Predictive Value of Free β-hCG Multiple of the Median for Women with Preeclampsia

Association between human chorionic gonadotropin (hCG) levels and adverse pregnancy outcomes: A systematic review and meta-analysis

Human chorionic gonadotropin (hCG), a glycoprotein produced in the placenta, is crucial for a healthy pregnancy. We investigated the relationship between hCG levels and adverse pregnancy outcomes. We conducted a systematic review including studies measuring hCG blood levels in the first or second trimester, reporting on any of the 12 predefined adverse pregnancy outcomes with logistic regression-adjusted association estimates. The primary outcomes were placenta-associated complications, such as miscarriage, preeclampsia, intrauterine growth restriction, and preterm delivery. We searched PubMed, Embase and CINAHL Complete. The hCG levels were analysed as multiple of the median (MoM). Odds ratio (OR) and 95% confidence interval (CI) were used. Risk of bias and the certainty of evidence were assessed using ROBINS-I and GRADE, respectively. Meta-analysis also showed that hCG levels, reported as MoM ≥2/2.31/2.5, might be associated with an increased risk of preeclampsia (OR 2.08, 95% CI 1.26 to 3.44) and preterm delivery (OR 1.29, 95% CI 1.12 to 1.47), but the evidence is very uncertain. High second trimester hCG levels may be associated with preeclampsia and preterm delivery but confidence in evidence is low.

High concentration of first-measured HCG after embryo transfer is associated with subsequent development of pre-eclampsia

RESEARCH QUESTION

Are outlier high values of first-measured human chorionic gonadotrophin (HCG) following embryo transfer related to pregnancy complications, specifically pre-eclampsia?

DESIGN

This retrospective cohort study screened 3448 women aged 18-45 years who underwent IVF between 2014 and 2019 and evaluated 614 women who had an intrauterine pregnancy following single embryo transfer (SET), 423 of whom had a live birth. Pregnancy and birth outcome information was available for final analysis in 280 cases. The setting was a university-based IVF centre. HCG was measured at a standardized time after the embryo transfer and the values correlated with adverse pregnancy outcomes associated with poor placentation.

RESULTS

Women with first-measured HCG in the highest quintile had a higher incidence of pre-eclampsia than those with lower HCG concentrations (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.41-11.82) even after controlling for age, body mass index, parity and type of embryo transfer. Additionally controlling for embryo stage at embryo transfer did not change the results (OR 3.97, 95% CI 1.37-11.46). No differences were found in the incidence of fetal growth restriction.

CONCLUSIONS

This is the first known report that links high first-measured HCG after SET to an adverse pregnancy outcome. If confirmed by future studies, initiation of preventive interventions at a very early stage of pregnancy merits further evaluation in this cohort of patients.

Postpartum Assessment of the Correlation between Serum Hormone Levels of Estradiol, Progesterone, Prolactin and ß-HCG and Blood Pressure Measurements in Pre-Eclampsia Patients

Background: Preeclampsia is a pregnancy-related hypertensive disease. Aberrant hormone levels have been implicated in blood pressure disorders. This study investigated the association of postpartum maternal serum hormone levels of estradiol, progesterone, prolactin, and ß-HCG with poorer PE-related complications including arterial hypertension. Methods: Thirty patient women with preeclampsia, and twenty women with uncomplicated pregnancy were included in this study. Serum levels of estradiol, progesterone, prolactin, and ß-HCG were determined immediately after delivery, and on the first and third postpartum days by means of ECLIA. Results: Compared with normal pregnancy cases, preeclampsia cases had higher serum levels of ß-HCG levels on Day-0 (319%), of progesterone on Day-0 (207%) and Day-1 (178%), and of estradiol on Day-1 (187%) and Day-3 (185%). Increased prolactin levels were positively associated with disease severity and estradiol and progesterone levels were decreased in poorer preeclampsia features including disease onset and IUGR diagnosis. No significant correlation between different hormone levels and blood pressure measurements was reported. Conclusions: This study is the first that detected postpartum maternal serum hormone levels and their correlation with blood pressure measurements in preeclampsia. We believe that the persistent arterial hypertension in the puerperium in preeclampsia as well as poorer disease specifications are most likely not of hormonal origin. Larger, well-defined prospective studies are recommended.

Relationship between extreme values of first trimester maternal pregnancy associated plasma Protein-A, free-β-human chorionic gonadotropin, nuchal translucency and adverse pregnancy outcomes

OBJECTIVE

The aim of our study was to investigate the relationship between extreme values of first trimester screening markers and adverse obstetric outcomes.

MATERIALS AND METHODS

Our study was conducted by examining the prenatal and postnatal perinatal records of 786 singleton gestations between the ages of 18-40, who applied to Prof. Dr. Cemil Taşçıoğlu City Hospital outpatient clinics for first-trimester screening for aneuploidy, between January 1, 2017 and December 31, 2019.

RESULTS

The presence of small for gestational age (SGA) was found to be statistically significant for the <5 percentile (<0.37) pregnancy-associated plasma protein A (PAPP-A) group (p = 0.016). For <5 percentile β-hCG group, the presence of gestational diabetes mellitus (GDM), premature rupture of membrane (PROM) and preterm premature rupture of membrane (PPROM) was determined as a statistically significant risk (p = 0.015, p = 0.005, p = 0.02 respectively) In the univariate test, fetal death rate was found to be high for ≥90 percentile at nuchal translucency (NT), but the presence of fetal death was found to be statistically insignificant in logistic regression analysis. (p: 0.057).

CONCLUSION

First trimester screening test can be used in predicting pregnancy complications. In this study we found that serum levels of PAPP-A are associated with developing SGA, while GDM, PROM and PPROM are more common in low serum free β-hCG.

Use of FMF algorithm for prediction of preeclampsia in high risk pregnancies: a single center longitudinal study

OBJECTIVE: This study aimed to assess the accuracy of The Fetal Medicine Foundation (FMF) screening algorithm for the prediction of preeclampsia.METHODS: Out of 138 women with high-risk pregnancies prospectively followed, 30 developed preeclampsia. The clinical examination and biochemical measurements were performed at first, second, early and late third trimester.RESULTS: A lower PAPP-A levels were found in the first trimester, while sFlt/PlGF was increased in the second and early third trimester in preeclampsia (p>0.05). FMF algorithm presented higher specificity (>70%), but had a drawback of lower sensitivity (35-77%).CONCLUSION: FMF algorithm had modest performance in the prediction of preeclampsia for high-risk pregnancies.

Predictive Performance of Serum β-hCG MoM Levels for Preeclampsia Screening: A Meta-Analysis

OBJECTIVE

The aim of the present study was to investigate the predictive value of using the multiple of the median (MoM) of β-human chorionic gonadotropin (β-hCG) levels in patients with preeclampsia (PE) and healthy pregnant women.

METHODS

Electronic databases including PubMed, EBSCO, Ovid, Web of Science, China National Knowledge Infrastructure (CNKI), SinoMed, Wangfang and the Weipu Journal were searched up to May 31, 2020. Two reviewers independently selected the articles and extracted data on study characteristics, quality and results. A random-effects model was employed, and standardized mean difference and 95% confidence intervals were calculated. Twenty-one case-control studies were analyzed in the present meta-analysis, including a total of 2,266 cases and 25,872 healthy controls.

RESULTS

Women who were diagnosed with PE were found to have higher early second-trimester levels of serum β-hCG MoM compared with healthy controls, although the levels in the first trimester were not significantly different. Ethnicity subgroup analysis demonstrated that the MoM of β-hCG serum levels was significantly higher in PE patients in both Asian and Caucasian populations during the early second trimester.

CONCLUSION

The MoM of β-hCG serum levels was found to be a valuable clinical indicator for predicting PE in the early second trimester, but had little predictive value in the first trimester. However, further assessment of the predictive capacity of β-hCG within larger, diverse populations is required.

Association between serum beta-human chorionic gonadotropin and inflammation, oxidative stress in pregnancy-induced hypertension

The aberrant increase of circulating beta-human chorionic gonadotropin (β-HCG) at early stages of pregnancy can be used to predict gestational hypertension. However, the association of β-HCG and inflammation, oxidative stress in pregnancy-caused hypertensive disorder on perinatal stage remains unclear. A case-controlled study was performed, with 133 adult pregnant women participated in their perinatal stage. Participants in this research included 45 with mild preeclampsia, 40 with severe preeclampsia and 48 without hypertension. Higher circulating β-HCG level was correlated with severer pregnancy-induced hypertension. Independent contribution of inflammatory factors including interleukin-6, tumor necrosis factor-α and interferon-γ and oxidative stress factors including thiobarbituric acid reactive substance and total antioxidant capacity to severe pregnancy-induced hypertension was significant (P < 0.001). The correlation of circulating β-HCG levels with inflammatory and oxidative stress markers in patients with pregnancy-induced hypertension in perinatal stage was statistically significant.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction

BACKGROUND

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders.

OBJECTIVE AND RATIONALE

The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth.

SEARCH METHODS

An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020).

OUTCOMES

Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR.

WIDER IMPLICATIONS

There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.

Assessment of β-human-derived chorionic gonadotrophic hormone (βhCG) and pregnancy-associated plasma protein A (PAPP-A) levels as predictive factors of preeclampsia in the first trimester among Iranian women: a cohort study

Background

Preeclampsia (PE) is a leading cause of maternal and perinatal mortality. There are controversial findings regarding the prediction of PE through the assessment of the Pregnancy-Associated Plasma Protein A (PAPP-A) and β-Human-Derived Chorionic Gonadotrophic hormone (βhCG) levels in the first trimester of pregnancy. Therefore, this cohort study was conducted to evaluate of PAPP-A and βhCG levels as predictive factors for PE development in the first trimester among Iranian women.

Methods

In this cohort study, a total of 4605 volunteer Primigravida and Multigravida women were selected by the census from 16 randomly selected Health Centers in Isfahan, Iran, from July 2016 to June 2018. Eligible pregnant women participated in the study had already undergone fetal anomalies screening tests between 11 + 0 and 13 + 6 weeks of pregnancy and their PAPP-A and βhCG biomarkers were adjusted to the Multiples of the Median (MOM). MOM PAPP-A <  0.4 and MOM βhCG > 3 were considered abnormal. The samples were followed up until delivery. The biomarkers’ levels were compared in the two groups of women with and without PE and Relative risk (RR) and odds ratio (OR) of PE calculated.

Results

In the PE group, the mean MOM PAPP-A was significantly lower (1 vs. 1.09 with P = 0.006) and MOM βhCG was significantly higher (1.51 vs. 1.14 with P = 0.001) than the group without PE. RR and OR for PE in subjects with MOM PAPP-A <  0.4 were reported as follows: RR = 2.49, (p = 0.001) and OR = 2.09, (p = 0.001). RR and OR for PE in subjects with MOM βhCG > 3 were also reported as follows: RR = 4.02, (p = 0.001) and OR = 5.65, (p = 0.001). Adjusted OR for MOM PAPP-A <  0.4 and MOM βhCG > 3 was obtained as follows: OR = 2.09 (P = 0.001) and OR = 5.65 (P = 0.001), respectively.

Conclusion

The results of the study showed that the high levels of βhCG would cause 5.65 times increase and the low levels of PAPP-A would cause 2.09 times increase in the chance of developing PE.

Human chorionic gonadotropin and risk of pre-eclampsia: prospective population-based cohort study

OBJECTIVES

Abnormal placentation in early pregnancy may play a role in the pathogenesis of pre-eclampsia. Human chorionic gonadotropin (hCG) regulates placental development and angiogenesis and may affect the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) in the serum. The aims of this study were to investigate the association of total hCG with the risk of pre-eclampsia and to examine the potential effect of pro- and anti-angiogenic factors on this association.

METHODS

This was a population-based prospective cohort study of 7754 women with a singleton pregnancy. Total hCG was measured in the first available sample (median gestational age, 14.4 weeks; 95% range, 10.1-26.1 weeks) and sFlt-1 and PlGF concentrations in early (< 18 weeks; median, 13.2 weeks; 95% range, 9.6-17.6 weeks) and in mid- (18-25 weeks; median, 20.4 weeks; 95% range, 18.5-23.5 weeks) pregnancy. We tested the association of hCG concentration and risk of pre-eclampsia using regression analysis, adjusting for maternal age, ethnicity, body mass index, parity, education level, smoking status and fetal sex. Additionally, we assessed whether this association was affected by the sFlt-1/PlGF ratio.

RESULTS

High hCG concentration was associated with a 1.5-2.7-fold increased risk of pre-eclampsia (P = 0.0001), depending on the cut-off used, and with increased sFlt-1/PlGF ratio during early pregnancy (P < 0.0001). The association between high hCG and pre-eclampsia attenuated by roughly 40% after adjustment for early-pregnancy sFlt-1/PlGF ratio (β-estimate change from 0.19 ± 0.10 (P = 0.052) to 0.12 ± 0.10 (P = 0.22)).

CONCLUSIONS

High total hCG concentration in early pregnancy is associated with an increased risk of pre-eclampsia. The effect of high hCG concentration on the balance between pro- and anti-angiogenic factors during pregnancy may have a role in the pathophysiology of pre-eclampsia. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

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.

Genetic and non-genetic risk factors for pre-eclampsia: umbrella review of systematic reviews and meta-analyses of observational studies

OBJECTIVE

To summarize evidence from the literature on genetic and non-genetic risk factors associated with pre-eclampsia (PE), assess the presence of statistical bias in the studies and identify risk factors for which there is robust evidence supporting their association with PE.

METHODS

PubMed and ISI Web of Science were searched from inception to October 2016, to identify systematic reviews and meta-analyses of observational studies examining associations between genetic or non-genetic risk factors and PE. For each meta-analysis, the summary-effect size was estimated using random-effects and fixed-effects models, along with 95% CIs and the 95% prediction interval. Between-study heterogeneity was expressed using the I² statistic, and evidence of small-study effects (large studies had significantly more conservative results than smaller studies) and evidence of excess significance bias (too many studies with statistically significant results) were estimated.

RESULTS

Fifty-eight eligible meta-analyses were identified, which included 1466 primary studies and provided data on 130 comparisons of risk factors associated with PE, covering a wide range of comorbid diseases, genetic factors, exposure to environmental agents and biomarkers. Sixty-five (50%) associations had nominally statistically significant findings at P < 0.05, while 16 (12%) were significant at P < 10^-6 . Sixty-five (50%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 10 (8%) and 26 (20%) associations, respectively. The only non-genetic risk factor with convincing evidence for an association with PE was oocyte donation vs spontaneous conception, which had a summary odds ratio of 4.33 (95% CI, 3.11-6.03), was supported by 2712 cases with small heterogeneity (I²  = 26%) and 95% prediction intervals excluding the null value, and without hints of small-study effects (P for Egger's test > 0.10) or excess of significance (P > 0.05). Of the statistically significant (P < 0.05) genetic risk factors for PE, only PAI-1 4G/5G (recessive model) polymorphism was supported by strong evidence for a contribution to the pathogenesis of PE. Eleven factors (serum iron level, pregnancy-associated plasma protein-A, chronic kidney disease, polycystic ovary syndrome, mental stress, bacterial and viral infections, cigarette smoking, oocyte donation vs assisted reproductive technology, obesity vs normal weight, severe obesity vs normal weight and primiparity) presented highly suggestive evidence for an association with PE.

CONCLUSIONS

A large proportion of meta-analyses of genetic and non-genetic risk factors for PE have caveats that threaten their validity. Oocyte donation vs spontaneous conception and PAI-1 4G/5G polymorphism (recessive model) showed the strongest consistent evidence for an association with risk for PE. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.