Systematic review: Accuracy of body mass index in predicting pre-eclampsia: bivariate meta-analysis

Association between pre-pregnancy body mass index and gestational weight gain on pregnancy outcomes: a cohort study in Indonesian pregnant women

Background

Pre-pregnancy BMI (PP BMI) and gestational weight gain (GWG) are prominent anthropometric indicators for maternal nutritional status and are related to an increased risk of adverse pregnancy outcomes. This study aimed to determine the factors affecting total GWG, PP BMI and pregnancy outcomes among pregnant women in West Sumatra, Indonesia.

Methods

This observational analysis was conducted among healthy women in the Vitamin D Pregnant Mother (VDPM) cohort study. A total of 195 pregnant women and their newborn babies were enrolled, and information regarding their socio-demographic characteristics, obstetric history, dietary intake and anthropometric data were assessed through direct interviews. Furthermore, the Institute of Medicine (IOM) 2009 guidelines were used to obtain the total GWG.

Results

PP BMI was used to categorise the 195 pregnant women as overweight/obese (43.1%), normal (46.7%) and underweight (10.2%). There were 53.3%, 34.4% and 12.3% of women who had inadequate, adequate and excessive GWG, respectively. The multinomial logistic regression model indicated that overweight or obese women at the pre-pregnancy stage were 4.09 times more likely to have an excessive rate of GWG (AOR = 4.09, 95% CI: 1.38–12.12, p = 0.011) than those whose weight was normal. Furthermore, women with excessive GWG were 27.11 times more likely to have a baby with macrosomia (AOR = 27.11, 95% CI: 2.99–245.14) (p = 0.001) and those with inadequate GWG were 9.6 times more likely to give birth to a baby with low birth weight (LBW) (AOR = 9.60, 95% CI; 0.88–105.2) (p = 0.002).

Conclusions

This study demonstrates that the malnutrition status prior to pregnancy and inadequate or excessive GWG status during pregnancy as significant risk factors for developing adverse pregnancy outcomes. These findings highlight the importance of providing information, preconception counselling and health education on weight management for healthy pregnancies.

Supplementary information

The online version contains supplementary material available at 10.1186/s12884-022-04815-8.

Validation and development of models using clinical, biochemical and ultrasound markers for predicting pre-eclampsia: an individual participant data meta-analysis

BACKGROUND

Pre-eclampsia is a leading cause of maternal and perinatal mortality and morbidity. Early identification of women at risk is needed to plan management.

OBJECTIVES

To assess the performance of existing pre-eclampsia prediction models and to develop and validate models for pre-eclampsia using individual participant data meta-analysis. We also estimated the prognostic value of individual markers.

DESIGN

This was an individual participant data meta-analysis of cohort studies.

SETTING

Source data from secondary and tertiary care.

PREDICTORS

We identified predictors from systematic reviews, and prioritised for importance in an international survey.

PRIMARY OUTCOMES

Early-onset (delivery at < 34 weeks' gestation), late-onset (delivery at ≥ 34 weeks' gestation) and any-onset pre-eclampsia.

ANALYSIS

We externally validated existing prediction models in UK cohorts and reported their performance in terms of discrimination and calibration. We developed and validated 12 new models based on clinical characteristics, clinical characteristics and biochemical markers, and clinical characteristics and ultrasound markers in the first and second trimesters. We summarised the data set-specific performance of each model using a random-effects meta-analysis. Discrimination was considered promising for C-statistics of ≥ 0.7, and calibration was considered good if the slope was near 1 and calibration-in-the-large was near 0. Heterogeneity was quantified using I ² and τ². A decision curve analysis was undertaken to determine the clinical utility (net benefit) of the models. We reported the unadjusted prognostic value of individual predictors for pre-eclampsia as odds ratios with 95% confidence and prediction intervals.

RESULTS

The International Prediction of Pregnancy Complications network comprised 78 studies (3,570,993 singleton pregnancies) identified from systematic reviews of tests to predict pre-eclampsia. Twenty-four of the 131 published prediction models could be validated in 11 UK cohorts. Summary C-statistics were between 0.6 and 0.7 for most models, and calibration was generally poor owing to large between-study heterogeneity, suggesting model overfitting. The clinical utility of the models varied between showing net harm to showing minimal or no net benefit. The average discrimination for IPPIC models ranged between 0.68 and 0.83. This was highest for the second-trimester clinical characteristics and biochemical markers model to predict early-onset pre-eclampsia, and lowest for the first-trimester clinical characteristics models to predict any pre-eclampsia. Calibration performance was heterogeneous across studies. Net benefit was observed for International Prediction of Pregnancy Complications first and second-trimester clinical characteristics and clinical characteristics and biochemical markers models predicting any pre-eclampsia, when validated in singleton nulliparous women managed in the UK NHS. History of hypertension, parity, smoking, mode of conception, placental growth factor and uterine artery pulsatility index had the strongest unadjusted associations with pre-eclampsia.

LIMITATIONS

Variations in study population characteristics, type of predictors reported, too few events in some validation cohorts and the type of measurements contributed to heterogeneity in performance of the International Prediction of Pregnancy Complications models. Some published models were not validated because model predictors were unavailable in the individual participant data.

CONCLUSION

For models that could be validated, predictive performance was generally poor across data sets. Although the International Prediction of Pregnancy Complications models show good predictive performance on average, and in the singleton nulliparous population, heterogeneity in calibration performance is likely across settings.

FUTURE WORK

Recalibration of model parameters within populations may improve calibration performance. Additional strong predictors need to be identified to improve model performance and consistency. Validation, including examination of calibration heterogeneity, is required for the models we could not validate.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015029349.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 72. See the NIHR Journals Library website for further project information.

Determining optimal gestational weight gain (GWG) in a northwest Chinese population: A CONSORT

ABSTRACT

To determine optimal gestational weight gain (GWG) for the Chinese population.Live singleton deliveries at the largest maternal & childcare hospital in northwest China from 2010 to 2012 were analyzed retrospectively. Multivariable logistic regression analysis was conducted to determine the lowest aggregated risk of interested perinatal outcomes based on Chinese adult body mass index (BMI) categories.Eight thousand eight hundred seventy enrolled parturients were divided into 4 groups according to their prepregnancy BMI: underweight (21.31%, BMI < 18.5 kg/m2), normal weight (67.81%, 18.5 kg/m2 ≤ BMI < 24 kg/m2), overweight (8.99%, 24 kg/m2 ≤ BMI < 28 kg/m2 and obese (1.89%, BMI ≥ 28 kg/m2). The optimal GWG values for the above 4 groups were 16.7 kg (GWG range, 12.0-21.5), 14.5 kg (9.5-19.5), 11.5 kg (7.0-16.5), and 8.0 kg (5.0-13.0). The rates of inadequate, optimal and excessive GWG in present study were 6.14% (545), 62.34% (5529), and 31.52% (2796) respectively, which were significantly different from those of the 2009 Institute of Medicine recommendation (χ2 = 1416.05, Pinteraction < 0.0001).Wider optimal GWG ranges than those recommended by Institute of Medicine were found in our study, and our proposed criteria seems to be practical to the Chinese population.

Maternal adipose tissue to early preeclampsia risk detection: Is the time to maternal ultrasound beyond fetal evaluation?

INTRODUCTION

This study aims to determine the predictive capacity of isolated maternal periumbilical and epigastric fat measurements during pregnancy to hypertensive outcomes.

METHODS

A cohort study was conducted with pregnant women in any trimester and followed until delivery to identify the outcomes of interest, preeclampsia (PE) and gestational hypertension (GH). The predictive capacity of fourth quartile measurements was compared with the first three quartiles of maternal subcutaneous and visceral adipose tissue from the periumbilical site (periumbilical m-SAT and m-VAT) (n = 155) and maternal adipose tissue from the epigastric site (preperitoneal m-SAT and m-VAT) (n = 261). The predictive ability of prepregnant body mass index (BMI) above 30 kg/m² for PE and GH was also assessed.

RESULTS

Fourth quartiles for the periumbilical ultrasound measurements were m-VAT 52.7 mm and m-SAT 21.7 mm. Preperitoneal site presents fourth quartiles m-VAT 15.2 mm and m-SAT 18.6 mm. Both m-VAT and m-SAT maternal periumbilical and preperitoneal sites are unable to predict PE, with the utmost sensitivity attributed to the periumbilical site m-SAT at 54%. The best PE predictor odds ratio (OR) found was the prepregnant BMI consistent with obesity, with an OR of 3.2 (95% CI 1.1-9.4), whereas the best OR to GH predictor was preperitoneal m-SAT with 8.9 (95% CI 2.3-34.6).

CONCLUSION

PE pathogenic mechanisms related to maternal abdominal adipose tissue include differences in molecular, cytological, and tissue levels not detected by ultrasound in a quantified gray scale assessment. Periumbilical or epigastric m-VAT use is not able to predict PE during pregnancy.

Maternal prepregnancy overweight and obesity and the risk of preeclampsia: A meta-analysis of cohort studies

OBJECTIVE

The aim of our meta-analysis was to explore whether overweight and obesity was associated with preeclampsia or not.

DESIGN

Three databases were systematically reviewed and reference lists of relevant articles were checked. Meta-analysis of published cohort studies comparing whether overweight and obesity was associated with preeclampsia and adjusting for potential confounding factors. Calculations of pooled estimates were conducted in random-effects models. Heterogeneity was tested by using Chi-square test with Cochrane and heterogeneity was explored with meta-regression. Publication bias was estimated from Egger's test (linear regression method) and Begg's test (rank correlation method).

RESULTS

Nineteen studies met the inclusion criteria. The meta-analysis showed that overweight and obesity was associated with an increased risk of preeclampsia. The aOR calculated for 13 studies (compared overweight to normal weight) was 1.71, 95% CI (1.52, 1.91) for random-effects models and 19 studies (compared obesity to normal weight) was 2.48, 95% CI (2.05, 2.90) for random-effects models, stratified analyses showed no differences regarding quality grade, location of study and period of anthropometric measurement. There was no indication of a publication bias either from the result of Egger's test or Begg's test.

CONCLUSIONS

Our results suggested that prepregnancy maternal overweight and obesity are significantly associated with an increased risk of preeclampsia.

MTHFR and F5 genetic variations have association with preeclampsia in Pakistani patients: a case control study

BACKGROUND

To study the role of single nucleotide variants (SNVs) of genes related to preeclampsia in Pakistani pregnant women.

METHODS

After ethical approval and getting informed consent; 250 pregnant women were enrolled and equally divided into two groups (125 preeclamptic cases and 125 normotensive pregnant women). Demographic details and medical history were recorded, and 10 ml blood sample was obtained for DNA extraction. The tetra-primer amplification refractory mutation system (ARMS) assays were developed for assessing the variants of three preeclampsia related genes; F5, MTHFR and VEGFA. An association of six SNVs; F5:c.1601G > A (rs6025), F5:c.6665A > G (rs6027), MTHFR: c.665C > T (rs1801133), MTHFR: c.1286A > C (rs1801131), VEGFA: c.-2055A > C (rs699947) and VEGFA: c.*237C > T (rs3025039) with preeclampsia was determined by using different genetic models.

RESULTS

Genotyping of the SNVs revealed that patients with MTHFR:c.665C > T, have increased susceptibility to preeclampsia (CT versus CC/TT: OR = 2.79, 95% CI = 1.18-6.59; P* = 0.046 and CT/TT vs CC: OR = 2.91, 95% CI = 1.29-6.57; P* = 0.0497, in overdominant and dominant models, respectively), whereas F5:c.6665A > G, (A/G vs AA/GG: OR = 0.42, 95% CI = 0.21-0.84; P* = 0.038 in overdominant model) and MTHFR:c.1286A > C, (CC versus AA: OR = 0.36, 95% CI = 0.18-0.72; P* = 0.0392 in codominant model) have significantly decreased risk for preeclampsia. F5:c.1601G > A, VEGFA: c.-2055A > C and VEGFA: c.*237C > T variants revealed no relationship with the disease.

CONCLUSION

This is the first case control study describing the protective role of F5:c.6665A > G against preeclampsia in any world population. In addition, the present study confirmed the association and role of MTHFR gene variations in the development of preeclampsia in Pakistani patients. Further genetic studies may be required to better understand the complex genetic mechanism of SNVs in preeclampsia related genes in pregnant women.

Prediction of pre-eclampsia: review of reviews

OBJECTIVE

Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to review published systematic reviews to collate evidence on the ability of available tests to predict pre-eclampsia, to identify high-value avenues for future research and to minimize future research waste in this field.

METHODS

MEDLINE, EMBASE and The Cochrane Library including DARE (Database of Abstracts of Reviews of Effects) databases, from database inception to March 2017, and bibliographies of relevant articles were searched, without language restrictions, for systematic reviews and meta-analyses on the prediction of pre-eclampsia. The quality of the included reviews was assessed using the AMSTAR tool and a modified version of the QUIPS tool. We evaluated the comprehensiveness of search, sample size, tests and outcomes evaluated, data synthesis methods, predictive ability estimates, risk of bias related to the population studied, measurement of predictors and outcomes, study attrition and adjustment for confounding.

RESULTS

From 2444 citations identified, 126 reviews were included, reporting on over 90 predictors and 52 prediction models for pre-eclampsia. Around a third (n = 37 (29.4%)) of all reviews investigated solely biochemical markers for predicting pre-eclampsia, 31 (24.6%) investigated genetic associations with pre-eclampsia, 46 (36.5%) reported on clinical characteristics, four (3.2%) evaluated only ultrasound markers and six (4.8%) studied a combination of tests; two (1.6%) additional reviews evaluated primary studies investigating any screening test for pre-eclampsia. Reviews included between two and 265 primary studies, including up to 25 356 688 women in the largest review. Only approximately half (n = 67 (53.2%)) of the reviews assessed the quality of the included studies. There was a high risk of bias in many of the included reviews, particularly in relation to population representativeness and study attrition. Over 80% (n = 106 (84.1%)) summarized the findings using meta-analysis. Thirty-two (25.4%) studies lacked a formal statement on funding. The predictors with the best test performance were body mass index (BMI) > 35 kg/m² , with a specificity of 92% (95% CI, 89-95%) and a sensitivity of 21% (95% CI, 12-31%); BMI > 25 kg/m² , with a specificity of 73% (95% CI, 64-83%) and a sensitivity of 47% (95% CI, 33-61%); first-trimester uterine artery pulsatility index or resistance index > 90^th centile (specificity 93% (95% CI, 90-96%) and sensitivity 26% (95% CI, 23-31%)); placental growth factor (specificity 89% (95% CI, 89-89%) and sensitivity 65% (95% CI, 63-67%)); and placental protein 13 (specificity 88% (95% CI, 87-89%) and sensitivity 37% (95% CI, 33-41%)). No single marker had a test performance suitable for routine clinical use. Models combining markers showed promise, but none had undergone external validation.

CONCLUSIONS

This review of reviews calls into question the need for further aggregate meta-analysis in this area given the large number of published reviews subject to the common limitations of primary predictive studies. Prospective, well-designed studies of predictive markers, preferably randomized intervention studies, and combined through individual-patient data meta-analysis are needed to develop and validate new prediction models to facilitate the prediction of pre-eclampsia and minimize further research waste in this field. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of ischemic placental diseases during the first trimester combined test period: a retrospective cohort of low-risk pregnancies in search of the link between parity and disease

Objective: To assess the predictive power of a multifactorial model established on maternal characteristics, placenta-associated plasma protein A (PAPPA), and the mean uterine artery pulsatility index (Ut A PI) levels for the development of ischemic placental diseases (IPD) during the first-trimester combined test (FTCT) period and to evaluate the strength of some generally accepted clinical risk factors.Method: The studied data were obtained from a retrospective cohort of low-risk singleton pregnancies in the FTCT between 1 August 2016 and 1 December 2017. After routine 11-13-week examinations for FTCT, the Ut A PI was measured and stored electronically. The PAPPA multiple of median (MoM) was obtained as a routine component of aneuploidy screening.Results: A sample of 2493 pregnancies with clearly documented outcomes was studied. Early-onset preeclampsia, late-onset preeclampsia and fetal growth restriction (FGR) were observed in 9 (0.36%), 27 (1.08%), and 41 (1.64%) cases, respectively. With optimum cut-off levels of 0.69 for PAPPA MoM and 2.05 for mean Ut A PI and a false positive rate of 4.9%, IPD cases could be predicted with 83.3% sensitivity and 73.7% specificity. Nulliparity, previous abortion in nulliparous women and first pregnancy from second marriage were not independent risk factors. Maternal age, an interval from the last delivery longer than 6 years, and body mass index were found to be independent risk factors.Conclusion: The IPD showed some common and distinct clinical, laboratory and Doppler findings during the FTCT and were predictable with the help of multifactorial analysis. Some widely accepted risk factors could be affected by various confounders. Because of the increased IPD frequencies, parous women with a time interval from the last delivery of 6 years or longer should be screened as a high-risk group for placental dysfunction-related diseases.

Determining optimal gestational weight gain in the Korean population: a retrospective cohort study

BACKGROUND

The World Health Organization (WHO) international body mass index (BMI) cut-off points defining pre-pregnancy BMI categories in the Institute of Medicine (IOM) guidelines are not directly applicable to Asians. We aimed to define the optimal gestational weight gain (GWG) for the Korean population based on Asia-specific BMI categories.

METHODS

Data from 2702 live singleton deliveries in three tertiary centers between 2010 and 2011 were analyzed retrospectively. A multivariable logistic regression analysis was conducted to determine the lowest aggregated risk of composite perinatal outcomes based on Asia-specific BMI categories. The perinatal outcomes included gestational hypertensive disorder, emergency cesarean section, and fetal size for gestational age. In each BMI category, the GWG value corresponding to the lowest aggregated risk was defined as the optimal GWG.

RESULTS

Among the study population, 440 (16.3%) were underweight (BMI < 18.5), 1459 (54.0%) were normal weight (18.5 ≤ BMI < 23), 392 (14.5%) were overweight (23 ≤ BMI < 25) and 411 (15.2%) were obese (BMI ≥ 25). The optimal GWG by Asia-specific BMI category was 20.8 kg (range, 16.7 to 24.7) for underweight, 16.6 kg (11.5 to 21.5) for normal weight, 13.1 kg (8.0 to 17.7) for overweight, and 14.4 kg (7.5 to 21.9) for obese.

CONCLUSION

Considerably higher and wider optimal GWG ranges than recommended by IOM are found in our study in order to avoid adverse perinatal outcomes. Revised IOM recommendations for GWG could be considered for Korean women according to Asian BMI categories. Further prospective studies are needed in order to determine the optimal GWG for the Korean population.

It is not justified to reject fertility treatment based on obesity

Obesity can lead to anovulation and subfertility. Around the world fertility treatment is withheld from women above a certain BMI, with a threshold ranging from 25 to 40 kg/m². The proponents of this policy use three different arguments to justify their restrictions: risks for the woman, health and wellbeing of the future child, and importance for society. In this article we critically appraise these arguments. We conclude that obese women should be informed about the consequences of their weight on fertility and pregnancy complications and encouraged to lose weight. If, however, a woman is unable to lose weight despite effort, we feel there is no argument to withhold treatment from her. This would be unjustified with respect to the treatment of other women with a high risk of complications.

Epidemiology of hypertensive disorders in pregnancy: prevalence, risk factors, predictors and prognosis

Hypertensive disorders in pregnancy (HDP) represent some of the most important problems faced by public health because HDP is a major cause of maternal and prenatal morbidity and mortality. Several epidemiological studies have been performed to determine the prevalence and risk factors of HDP as well as its subtypes. The prevalences of HDP, gestational hypertension and preeclampsia are 5.2-8.2%, 1.8-4.4% and 0.2-9.2%, respectively. Body mass index, anemia and lower education appear to be modifiable risk factors for HDP. Maternal age, primiparous, multiple pregnancy, HDP in previous pregnancy, gestational diabetes mellitus, preexisting hypertension, preexisting type 2 diabetes mellitus, preexisting urinary tract infection and a family history of hypertension, type 2 diabetes mellitus and preeclampsia appear to be nonmodifiable risk factors. Genetic variants including a single-nucleotide polymorphism in the angiotensinogen gene have also been reported to be nonmodifiable risk factors. Epidemiological studies have recently examined the associations between a history of HDP and its subtypes and future risks of other diseases. These studies have reported associations between a history of HDP and a risk of coronary heart disease, heart failure, dysrhythmia, stroke, hypertension, diabetes mellitus, end-stage renal dysfunction and cardiomyopathy. HDP is not associated with the future incidence of total cancer. In conclusion, HDP is not a rare complication of pregnancy and the influence of HDP remains for an extended duration. Physicians should consider the effects of HDP when treating chronic diseases in women.

The association between body mass index and preeclampsia: a meta-analysis

BACKGROUND

Several observational studies have reported a positive association between elevated body mass index (BMI) and preeclampsia, but no meta-analysis has been conducted yet. This meta-analysis was conducted to estimate the overall association between overweight or obesity and preeclampsia.

METHODS

Major electronic databases, including PubMed, Web of Science, and Scopus were searched until August 2015. The reference lists of included studies were screened as well. Epidemiological studies addressing the association between BMI and preeclampsia were enrolled. The heterogeneity across studies was explored by Q-test and I(2) statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model.

RESULTS

We identified a total of 1298 references and included 23 studies with 1 387 599 participants. Preeclampsia was associated with overweight (OR = 1.73; 95% CI: 1.59, 1.87; 21 studies; I(2 )=( )62.3%) and obesity (OR = 3.15; 95% CI: 2.96, 3.35; 22 studies; I(2 )=( )36.0%). There was no evidence of publication bias.

CONCLUSIONS

There is sufficient evidence that excess body mass index is significantly associated with an increased risk of preeclampsia. Therefore, overweight and obesity can be considered as a predictor of preeclampsia.

History of preeclampsia is more predictive of cardiometabolic and cardiovascular risk factors than obesity

OBJECTIVE

To determine to what extent a history of preeclampsia affects traditional cardiometabolic (insulin resistance and dyslipidemia) and cardiovascular (hypertension and micro-albuminuria) risk factors of the metabolic syndrome irrespective of BMI.

STUDY DESIGN

In a retrospective case-control study we compared 90 formerly preeclamptic women, divided in 3 BMI-classes (BMI 19.5-24.9, 25.0-29.9, ≥30.0kg/m(2)) to 30 controls, matched for BMI, age and parity. Cardiometabolic and cardiovascular risk factors (WHO-criteria) were tested 6-18 months post partum. Statistical analysis included unpaired t-tests, Mann-Whitney U test, or Chi square test and two-way ANOVA.

RESULTS

Constituents of the metabolic syndrome (glucose, insulin, HOMAIR, HDL-cholesterol, triglycerides, blood pressure, micro-albuminuria) were higher in formerly preeclamptic women than in BMI-matched controls. Resultantly, traditional risk factors were more prevalent in formerly preeclamptic women than in controls (insulin resistance 80% vs 30%, dyslipidemia 52% vs 3%, hypertension 24% vs 0%, micro-albuminuria 30% vs 0%). Cardiometabolic risk factors increased with BMI, to the same extent in both groups. Formerly preeclamptic women had metabolic syndrome more often than their BMI-matched controls (38% vs 3%, p<0.001).

CONCLUSION

Traditional risk factors of the metabolic syndrome are more prevalent in formerly preeclamptic women than in BMI-matched controls and increase with BMI to the same extent in both groups. A history of preeclampsia seems to be a stronger indicator of cardiovascular risk than obesity per se.

The 2011 survey on hypertensive disorders of pregnancy (HDP) in China: prevalence, risk factors, complications, pregnancy and perinatal outcomes

Hypertensive disorders of pregnancy (HDP) are a group of medical complications in pregnancy and also a risk factor for severe pregnancy outcomes, but it lacks a large-scale epidemiological investigation in recent years. This survey represents a multicenter cross-sectional retrospective study to estimate the prevalence and analyze the risk factors for HDP among the pregnant women who had referred for delivery between January 1st 2011 and December 31st 2011 in China Mainland. A total of 112,386 pregnant women were investigated from 38 secondary and tertiary specialized or general hospitals randomly selected across the country, of which 5,869 had HDP, accounting for 5.22% of all pregnancies. There were significant differences in the prevalence of HDP between geographical regions, in which the North China showed the highest (7.44%) and Central China showed the lowest (1.23%). Of six subtypes of HDP, severe preeclampsia accounted for 39.96%, gestational hypertension for 31.40%, mild preeclampsia for 15.13%, chronic hypertension in pregnancy for 6.00%, preeclampsia superimposed on chronic hypertension for 3.68% and eclampsia for 0.89%. A number of risk factors for HDP were identified, including twin pregnancy, age of >35 years, overweight and obesity, primipara, history of hypertension as well as family history of hypertension and diabetes. The prevalence of pre-term birth, placental abruption and postpartum hemorrhage were significantly higher in women with HDP than those without HDP. The possible risk factors confirmed in this study may be useful for the development of early diagnosis and appropriate treatment of HDP.

The impact of obesity on outcomes of midwife-led pregnancy and childbirth in a primary care population: a prospective cohort study

OBJECTIVE

To assess the impact of obesity on the likelihood of remaining in midwife-led care throughout pregnancy and childbirth.

DESIGN

Secondary analysis of data from a prospective cohort study.

SETTING

Dutch midwife-led practices.

POPULATION

A cohort of 1369 women eligible for midwife-led care after their first antenatal visit.

METHODS

First-trimester body mass index (BMI) was calculated as weight measured at booking divided by height squared. Obstetric data were retrieved from medical records. Multiple logistic regressions were performed to examine the effects of BMI classification on midwife-led pregnancies and childbirths.

MAIN OUTCOME MEASURES

Percentages of women remaining in midwife-led care throughout pregnancy and throughout childbirth.

RESULTS

Of women in obesity classes II and III, 55% remained in midwife-led care throughout pregnancy and 30% remained in midwife-led care throughout birth. Compared with women of normal weight, women in obesity classes II and III had fewer midwife-led pregnancies (OR 0.38, 95% CI 0.21-0.69), and women who were overweight or in obesity class I had fewer midwife-led childbirths (OR 0.63, 95% CI 0.44-0.90; OR 0.49, 95% CI 0.29-0.84, respectively). Compared with women of normal weight, women who were obese had higher referral rates for hypertensive disorders (4 versus 14%), prolonged labour (4.6 versus 10.4%), and intrapartum pain relief (4 versus 10.4%). The women who were eligible for midwife-led birth and who were overweight or obese, had no more urgent referrals than women of normal weight. Women who were obese and who completed a midwife-led birth had no more adverse outcomes than women of normal weight, with the exception of higher rates of large for gestational age (LGA) babies (>97.7 centile; 12.1%, versus 1.9% in normal weight and versus 3.3% in overweight women).

CONCLUSIONS

Although fewer women who were obese remain in midwife-led care during pregnancy and childbirth, there was no increased risk of unfavourable birth outcomes for women who were obese and eligible for a midwife-led birth when compared with women of normal weight. This indicates that when primary care midwives use a risk assessment tool throughout pregnancy and childbirth they are able to safely assign women who are obese to either midwife-led or obstetrician-led care.

Determining optimal gestational weight gain in a multiethnic Asian population

AIM

To define the optimal gestational weight gain (GWG) for the multiethnic Singaporean population.

METHODS

Data from 1529 live singleton deliveries was analyzed. A multinomial logistic regression analysis, with GWG as the predictor, was conducted to determine the lowest aggregated risk of a composite perinatal outcome, stratified by Asia-specific body mass index (BMI) categories. The composite perinatal outcome, based on a combination of delivery type (cesarean section [CS], vaginal delivery [VD]) and size for gestational age (small [SGA], appropriate [AGA], large [LGA]), had six categories: (i) VD with LGA; (ii) VD with SGA; (iii) CS with AGA; (iv) CS with SGA; (v) CS with LGA; (vi) and VD with AGA. The last was considered as the 'normal' reference category. In each BMI category, the GWG value corresponding to the lowest aggregated risk was defined as the optimal GWG, and the GWG values at which the aggregated risk did not exceed a 5% increase from the lowest aggregated risk were defined as the margins of the optimal GWG range.

RESULTS

The optimal GWG by pre-pregnancy BMI category, was 19.5 kg (range, 12.9 to 23.9) for underweight, 13.7 kg (7.7 to 18.8) for normal weight, 7.9 kg (2.6 to 14.0) for overweight and 1.8 kg (-5.0 to 7.0) for obese.

CONCLUSION

The results of this study, the first to determine optimal GWG in the multiethnic Singaporean population, concur with the Institute of Medicine (IOM) guidelines in that GWG among Asian women who are heavier prior to pregnancy, especially those who are obese, should be lower. However, the optimal GWG for underweight and obese women was outside the IOM recommended range.

Does the patient with chest pain have a coronary heart disease? Diagnostic value of single symptoms and signs--a meta-analysis

AIM

To determine the diagnostic value of single symptoms and signs for coronary heart disease (CHD) in patients with chest pain.

METHODS

Searches of two electronic databases (EMBASE 1980 to March 2008, PubMed 1966 to May 2009) and hand searching in seven journals were conducted. Eligible studies recruited patients presenting with acute or chronic chest pain. The target disease was CHD, with no restrictions regarding case definitions, eg, stable CHD, acute coronary syndrome (ACS), acute myocardial infarction (MI), or major cardiac event (MCE). Diagnostic tests of interest were items of medical history and physical examination. Bivariate random effects model was used to derive summary estimates of positive (pLR) and negative likelihood ratios (nLR).

RESULTS

We included 172 studies providing data on the diagnostic value of 42 symptoms and signs. With respect to case definition of CHD, diagnostically most useful tests were history of CHD (pLR=3.59), known MI (pLR=3.21), typical angina (pLR=2.35), history of diabetes mellitus (pLR=2.16), exertional pain (pLR=2.13), history of angina pectoris (nLR=0.42), and male sex (nLR=0.49) for diagnosing stable CHD; pain radiation to right arm/shoulder (pLR=4.43) and palpitation (pLR=0.47) for diagnosing MI; visceral pain (pLR=2.05) for diagnosing ACS; and typical angina (pLR=2.60) and pain reproducible by palpation (pLR=0.13) for predicting MCE.

CONCLUSIONS

We comprehensively reported the accuracy of a broad spectrum of single symptoms and signs for diagnosing myocardial ischemia. Our results suggested that the accuracy of several symptoms and signs varied in the published studies according to the case definition of CHD.

Serum placental growth factor as a predictor of early onset preeclampsia in overweight/obese pregnant women

The purpose of this study was to analyze whether maternal serum placental growth factor (PlGF) could predict early onset preeclampsia (<32 weeks of gestation) in overweight/obese pregnant women, and whether it could do it more effectively than in normal/underweight pregnant women. A prospective cohort study was conducted on 1678 pregnant women with singleton pregnancies, who were grouped as underweight, normal, overweight, and obese on the basis of body mass index, followed by serum PlGF estimation at 20 to 22 weeks of gestation. A cut-off value of <144 pg/mL for PlGF was determined by Receiver Operating Characteristic curve analysis to identify risk of early onset preeclampsia. Univariate logistic regression analysis revealed significantly stronger association between PlGF <144 pg/mL and early onset preeclampsia in overweight/obese pregnant women (odds ratio 7.64; 95% confidence interval 5.34-10.12; P = .000) than in normal/underweight pregnant women (odds ratio 2.95; 95% confidence interval 1.74-4.26; P = .007). Weight and PlGF levels in study women had a significant negative correlation (r = 0.663; P = .002). Serum PlGF in early second trimester could be an effective predictor of early onset preeclampsia in overweight/obese pregnant women and may be more effective than in normal/underweight pregnant women.

Gestational diabetes mellitus: a positive predictor of type 2 diabetes?

The aim of this paper is to consider the relative benefits of screening for type two diabetes mellitus in women with a previous pregnancy complicated by gestational diabetes mellitus. Recent studies suggest that women who experience GDM are at a greater risk of developing type 2 diabetes within 10-20 years of their index pregnancy. If considered as a stand-alone indicator of the risk of developing type 2 diabetes, GDM is a poor diagnostic test. Most women do not develop GDM during pregnancy and of those that do most do not develop type 2 diabetes. There is, however, a clear need for better early detection of predisposition to disease and/or disease onset to significantly impact on this global pandemic. The putative benefits of multivariate approaches and first trimester and preconception screening to increase the sensitivity of risk assignment modalities for type 2 diabetes are proposed.

Women born preterm or with inappropriate weight for gestational age are at risk of subsequent gestational diabetes and pre-eclampsia

Introduction

Low birthweight, which can be caused by inappropriate intrauterine growth or prematurity, is associated with development of gestational diabetes mellitus (GDM) as well as pre-eclampsia later in life, but the relative effects of prematurity and inappropriate intrauterine growth remain uncertain.

Methods

Through nation-wide registries we identified all Danish mothers in the years 1989–2007. Two separate cohorts consisting mothers born 1974–1977 (n = 84219) and 1978–1981 (n = 32376) were studied, due to different methods of registering birthweight and gestational age in the two periods. Data was linked with information on GDM, pre-eclampsia and education.

Results

In a multivariate logistic regression model the odds of developing GDM was increased by 5–7% for each week the mother was born before term (p = 0.018 for 1974–1977, p = 0.048 for 1978–1981), while the odds were increased by 13–17% for each standard deviation (SD) reduction in birthweight for gestational age for those who were small or normal for gestational age (p<0.0001 and p = 0.035) and increased by 118–122% for each SD increase above the normal range (p<0.0001 and p = 0.024). The odds of pre-eclampsia was increased by 3–5% for each week the mother was born before term (p = 0.064 and p = 0.04), while the odds were increased 11–12% for each SD reduction in birthweight for gestational age (p<0.0001 and p = 0.0002).

Conclusion

In this cohort of young Danish mothers, being born premature or with increasingly low birthweight for gestational age was associated with an increased risk of GDM and pre-eclampsia in adulthood, while increasingly high birthweight for gestational age was associated with an increased risk of GDM and a decreased risk of pre-eclampsia. Inappropriate weight for gestational age was a more important risk factor than prematurity.

Body mass index and hypertensive disorders of pregnancy

OBJECTIVES

We compared the incidence of the hypertensive disorders of pregnancy in obese women with women of a normal body mass index (BMI).

STUDY DESIGN

Prospective observational study in which BMI was calculated accurately early in pregnancy. Women were enrolled after a sonographic confirmation of an ongoing pregnancy. To reduce confounding variables the study was confined to white European women with a singleton pregnancy.

MAIN OUTCOME MEASURES

Incidence of pre-eclampsia and gestational hypertension.

RESULTS

In 2230 women, 16.8% were obese. Pre-eclampsia was diagnosed in 3.3% (n=74) and gestational hypertension in 3.0% (n=67). Both pre-eclampsia (p=0.01) and gestational hypertension (p<0.01) were common in obese women compared with normal weight women. Overall 13.1% of obese women developed a hypertensive disorder during pregnancy. When analysed by parity pre-eclampsia occurred in 2.1% of primigravidas and 0.3% of multigravidas. Pre-eclampsia was increased in obese multigravidas (p=0.001), but not obese primigravidas, suggesting that parity is more influential than obesity in the development of pre-eclampsia.

CONCLUSIONS

Obese multigravidas are more likely to develop hypertensive disorders in pregnancy and obese primigravidas are more likely to develop gestational hypertension. This is important in clinical practice because maternal weight, unlike parity, is potentially modifiable before or during pregnancy.

Antepartum obstetrical complications associated with obesity

Obesity is a major risk factor for many obstetrical complications, including pre-eclampsia, gestational diabetes, indicated preterm birth, macrosomia, and stillbirth. Clinicians should be aware of the unique obstetrical management considerations related to obesity, including recommendations for alterations in prenatal care. In addition, obese gravidas commonly have underlying medical conditions that can impact pregnancy and must be appreciated to optimize care. Obese women should be educated about these risks, ideally before pregnancy. Awareness of the complications that can arise for these women and potential changes in management offer opportunities to improve both prenatal and lifelong health.

Screening for pre-eclampsia--lessons from aneuploidy screening

BACKGROUND

Antenatal screening for aneuploidy is an established routine clinical practice worldwide. The same statistical methodology, developed and refined over three decades, might be adapted to screening for pre-eclampsia.

METHODS

The published literature is reviewed for evidence that the methodology is valid for pre-eclampsia using first trimester maternal serum PP13, PAPP-A, PlGF, ADAM12 and inhibin A, together with MAP and uterine artery Doppler PI. Risk is estimated for both early onset pre-eclampsia, requiring delivery before 34 weeks, or late onset disease. Prior risk from the background prevalence multiplied by likelihood ratios (LRs) for ethnicity, parity, adiposity and family history is multiplied by an LR from the screening marker profile. Markers are expressed in multiples of the gestation-specific median and adjusted for body mass, ethnicity and smoking status as appropriate. A standardized population with a fixed distribution of risk factors and a multi-variate Gaussian model of marker profiles is used to predict performance.

RESULTS

There is sufficient published data to estimate individual risks reasonably well. Modeling predicts that using PAPP-A and one other serum marker, together with the physical markers more than two-thirds of early and one-third of late onset cases can be detected by classifying less than 2% of pregnancies as high risk; three-quarters of early case could be detected with a 5% high risk rate.

CONCLUSION

Whilst more data on some markers is still required modeling so far suggests that extending first trimester aneuploidy screening programs to include pre-eclampsia screening would yield a high detection. However, prospective studies are needed to verify the model predictions.

Clinical risk prediction for pre-eclampsia in nulliparous women: development of model in international prospective cohort

OBJECTIVES

To develop a predictive model for pre-eclampsia based on clinical risk factors for nulliparous women and to identify a subgroup at increased risk, in whom specialist referral might be indicated.

DESIGN

Prospective multicentre cohort.

SETTING

Five centres in Auckland, New Zealand; Adelaide, Australia; Manchester and London, United Kingdom; and Cork, Republic of Ireland.

PARTICIPANTS

3572 "healthy" nulliparous women with a singleton pregnancy from a large international study; data on pregnancy outcome were available for 3529 (99%).

MAIN OUTCOME MEASURE

Pre-eclampsia defined as ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg, or both, on at least two occasions four hours apart after 20 weeks' gestation but before the onset of labour, or postpartum, with either proteinuria or any multisystem complication. Preterm pre-eclampsia was defined as women with pre-eclampsia delivered before 37(+0) weeks' gestation. In the stepwise logistic regression the comparison group was women without pre-eclampsia.

RESULTS

Of the 3529 women, 186 (5.3%) developed pre-eclampsia, including 47 (1.3%) with preterm pre-eclampsia. Clinical risk factors at 14-16 weeks' gestation were age, mean arterial blood pressure, body mass index (BMI), family history of pre-eclampsia, family history of coronary heart disease, maternal birth weight, and vaginal bleeding for at least five days. Factors associated with reduced risk were a previous single miscarriage with the same partner, taking at least 12 months to conceive, high intake of fruit, cigarette smoking, and alcohol use in the first trimester. The area under the receiver operating characteristics curve (AUC), under internal validation, was 0.71. Addition of uterine artery Doppler indices did not improve performance (internal validation AUC 0.71). A framework for specialist referral was developed based on a probability of pre-eclampsia generated by the model of at least 15% or an abnormal uterine artery Doppler waveform in a subset of women with single risk factors. Nine per cent of nulliparous women would be referred for a specialist opinion, of whom 21% would develop pre-eclampsia. The relative risk for developing pre-eclampsia and preterm pre-eclampsia in women referred to a specialist compared with standard care was 5.5 and 12.2, respectively.

CONCLUSIONS

The ability to predict pre-eclampsia in healthy nulliparous women using clinical phenotype is modest and requires external validation in other populations. If validated, it could provide a personalised clinical risk profile for nulliparous women to which biomarkers could be added. Trial registration ACTRN12607000551493.

Are insulin resistance index, IGF-1 and metabolic syndrome components correlates with severe preeclampsia?

OBJECTIVE

Analyse the relation between insulin resistance and severe preeclampsia (SPE).

METHODS

Case control study paired by body mass index and gestational age; including 16 patients with severe SPE and 16 normotensive controls. Insulin resistance was assessed through the HOMA-IR and QUICKI-IS indexes.

RESULTS

There was no significant difference between the groups regarding the HOMA-IR and QUICKI-IS indexes and HDL cholesterol. Triglyceride levels were higher and the IGF-1 was lower in the SPE group than in the control group.

CONCLUSIONS

There were no differences in the insulin resitance indexes between the group with SPE and normal controls.

Management of maternal obesity prior to and during pregnancy

The prevalence of obesity is high and rising worldwide. The greatest prevalence of obesity is found in the western world and in urban developing countries. There is an increased maternal mortality associated with maternal obesity. There are increased risks of most maternal complications in pregnancy including pre-eclampsia, gestational and pre-existing type 2 diabetes mellitus and thromboembolic disorders. There is an increased perinatal mortality associated with maternal obesity; there are increased risks of congenital malformation, fetal macrosomia and indeed risks for the fetus as a child and adult in the years to come. There are increased risks of complications of pregnancy including caesarean section, traumatic delivery and a reduced chance of breastfeeding. Maternal obesity in pregnancy predicts long-term risks for that mother. The management includes increased surveillance for these risks and lifestyle modulation during pregnancy. This includes dietary measures and encouraging modest increase in exercise. Ideally, the mother should achieve closer to an ideal body mass index prior to pregnancy using lifestyle intervention but possibly with pharmacological therapy or bariatric surgery. The ideal weight gain for an obese mother is less than the ideal weight gain for a lean mother.

Economic consequences of overweight and obesity in infertility: a framework for evaluating the costs and outcomes of fertility care

BACKGROUND

Overweight and obesity are an epidemic in Western society, and have a strong impact on fertility. We studied the consequences of overweight and obesity with respect to fecundity, costs of fertility treatment and pregnancy outcome in subfertile women.

METHODS

We searched the literature for systematic reviews and large studies reporting on the effect of weight on both fecundity and pregnancy outcome in subfertile women. We collected data on costs of treatment with ovulation induction, intrauterine insemination and in vitro fertilization, as well as costs of pregnancy complications. We calculated, for ovulatory and anovulatory women separately, the number of expected pregnancies, complications and costs in a hypothetical cohort of 1000 normal weight, overweight and obese women each.

RESULTS

In our hypothetical cohort of 1000 women, compared with women with normal weight, live birth was decreased by 14 and 15% (from 806 live births to 692 and 687 live births) in overweight and obese anovulatory women, respectively, for ovulatory women it was decreased by 22 and 24% (from 698 live births to 546 and 531 live births), respectively. These outcomes were associated with an increase in the number of complications and associated costs leading to cost per live birth in anovulatory overweight and obese women were 54 and 100% higher than their normal weight counterparts, for ovulatory women they were 44 and 70% higher, respectively.

CONCLUSIONS

Overweight and obese subfertile women have a reduced probability of successful fertility treatment and their pregnancies are associated with more complications and higher costs.

Antenatal screening and predicting hypertension in pregnancy for midwives

BACKGROUND

The cause of hypertension in pregnancy remains unknown and results in increased risk of complications for mother and baby. Symptoms of developing pre-eclampsia, such as an elevated blood pressure, can be vague and singular. The purpose of this literature review is to evaluate research investigating antenatal screening practices for hypertension which fall within the midwives scope of practice.

METHOD

Inclusion criteria for this literature review were English language, peer reviewed primary research journal articles, published in the previous 20 years where the population under study was pregnant with reported outcomes of prevention, screening or prediction of hypertension in pregnancy. A large number of papers (n=201) were identified and these were screened and subsequently excluded if they addressed diagnostic testing, screening and interpretation that depended solely on a medical practitioner.

RESULTS

There was no single predictive factor found, however the relevant papers included in this review (n=33) found evidence of modifiable, non-modifiable and clinical assessment factors for inclusion in a midwifery screening model.

CONCLUSIONS

Further research should be focused on the factors observed by midwives during history taking and the antenatal course in the second and third trimesters and whether or not these can be synthesised in to a hypertension-specific diagnostic tool for use in midwifery practice.