Mortality and severe neurological morbidity in extremely preterm growth-restricted fetuses

OBJECTIVE

To develop a model for the prediction of adverse perinatal outcome in growth-restricted fetuses requiring delivery before 28 weeks in order to provide individualized patient counseling.

METHODS

This was a retrospective multicenter cohort study of singleton pregnancies with antenatal suspicion of fetal growth restriction requiring delivery before 28 weeks' gestation between January 2010 and January 2020 in six tertiary public hospitals in the Barcelona area, Spain. Separate predictive models for mortality only and mortality or severe neurological morbidity were created using logistic regression from variables available antenatally. For each model, predictive performance was evaluated using receiver-operating-characteristics (ROC)-curve analysis. Predictive models were validated externally in an additional cohort of growth-restricted fetuses from another public tertiary hospital with the same inclusion and exclusion criteria.

RESULTS

A total of 110 cases were included. The neonatal mortality rate was 37.3% and, among the survivors, the rate of severe neurological morbidity was 21.7%. The following factors were retained in the multivariate analysis as significant predictors of mortality: magnesium sulfate neuroprotection, gestational age at birth, estimated fetal weight, male sex and Doppler stage. This model had a significantly higher area under the ROC curve (AUC) compared with a model including only gestational age at birth (0.810 (95% CI, 0.730-0.889) vs 0.695 (95% CI, 0.594-0.795); P = 0.016). At a 20% false-positive rate, the model showed a sensitivity, negative predictive value and positive predictive value of 66%, 80% and 66%, respectively. For the prediction of the composite adverse outcome (mortality or severe neurological morbidity), the model included: gestational age at birth, male sex and Doppler stage. This model had a significantly higher AUC compared with a model including only gestational age at birth (0.810 (95% CI, 0.731-0.892) vs 0.689 (95% CI, 0.588-0.799); P = 0.017). At a 20% false-positive rate, the model showed a sensitivity, negative predictive value and positive predictive value of 55%, 63% and 74%, respectively. External validation of both models yielded similar AUCs that did not differ significantly from those obtained in the original sample.

CONCLUSIONS

Estimated fetal weight, fetal sex and Doppler stage can be combined with gestational age to improve the prediction of death or severe neurological sequelae in growth-restricted fetuses requiring delivery before 28 weeks. This approach may be useful for parental counseling and decision-making. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Usefulness of angiogenic factors in prenatal counseling of late-onset fetal growth-restricted and small-for-gestational-age gestations: a prospective observational study

OBJECTIVES

To create a predictive model including biomarkers and evaluate its ability to predict adverse perinatal outcomes in late-onset small fetuses, ultimately helping to provide individualized counseling at the time of diagnosis.

METHODS

This was a prospective observational study, including singleton pregnancies with an estimated fetal weight (EFW) below the 10th percentile, at a gestational age between 32 + 0 and 36 + 6 weeks of gestation (WG). Variables recorded at diagnosis to predict adverse pregnancy outcomes were: soluble fms-like tyrosine-kinase-1 to placental growth factor ratio (sFlt-1/PlGF), fetal Doppler (umbilical artery and middle cerebral artery), uterine artery pulsatility index (UtAPI), EFW percentile, gestational age, and the presence of maternal risk factors for placental insufficiency. Logistic regression models were developed for the prediction of three co-primary outcomes: composite adverse perinatal outcomes (APO), and the need for elective delivery before 35 or 37 WG.

RESULTS

Sixty (52.2%) fetal growth restricted (FGR) and 55 (47.8%) small for gestational age (SGA) were enrolled. Thirteen (11.3%) women needed elective delivery before 35 WG and 27 (23.5%) women before 37 WG. At least one APO occurred in 43 (37.4%) pregnancies. The best marker in univariate analyses was the sFlt-1/PlGF ratio [AUC = 0.932 (95% CI, 0.864-0.999)]. The multivariate model including sFlt-1/PlGF showed a better predictive performance for APO than the multivariate model without sFlt-1/PlGF (P < 0.024).

CONCLUSIONS

sFlt-1/PlGF is a good predictor of APO at the time of late-onset FGR/SGA diagnosis. Our predictive models may be useful to provide early individualized prenatal counseling in this group of women. Further studies are needed to validate these preliminary findings in a larger cohort.

First-trimester screening for pre-eclampsia and small for gestational age: A comparison of the gaussian and Fetal Medicine Foundation algorithms

OBJECTIVE

Pre-eclampsia (PE) and small for gestational age (SGA) can be predicted from the first trimester. The most widely used algorithm worldwide is the Fetal Medicine Foundation (FMF) algorithm. The recently described Gaussian algorithm has reported excellent results although it is unlikely to be externally validated. Therefore, as an alternative approach, we compared the predictive accuracy for PE and SGA of the Gaussian and FMF algorithms.

METHODS

Secondary analysis of a prospective cohort study was conducted at Vall d'Hebron University Hospital (Barcelona) with 2641 singleton pregnancies. The areas under the curve for the predictive performance for early-onset and preterm PE and early-onset and preterm SGA were calculated with the Gaussian and FMF algorithms and subsequently compared.

RESULTS

The FMF and Gaussian algorithms showed a similar predictive performance for most outcomes and marker combinations. Nevertheless, significant differences for early-onset PE prediction favored the Gaussian algorithm in the following combinations: mean arterial blood pressure (MAP) with pregnancy-associated plasma protein A, MAP with placental growth factor, and MAP alone.

CONCLUSIONS

The first-trimester Gaussian and FMF algorithms have similar performances for PE and SGA prediction when applied with all markers within a routine care setting in a Spanish population, adding evidence to the external validity of the FMF algorithm.

Confirmation of preeclampsia-like syndrome induced by severe COVID-19: an observational study

BACKGROUND

Since the outbreak of the COVID-19 pandemic, some studies have reported an increased preeclampsia incidence in pregnant women with SARS-CoV-2 infection. Several explanations for this association have been proposed, including a preeclampsia-like syndrome induced by severe COVID-19. This syndrome was described in a small case series and has not been confirmed in larger studies, and its effect on perinatal outcomes has not been studied.

OBJECTIVE

This study aimed to confirm the preeclampsia-like syndrome because of COVID-19 and to investigate its implications on pregnancy outcomes and prognosis.

STUDY DESIGN

This was a prospective, observational study conducted in a tertiary referral hospital. The inclusion criteria were pregnant women admitted to the intensive care unit for severe pneumonia because of COVID-19. They were classified into 3 groups based on clinical and laboratory findings: preeclampsia, preeclampsia-like syndrome, and women without preeclampsia features. The 3 cohorts were analyzed and compared at 3 different times: before, during, and after severe pneumonia. The main outcomes were incidence of adverse perinatal outcomes and signs and symptoms of PE, such as hypertension, proteinuria, thrombocytopenia, elevated liver enzymes, and increased angiogenic factors (soluble fms-like tyrosine kinase 1-to-placental growth factor ratio).

RESULTS

A total of 106 women were admitted to the intensive care unit because of severe pneumonia, and 68 women were included in the study. Of those, 53 (50.0%) did not meet the diagnostic criteria for preeclampsia and remained pregnant after pneumonia (non-preeclampsia); 7 (6.6%) met the diagnostic criteria for preeclampsia, had abnormal (>38) soluble fms-like tyrosine kinase 1-to-placental growth factor ratio (preeclampsia), and delivered during severe pneumonia, and 8 (7.5%) met the diagnostic criteria for preeclampsia, had normal (≤38) soluble fms-like tyrosine kinase 1-to-placental growth factor ratio (preeclampsia like), and did not deliver during pneumonia. Despite not having delivered, most preeclampsia-related features improved after severe pneumonia in women with preeclampsia-like syndrome. Women with preeclampsia had significantly poorer outcomes than women with preeclampsia-like syndrome or without preeclampsia.

CONCLUSION

More than 50% of women with severe COVID-19 and diagnostic criteria for preeclampsia may not be preeclampsia but a preeclampsia-like syndrome, which may affect up to 7.5% of women with severe COVID-19. Preeclampsia-like syndrome might have similar perinatal outcomes to those of normotensive women with severe pneumonia because of COVID-19. For these reasons, preeclampsia-like syndrome should be excluded by using soluble fms-like tyrosine kinase 1-to-placental growth factor ratio in future research and before making clinical decisions.

sFlt-1 to PlGF ratio cut-offs to predict adverse pregnancy outcomes in early-onset FGR and SGA: a prospective observational study

This is a prospective, observational study, conducted in a tertiary referral hospital. We enrolled 175 singleton pregnancies with estimated foetal weight below the 10th centile between 20 + 0 and 31 + 6 weeks. Placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and fetoplacental circulation were assessed at the time of diagnosis. Receiver operating characteristic curves were used to assess the performance of sFlt-1/PlGF for predicting adverse perinatal outcomes (APO). The optimal cut-offs to predict each adverse outcome were calculated and the resulting areas under the curve (AUC) were compared to those calculated from the cut-off points of 38, 85 and 110. The need for delivery at <30 and <34 weeks and APO were the main outcome measures. The optimal cut-off points to predict APO, delivery <30 and <34 weeks were 24.9, 116.7 and 97.5, respectively. None of them proved to be superior to 38, 85 or 110 for predicting any adverse pregnancy outcome. Impact StatementWhat is already known on this subject? Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are biomarkers of placental dysfunction. High sFlt-1/PlGF values predict adverse perinatal outcomes in preeclampsia (PE).What do the results of this study add? No specific thresholds have been described to identify early-onset foetal growth restriction (FGR) and small for gestational age (SGA) foetuses at higher risk of adverse outcomes. This study describes these specific cut-offs and compares their predictive capacity to those described for PE.What are the implications of these findings for clinical practice and/or further research? The sFlt-1/PlGF cut-off points of 38, 85 and 110 might be useful for ruling out the occurrence of APO and the need for elective delivery at <30 and at <34 weeks from the moment of diagnosis in early-onset FGR and SGA. These cut-offs could aid Doppler studies in the distinction between FGR and SGA.

Shared risk factors for COVID-19 and preeclampsia in the first trimester: An observational study

INTRODUCTION

The association between preeclampsia and coronavirus disease 2019 (COVID-19) is under study. Previous publications have hypothesized the existence of shared risk factors for both conditions or a deficient trophoblastic invasion as possible explanations for this association. The primary aim of this study was to examine baseline risk factors measured in the first-trimester combined screening for preeclampsia in pregnant women with COVID-19 compared with the general population. A secondary aim of this study was to compare risk factors among patients with mild and severe COVID-19.

MATERIAL AND METHODS

This was an observational retrospective study conducted at Vall d'Hebron Hospital Campus (Catalonia, Spain). Study patients were 231 pregnant women undergoing the first-trimester screening for preeclampsia and positive for severe acute respiratory syndrome coronavirus 2 between February 2020 and September 2021. The reference cohort were 13 033 women of the general population from six centers across Catalonia from May 2019 to June 2021. Based on the need for hospitalization, patients were classified in two groups: mild and severe COVID-19. First-trimester screening for preeclampsia included maternal history, mean arterial blood pressure, mean uterine artery pulsatility index (UtAPI), placental growth factor (PlGF), and pregnancy-associated plasma protein-A (PAPP-A).

RESULTS

The proportion of cases at high risk for preeclampsia was significantly higher among the COVID-19 group compared with the general population (19.0% and 13.2%, respectively; p = 0.012). When analyzing risk factors for preeclampsia individually, women with COVID-19 had higher median body mass index (25.2 vs 24.5, p = 0.041), higher UtAPI multiple of the median (MoM) (1.08 vs 1.00, p < 0.001), higher incidence of chronic hypertension (2.8% vs 0.9%, p = 0.015), and there were fewer smokers (5.7% vs 11.6%, p = 0.007). The MoMs of PlGF and PAPP-A did not differ significantly between both groups (0.96 vs 0.97, p = 0.760 and 1.00 vs 1.01, p = 0.432; respectively).

CONCLUSIONS

In patients with COVID-19, there was a higher proportion of women at high risk for preeclampsia at the first-trimester screening than in the general population, mainly because of maternal risk factors, rather than placental signs of a deficient trophoblastic invasion.

Implementation of routine first-trimester combined screening for preeclampsia based on the Gaussian algorithm: A clinical effectiveness study

OBJECTIVE

To evaluate the clinical effectiveness of the routine first-trimester screening for preeclampsia (PE) after being implemented in six Catalan maternities.

METHODS

Participants in the reference group were recruited prospectively between October 2015 and September 2017. Participants in the study group were recruited retrospectively between November 2018 and May 2019, after implementing the screening program. PE risk was assessed between 11 + 0 and 13 + 6 weeks of gestation using the Gaussian algorithm combining maternal characteristics, mean arterial blood pressure, uterine artery pulsatility index, and maternal serum pregnancy-associated plasma protein-A. Women with a risk ≥1/137 were prescribed daily salicylic acid (150 mg) until 36 weeks of gestation.

RESULTS

Preterm PE occurred in 30 of 2641 participants (1.14%) in the reference group, as compared with 18 of 2848 participants (0.63%) in the study group (OR: 0.55; 95% CI, 0.31-0.99; P = 0.045). In the reference group, 37 participants (1.40%) were admitted to ICU, as compared with 23 participants (0.81%) in the study group (OR: 0.57; 95% CI, 0.34-0.96; P = 0.035).

CONCLUSION

The routine first-trimester PE screening can be implemented in a public healthcare setting, leading to a significant reduction in the incidence of preterm PE and of maternal ICU admission.

Angiogenic factors for planning fetal surveillance in fetal growth restriction and small-for-gestational-age fetuses: A prospective observational study

Objective

The aim of this study was to assess the added value of the soluble fms‐like tyrosine kinase‐1 (sFlt‐1) and placental growth factor (PlGF) ratio for adjusting the periodicity of ultrasound examinations in early‐onset fetal growth restriction (FGR) and small for gestational age (SGA).

Design

A prospective, observational study.

Setting

Tertiary referral hospital.

Population

One hundred and thirty‐four single pregnancies with ultrasonographic estimated fetal weight (EFW) below the 10th centile between 20⁺⁰ and 31⁺⁶ weeks of gestation with antegrade umbilical artery flow.

Methods

The time from Doppler and sFlt‐1/PlGF assessment to delivery was recorded and classified into four ranges: <1, <2, <3 and <4 weeks.

Main outcome measures

Sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of sFlt‐1/PlGF values to predict the time to delivery.

Results

In the SGA cohort, the NPV calculated for an sFlt‐1/PlGF cut‐off value of 38 was 100% for delivery before 3 weeks, and 98% for delivery before 4 weeks after diagnosis (95% CI 0.89–1.00). In the FGR cohort, the NPV calculated for an sFlt‐1/PlGF cut‐off value of 38 was 100% for delivery before 2 weeks after diagnosis (95% CI 0.92–1.00). By contrast, more than 50% of cases with an sFlt‐1/PlGF value of >85 required an elective delivery before 1 week.

Conclusions

sFlt‐1/PlGF values in early‐onset SGA and FGR are predictive of the time to delivery and could be used for planning fetal surveillance, by reducing the frequency of ultrasound in cases with sFlt‐1/PlGF < 38 and by providing closer follow‐up in cases with sFlt‐1/PlGF >85.

Tweetable abstract

sFlt‐1/PlGF values in early‐onset SGA/FGR could be used in addition to Doppler for planning fetal surveillance.

sFlt‐1/PlGF values in early‐onset SGA/FGR could be used in addition to Doppler for planning fetal surveillance.

Linked article: This article is commented on by Cecilia Villalaín, pp. 1878 in this issue. To view this minicommentary visit https://doi.org/10.1111/1471‐0528.17172