until 36 weeks of gestation, when delivery occurs, or when PE is diagnosed. Low‐dose aspirin should not be prescribed to all pregnant women. In women with low calcium intake (<800 mg/d), either calcium replacement (≤1 g elemental calcium/d) or calcium supplementation (1.5–2 g elemental calcium/d) may reduce the burden of both early‐ and late‐onset PE.

External validation of prognostic models for preeclampsia in a Dutch multicenter prospective cohort

OBJECTIVE

To perform an external validation of all published prognostic models for first-trimester prediction of the risk of developing preeclampsia (PE).

METHODS

Women <14 weeks of pregnancy were recruited in the Netherlands. All systematically identified prognostic models for PE that contained predictors commonly available were eligible for external validation.

RESULTS

3,736 women were included; 87 (2.3%) developed PE. Calibration was poor due to overestimation. Discrimination of 9 models for LO-PE ranged from 0.58 to 0.71 and of 9 models for all PE from 0.55 to 0.75.

CONCLUSION

Only a few easily applicable prognostic models for all PE showed discrimination above 0.70, which is considered an acceptable performance.

External validation and clinical usefulness of first-trimester prediction models for small- and large-for-gestational-age infants: a prospective cohort study

Objective

To assess the external validity of all published first‐trimester prediction models based on routinely collected maternal predictors for the risk of small‐ and large‐for‐gestational‐age (SGA and LGA) infants. Furthermore, the clinical potential of the best‐performing models was evaluated.

Design

Multicentre prospective cohort.

Setting

Thirty‐six midwifery practices and six hospitals (in the Netherlands).

Population

Pregnant women were recruited at <16 weeks of gestation between 1 July 2013 and 31 December 2015.

Methods

Prediction models were systematically selected from the literature. Information on predictors was obtained by a web‐based questionnaire. Birthweight centiles were corrected for gestational age, parity, fetal sex, and ethnicity.

Main outcome measures

Predictive performance was assessed by means of discrimination (C‐statistic) and calibration.

Results

The validation cohort consisted of 2582 pregnant women. The outcomes of SGA <10th percentile and LGA >90th percentile occurred in 203 and 224 women, respectively. The C‐statistics of the included models ranged from 0.52 to 0.64 for SGA (n = 6), and from 0.60 to 0.69 for LGA (n = 6). All models yielded higher C‐statistics for more severe cases of SGA (<5th percentile) and LGA (>95th percentile). Initial calibration showed poor‐to‐moderate agreement between the predicted probabilities and the observed outcomes, but this improved substantially after recalibration.

Conclusion

The clinical relevance of the models is limited because of their moderate predictive performance, and because the definitions of SGA and LGA do not exclude constitutionally small or large infants. As most clinically relevant fetal growth deviations are related to ‘vascular’ or ‘metabolic’ factors, models predicting hypertensive disorders and gestational diabetes are likely to be more specific.

Tweetable abstract

The clinical relevance of prediction models for the risk of small‐ and large‐for‐gestational‐age is limited.

The clinical relevance of prediction models for the risk of small‐ and large‐for‐gestational‐age is limited.

THE PREVALENCE OF UNDERWEIGHT, OVERWEIGHT AND OBESITY IN A ROMANIAN POPULATION IN THE FIRST TRIMESTER OF PREGNANCY - CLINICAL IMPLICATIONS

Context

Underweight, overweight and obesity are important global public health issues and risk factors for adverse perinatal outcomes.

Objective

To assess the distribution of the body mass index (BMI) in the Romanian obstetric population in the first trimester of pregnancy and its correlation with pregnancy outcomes. We also report the distribution of blood pressure (BP) parameters and their correlation with BMI.

Design

This retrospective study includes 9,064 women attending routine first trimester visit and ultrasound scan at 12.8(±0.6) gestational weeks. Characteristics, parity, method of conception, blood pressure (from 3,650 women), maternal weight and height, BMI and foetal ultrasound were recorded. Pregnancy outcomes were available for 1,607 deliveries. The Pearson correlation coefficient was assessed for each BMI group vs. blood pressure parameters, gestational age and birth weight. ANOVA analysis and post hoc tests were used to determine group differences. Linear regression was applied to estimate the contribution of BMI and gestational age to birth weight variance.

Results

In our population, 66.37% pregnant women had a normal BMI, 19.29% were overweight, and 7.56% were obese. There was a weak-to-medium positive correlation between BMI and blood pressure parameters, for all weight categories. The correlation between maternal BMI and birth weight was positive for normal and overweight.

Conclusions

Our findings highlight the need for more effective health strategies targeting reduction of weight-related problems in women of childbearing age.

Diet and exercise for preeclampsia prevention in overweight and obese pregnant women: systematic review and meta-analysis

Objective: To investigate the effect of diet and/or exercise in overweight or obese pregnant women on the risk of preeclampsia (PE). Methods: We performed a systematic review and meta-analysis of randomized controlled trials examining the effect of diet and/or exercise interventions in overweight and obese pregnant women on the risk of PE and hypertensive disorders. We completed a literature search through PubMed, Embase, Cinahl, Web of science, Cochrane CENTRAL Library from their earliest entries to November 2017 and from references of other systematic reviews. No language restrictions were applied. Relative risks (RR) with random effect were calculated with their 95% confidence intervals (CI). Results: There were 23 eligible trials (7236 participants), including 11 (5023 participants) investigating the effect of diet and three (387 participants) investigating the effect of exercise on risk of PE, 14 (4345 participants) investigating the effect of diet, five (884 participants) investigating the effect of exercise and one (304 participants) investigating the effect of diet and exercise on risk of hypertensive disorders. Most studies were considered to be at low risk of bias for random sequence allocation and incomplete outcome data but at high risk of bias for blinding of participant and personnel. The heterogeneity of the studies on PE was low (I² = 0-11%), but the heterogeneity of the studies on hypertensive disorders was variable (I² = 0-53%). In women randomized to diet and/or exercise, compared to expectant management, there was no significant difference in the risk of PE (RR 1.01, 95% CI 0.80-1.27; p = .96) or hypertensive disorders of pregnancy (RR 0.87, 95% CI 0.70-1.06; p = .17). In the intervention group, compared to expectant management, gestational weight gain was significantly lower (-1.47 kg, 95% CI -1.97 to -0.97; p < .00001). Metaregression weighted by the size of the studies showed no significant association between gestational weight gain and the risk of PE or hypertensive disorders (p = .314 and p = .124, respectively). Conclusions: Diet and exercise in overweight or obese pregnant women are beneficial in reducing gestational weight gain. However, these interventions do not reduce the risk of PE or hypertensive disorders of pregnancy.

External Validation and Clinical Usefulness of First Trimester Prediction Models for the Risk of Preeclampsia: A Prospective Cohort Study

INTRODUCTION

This study assessed the external validity of all published first trimester prediction models for the risk of preeclampsia (PE) based on routinely collected maternal predictors. Moreover, the potential utility of the best-performing models in clinical practice was evaluated.

MATERIAL AND METHODS

Ten prediction models were systematically selected from the literature. We performed a multicenter prospective cohort study in the Netherlands between July 1, 2013, and December 31, 2015. Eligible pregnant women completed a web-based questionnaire before 16 weeks' gestation. The outcome PE was established using postpartum questionnaires and medical records. Predictive performance of each model was assessed by means of discrimination (c-statistic) and a calibration plot. Clinical usefulness was evaluated by means of decision curve analysis and by calculating the potential impact at different risk thresholds.

RESULTS

The validation cohort contained 2,614 women of whom 76 developed PE (2.9%). Five models showed moderate discriminative performance with c-statistics ranging from 0.73 to 0.77. Adequate calibration was obtained after refitting. The best models were clinically useful over a small range of predicted probabilities.

DISCUSSION

Five of the ten included first trimester prediction models for PE showed moderate predictive performance. The best models may provide more benefit compared to risk selection as used in current guidelines.

First-trimester metabolomic prediction of stillbirth

Background: Stillbirth remains a major problem in both developing and developed countries. Omics evaluation of stillbirth has been highlighted as a top research priority. Objective: To identify new putative first-trimester biomarkers in maternal serum for stillbirth prediction using metabolomics-based approach. Methods: Targeted, nuclear magnetic resonance (NMR) and mass spectrometry (MS), and untargeted liquid chromatography-MS (LC-MS) metabolomic analyses were performed on first-trimester maternal serum obtained from 60 cases that subsequently had a stillbirth and 120 matched controls. Metabolites by themselves or in combination with clinical factors were used to develop logistic regression models for stillbirth prediction. Prediction of stillbirths overall, early (<28 weeks and <32 weeks), those related to growth restriction/placental disorder, and unexplained stillbirths were evaluated. Results: Targeted metabolites including glycine, acetic acid, L-carnitine, creatine, lysoPCaC18:1, PCaeC34:3, and PCaeC44:4 predicted stillbirth overall with an area under the curve [AUC, 95% confidence interval (CI)] = 0.707 (0.628-0.785). When combined with clinical predictors the AUC value increased to 0.740 (0.667-0.812). First-trimester targeted metabolites also significantly predicted early, unexplained, and placental-related stillbirths. Untargeted LC-MS features combined with other clinical predictors achieved an AUC (95%CI) = 0.860 (0.793-0.927) for the prediction of stillbirths overall. We found novel preliminary evidence that, verruculotoxin, a toxin produced by common household molds, might be linked to stillbirth. Conclusions: We have identified novel biomarkers for stillbirth using metabolomics and demonstrated the feasibility of first-trimester prediction.

Association between insulin resistance and preeclampsia in obese non-diabetic women receiving metformin

Objectives

To examine whether the reduced incidence of preeclampsia in non-diabetic obese pregnant women treated with metformin is mediated by changes in insulin resistance.

Methods

This was a secondary analysis of obese pregnant women in a randomised trial (MOP trial). Fasting plasma glucose and insulin were measured in 384 of the 400 women who participated in the MOP trial. Homeostasis model assessment of insulin resistance (HOMA-IR) was compared in the metformin and placebo groups and in those that developed preeclampsia versus those that did not develop preeclampsia.

Results

At 28 weeks, median HOMA-IR was significantly lower in the metformin group. Logistic regression analysis demonstrated that there was a significant contribution in the prediction of preeclampsia from maternal history of chronic hypertension and gestational weight gain, but not HOMA-IR either at randomisation (p = 0.514) or at 28 weeks (p = 0.643).

Conclusions

Reduced incidence of preeclampsia in non-diabetic obese pregnant women treated with metformin is unlikely to be due to changes in insulin resistance.

Prediction models for the risk of gestational diabetes: a systematic review

BACKGROUND

Numerous prediction models for gestational diabetes mellitus (GDM) have been developed, but their methodological quality is unknown. The objective is to systematically review all studies describing first-trimester prediction models for GDM and to assess their methodological quality.

METHODS

MEDLINE and EMBASE were searched until December 2014. Key words for GDM, first trimester of pregnancy, and prediction modeling studies were combined. Prediction models for GDM performed up to 14 weeks of gestation that only include routinely measured predictors were eligible.Data was extracted by the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies (CHARMS). Data on risk predictors and performance measures were also extracted. Each study was scored for risk of bias.

RESULTS

Our search yielded 7761 articles, of which 17 were eligible for review (14 development studies and 3 external validation studies). The definition and prevalence of GDM varied widely across studies. Maternal age and body mass index were the most common predictors. Discrimination was acceptable for all studies. Calibration was reported for four studies. Risk of bias for participant selection, predictor assessment, and outcome assessment was low in general. Moderate to high risk of bias was seen for the number of events, attrition, and analysis.

CONCLUSIONS

Most studies showed moderate to low methodological quality, and few prediction models for GDM have been externally validated. External validation is recommended to enhance generalizability and assess their true value in clinical practice.

Prediction of stillbirth from maternal demographic and pregnancy characteristics

OBJECTIVES

To develop a model for prediction of stillbirth based on maternal characteristics and components of medical history and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and to unexplained causes.

METHODS

This was a prospective screening study of 113 415 singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation and at 19 + 0 to 24 + 6 weeks. The study population included 113 019 live births and 396 (0.35%) antepartum stillbirths; 230 (58%) were secondary to impaired placentation and 166 (42%) were due to other or unexplained causes. Multivariable logistic regression analysis was used to determine the factors from maternal characteristics and medical history which provided a significant contribution to the prediction of stillbirth.

RESULTS

The risk for stillbirth increased with maternal weight (odds ratio (OR), 1.01 per kg above 69 kg), was higher in women of Afro-Caribbean racial origin (OR, 2.01), those with assisted conception (OR, 1.79), cigarette smokers (OR, 1.71), and in those with a history of chronic hypertension (OR, 2.62), systemic lupus erythematosus/antiphospholipid syndrome (OR, 3.61) or diabetes mellitus (OR, 2.55) and was increased in women with a history of previous stillbirth (OR, 4.81). Screening with the model predicted 26% of unexplained stillbirths and 31% of those due to impaired placentation, at a false-positive rate of 10%; within the impaired-placentation group the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (38% vs 28%).

CONCLUSIONS

A model based on maternal characteristics and medical history recorded in early pregnancy can potentially predict one-third of subsequent stillbirths. The extent to which such stillbirths could be prevented remains to be determined. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Can adverse maternal and perinatal outcomes be predicted when blood pressure becomes elevated? Secondary analyses from the CHIPS (Control of Hypertension In Pregnancy Study) randomized controlled trial

Introduction

For women with chronic or gestational hypertension in CHIPS (Control of Hypertension In Pregnancy Study, NCT01192412), we aimed to examine whether clinical predictors collected at randomization could predict adverse outcomes.

Material and methods

This was a planned, secondary analysis of data from the 987 women in the CHIPS Trial. Logistic regression was used to examine the impact of 19 candidate predictors on the probability of adverse perinatal (pregnancy loss or high level neonatal care for >48 h, or birthweight <10th percentile) or maternal outcomes (severe hypertension, preeclampsia, or delivery at <34 or <37 weeks). A model containing all candidate predictors was used to start the stepwise regression process based on goodness of fit as measured by the Akaike information criterion. For face validity, these variables were forced into the model: treatment group (“less tight” or “tight” control), antihypertensive type at randomization, and blood pressure within 1 week before randomization. Continuous variables were represented continuously or dichotomized based on the smaller p‐value in univariate analyses. An area‐under‐the‐receiver‐operating‐curve (AUC ROC) of ≥0.70 was taken to reflect a potentially useful model.

Results

Point estimates for AUC ROC were <0.70 for all but severe hypertension (0.70, 95% CI 0.67–0.74) and delivery at <34 weeks (0.71, 95% CI 0.66–0.75). Therefore, no model warranted further assessment of performance.

Conclusions

CHIPS data suggest that when women with chronic hypertension develop an elevated blood pressure in pregnancy, or formerly normotensive women develop new gestational hypertension, maternal and current pregnancy clinical characteristics cannot predict adverse outcomes in the index pregnancy.

Metformin versus Placebo in Obese Pregnant Women without Diabetes Mellitus

BACKGROUND

Obesity is associated with an increased risk of adverse pregnancy outcomes. Lifestyle-intervention studies have not shown improved outcomes. Metformin improves insulin sensitivity and in pregnant patients with gestational diabetes it leads to less weight gain than occurs in those who do not take metformin.

METHODS

In this double-blind, placebo-controlled trial, we randomly assigned pregnant women without diabetes who had a body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) of more than 35 to receive metformin, at a dose of 3.0 g per day, or placebo (225 women in each group) from 12 to 18 weeks of gestation until delivery. The BMI was calculated at the time of study entry (12 to 18 weeks of gestation). The primary outcome was a reduction in the median neonatal birth-weight z score by 0.3 SD (equivalent to a 50% reduction, from 20% to 10%, in the incidence of large-for-gestational-age neonates). Secondary outcomes included maternal gestational weight gain and the incidence of gestational diabetes and of preeclampsia, as well as the incidence of adverse neonatal outcomes. Randomization was performed with the use of computer-generated random numbers. The analysis was performed according to the intention-to-treat principle.

RESULTS

A total of 50 women withdrew consent during the trial, which left 202 women in the metformin group and 198 in the placebo group. There was no significant between-group difference in the median neonatal birth-weight z score (0.05 in the metformin group [interquartile range, -0.71 to 0.92] and 0.17 in the placebo group [interquartile range, -0.62 to 0.89], P=0.66). The median maternal gestational weight gain was lower in the metformin group than in the placebo group (4.6 kg [interquartile range, 1.3 to 7.2] vs. 6.3 kg [interquartile range, 2.9 to 9.2], P<0.001), as was the incidence of preeclampsia (3.0% vs. 11.3%; odds ratio, 0.24; 95% confidence interval, 0.10 to 0.61; P=0.001). The incidence of side effects was higher in the metformin group than in the placebo group. There were no significant between-group differences in the incidence of gestational diabetes, large-for-gestational-age neonates, or adverse neonatal outcomes.

CONCLUSIONS

Among women without diabetes who had a BMI of more than 35, the antenatal administration of metformin reduced maternal weight gain but not neonatal birth weight. (Funded by the Fetal Medicine Foundation; ClinicalTrials.gov number, NCT01273584; EudraCT number, 2008-005892-83.).

Obesity and anxiety during pregnancy and postpartum: A systematic review

BACKGROUND

Obesity and anxiety during the perinatal period are common and associated with poor health outcomes for the mother and the child. Despite the well-documented health risks of both pregnancy obesity and anxiety, associations between the two have rarely been explored. With this review we aim to provide a systematic overview of the current state of evidence concerning associations between ante- and postnatal anxiety and pregnancy obesity, excessive gestational weight gain, and postpartum weight retention.

METHODS

We conducted a systematic literature search in PubMed, Web of Science, and PsychINFO.

RESULTS

13 Records matched our inclusion criteria. Five out of seven studies focusing on pregnancy obesity and anxiety suggest a positive association with ante- or postnatal anxiety. Surprisingly, no study examined anxiety disorders according to DSM and it remains unknown whether anxiety symptomatology reaches clinical relevance. Results from a small number of life-style intervention studies (n=3) suggest that interventions could benefit from a stronger focus on mental health. There were not enough studies on associations between excessive gestational weight gain (n=2) or postpartum weight retention (n=3) and anxiety making it difficult to draw conclusions about possible associations.

LIMITATION

The number of included studies is rather small and studies were included irrespective of the study quality which might limit the generalizability of the results.

CONCLUSIONS

The majority of the included studies suggest that obese pregnant women might constitute a subgroup that is especially vulnerable for comorbid anxiety and in need of targeted psychological support. However, further high-quality studies, particularly including anxiety disorders, are needed.

First trimester prediction of maternal glycemic status

OBJECTIVE

To predict gestational diabetes mellitus (GDM) or normoglycemic status using first trimester maternal characteristics.

METHODS

We used data from a prospective cohort study. First trimester maternal characteristics were compared between women with and without GDM. Association of these variables with sugar values at glucose challenge test (GCT) and subsequent GDM was tested to identify key parameters. A predictive algorithm for GDM was developed and receiver operating characteristics (ROC) statistics was used to derive the optimal risk score. We defined normoglycemic state, when GCT and all four sugar values at oral glucose tolerance test, whenever obtained, were normal. Using same statistical approach, we developed an algorithm to predict the normoglycemic state.

RESULTS

Maternal age, race, prior GDM, first trimester BMI, and systolic blood pressure (SBP) were all significantly associated with GDM. Age, BMI, and SBP were also associated with GCT values. The logistic regression analysis constructed equation and the calculated risk score yielded sensitivity, specificity, positive predictive value, and negative predictive value of 85%, 62%, 13.8%, and 98.3% for a cut-off value of 0.042, respectively (ROC-AUC - area under the curve 0.819, CI - confidence interval 0.769-0.868). The model constructed for normoglycemia prediction demonstrated lower performance (ROC-AUC 0.707, CI 0.668-0.746).

CONCLUSIONS

GDM prediction can be achieved during the first trimester encounter by integration of maternal characteristics and basic measurements while normoglycemic status prediction is less effective.

Maternal and neonatal outcomes in women undergoing bariatric surgery: a systematic review and meta-analysis

BACKGROUND

Obese women are at increased risk for many pregnancy complications, and bariatric surgery (BS) before pregnancy has shown to improve some of these.

OBJECTIVES

To review the current literature and quantitatively assess the obstetric and neonatal outcomes in pregnant women who have undergone BS.

SEARCH STRATEGY

MEDLINE, EMBASE and Cochrane databases were searched using relevant keywords to identify studies that reported on pregnancy outcomes after BS.

SELECTION CRITERIA

Pregnancy outcome in firstly, women after BS compared to obese or BMI-matched women with no BS and secondly, women after BS compared to the same or different women before BS. Only observational studies were included.

DATA COLLECTION AND ANALYSIS

Two investigators independently collected data on study characteristics and outcome measures of interest. These were analysed using the random effects model. Heterogeneity was assessed and sensitivity analysis was performed to account for publication bias.

MAIN RESULTS

The entry criteria were fulfilled by 17 non-randomised cohort or case-control studies, including seven with high methodological quality scores. In the BS group, compared to controls, there was a lower incidence of preeclampsia (OR 0.45, 95% CI 0.25-0.80; P=0.007), GDM (OR 0.47, 95% CI 0.40-0.56; P<0.001) and large neonates (OR 0.46, 95% CI 0.34-0.62; P<0.001) and a higher incidence of small neonates (OR 1.93, 95% CI 1.52-2.44; P<0.001), preterm birth (OR 1.31, 95% CI 1.08-1.58; P=0.006), admission for neonatal intensive care (OR 1.33, 95% CI 1.02-1.72; P=0.03) and maternal anaemia (OR 3.41, 95% CI 1.56-7.44, P=0.002).

CONCLUSIONS

BS as a whole improves some pregnancy outcomes. Laparoscopic adjustable gastric banding does not appear to increase the rate of small neonates that was seen with other BS procedures. Obese women of childbearing age undergoing BS need to be aware of these outcomes.

Physical activity and excess weight in pregnancy have independent and unique effects on delivery and perinatal outcomes

Background

This study examines the effect of low daily physical activity levels and overweight/obesity in pregnancy on delivery and perinatal outcomes.

Methods

A prospective cohort study combining manually collected postnatal notes with anonymised data linkage. A total of 466 women sampled from the Growing Up in Wales: Environments for Healthy Living study. Women completed a questionnaire and were included in the study if they had an available Body mass index (BMI) (collected at 12 weeks gestation from antenatal records) and/or a physical activity score during pregnancy (7-day Actigraph reading). The full statistical model included the following potential confounding factors: maternal age, parity and smoking status. Main outcome measures included induction rates, duration of labour, mode of delivery, infant health and duration of hospital stay.

Findings

Mothers with lower physical activity levels were more likely to have an instrumental delivery (including forceps, ventouse and elective and emergency caesarean) in comparison to mothers with higher activity levels (adjusted OR:1.72(95%CI: 1.05 to 2.9)). Overweight/obese mothers were more likely to require an induction (adjusted OR:1.93 (95%CI 1.14 to 3.26), have a macrosomic baby (adjusted OR:1.96 (95%CI 1.08 to 3.56) and a longer hospital stay after delivery (adjusted OR:2.69 (95%CI 1.11 to 6.47).

Conclusions

The type of delivery was associated with maternal physical activity level and not BMI. Perinatal outcomes (large for gestational age only) were determined by maternal BMI.

Prognostic risk factors for early diagnosing of Preeclampsia in Nulliparas

Background:

Preeclampsia is of major complications of pregnancy that is associated with maternal morbidity and mortality. Therefore, prediction and early diagnosis of preeclampsia would be helpful for better controlling of related complications. Our study aimed to investigate risk factors helping to predict and early diagnose of preeclampsia.

Materials and Methods:

A total of 739 nulliparous women at their 24-28^th weeks of the first pregnancy were enrolled in this multi-center cohort study. Incidence or absence of preeclampsia in this population was evaluated up to the end of pregnancy period. For each case, a record sheet was assigned that contained information about haematocrit level in weeks 24-28^th of pregnancy, blood pressure, result of roll-over test in weeks 24-28^th of pregnancy and the presence of disease up to end of the study. Diagnosis of preeclampsia was made based on gold standard.

Results:

Overall, 3.9 % of all cases developed preeclampsia. The mean maternal age, body mass index (BMI), years of education and positive roll-over test were significantly higher in preeclampsia group (P < 0.001). However, the mean gestational age and changes in the levels of haematocrit were significantly higher in normotensive cases (P < 0.001). Our combined model could predict preeclampsia with a sensitivity of 93% and a specificity of 80%.

Conclusion:

Simple combined model of demographic characteristics including maternal age, BMI, years of education and positive roll-over tests can predict preeclampsia without any cost for the patients.

Risk of large-for-gestational-age newborns in women with gestational diabetes by race and ethnicity and body mass index categories

OBJECTIVE

To compare the prevalence of large-for-gestational-age (LGA) newborns across categories of body mass index (BMI) in five racial and ethnic groups.

METHODS

This cohort study examined 7,468 women with gestational diabetes mellitus (GDM) who delivered a live newborn between 1995 and 2006 at Kaiser Permanente Northern California. The racial and ethnic groups were non-Hispanic white, African American, Hispanic, Asian, and Filipina. The BMI was classified using the World Health Organization International guidelines (normal, 18.50-24.99; overweight, 25.00-29.99; obese, 30.00-34.99; obese class II, 35.00 or higher). Having an LGA newborn was defined as birth weight more than 90th percentile for the study population's race or ethnicity and gestational age--specific birth weight distribution. Logistic regression was used to estimate odds of having an LGA newborn by BMI and race and ethnicity.

RESULTS

Overall prevalence of LGA newborns was highest in African American women (25.1%), lowest in Asians (13.9%), and intermediate among Hispanic (17.3%), white (16.4%), and Filipina women (15.3%). The highest increased risk of LGA newborns was observed among women with class II obesity in most racial and ethnic groups, and African American and Asian women with class II obesity had a four-fold increased risk of LGA newborns compared with women of normal weight in the same racial and ethnic group.

CONCLUSIONS

African American women with GDM have a greater risk of LGA newborns at a lower BMI than other racial and ethnic groups. Clinicians should be aware that among women with GDM, there may be significant racial and ethnic differences in the risk of LGA newborns by BMI threshold.

Levels of key enzymes of methionine-homocysteine metabolism in preeclampsia

OBJECTIVE

To evaluate the role of key enzymes in the methionine-homocysteine metabolism (MHM) in the physiopathology of preeclampsia (PE).

METHODS

Plasma and placenta from pregnant women (32 controls and 16 PE patients) were analyzed after informed consent. Protein was quantified by western blot. RNA was obtained with RNA purification kit and was quantified by reverse transcritase followed by real-time PCR (RT-qPCR). Identification of the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) single-nucleotide polymorphisms (SNPs) and A2756G methionine synthase (MTR) SNP was performed using PCR followed by a high-resolution melting (HRM) analysis. S-adenosyl methionine (SAM) and S-adenosyl homocysteine (SAH) were measured in plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). The SNP association analysis was carried out using Fisher's exact test. Statistical analysis was performed using a Mann-Whitney test.

RESULTS

RNA expression of MTHFR and MTR was significantly higher in patients with PE as compared with controls. Protein, SAM, and SAH levels showed no significant difference between preeclamptic patients and controls. No statistical differences between controls and PE patients were observed with the different SNPs studied.

CONCLUSION

The RNA expression of MTHFR and MTR is elevated in placentas of PE patients, highlighting a potential compensation mechanism of the methionine-homocysteine metabolism in the physiopathology of this disease.

Individual risk assessment of adverse pregnancy outcome by multivariate regression analysis may serve as basis for drug intervention studies: retrospective analysis of 426 high-risk patients including ethical aspects

OBJECTIVE

To identify patients at very high risk for adverse pregnancy outcome (APO) at the 20- to 23-week scan and to assess the effectiveness of Aspirin (ASS) and low molecular weight heparin (LMWH) starting after this examination.

PATIENTS AND METHODS

By applying an algorithm based on multivariate logistic regression analysis using the parameters maternal age, parity, body mass index (BMI), mean pulsatility index of both uterine arteries (meanPI), presence of uni- or bilateral notch, and depth of notch (mean notch index (meanNI), we retrospectively calculated the individual risk for APO of 21,302 singleton pregnancies. We isolated a subgroup of 426 patients with the highest calculated probability for APO (cpAPO > 27.8 %). 147 had been treated with ASS; 73 with LMWH, 15 patients with a combination of ASS and LMWH, and 191 patients had not received anticoagulants.

RESULTS

Administration of ASS starting after 20 gestational weeks in comparison to non-treated patients significantly reduced the frequency of intrauterine/neonatal death (IUD/NND), preeclampsia <33 weeks (PE < 33), and preterm delivery <33 weeks (PD < 33), while the frequency of IUGR showed a tendency to be elevated (P = 0.061). The subgroup of high-risk patients treated with LMWH was characterised by a higher a priori risk for APO and showed no significant reduction of any form of APO but an increased frequency of PE.

CONCLUSION

Individual assessment of risk for APO by applying a simple algorithm based on biometrical/biographical as well as sonographic parameters may serve as basis for drug intervention studies. The administration of ASS in high-risk patients starting after 20 gestational weeks reduced the frequency of most of the severe forms of adverse pregnancy outcome in high-risk patients. A complication-reducing effect of LMWH starting after 20 weeks of gestation in patients could not be proven. From an ethical point of view, it may not be justified any more to preclude high-risk patients from administration of ASS or to perform studies of ASS against placebo.

Pregnancy outcomes in women with and without gestational diabetes mellitus according to the International Association of the Diabetes and Pregnancy Study Groups criteria

OBJECTIVE

To estimate the incidence of gestational diabetes mellitus (GDM) according to The International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria and the pregnancy complications in women fulfilling these criteria but who are not considered diabetic according to the Canadian Diabetes Association criteria.

METHODS

We estimated the rate of GDM according to the IADPSG criteria from November 2008 to October 2010. Then, we conducted a chart review to compare maternal and neonatal outcomes between women classified as GDM according to the IADPSG criteria but not by the Canadian Diabetes Association criteria (group 1; n=186) and nondiabetic women according to both criteria (group 2; n=372). Results were expressed as crude (odds ratio [OR]) or adjusted OR and 95% confidence interval (CI). The study has a statistical power of 80% to detect a difference between 16% and 8% in large for gestational age newborns (α level of 0.05; two-tailed).

RESULTS

The rate of GDM using the IADPSG criteria was 27.51% (95% CI 25.92-29.11). Group 1 presented similar rates of large-for-gestational-age newborns (9.1% compared with 5.9%, adjusted OR 1.58, 95% CI 0.79-3.13; P=.19), delivery complications (37.1% compared with 30.1%, OR 1.37, 95% CI 0.95-1.98; P=.10), preeclampsia (6.5% compared with 2.7%, adjusted OR 2.40, 95% CI 0.92-6.27; P=.07), prematurity (6.5% compared with 2.7%, OR 1.10, 95% CI 0.53-2.27; P=.85), neonatal complications at delivery (13.4% compared with 9.7%, OR 1.45, 95% CI 0.84-2.49; P=.20), and metabolic complications (10.8% compared with 14.2%, OR 0.73, 95% CI 0.42-1.26; P=.29) compared with group 2.

CONCLUSION

Women classified as nondiabetic by the Canadian Diabetes Association Criteria but considered GDM according to the IADPSG criteria have similar pregnancy outcomes as women without GDM. More randomized studies with cost-effectiveness analyses are needed before implementation of these criteria.

LEVEL OF EVIDENCE

II.

ASPIRIN ADMINISTRATION FOR PREVENTION OF ADVERSE PREGNANCY OUTCOMES

The prophylactic use of low-dose aspirin for prevention of preeclampsia has been an important research question in obstetrics for the last three decades. In 1979, Crandon and Isherwood observed that nulliparous women who had taken aspirin regularly during pregnancy were less likely to have preeclampsia than women who did not. In 1985, Beaufils et al published the first randomized trial suggesting that 150 mg aspirin and 300 mg dipyridamole daily from 3 months’ gestation onwards decreased the risk of preeclampsia, fetal growth restriction and stillbirth in high-risk women. Subsequently, more than 50 trials have been carried out throughout the world and a meta-analysis of these studies reported that the administration of low-dose aspirin in high-risk pregnancies is associated with a decrease in the rate of preeclampsia by approximately 10%. Consequently, several national professional bodies recommend that high-risk pregnancies should be treated with aspirin (50–150 mg daily).

Birthweight with gestation and maternal characteristics in live births and stillbirths

OBJECTIVE

To establish a normal range of birthweight with gestational age (GA) at delivery and examine the contribution of maternal characteristics in defining growth restriction in stillbirths.

METHODS

In 69,895 normal singleton pregnancies, regression analysis was used to determine the association of birthweight with GA and maternal characteristics. The proportion of 290 stillbirths classified as small for GA depending on inclusion or exclusion of maternal characteristics was determined.

RESULTS

In normal pregnancies, there was a polynomial association between birthweight and GA. Birthweight increased with maternal weight, height and parity and was lower in Africans and South Asians than in Caucasians. Birthweight for GA was reduced in antepartum stillbirths (n = 243; p < 0.0001) but not in intrapartum stillbirths (n = 47; p = 0.334). There was no significant difference in the proportion of antepartum stillbirths with birthweight below the 10th percentile when birthweight was corrected for GA only compared to correction for GA and maternal characteristics (53.1 vs. 54.3%). The birthweight was below the 10th percentile in 71.8% of antepartum stillbirths at <32 weeks' gestation, in 47.2% at 33-36 weeks and in 31.5% at ≥37 weeks.

CONCLUSION

Correction of birthweight for maternal characteristics does not alter the proportion of stillbirths that are small for GA.