Prediction and prevention of small-for-gestational-age neonates: evidence from SPREE and ASPRE

First-trimester uterine artery Doppler and hypertensive disorders in twin pregnancies: Use of twin versus singleton references

OBJECTIVE

To determine the association of first-trimester uterine artery Doppler with hypertensive disorders of pregnancy in twin pregnancies.

METHODS

This was a retrospective cohort study of twin pregnancies followed at the University Hospital Center of Central Lisbon, Portugal, between January 2010 and December 2022. First-trimester uterine artery pulsatility index (UtA-PI) was determined and compared between twin pregnancies (n = 454) and singleton pregnancies (n = 908), matched to maternal and pregnancy characteristics. Maternal characteristics and mean UtA-PI were analyzed for gestational age, birth weight, gestational hypertension, early- and late-onset pre-eclampsia, HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, and preterm birth. Univariable and multivariable logistic regression models were used.

RESULTS

The mean first-trimester UtA-PI was significantly lower in dichorionic twins than in singletons (P < 0.001). To study hypertensive disorders of pregnancy in twins, 390 pregnancies were included: 311 (79.7%) dichorionic and 79 (20.3%) monochorionic twins. The observed rates of early- and late-onset pre-eclampsia, gestational hypertension, and HELLP syndrome were 1.0%, 4.4%, 7.4%, and 1.5%, respectively. We achieved a 100% detection rate for early-onset pre-eclampsia using the UtA-PI 90th centile for twins. However, when singleton references were considered, the detection rate decreased to 50%. UtA-PI at or above the 95th centile was associated with increased odds for preterm birth before 32 weeks (adjusted odds ratio 4.1, 95% confidence interval 1.0-16.7, P = 0.043).

CONCLUSIONS

Unless other major risk factors for hypertensive disorders are present, women with low UtA-PI will probably not benefit from aspirin prophylaxis. Close monitoring of all twin pregnancies for hypertensive disorders is still recommended.

Redesigning antenatal care: Prospective use of an implementation framework to establish a population-based multidisciplinary first-trimester screening, assessment and prevention service

BACKGROUND

Australian rates of adverse obstetric outcomes have improved little despite guidelines recommending history-based screening and intervention. The first trimester provides a unique opportunity to predict and prevent complications, yet population-based screening has failed to be translated into broad clinical practice.

AIMS

This study aimed to redesign antenatal care within an Australian public healthcare centre to align with evidence-based maternity care, including population-based first-trimester screening with early initiation of preventative strategies in high-risk pregnancies.

METHODS

A five-phase action-process model, sharing key elements with implementation science theory, was used to explore barriers to change in antenatal care, co-design a novel service with consumers and establish a population-based antenatal pathway commencing with a multidisciplinary first-trimester screening, assessment and planning visit.

RESULTS

The case for change and associated barriers were defined from the perspective of antenatal care stakeholders. Key needs of each group were established, and solutions were created using co-design methodology, allowing the team to create a novel approach to antenatal care which directly addressed identified barriers. Implementation of the service was associated with a fall in the median gestation at first specialist maternity care provider visit from 20 to 13 weeks.

CONCLUSIONS

This study confirms the feasibility of establishing a comprehensive first-trimester screening program within a public Australian healthcare setting and highlights a co-design process which places individualised assessment at the forefront of antenatal care. This framework may be applicable to most public maternity settings in Australia, with expansion aimed at providing equity of care, including in rural and remote settings.

First-trimester serum biomarkers in twin pregnancies and adverse obstetric outcomes-a single center cohort study

PURPOSE

This study aimed to determine the association of first-trimester maternal serum biomarkers with preterm birth (PTB), fetal growth restriction (FGR) and hypertensive disorders of pregnancy (HDP) in twin pregnancies.

METHODS

This is a retrospective cohort study of twin pregnancies followed at Maternidade Dr. Alfredo da Costa, Lisbon, Portugal, between January 2010 and December 2022. We included women who completed first-trimester screening in our unit and had ongoing pregnancies with two live fetuses, and delivered after 24 weeks. Maternal characteristics, pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (β-hCG) levels were analyzed for different outcomes: small for gestational age (SGA), gestational hypertension (GH), early and late-onset pre-eclampsia (PE), as well as the composite outcome of PTB associated with FGR and/or HDP. Univariable, multivariable logistic regression analyses and receiver-operating characteristic curve were used.

RESULTS

466 twin pregnancies met the inclusion criteria. Overall, 185 (39.7%) pregnancies were affected by SGA < 5th percentile and/or HDP. PAPP-A demonstrated a linear association with gestational age at birth and mean birth weight. PAPP-A proved to be an independent risk factor for SGA and PTB (< 34 and < 36 weeks) related to FGR and/or HDP. None of the women with PAPP-A MoM > 90th percentile developed early-onset PE or PTB < 34 weeks.

CONCLUSION

A high serum PAPP-A (> 90th percentile) ruled out early-onset PE and PTB < 34 weeks. Unless other major risk factors for hypertensive disorders are present, these women should not be considered candidates for aspirin prophylaxis. Nevertheless, close monitoring of all TwP for adverse obstetric outcomes is still recommended.

Adverse pregnancy outcomes in women at increased risk of preterm pre-eclampsia on first-trimester combined screening

OBJECTIVE

Uteroplacental dysfunction may not only result in pre-eclampsia (PE) but also in preterm birth (PTB), small-for-gestational-age (SGA) birth and stillbirth. The aim of this study is to evaluate the positive predictive value (PPV) of first-trimester combined PE screening for all of these placenta-mediated adverse pregnancy outcomes.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral maternity unit.

SAMPLE

A total of 13 211 singleton pregnancies.

METHODS

First-trimester combined screening for preterm PE using the Fetal Medicine Foundation (FMF) algorithm.

MAIN OUTCOMES MEASURES

Hypertensive disorders of pregnancy (HDP), PTB, SGA birth and stillbirth were combined to assess composite adverse and severe adverse pregnancy outcomes (CAPO and CAPO-S). The PPVs for CAPO and CAPO-S were calculated for women with a combined risk for preterm PE of ≥1 in 50 and ≥1 in 100.

RESULTS

First-trimester combined screening identified 2215 women (16.8%) with a risk of ≥1 in 100 for preterm PE. The PPVs for a risk of ≥1 in 100 for CAPO and CAPO-S were 38.8% and 18.2%, respectively. The equivalent PPVs for a risk of ≥1 in 50 were 45.1% and 21.1%, respectively.

CONCLUSIONS

Women identified at high risk of preterm PE are also at increased risk of other placenta-mediated adverse pregnancy outcomes, such as PTB, SGA birth and stillbirth. Women at high risk for preterm PE after first-trimester screening may benefit from a higher surveillance care pathway, with interventions to mitigate all the adverse outcomes associated with placental dysfunction.

First trimester prediction models for small-for- gestational age and fetal growth restricted fetuses without the presence of preeclampsia

We established efficient first trimester prediction models for small-for-gestational age (SGA) and fetal growth restriction (FGR) without the presence of preeclampsia (PE) regardless of the gestational age of the onset of the disease [early FGR occurring before 32 gestational week or late FGR occurring after 32 gestational week]. The retrospective study was performed on singleton Caucasian pregnancies (n = 6440) during the period 11/2012-3/2020. Finally, 4469 out of 6440 pregnancies had complete medical records since they delivered in the Institute for the Care of Mother and Child, Prague, Czech Republic. The study included all cases diagnosed with SGA (n = 37) or FGR (n = 82) without PE, and 80 selected normal pregnancies. Four microRNAs (miR-1-3p, miR-20a-5p, miR-146a-5p, and miR-181a-5p) identified 75.68 % SGA cases at 10.0 % false positive rate (FPR). Eight microRNAs (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-126-3p, miR-130b-3p, miR-146a-5p, miR-181a-5p, and miR-499a-5p) identified 83.80 % SGA cases at 10.0 % FPR. The prediction model for SGA based on microRNAs was further improved via implementation of maternal clinical characteristics [maternal age and BMI, an infertility treatment by assisted reproductive technology (ART), first trimester screening for PE and/or FGR and for spontaneous preterm, both by FMF algorithm]. Then 81.08 % and 89.19 % pregnancies developing SGA were identified at 10.0 % FPR in case of utilization of 4 microRNA and 8 microRNA biomarkers. Simplified prediction model for SGA based on limited number of maternal clinical characteristics (maternal age and BMI, an infertility treatment by ART, and 4 microRNAs) does not improve the detection rate of SGA (70.27 % SGA cases at 10.0 % FPR) when compared with prediction model for SGA based just on the expression profile of 4 or 8 microRNAs biomarkers. Seven microRNAs only (miR-16-5p, miR-20a-5p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-342-3p, and miR-574-3p) identified 42.68 % FGR cases at 10.0 % FPR (AUC 0.725). However, the combination of 10 microRNAs only (miR-16-5p, miR-20a-5p, miR-100-5p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-195-5p, miR-342-3p, and miR-574-3p) reached a higher discrimination power (AUC 0.774). It identified 40.24 % FGR cases at 10.0 % FPR. The prediction model for any subtype of FGR based on microRNAs was further improved via implementation of maternal clinical characteristics [maternal age and BMI, an infertility treatment by ART, the parity (nulliparity), the occurrence of SGA or FGR in previous gestation, and the occurrence of any autoimmune disorder, and the presence of chronic hypertension]. Then 64.63 % and 65.85 % pregnancies destinated to develop FGR were identified at 10.0 % FPR in case of utilization of 7 microRNA biomarkers or 10 microRNA biomarkers. When other clinical variables next to those ones mentioned above such as first trimester screening for PE and/or FGR and for spontaneous preterm, both by FMF algorithm, were added to the prediction model for FGR, the detection power was even increased to 74.39 % cases and 78.05 % cases at 10.0 % FPR.

Clinical effectiveness of routine first-trimester combined screening for pre-eclampsia in Spain with the addition of placental growth factor

INTRODUCTION

Pre-eclampsia affects 2%-8% of pregnancies and is one of the leading causes of maternal and perinatal morbidity and mortality. First-trimester screening using an algorithm that combines maternal characteristics, mean arterial blood pressure, uterine artery pulsatility index and biomarkers (pregnancy-associated plasma protein-A and placental growth factor) is the method that achieves a greater diagnostic accuracy. It has been shown that daily salicylic acid administration before 16 weeks in women at a high risk for pre-eclampsia can reduce the incidence of preterm pre-eclampsia. However, no previous studies have evaluated the impact of routine first-trimester combined screening for pre-eclampsia with placental growth factor after being implemented in the clinical practice.

MATERIAL AND METHODS

This was a multicenter cohort study conducted in eight different maternities across Spain. Participants in the reference group were prospectively recruited between October 2015 and September 2017. Participants in the study group were retrospectively recruited between March 2019 and May 2021. Pre-eclampsia risk was calculated between 11+0 and 13+6  weeks using the Gaussian algorithm combining maternal characteristics, mean arterial pressure, uterine arteries pulsatility index, pregnancy-associated plasma protein-A and placental growth factor. Patients with a risk greater than 1/170 were prescribed daily salicylic acid 150 mg until 36 weeks. Patients in the reference group did not receive salicylic acid during gestation.

RESULTS

A significant reduction was observed in preterm pre-eclampsia (OR 0.47; 95% CI: 0.30-0.73), early-onset (<34 weeks) pre-eclampsia (OR 0.35; 95% CI: 0.16-0.77), preterm small for gestational age newborn (OR 0.57; 95% CI: 0.40-0.82), spontaneous preterm birth (OR 0.72; 95% CI: 0.57-0.90), and admission to intensive care unit (OR 0.55; 95% CI: 0.37-0.81). A greater treatment adherence resulted in a significant reduction in adverse outcomes.

CONCLUSIONS

Routine first-trimester screening for pre-eclampsia with placental growth factor leads to a reduction in preterm pre-eclampsia and other pregnancy complications. Aspirin treatment compliance has a great impact on the effectiveness of this screening program.

Directive clinique no 442 : Retard de croissance intra-utérin : Dépistage, diagnostic et prise en charge en contexte de grossesse monofœtale

OBJECTIF

Le retard de croissance intra-utérin est une complication obstétricale fréquente qui touche jusqu'à 10 % des grossesses dans la population générale et qui est le plus souvent due à une pathologie placentaire sous-jacente. L'objectif de la présente directive clinique est de fournir des déclarations sommaires et des recommandations pour appuyer un protocole clinique de dépistage, diagnostic et prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes.

POPULATION CIBLE

Toutes les patientes enceintes menant une grossesse monofœtale. BéNéFICES, RISQUES ET COûTS: La mise en application des recommandations de la présente directive devrait améliorer la compétence des cliniciens quant à la détection du retard de croissance intra-utérin et à la réalisation des interventions indiquées. DONNéES PROBANTES: La littérature publiée a été colligée par des recherches effectuées jusqu'en septembre 2022 dans les bases de données PubMed, Medline, CINAHL et Cochrane Library en utilisant un vocabulaire contrôlé au moyen de termes MeSH pertinents (fetal growth retardation and small for gestational age) et de mots-clés (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. La littérature grise a été obtenue par des recherches menées dans des sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, des registres d'essais cliniques et des sites Web de sociétés de spécialité médicale nationales et internationales. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Obstétriciens, médecins de famille, infirmières, sages-femmes, spécialistes en médecine fœto-maternelle, radiologistes et autres professionnels de la santé qui prodiguent des soins aux patientes enceintes. RéSUMé POUR TWITTER: Mise à jour de la directive sur le dépistage, le diagnostic et la prise en charge du retard de croissance intra-utérin pour les grossesses à risque ou atteintes. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS: Prédiction du retard de croissance intra-utérin Prévention du retard de croissance intra-utérin Détection du retard de croissance intra-utérin Examens en cas de retard de croissance intra-utérin soupçonné Prise en charge du retard de croissance intra-utérin précoce Prise en charge du retard de croissance intra-utérin tardif Prise en charge du post-partum et consultations préconception.

Guideline No. 442: Fetal Growth Restriction: Screening, Diagnosis, and Management in Singleton Pregnancies

OBJECTIVE

Fetal growth restriction is a common obstetrical complication that affects up to 10% of pregnancies in the general population and is most commonly due to underlying placental diseases. The purpose of this guideline is to provide summary statements and recommendations to support a clinical framework for effective screening, diagnosis, and management of pregnancies that are either at risk of or affected by fetal growth restriction.

TARGET POPULATION

All pregnant patients with a singleton pregnancy.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should increase clinician competency to detect fetal growth restriction and provide appropriate interventions.

EVIDENCE

Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library through to September 2022 using appropriate controlled vocabulary via MeSH terms (fetal growth retardation and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, FGR, low birth weight, small for gestational age, Doppler, placenta, pathology). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Grey literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Table A1 for definitions and Table A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for pregnant patients.

TWEETABLE ABSTRACT

Updated guidelines on screening, diagnosis, and management of pregnancies at risk of or affected by FGR.

SUMMARY STATEMENTS

RECOMMENDATIONS: Prediction of FGR Prevention of FGR Detection of FGR Investigations in Pregnancies with Suspected Fetal Growth Restriction Management of Early-Onset Fetal Growth Restriction Management of Late-Onset FGR Postpartum management and preconception counselling.

The Role of Acetylsalicylic Acid in the Prevention of Pre-Eclampsia, Fetal Growth Restriction, and Preterm Birth

BACKGROUND

Recent studies suggest that low-dose acetylsalicylic acid (ASA) can lower pregnancy-associated morbidity.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in PubMed, with special attention to systematic reviews, metaanalyses, and randomized controlled trials.

RESULTS

Current meta-analyses document a reduction of the risk of the occurrence of pre-eclampsia (RR 0.85, NNT 50), as well as beneficial effects on the rates of preterm birth (RR 0.80, NNT 37), fetal growth restriction (RR 0.82, NNT 77), and perinatal death (RR 0.79, NNT 167). Moreover, there is evidence that ASA raises the rate of live births after a prior spontaneous abortion, while also lowering the rate of spontaneous preterm births (RR 0.89, NNT 67). The prerequisites for therapeutic success are an adequate ASA dose, early initiation of ASA, and the identification of women at risk of pregnancy-associated morbidity. Side effects of treatment with ASA in this patient group are rare and mainly involve bleeding in connection with the pregnancy (RR 0.87, NNH 200).

CONCLUSION

ASA use during pregnancy has benefits beyond reducing the risk of pre-eclampsia. The indications for taking ASA during pregnancy may be extended at some point in the future; at present, in view of the available evidence, it is still restricted to high-risk pregnancies.

Screening for Preeclampsia and Fetal Growth Restriction in the First Trimester in Women without Chronic Hypertension

BACKGROUND

Nowadays, it is possible to identify a group at increased risk of preeclampsia (PE) and fetal growth restriction (FGR) using the principles of the Fetal Medicine Foundation (FMF). It has been established for several years that acetylsalicylic acid (ASA) reduces the incidence of PE and FGR in high-risk populations. This study aimed to evaluate the implementation of ASA use after the first-trimester screening in a Polish population without chronic hypertension, as well as its impact on perinatal complications.

MATERIAL AND METHODS

A total of 874 patients were enrolled in the study during the first-trimester ultrasound examination. The risk of PE and FGR was assessed according to the FMF guidelines, which include the maternal history, mean arterial pressure (MAP), uterine artery pulsatility index (UtPI), pregnancy-associated plasma protein A (PAPP-A) and placental growth factor (PLGF). Among patients with a risk higher than >1:100, ASA was administered at a dose of 150 mg. Perinatal outcomes were assessed among the different groups.

RESULTS

When comparing women in the high-risk group with those in the low-risk group, a statistically significantly higher risk of pregnancy complications was observed in the high-risk group. These complications included pregnancy-induced hypertension (PIH) (OR 3.6 (1.9-7)), any PE (OR 7.8 (3-20)), late-onset PE (OR 8.5 (3.3-22.4)), FGR or small for gestational age (SGA) (OR 4.8 (2.5-9.2)), and gestational diabetes mellitus type 1 (GDM1) (OR 2.4 (1.4-4.2)). The pregnancies in the high-risk group were more likely to end with a cesarean section (OR 1.9 (1.2-3.1)), while the newborns had significantly lower weights (<10 pc (OR 2.9 (1.2-6.9)), <3 pc (OR 10.2 (2.5-41.7))).

CONCLUSIONS

The first-trimester screening test for PE and FGR is a necessary and effective tool in identifying high-risk pregnancies. ASA prophylaxis among high-risk patients may have the most beneficial effect. Furthermore, this screening tool may significantly reduce the incidence of early-onset PE (eo-PE).

Implementing Preeclampsia Screening in Switzerland (IPSISS): First Results from a Multicentre Registry

INTRODUCTION

The Fetal Medicine Foundation (FMF) London developed a first trimester combined screening algorithm for preterm preeclampsia (pPE) that allows a significantly higher detection of pregnancies at risk compared to conventional screening by maternal risk factors only. The aim of this trial is to validate this screening model in the Swiss population in order to implement this screening into routine first trimester ultrasound and to prescribe low-dose aspirin 150 mg (LDA) in patients at risk for pPE. Therefore, a multicentre registry study collecting and screening pregnancy outcome data was initiated in 2020; these are the preliminary results.

METHODS

Between June 1, 2020, and May 31, 2021, we included all singleton pregnancies with pPE screening at the hospitals of Basel, Lucerne, and Bern. Multiple of medians of uterine artery pulsatility index (UtA-PI), mean arterial pressure (MAP), placental growth factor (PlGF), and pregnancy-associated plasma protein A (PAPP-A) as well as risks were analysed as calculated by each centre's software and recalculated on the FMF online calculator for comparative reasons. Statistical analyses were performed by GraphPad Version 9.1.

RESULTS

During the study period, 1,027 patients with singleton pregnancies were included. 174 (16.9%) had a risk >1:100 at first trimester combined screening. Combining the background risk, MAP, UtA-PI, and PlGF only, the cut-off to obtain a screen positive rate (SPR) of 11% is ≥1:75. Outcomes were available for 968/1,027 (94.3%) of all patients; 951 resulted in live birth. Fifteen (1.58%) developed classical preeclampsia (PE), 23 (2.42%) developed PE according to the International Society for the Study of Hypertension in Pregnancy (ISSHP) definition.

CONCLUSION

First trimester combined screening for PE and prevention with LDA results in a low prevalence of PE. The screening algorithm performs according to expectations; however, the cut-off of >1:100 results in a SPR above the accepted range and a cut-off of ≥1:75 should be considered for screening. More data are needed to evaluate, if these results are representative for the general Swiss population.

Fetal Growth Restriction Is Associated with Pregnancy Associated Plasma Protein A and Uterine Artery Doppler in First Trimester

Fetal growth restriction (FGR) is a major cause of stillbirth and poor neurodevelopmental outcomes. The early prediction may be important to establish treatment options and improve neonatal outcomes. The aim of this study was to assess the association of parameters used in first-trimester screening, uterine artery Doppler pulsatility index and the development of FGR. In this retrospective cohort study, 1930 singleton pregnancies prenatally diagnosed with an estimated fetal weight under the third percentile were included. All women underwent first-trimester screening assessing maternal serum pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotrophin levels, fetal nuchal translucency and uterine artery Doppler pulsatility index (PI). We constructed a Receiver Operating Characteristics curve to calculate the sensitivity and specificity of early diagnosis of FGR. In pregnancies with FGR, PAPP-A was significantly lower, and uterine artery Doppler pulsatility index was significantly higher compared with the normal birth weight group (0.79 ± 0.38 vs. 1.15 ± 0.59, p < 0.001 and 1.82 ± 0.7 vs. 1.55 ± 0.47, p = 0.01). Multivariate logistic regression analyses demonstrated that PAPP-A levels and uterine artery Doppler pulsatility index were significantly associated with FGR (p = 0.009 and p = 0.01, respectively). To conclude, these two parameters can predict FGR < 3rd percentile.

Is mid-gestational uterine artery Doppler still useful in a setting with routine first-trimester pre-eclampsia screening? A cohort study

OBJECTIVE

To evaluate whether routine mid-gestational uterine artery Doppler (UtAD) modifies the risk for preterm pre-eclampsia after first-trimester combined pre-eclampsia screening.

DESIGN

Retrospective cohort study.

SETTING

London Tertiary Hospital.

POPULATION

A cohort of 7793 women with singleton pregnancies, first-trimester pre-eclampsia screening using the Fetal Medicine Foundation (FMF) algorithm and UtAD pulsatility index (PI) assessment at the mid-gestation ultrasound.

METHODS

Pregnancies were divided into four groups: high risk in both trimesters (H¹ H² ), high risk in the first but not in the second trimester (H¹ L² ), low risk in the first but high risk in the second trimester (L¹ H² ) and low risk in both trimesters (L¹ L² ).

MAIN OUTCOME MEASURES

Small for gestational age (SGA), hypertensive disorders of pregnancy (HDP) and stillbirth.

RESULTS

In this cohort, 600 (7.7%) and 620 (7.9%) women were designated as being at high risk in the first and second trimesters, respectively. Preterm pre-eclampsia was more prevalent in the H¹ L² group (4.5%) than in women considered at low risk in the first trimester (0.4%, p < 0.0001). The prevalence of preterm pre-eclampsia in the L¹ H² group (3.3%) was significantly lower than that in women considered at high risk in the first trimester (7.0%, p = 0.0076), and was higher than that observed in the L¹ L² group (0.2%, p < 0.0001). The prevalence of SGA and term HDP followed similar trends.

CONCLUSIONS

Pre-eclampsia risk after first-trimester FMF pre-eclampsia screening may be stratified through mid-gestational routine UtAD assessment. Pregnancy care should not be de-escalated for low mid-gestational UtAD resistance in women classified as being at high risk in the first trimester. The escalation of care may be justified in women at low risk but with high mid-gestational UtAD resistance.

Comparison of the Soluble fms-Like Tyrosine Kinase 1/Placental Growth Factor Ratio Alone versus a Multi-Marker Regression Model for the Prediction of Preeclampsia-Related Adverse Outcomes after 34 Weeks of Gestation

INTRODUCTION

The objective of this retrospective study was to compare the predictive performance of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio alone or in a multi-marker regression model for preeclampsia-related maternal and/or fetal adverse outcomes in women >34 weeks of gestation.

METHODS

We analyzed the data collected from 655 women with suspected preeclampsia. Adverse outcomes were predicted by multivariable and univariable logistic regression models. The outcome of patients was evaluated within 14 days after presentation with signs and symptoms of preeclampsia or diagnosed preeclampsia.

RESULTS

The full model integrating available, standard clinical information and the sFlt-1/PlGF ratio had the best predictive performance for adverse outcomes with an AUC of 72.6%, which corresponds to a sensitivity of 73.3% and specificity of 66.0%. The positive predictive value of the full model was 51.4%, and the negative predictive value was 83.5%. 24.5% of patients, who did not experience adverse outcomes but were classified as high risk by sFlt-1/PlGF ratio (≥38), were correctly classified by the regression model. The sFlt-1/PlGF ratio alone had a significantly lower AUC of 65.6%.

CONCLUSIONS

Integrating angiogenic biomarkers in a regression model improved the prediction of preeclampsia-related adverse outcomes in women at risk after 34 weeks of gestation.

Incidence of stillbirth: effect of deprivation

OBJECTIVES

To examine the relationship between the English index of multiple deprivation (IMD) and the incidence of stillbirth and assess whether IMD contributes to the prediction of stillbirth provided by the combination of maternal demographic characteristics and elements of medical history.

METHODS

This was a prospective, observational study of 159 125 women with a singleton pregnancy who attended their first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation in two maternity hospitals in the UK. The inclusion criterion was delivery at ≥ 24 weeks' gestation of a fetus without major abnormality. Participants completed a questionnaire on demographic characteristics and obstetric and medical history. IMD was used as a measure of socioeconomic status, which takes into account income, employment, education, skills and training, health and disability, crime, barriers to housing and services, and living environment. Each neighborhood is ranked according to its level of deprivation relative to that of other areas into one of five equal groups, with Quintile 1 containing the 20% most deprived areas and Quintile 5 containing the 20% least deprived areas. Logistic regression analysis was used to determine whether IMD provided a significant independent contribution to stillbirth after adjustment for known maternal risk factors.

RESULTS

The overall incidence of stillbirth was 0.35% (551/159 125), and this was significantly higher in the most deprived compared with the least deprived group (Quintile 1 vs Quintile 5). The odds ratio (OR) in Quintile 1 was 1.57 (95% CI, 1.16-2.14) for any stillbirth, 1.64 (95% CI, 1.20-2.28) for antenatal stillbirth and 1.89 (95% CI, 1.23-2.98) for placental dysfunction-related stillbirth. In Quintile 1 (vs Quintile 5), there was a higher incidence of factors that contribute to stillbirth, including black race, increased body mass index, smoking, chronic hypertension and previous stillbirth. The OR of black (vs white) race was 2.58 (95% CI, 2.14-3.10) for any stillbirth, 2.62 (95% CI, 2.16-3.17) for antenatal stillbirth and 3.34 (95% CI, 2.59-4.28) for placental dysfunction-related stillbirth. Multivariate analysis showed that IMD did not have a significant contribution to the prediction of stillbirth provided by maternal race and other maternal risk factors. In contrast, in black (vs white) women, the risk of any and antenatal stillbirth was 2.4-fold higher and the risk of placental dysfunction-related stillbirth was 2.9-fold higher after adjustment for other maternal risk factors.

CONCLUSIONS

The incidence of stillbirth, particularly placental dysfunction-related stillbirth, is higher in women living in the most deprived areas in South East England. However, in screening for stillbirth, inclusion of IMD does not improve the prediction provided by race, other maternal characteristics and elements of medical history. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

The Proper Diagnosis of Thrombophilic Status in Preventing Fetal Growth Restriction

Fetal growth restriction is an important part of monitoring a pregnancy. Because guidelines or diagnostic criteria for either minor or major thrombophilia are scarce, this systematic review aims to summarize the present knowledge in the field. We performed the CRD42022376006 protocol in Prospero with a systematic literature search in PubMed and Web of Science databases and included original full-text articles (randomized control trials and clinical trials) from the last 10 years, published in English, and with the "thrombophilia AND (pregnancy OR diagnostic criteria) AND fetal growth restriction" criteria. After two researchers extracted the articles of interest, they were assessed using the Newcastle-Ottawa Scale and eight articles were included. The elements from the thrombophilia diagnostic predict IUGR, factor V Leiden mutation, MTHFR C667T mutation, protein S deficiency, antithrombin deficiency, factor VII polymorphism, and antiphospholipid antibodies, while the association of protein C, PAI-1 and certain combinations of mutations are still under debate and require the collection of more data. The present systematic review provides an extensive picture of the actual knowledge about thrombophilia diagnosis and its links with pregnancy complications, such as intrauterine growth restriction, despite its limitation in the inclusion of other actually debated disorders such as PAI-1 mutation, protein C deficiency and other thrombophilia types.

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.

First trimester low maternal serum pregnancy associated plasma protein-A (PAPP-A) as a screening method for adverse pregnancy outcomes

OBJECTIVES

To evaluate different cut-off values of first trimester pregnancy associated plasma protein-A (PAPP-A) in screening for adverse pregnancy outcomes in a retrospective cohort study.

METHODS

During the study period of 1.1.2014-31.12.2018, total of 23,482 women with singleton pregnancies participated in first trimester combined screening for chromosomal abnormalities. Maternal serum PAPP-A multiple of medians (MoM) levels were measured, and study population was divided into three study groups of PAPP-A ≤0.40 (n=1,030), ≤0.35 (n=630) and ≤0.30 (n=363) MoM.

RESULTS

Small for gestational age (SGA), preterm birth (PTB) and composite outcome (SGA, hypertensive disorder of pregnancy (HDP) and/or PTB) were more frequent in all three PAPP-A MoM study groups and pre-eclampsia in ≤0.40 and ≤0.35 study groups than in their control groups (p < 0.05). The odds ratio (OR) for SGA varied from 3.7 to 5.4 and sensitivity and specificity from 6.9 to 13.8% and from 95.9 to 98.6%, between study groups. Using PAPP-A ≤0.30 MoM as a screening cut-off instead of PAPP-A ≤0.40 MoM, resulted in approximately 50% reduction in screening detection of SGA and PTB.

CONCLUSIONS

PAPP-A ≤0.40 MoM should be considered as a primary screening cut-off for adverse pregnancy outcomes as approximately 23% will develop either SGA, HDP or PTB. It seems to be the best cut-off to screen for SGA.

First Trimester Screening - Current Status and Future Prospects After Introduction of Non-invasive Prenatal Testing (NIPT) at a Tertiary Referral Center

Objective To investigate the uptake of different components of first trimester screening (FTS) and the impact on invasive diagnostic testing (IPT) since the introduction of non-invasive prenatal testing (NIPT) at a level III center. Methods Retrospective data analysis was conducted for singleton pregnancies that presented for FTS between 01/2019-12/2019 (group 1, n = 990). Patients were categorized into three risk groups: low risk for trisomy 21 (< 1 : 1000), intermediate risk (1 : 101-1 : 1000) and high risk (≥ 1 : 100). Uptake of NIPT and IPT was analyzed for each of the risk groups. Results were compared to a previous cohort from 2012/2013 (immediately after the introduction of NIPT, group 2, n = 1178). Results Group 1 showed a significant increase in the use of NIPT as part of FTS (29.5% vs. 3.7% for group 2, p = 0.001) in all three risk groups. Overall IPT rates were lower in group 1 (8.6%) vs. group 2 (11.3%, p = 0.038), mainly due to a significant reduction of IPT in the intermediate risk group. IPT rates in the high-risk group remained stable over time. Conclusion Appropriate clinical implementation of NIPT is still currently a challenge for prenatal medicine experts. Our data suggest that widespread uptake of NIPT is becoming more common these days; however, a contingent approach might prevent redundant uptake.

Development of a prediction model on preeclampsia using machine learning-based method: a retrospective cohort study in China

Objective: The aim of this study was to use machine learning methods to analyze all available clinical and laboratory data obtained during prenatal screening in early pregnancy to develop predictive models in preeclampsia (PE).

Material and Methods: Data were collected by retrospective medical records review. This study used 5 machine learning algorithms to predict the PE: deep neural network (DNN), logistic regression (LR), support vector machine (SVM), decision tree (DT), and random forest (RF). Our model incorporated 18 variables including maternal characteristics, medical history, prenatal laboratory results, and ultrasound results. The area under the receiver operating curve (AUROC), calibration and discrimination were evaluated by cross-validation.

Results: Compared with other prediction algorithms, the RF model showed the highest accuracy rate. The AUROC of RF model was 0.86 (95% CI 0.80–0.92), the accuracy was 0.74 (95% CI 0.74–0.75), the precision was 0.82 (95% CI 0.79–0.84), the recall rate was 0.42 (95% CI 0.41–0.44), and Brier score was 0.17 (95% CI 0.17–0.17).

Conclusion: The machine learning method in our study automatically identified a set of important predictive features, and produced high predictive performance on the risk of PE from the early pregnancy information.

Association between aspirin use during pregnancy and cardiovascular risk factors 2-7 years after delivery: The nuMoM2b Heart Health Study

OBJECTIVES

To evaluate the association between aspirin use during first pregnancy and later maternal cardiovascular risk.

STUDY DESIGN

In this secondary analysis of a prospective cohort, we included participants who carried their first pregnancy to 20 + weeks, had data regarding aspirin use, and attended a study visit 2-7 years following delivery. The exposure was aspirin use during the first pregnancy. We calculated aspirin use propensity scores from logistic regression models including baseline variables associated with aspirin use in pregnancy and cardiovascular risk. Outcomes of interest were incident cardiovascular-related diagnoses 2-7 years following delivery. Robust Poisson regression calculated the risk of outcomes by aspirin exposure, adjusting for the aspirin use propensity score.

MAIN OUTCOME MEASURES

The primary outcome was a composite of incident cardiovascular diagnoses at the time of the study visit: cardiovascular events, chronic hypertension, metabolic syndrome, prediabetes or type 2 diabetes, dyslipidemia, and chronic kidney disease.

RESULTS

Of 4,480 women included, 84 (1.9%) reported taking aspirin during their first pregnancy. 52.6% of participants in the aspirin-exposed group and 43.0% in the unexposed group had the primary outcome. After adjusting for the aspirin use propensity scores, aspirin use during the first pregnancy was not associated with any of the outcomes.

CONCLUSION

We did not detect an association between aspirin use during the first pregnancy and cardiovascular-related diagnoses 2-7 years later. Our study was only powered to detect a large difference in relative risk, so we cannot rule out a smaller difference that may be clinically meaningful.

Pre-eclampsia: a Scoping Review of Risk Factors and Suggestions for Future Research Direction

Abstract

Most of maternal deaths are preventable, and one-quarter of maternal deaths are due to pre-eclampsia and eclampsia. Prenatal screening is essential for detecting and managing pre-eclampsia. However, pre-eclampsia screening is solely based on maternal risk factors and has low (< 5% in the USA) detection rates. This review looks at pre-eclampsia from engineering, public health, and medical points of view. First, pre-eclampsia is defined clinically, and the biological basis of established risk factors is described. The multiple theories behind pre-eclampsia etiology should serve as the scientific basis behind established risk factors for pre-eclampsia; however, African American race does not have sufficient evidence as a risk factor. We then briefly describe predictive statistical models that have been created to improve screening detection rates, which use a combination of biophysical and biochemical biomarkers, as well as aspects of patient medical history as inputs. Lastly, technologies that aid in advancing pre-eclampsia screening worldwide are explored. The review concludes with suggestions for more robust pre-eclampsia research, which includes diversifying study sites, improving biomarker analytical tools, and for researchers to consider studying patients before they become pregnant to improve pre-eclampsia detection rates. Additionally, researchers must acknowledge the systemic racism involved in using race as a risk factor and include qualitative measures in study designs to capture the effects of racism on patients.

Lay Summary

Pre-eclampsia is a pregnancy-specific hypertensive disorder that can affect almost every organ system and complicates 2-8% of pregnancies globally. Here, we focus on the biological basis of the risk factors that have been identified for the condition. African American race currently does not have sufficient evidence as a risk factor and has been poorly studied. Current clinical methods poorly predict a patient's likelihood of developing pre-eclampsia; thus, researchers have made statistical models that are briefly described in this review. Then, low-cost technologies that aid in advancing pre-eclampsia screening are discussed. The review ends with suggestions for research direction to improve pre-eclampsia screening in all settings.Overall, we suggest that the future of pre-eclampsia screening should aim to identify those at risk before they become pregnant. We also suggest that the clinical standard of assessing patient risk solely on patient characteristics needs to be reevaluated, that study locations of pre-eclampsia research need to be expanded beyond a few high-income countries, and that low-cost technologies should be developed to increase access to prenatal screening.

Use of a Feed-Forward Back Propagation Network for the Prediction of Small for Gestational Age Newborns in a Cohort of Pregnant Patients with Thrombophilia

(1) Background: Fetal growth restriction is a relatively common disorder in pregnant patients with thrombophilia. New artificial intelligence algorithms are a promising option for the prediction of adverse obstetrical outcomes. The aim of this study was to evaluate the predictive performance of a Feed-Forward Back Propagation Network (FFBPN) for the prediction of small for gestational age (SGA) newborns in a cohort of pregnant patients with thrombophilia. (2) Methods: This observational retrospective study included all pregnancies in women with thrombophilia who attended two tertiary maternity hospitals in Romania between January 2013 and December 2020. Bivariate associations of SGA and each predictor variable were evaluated. Clinical and paraclinical predictors were further included in a FFBPN, and its predictive performance was assessed. (3) Results: The model had an area under the curve (AUC) of 0.95, with a true positive rate of 86.7%, and a false discovery rate of 10.5%. The overall accuracy of our model was 90%. (4) Conclusion: This is the first study in the literature that evaluated the performance of a FFBPN for the prediction of pregnant patients with thrombophilia at a high risk of giving birth to SGA newborns, and its promising results could lead to a tailored prenatal management.

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.

First-Trimester Screening for Fetal Growth Restriction and Small-for-Gestational-Age Pregnancies without Preeclampsia Using Cardiovascular Disease-Associated MicroRNA Biomarkers

The goal of the study was to determine the early diagnostical potential of cardiovascular disease-associated microRNAs for prediction of small-for-gestational-age (SGA) and fetal growth restriction (FGR) without preeclampsia (PE). The whole peripheral venous blood samples were collected within 10 to 13 weeks of gestation from singleton Caucasian pregnancies within the period November 2012 to March 2020. The case-control retrospective study, nested in a cohort, involved all pregnancies diagnosed with SGA (n = 37) or FGR (n = 82) without PE and 80 appropriate-for-gestational age (AGA) pregnancies selected with regard to equality of sample storage time. Gene expression of 29 cardiovascular disease-associated microRNAs was assessed using real-time RT-PCR. Upregulation of miR-16-5p, miR-20a-5p, miR-146a-5p, miR-155-5p, miR-181a-5p, and miR-195-5p was observed in SGA or FGR pregnancies at 10.0% false positive rate (FPR). Upregulation of miR-1-3p, miR-20b-5p, miR-126-3p, miR-130b-3p, and miR-499a-5p was observed in SGA pregnancies only at 10.0% FPR. Upregulation of miR-145-5p, miR-342-3p, and miR-574-3p was detected in FGR pregnancies at 10.0% FPR. The combination of four microRNA biomarkers (miR-1-3p, miR-20a-5p, miR-146a-5p, and miR-181a-5p) was able to identify 75.68% SGA pregnancies at 10.0% FPR in early stages of gestation. The detection rate of SGA pregnancies without PE increased 4.67-fold (75.68% vs. 16.22%) when compared with the routine first-trimester screening for PE and/or FGR based on the criteria of the Fetal Medicine Foundation. The combination of seven microRNA biomarkers (miR-16-5p, miR-20a-5p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-342-3p, and miR-574-3p) was able to identify 42.68% FGR pregnancies at 10.0% FPR in early stages of gestation. The detection rate of FGR pregnancies without PE increased 1.52-fold (42.68% vs. 28.05%) when compared with the routine first-trimester screening for PE and/or FGR based on the criteria of the Fetal Medicine Foundation. Cardiovascular disease-associated microRNAs represent promising early biomarkers with very suitable predictive potential for SGA or FGR without PE to be implemented into the routine screening programs.

First Trimester Prediction of Adverse Pregnancy Outcomes—Identifying Pregnancies at Risk from as Early as 11–13 Weeks

There is consistent evidence that many of the pregnancy complications that occur late in the second and third trimester can be predicted from an integrated 11–13 weeks visit, where a maternal and fetal assessment are comprehensively performed. The traditional aims of the 11–13 weeks visit have been: establishing fetal viability, chorionicity and dating of the pregnancy, and performing the combined screening test for common chromosomal abnormalities. Recent studies have shown that the first trimester provides important information that may help to predict pregnancy complications, such as preeclampsia and fetal growth restriction, stillbirth, preterm birth, gestational diabetes mellitus and placenta accreta spectrum disorder. The aim of this manuscript is to review the methods available to identify pregnancies at risk for adverse outcomes after screening at 11–13 weeks. Effective screening in the first trimester improves pregnancy outcomes by allowing specific interventions such as administering aspirin and directing patients to specialist clinics for regular monitoring.

Low-molecular-weight heparin for prevention of preeclampsia and other placenta-mediated complications: a systematic review and meta-analysis

BACKGROUND

Evidence on the impact of low-molecular-weight heparin, alone or in combination with low-dose aspirin, for the prevention for preeclampsia in high-risk patients is conflicting.

OBJECTIVE

We conducted a meta-analysis of studies published to assess the effectiveness of low-molecular-weight heparin for the prevention of preeclampsia and other placenta-related complications in high-risk women.

DATA SOURCES

A systematic search was performed to identify relevant studies, using the databases PubMed and Cochrane Central Register of Controlled Trials, without publication time restrictions.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials comparing treatment with low-molecular-weight heparin or unfractionated heparin (with or without low-dose aspirin), in high-risk women, defined as either history of preeclampsia, intrauterine growth restriction, fetal demise, or miscarriage or being at high risk after first-trimester screening of preeclampsia.

STUDY APPRAISAL AND SYNTHESIS METHODS

The systematic review was conducted according to the Cochrane Handbook guidelines. The primary outcome was the development of preeclampsia. We performed prespecified subgroup analyses according to combination with low-dose aspirin, low-molecular-weight heparin type, gestational age when treatment was started, and study population (patients with thrombophilia, at high risk of preeclampsia or miscarriage). Secondary outcomes included small for gestational age, perinatal death, miscarriage, and placental abruption. Pooled odds ratios with 95% confidence intervals were calculated using a random-effects model. Quality of evidence was assessed using the grading of recommendations assessment, development, and evaluation methodology.

RESULTS

A total of 15 studies (2795 participants) were included. In high-risk women, treatment with low-molecular-weight heparin was associated with a reduction in the development of preeclampsia (odds ratio, 0.62; 95% confidence interval, 0.43-0.90; P=.010); small for gestational age (odds ratio, 0.61; 95% confidence interval, 0.44-0.85; P=.003), and perinatal death (odds ratio, 0.49; 95% confidence interval, 0.25-0.94; P=.030). This reduction was stronger if low-molecular-weight heparin was started before 16 weeks' gestation (13 studies, 2474 participants) for preeclampsia (odds ratio, 0.55; 95% confidence interval, 0.39-0.76; P=.0004). When only studies including low-dose aspirin as an intervention were analyzed (6 randomized controlled trials, 920 participants), a significant reduction was observed in those with combined treatment (low-molecular-weight heparin plus low-dose aspirin) compared with low-dose aspirin alone (odds ratio, 0.62; 95% confidence interval, 0.41-0.95; P=.030). Overall, adverse events were neither serious nor significantly different. Quality of evidence ranged from very low to moderate, mostly because of the lack of blinding, imprecision, and inconsistency.

CONCLUSION

Low-molecular-weight heparin use was associated with a significant reduction in the risk of preeclampsia and other placenta-mediated complications in high-risk women and when treatment was started before 16 weeks' gestation. Combined treatment with low-dose aspirin was associated with a significant reduction in the risk of preeclampsia compared with low-dose aspirin alone. However, there exists important clinical and statistical heterogeneity, and therefore, these results merit confirmation in large well-designed clinical trials.

Prevention of preeclampsia with aspirin

Preeclampsia is defined as hypertension arising after 20 weeks of gestational age with proteinuria or other signs of end-organ damage and is an important cause of maternal and perinatal morbidity and mortality, particularly when of early onset. Although a significant amount of research has been dedicated in identifying preventive measures for preeclampsia, the incidence of the condition has been relatively unchanged in the last decades. This could be attributed to the fact that the underlying pathophysiology of preeclampsia is not entirely understood. There is increasing evidence suggesting that suboptimal trophoblastic invasion leads to an imbalance of angiogenic and antiangiogenic proteins, ultimately causing widespread inflammation and endothelial damage, increased platelet aggregation, and thrombotic events with placental infarcts. Aspirin at doses below 300 mg selectively and irreversibly inactivates the cyclooxygenase-1 enzyme, suppressing the production of prostaglandins and thromboxane and inhibiting inflammation and platelet aggregation. Such an effect has led to the hypothesis that aspirin could be useful for preventing preeclampsia. The first possible link between the use of aspirin and the prevention of preeclampsia was suggested by a case report published in 1978, followed by the first randomized controlled trial published in 1985. Since then, numerous randomized trials have been published, reporting the safety of the use of aspirin in pregnancy and the inconsistent effects of aspirin on the rates of preeclampsia. These inconsistencies, however, can be largely explained by a high degree of heterogeneity regarding the selection of trial participants, baseline risk of the included women, dosage of aspirin, gestational age of prophylaxis initiation, and preeclampsia definition. An individual patient data meta-analysis has indicated a modest 10% reduction in preeclampsia rates with the use of aspirin, but later meta-analyses of aggregate data have revealed a dose-response effect of aspirin on preeclampsia rates, which is maximized when the medication is initiated before 16 weeks of gestational age. Recently, the Aspirin for Evidence-Based Preeclampsia Prevention trial has revealed that aspirin at a daily dosage of 150 mg, initiated before 16 weeks of gestational age, and given at night to a high-risk population, identified by a combined first trimester screening test, reduces the incidence of preterm preeclampsia by 62%. A secondary analysis of the Aspirin for Evidence-Based Preeclampsia Prevention trial data also indicated a reduction in the length of stay in the neonatal intensive care unit by 68% compared with placebo, mainly because of a reduction in births before 32 weeks of gestational age with preeclampsia. The beneficial effect of aspirin has been found to be similar in subgroups according to different maternal characteristics, except for the presence of chronic hypertension, where no beneficial effect is evident. In addition, the effect size of aspirin has been found to be more pronounced in women with good compliance to treatment. In general, randomized trials are underpowered to investigate the treatment effect of aspirin on the rates of other placental-associated adverse outcomes such as fetal growth restriction and stillbirth. This article summarizes the evidence around aspirin for the prevention of preeclampsia and its complications.

Effect of routine first-trimester combined screening for pre-eclampsia on small-for-gestational-age birth: secondary interrupted time series analysis

OBJECTIVE

To evaluate the impact of a first-trimester combined screening program for pre-eclampsia, based on the Fetal Medicine Foundation (FMF) algorithm, on the rate of small-for-gestational age (SGA) at birth and adverse pregnancy outcome.

METHODS

This was a retrospective cohort study of data obtained from a London tertiary hospital between January 2017 and March 2019. The data were derived from a secondary analysis of the cohort evaluated in a clinical-effectiveness study on the implementation of a first-trimester screening program for pre-eclampsia. The cohort included 7720 women screened according to the UK National Institute for Health and Care Excellence (NICE) risk-based approach and 4841 women screened by the FMF multimodal approach, which combines maternal risk factors, blood pressure, pregnancy-associated plasma protein-A and uterine artery Doppler indices. The care package for the FMF-screened group included 150-mg aspirin prophylaxis, ultrasound scans at 28 and 36 weeks' gestation and scheduled delivery at 40 weeks. Outcome measures included the rates of SGA neonates at birth, admission to the neonatal unit, intrauterine demise, neonatal death and hypoxic-ischemic encephalopathy assessed by interrupted time series analysis (ITSA).

RESULTS

There was no significant difference in the rates of intrauterine demise, neonatal death and hypoxic-ischemic encephalopathy between the FMF-screened and NICE-screened cohorts. ITSA showed a significant reduction in the rate of term SGA birth < 10^th percentile at 21 months following implementation of the FMF screening program, with a relative effect reduction of 45.1% (P = 0.004). However, there was no significant relative effect reduction in term SGA birth < 5^th or < 3^rd percentile.

CONCLUSIONS

First-trimester combined screening for pre-eclampsia based on the FMF algorithm accompanied by a care package including serial ultrasound scans for growth evaluation and elective birth from 40 weeks' gestation resulted in a significant 45% relative effect reduction in term SGA birth < 10^th percentile but did not affect term SGA birth < 5^th or < 3^rd percentile. Further screening strategies to detect and improve the outcome of cases with SGA birth < 5^th percentile need to be considered. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Development and validation of model for prediction of placental dysfunction-related stillbirth from maternal factors, fetal weight and uterine artery Doppler at mid-gestation

OBJECTIVE

To examine the performance of a model combining maternal risk factors, uterine artery pulsatility index (UtA-PI) and estimated fetal weight (EFW) at 19-24 weeks' gestation, for predicting all antepartum stillbirths and those due to impaired placentation, in a training dataset used for development of the model and in a validation dataset.

METHODS

The data for this study were derived from prospective screening for adverse obstetric outcome in women with singleton pregnancy attending for routine pregnancy care at 19 + 0 to 24 + 6 weeks' gestation. The study population was divided into a training dataset used to develop prediction models for placental dysfunction-related antepartum stillbirth and a validation dataset to which the models were then applied. Multivariable logistic regression analysis was used to develop a model based on a combination of maternal risk factors, EFW Z-score and UtA-PI multiples of the normal median. We examined the predictive performance of the model by, first, the ability of the model to discriminate between the stillbirth and live-birth groups, using the area under the receiver-operating-characteristics curve (AUC) and the detection rate (DR) at a fixed false-positive rate (FPR) of 10%, and, second, calibration by measurements of calibration slope and intercept.

RESULTS

The study population of 131 514 pregnancies included 131 037 live births and 477 (0.36%) stillbirths. There are four main findings of this study. First, 92.5% (441/477) of stillbirths were antepartum and 7.5% (36/477) were intrapartum, and 59.2% (261/441) of antepartum stillbirths were observed in association with placental dysfunction and 40.8% (180/441) were unexplained or due to other causes. Second, placental dysfunction accounted for 80.1% (161/201) of antepartum stillbirths at < 32 weeks' gestation, 54.2% (52/96) at 32 + 0 to 36 + 6 weeks and 33.3% (48/144) at ≥ 37 weeks. Third, the risk of placental dysfunction-related antepartum stillbirth increased with increasing maternal weight and decreasing maternal height, was 3-fold higher in black than in white women, was 5.5-fold higher in parous women with previous stillbirth than in those with previous live birth, and was increased in smokers, in women with chronic hypertension and in parous women with a previous pregnancy complicated by pre-eclampsia and/or birth of a small-for-gestational-age baby. Fourth, in screening for placental dysfunction-related antepartum stillbirth by a combination of maternal risk factors, EFW and UtA-PI in the validation dataset, the DR at a 10% FPR was 62.3% (95% CI, 57.2-67.4%) and the AUC was 0.838 (95% CI, 0.799-0.878); these results were consistent with those in the dataset used for developing the algorithm and demonstrate high discrimination between affected and unaffected pregnancies. Similarly, the calibration slope was 1.029 and the intercept was -0.009, demonstrating good agreement between the predicted risk and observed incidence of placental dysfunction-related antepartum stillbirth. The performance of screening was better for placental dysfunction-related antepartum stillbirth at < 37 weeks' gestation compared to at term (DR at a 10% FPR, 69.8% vs 29.2%).

CONCLUSIONS

Screening at mid-gestation by a combination of maternal risk factors, EFW and UtA-PI can predict a high proportion of placental dysfunction-related stillbirths and, in particular, those that occur preterm. Such screening provides poor prediction of unexplained stillbirth or stillbirth due to other causes. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Predictive performance for placental dysfunction related stillbirth of the competing risks model for small for gestational age fetuses

OBJECTIVES

First, to examine the predictive performance for placental dysfunction related stillbirths of the competing risks model for small for gestational age (SGA) fetuses based on a combination of maternal risk factors, estimated fetal weight (EFW) and uterine artery pulsatility index (UtA-PI); and second, to compare the performance of this model to that of stillbirth-specific model utilizing the same biomarkers and to the Royal College of Obstetricians and Gynecologists (RCOG) guideline for the investigation and management of the SGA fetus.

DESIGN

Prospective observational study.

SETTING

Two UK maternity hospitals.

POPULATION

131,514 women with singleton pregnancies attending for routine ultrasound examination at 19-24 weeks' gestation.

METHODS

The predictive performance for stillbirth achieved by three models was compared. Main outcome measure Placental dysfunction related stillbirth.

RESULTS

At 10% false positive rate, the competing risks model predicted 59%, 66% and 71% of placental dysfunction related stillbirths, at any gestation, at <37 weeks and at <32 weeks, respectively, which were similar to the respective figures of 62%, 70% and 73% for the stillbirth-specific model. At a screen positive rate of 21.8 %, as defined by the RCOG guideline, the competing risks model predicted 71%, 76% and 79% of placental dysfunction related stillbirths at any gestation, at <37 weeks and at <32 weeks, respectively, and the respective figures for the RCOG guideline were 40%, 44% and 42%.

CONCLUSION

The predictive performance for placental dysfunction related stillbirths by the competing risks model for SGA was similar to the stillbirth-specific model and superior to the RCOG guideline.

Arterial Stiffness as a Cardiovascular Risk Factor for the Development of Preeclampsia and Pharmacopreventive Options

Arterial stiffness (AS) describes the rigidity of the arterial walls. Epidemiological studies have shown that increased AS is an independent predictive marker of cardiovascular (CV) morbidity and mortality in both pregnant and non-pregnant women. Preeclampsia (PE), a form of pregnancy-induced hypertension, affects approximately 5% of pregnancies worldwide. Preeclamptic women have a higher risk of CV disease (CVD), mainly because PE damages the heart's ability to relax between contractions. Different pharmacological approaches for the prevention of PE have been tested in clinical trials (e.g. aspirin, enoxaparin, metformin, pravastatin, and sildenafil citrate). In current clinical practice, only low-dose aspirin is used for PE pharmacoprevention. However, low-dose aspirin does not prevent term PE, which is the most common form of PE. Compromised vascular integrity precedes the onset of PE and therefore, AS assessment may constitute a promising predictive marker of PE. Several non-invasive techniques have been developed to assess AS. Compared with normotensive pregnancies, both carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx) are increased in PE. In view of simplicity, reliability, and reproducibility, there is an interest in oscillometric AS measurements in pregnancies complicated by PE.

Prospective evaluation of first-trimester screening strategy for preterm pre-eclampsia and its clinical applicability in China

OBJECTIVES

To evaluate, in a Chinese population, the performance of a screening strategy for preterm pre-eclampsia (PE) using The Fetal Medicine Foundation (FMF)'s competing-risks model and to explore its clinical applicability in mainland China.

METHODS

This was a prospective, multicenter, observational cohort study including 10 899 women with singleton pregnancy who sought prenatal care at one of 13 hospitals, located in seven cities in mainland China, between 1 December 2017 and 30 December 2019. Mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and maternal serum levels of placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 to 13 + 6 weeks' gestation were measured and converted into multiples of the median using Chinese reference ranges. Individualized risk for preterm PE was calculated using the FMF algorithm. Prior risk was calculated based on maternal demographic characteristics and obstetric history. We evaluated the efficiency of the screening strategy using various combinations of biomarkers and analyzed its predictive performance for a composite of placenta-associated adverse pregnancy outcomes, including PE, placental abruption, small-for-gestational age (SGA) and preterm birth, at fixed false-positive rates for preterm PE.

RESULTS

We identified 312 pregnancies that developed PE, of which 117 cases were diagnosed as preterm PE (< 37 weeks' gestation). There were 386 pregnancies complicated by severe composite placenta-associated adverse outcome, including preterm PE, 146 cases of severe SGA (birth weight < 3^rd percentile) neonate, 61 cases with placental abruption and 109 cases of early preterm birth < 34 gestational weeks. The triple-marker model containing biomarkers MAP, UtA-PI and PAPP-A achieved, at fixed false-positive rates of 10%, 15% and 20%, detection rates for preterm PE of 65.0%, 72.7% and 76.1%, respectively, and detection rates for severe composite placenta-associated adverse outcome of 34.7%, 41.7% and 46.4%, respectively. Replacing PAPP-A with PlGF or adding PlGF to the model did not improve the performance. Of women screening positive for preterm PE at a fixed 5% false-positive rate, an estimated 30% developed at least one placenta-associated adverse pregnancy outcome, including PE, placental abruption, SGA (birth weight < 10^th percentile) and preterm birth < 37 weeks.

CONCLUSIONS

The FMF competing-risks model for preterm PE was found to be effective in screening a mainland Chinese population. Women who screened positive for preterm PE had increased risk for other placenta-associated pregnancy complications. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Ultrasound Diagnosis of the Small and Large Fetus

Antenatal imaging is crucial in the management of high-risk pregnancies. Accurate dating relies on acquisition of reliable and reproducible ultrasound images and measurements. Quality image acquisition is necessary for assessing fetal growth and performing Doppler measurements to help diagnose pregnancy complications, stratify risk, and guide management. Further research is needed to ascertain whether current methods for estimating fetal weight can be improved with 3-dimensional ultrasound or magnetic resonance imaging; optimize dating with late initiation of prenatal care; minimize under-diagnosis of fetal growth restriction; and identify the best strategies to make ultrasound more available in low-income and middle-income countries.

Antenatal screening of small for gestational age: Impact on obstetrical management and neonatal outcomes in case of trial of labor after 37 weeks

OBJECTIVE

Antenatal screening of small fetuses for gestational age (SGA) is a public health challenge. The aim of this study is to assess the obstetrical management and the immediate neonatal outcomes, according to the antenatal screening of the SGA fetuses.

METHODS

We performed a retrospective study in a French tertiary care hospital between January 1, 2016 and December 31, 2018. Women were eligible if they had a monofetal pregnancy with a fetus in head presentation and a trial of labor after 37 weeks. A fetus was considered SGA when the estimated fetal weight was less than the 10^th percentile at the third trimester ultrasound. A newborn was considered hypotrophic when the birthweight was less than the 10th percentile.

RESULTS

8 153 newborns were included and 948 of the newborns were hypotrophic (308 were suspected for SGA, 640 were not suspected for SGA) and 7205 were eutrophic. Among the hypotrophic neonates, we observed no significant difference regarding the immediate neonatal outcomes between the two groups of fetuses suspected and not suspected for SGA. Among the fetuses not suspected for SGA, the rate of arterial umbilical cord pH below 7.10 was significantly higher in the hypotrophic newborns compared to the non hypotrophic newborns (4.7% vs 3.1%, p = 0.041).

CONCLUSION

In our population, unsuspected fetal hypotrophy may be associated with an increased risk of neonatal acidosis. These results emphasize the benefit of improving prenatal screening to identify the SGA fetuses.

Low Molecular Weight Heparins (LMWH) and Implications along Pregnancy: a Focus on the Placenta

Low molecular weight heparins (LMWH) have been largely studied for their use during pregnancy. The biology and the pharmacology of these molecules are well known and may be summarized in three main mechanisms of action: anti-coagulant, anti-inflammatory, and immunomodulant. The clinical implications of these drugs during pregnancy are mainly related to their action on the placenta, because of the presence of specific molecular and cellular targets, particularly at the trophoblast-endometrial interface. As well as for the prevention and treatment of thromboembolism, LMWH have been largely investigated for the improvement of embryo implantation and for the prevention of placenta-related complications such as preeclampsia, fetal growth restriction, and intrauterine fetal death. However, data on this topic are still unclear. The present review discusses the biological features, the mechanisms of action, and the possible contribution of LMWH to the success of placentation along pregnancy, pointing out the need for future basic science and clinical researches in this important field with the final aim to improve clinical practice in high-risk pregnancies.

Preeclampsia and late fetal growth restriction

There is a strong but complex relationship between fetal growth restriction and preeclampsia. According to the International Society for the Study of Hypertension in Pregnancy the coexistence of gestational hypertension and fetal growth restriction identifies preeclampsia with no need for other signs of maternal organ impairment. While early-onset fetal growth restriction and preeclampsia are often strictly associated, such association becomes looser in the late preterm and term periods. The incidence of preeclampsia decreases dramatically from early preterm fetal growth restriction (39-43%) to late preterm fetal growth restriction (9-32%) and finally to term fetal growth restriction (4-7%). Different placental and cardiovascular mechanism underlie this trend: isolated fetal growth restriction has less frequent placental vascular lesions than fetal growth restriction associated with preeclampsia; moreover, late preterm and term fetal growth restriction show different patterns of maternal cardiac output and peripheral vascular resistance in comparison with preeclampsia. Consequently, current strategies for first trimester screening of placental dysfunction, originally implemented for preeclampsia, do not perform well for late-onset fetal growth restriction: the sensitivity of first trimester combined screening for small-for-gestational age newborns delivered at less than 32 weeks is 56-63%, and progressively decreases for those delivered at 32-36 weeks (43-48%) or at term (21-26%). Moreover, while the test is more sensitive for small-for-gestational age associated with preeclampsia at any gestational age, its sensitivity is much lower for small-for-gestational age without preeclampsia at 32-36 weeks (31-37%) or at term (19-23%).

Prospective longitudinal cohort study of uterine arteries Doppler in singleton pregnancies obtained by IVF/ICSI with oocyte donation or natural conception

STUDY QUESTION

Do uterine arteries Doppler studies show different pulsatility index (UtA-PI) measurements in IVF/ICSI pregnancies with oocyte donation (OD) as compared to natural conceptions?

SUMMARY ANSWER

In IVF/ICSI pregnancies with OD, UtA-PI is reduced by an average of about 40% as compared to pregnancies with natural conception.

WHAT IS KNOWN ALREADY

OD pregnancies present worse pregnancy outcomes as compared to natural conception, particularly for increased incidence of pre-eclampsia (PE). Recent evidence shows that IVF/ICSI pregnancies with frozen blastocyst transfer also present higher prevalence of PE and 15% lower UtA-PI as compared to pregnancies after fresh blastocyst transfers.

STUDY DESIGN, SIZE, DURATION

Prospective, longitudinal matched cohort study performed in the Fetal Medicine and Obstetric Departments of San Raffaele Hospital in Milan, between 2013 and 2018. The analysis is based on 584 Doppler observations collected from 296 women with different method of conception (OD n = 122; natural conception n = 174).

PARTICIPANTS/MATERIALS, SETTING, METHODS

IVF/ICSI viable singleton pregnancies with OD and natural conception control pregnancies matched for BMI and smoking, performing repeated UtA-PI measurements at 11-34 weeks. Miscarriages, abnormalities, twins, significant maternal diseases and other types of ARTs were excluded. Log mean left-right UtA-PI was used for analysis with linear mixed model (LMM) and correction for significant confounders. Pregnancy outcome was also analyzed.

MAIN RESULTS AND THE ROLE OF CHANCE

Participants after OD were older and more frequently nulliparous (mean age: OD 43.4, 95% CI from 42.3 to 44.6; natural conception 35.1, 95% CI from 34.5 to 35.7; P-value < 0.001; nulliparous: OD 96.6%; natural conception 56.2%; P-value < 0.001). Mean pulsatility index was lower in OD (UtA-PI: natural conception 1.22; 95% CI from 1.11 to 1.28; OD 1.04; 95% CI from 0.96 to 1.12; P-value < 0.001). A significant effect of parity, gestational age (GA) modeled with a cubic polynomial and BMI was described in the LMM. The mean Log UtA-PI was on average 37% lower in OD as compared to natural conception pregnancies at LMM (P-value < 0.001). We also found a significant interaction between longitudinal UtA-PI Doppler and GA. Therefore, at 11 weeks' gestation the Log UtA-PI was 42% lower and, at 34 weeks, the differences reduced to 32%. GA at delivery and birth weight were statistically lower in OD group; however, birthweight centile was not statistically different. Preeclampsia was 11-fold more common in the OD group (0.6% and 6.6%, P-value = 0.003). No other significant difference in pregnancy outcome was shown in the study groups (gestational diabetes mellitus, small or large for GA).

LIMITATIONS, REASONS FOR CAUTION

It was not possible to properly match for maternal age and to blind the assessment given the major differences between cohorts; however, we did not find significant within-groups effects related to maternal age. Future research is needed to reassess outcomes and correct them for maternal characteristics (e.g. cardiovascular function).

WIDER IMPLICATIONS OF THE FINDINGS

This finding reproduces our previous discovery of lower UtA-PI in frozen as compared to fresh blastocyst transfer. The vast majority of OD is obtained by the use of cryopreservation. We speculate that increased uterine perfusion may be the physiological response to compensate dysfunctions both in the mother and in the placenta.

STUDY FUNDING/COMPETING INTEREST(S)

This is a non-funded study. The authors do not declare competing interest.

TRIAL REGISTRATION NUMBER

N/A.

Factors associated with pregnancy outcomes in women with a history of cerebral sinus venous thrombosis

To collect and summarize pregnancy outcomes among women with a history of cerebral sinus vein thrombosis (CSVT). A retrospective multicenter case-control study. The study group comprised all women diagnosed with CSVT during 2004-2018 at four university hospitals, and with follow-up data of pregnancy. A control group of women with a singleton pregnancy was established by matching, four-to-one, according to maternal age. The data of 74 pregnancies of 65 women with CSVT were analyzed. The median time-to-pregnancy interval from the CSVT was 4.2 [2.7-6.8] years. Anticoagulation therapy in the form of enoxaparin was administered in 68 (91.9%) pregnancies. Adjunctive low-dose aspirin was used throughout 12 (16.2%) pregnancies. Overall, 54 (73.0%) of the pregnancies ended in live births and 20 (27.0%) in miscarriage. The use of anticoagulation therapy during pregnancy was positively associated with live birth outcome (P < 0.001). Late adverse outcomes were encountered in 19 (25.7%) pregnancies, including the delivery of a small for gestational age infant (n = 12), gestational hypertensive disorders (n = 6) and placental abruption (n = 3). The use of adjunctive aspirin was associated with a lower rate of late adverse pregnancy outcomes (P = 0.03). No recurrent CSVT, thrombosis at other sites, and major bleeding episodes were observed during pregnancy. Live-birth rate was higher (P = 0.007) and the rate of late adverse outcome was lower (P = 0.01) for the control (n = 296) than the study group. Among pregnant women with a prior CSVT, no recurrent thrombosis events were observed during gestation. The use of prophylactic anticoagulation was associated with live birth. The use of adjunctive aspirin should be further studied in this setting, as its utilization correlated with a lower rate of late pregnancy complications.

Doppler studies of placental function

Placental-associated diseases account for most cases of adverse perinatal outcome in developing countries. Doppler evaluation has been incorporated as a predictive parameter at early pregnancy for high-risk placental disease, in the diagnosis and management of those fetuses with impaired intrauterine growth and for the evaluation of fetal wellbeing in those high-risk pregnancies. Uterine Doppler at second trimester predicts most instances of early-onset preeclampsia and intrauterine growth restriction. However, the growing evidence of an effective early propylactic strategy, has turned Uterine Doppler an essential parameter to be included in first trimester predictive algorithms. Umbilical artery Doppler helps in the identification of small-for-gestational-age fetuses at higher risk, and is one of the essential vessels in the assessment of fetal hypoxia impairment, especially in the early cases. It helps in the decision timing for ending the pregnancy improving thus perinatal outcomes. Moreover, in high-risk pregnancies, umbilical artery Doppler has demonstrated to reduce the risk of perinatal deaths and the risk of obstetric interventions. On the other hand, middle cerebral artery Doppler reflects fetal adaptation to hypoxia, and with the cerebroplacental ratio, they improve the detection of fetuses a high risk of adverse perinatal outcome, mostly of those late small fetuses, where most instances of adverse outcome occur in fetuses with normal umbilical artery. Ductus venosous Doppler waveform is a surrogate parameter of the fetal base-acid status. Its use has demonstrated to improve perinatal outcomes, mainly reducing the risk of fetal intrauterine death. Alone or in combination with computerized CTG, it helps tailoring the best moment to end the pregnancy among early cases.

Establishment of Early Pregnancy Related Thyroid Hormone Models and Reference Intervals for Pregnant Women in China Based on Real World Data

Thyroid hormone reference intervals are crucial for diagnosing and monitoring thyroid dysfunction during early pregnancy, and the dynamic change trend of thyroid hormones during pregnancy can assist clinicians to assess the thyroid function of pregnant women. This study aims to establish early pregnancy related thyroid hormones models and reference intervals for pregnant women. We established two derived databases: derived database* and derived database#. Reference individuals in database* were used to establish gestational age-specific reference intervals for thyroid hormones and early pregnancy related thyroid hormones models for pregnant women. Individuals in database# were apparently healthy non-pregnant women. The thyroid hormones levels of individuals in database# were compared with that of individuals in database* using nonparametric methods and the comparative confidence interval method. The differences in thyroid stimulating hormone and free thyroxine between early pregnant and non-pregnant women were statistically significant (p<0.0001). The reference intervals of thyroid stimulating hormone, free thyroxine and free triiodothyronine for early pregnant women were 0.052-3.393 μIU/ml, 1.01-1.54 ng/dl, and 2.51-3.66 pg/ml, respectively. Results concerning thyroid stimulating hormone and free thyroxine reference intervals of early pregnancy are comparable with those from other studies using the same detection platform. Early pregnancy related thyroid hormones models showed various change patterns with gestational age for thyroid hormones. Early pregnancy related thyroid hormones models and reference intervals for pregnant women were established, so as to provide accurate and reliable reference basis for the diagnosing and monitoring of maternal thyroid disfunction in early pregnancy.

Parity and the risks of adverse birth outcomes: a retrospective study among Chinese

Background

Nulliparity is considered to be a risk factor of preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA). With the new two-child policy launched in 2016, more Chinese women have delivered their 2nd baby. Yet few studies have assessed the impact of parity on adverse birth outcomes in China. This study aimed to examine the association between parity and risks of PTB, LBW and SGA in a Chinese population. The combined effects of maternal age and parity on adverse birth outcomes were also assessed.

Methods

This retrospective study included all non-malformed live births born during January 1, 2014 and December 31, 2018 in Chengdu, China. A total of 746,410 eligible live singletons with complete information were included in the analysis. Parity was classified into nulliparity (i.e. has never delivered a newborn before) and multiparity (i.e. has delivered at least one newborn before). Log-binomial regression analyses were applied to evaluate the association between parity and PTB, LBW and SGA. We further divided maternal age into different groups (< 25 years, 25–29 years, 30–34 years and ≥ 35 years) to assess the combined effects of maternal age and parity on adverse birth outcomes.

Results

Multiparity was associated with reduced risks of PTB (aRR = 0.91, 95% CI: 0.89–0.93), LBW (aRR = 0.74, 95% CI: 0.72–0.77) and SGA (aRR = 0.67, 95% CI: 0.66–0.69) compared with nulliparity. In each age group, we observed that multiparity was associated with lower risks of adverse birth outcomes. Compared to nulliparous women aged between 25 and 29 years, women aged ≥35 years had greater risks of PTB and LBW, regardless of their parity status. In contrast, multiparous women aged ≥35 years (aRR = 0.73, 95% CI: 0.70–0.77) and those aged < 25 years (aRR = 0.88, 95% CI: 0.84–0.93) were at lower risk of SGA compared with nulliparous women aged between 25 and 29 years.

Conclusion

Multiparity was associated with lower risks of all adverse birth outcomes. Special attention should be paid to nulliparous mothers and those with advanced age during antenatal care, in order to reduce the risks of adverse birth outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03718-4.

Diagnostic accuracy of the Gaussian first-trimester combined screening for pre-eclampsia to predict small-for-gestational-age neonates

OBJECTIVE

Pre-eclampsia and delivery of small-for-gestational-age (SGA) neonates can be predicted from the first trimester. A Gaussian model for prediction of PE has recently been described, although its capacity to predict SGA is still unknown.

METHODS

This was a secondary analysis of a prospective cohort study conducted at Vall d'Hebron University Hospital (Barcelona) in 2483 single pregnancies from October 2015 to September 2017. Mean arterial blood pressure and mean uterine artery pulsatility index were recorded at the first-trimester scan. Serum concentrations of placental growth factor and pregnancy-associated plasma protein-A were assessed between 8⁺⁰ and 13⁺⁶  weeks. The predictive capacities of early (<32 weeks) and preterm (<37 weeks) SGA were tested.

RESULTS

For SGA without pre-eclampsia, detection rates of 25.0% (95% confidence interval [CI] 0-75.0) for early SGA and 14.3% (95% CI 3.6-28.6) for preterm SGA were achieved. For SGA with pre-eclampsia, the algorithm showed detection rates of 100.0% (95% CI 25.0-100.0) for early SGA and 56.3% (95% CI 31.3-81.3) for preterm SGA.

CONCLUSION

This algorithm identifies 62.5% of early SGA and 27.3% of preterm SGA. Combined screening for predicting both pre-eclampsia and SGA by using the Gaussian algorithm is feasible and would simplify clinical practice.

First- and second-trimester uterine artery pulsatility index as a combination factor in predictive diagnosis of pregnancy-induced hypertension

OBJECTIVE

Hypertensive disorder of pregnancy is a major cause of fetal and maternal morbidity and mortality. The current approach for pregnancy-induced hypertension (PIH) screening is complex and expensive. The present prospective cohort study assesses the advantage of combining first- and second-trimester uterine artery pulsatility index (UAPI) for predictive diagnosis of PIH.

METHODS

A total of 151 prenatal cases in their first trimester were studied and followed up till delivery. The mean UAPI was calculated for the first and second trimesters during the nuchal translucency and anomaly scans. Receiver operating characteristic analysis was used to calculate the cut-off of UAPI for first-trimester, second-trimester, and both trimesters combined.

RESULTS

Twenty-seven (17.9%) pregnant women developed PIH. Mean ± SD UAPI values for first and second trimesters were 1.92 ± 0.60 and 1.23 ± 0.36, respectively. The cut-offs for abnormal UAPI were ≥2.51, ≥1.32, and ≥1.91 for first trimester, second trimester, and both trimesters combined, respectively. The sensitivity and specificity of UAPI in predictive diagnosis of PIH were 82% and 95% for first trimester, 93% and 85% for the second trimester, and 93% and 98% for both trimesters combined.

CONCLUSION

Combining UAPI of first and second trimesters improves the predictive diagnosis of PIH, which can be carried out during the nuchal translucency and anomaly scans without imparting extra cost to the patient.

Pro- and Anti-Angiogenic Markers as Clinical Tools for Suspected Preeclampsia with and without FGR near Delivery—A Secondary Analysis

Objective—the objective of this study was to assess the accuracy of placental growth factor (PlGF), soluble Fms-like Tyrosine Kinase 1 (sFlt-1), and endoglin (sEng) in the diagnosis of suspected preeclampsia (PE) with and without fetal growth restriction (FGR) near delivery. Methods—this is a secondary analysis of a dataset of 125 pregnant women presenting at the high risk pregnancy clinic with suspected PE, FGR or PE + FGR in the University Medical Center of Slovenia. The dataset included 31 PE cases, 16 FGR cases, 42 PE + FGR cases, 15 cases who developed with unrelated complications before 37 weeks (wks) (PTD), and 21 unaffected controls who delivered a healthy baby at term. We also analyzed a sub-group of women who delivered early (<34 wks) including 10 PE, 12 FGR, 28 PE + FGR, and six PTD. Clinical management adhered to hospital guidelines. Marker levels were extracted from the dataset and were used to develop Receiver Operating Characteristic (ROC) curves and to calculate the area under the curve (AUC), the detection rates (DRs), and the false positive rates (FPRs). Previously published marker cutoffs for yes/no admission to hospital wards were extracted from the literature. Negative and positive predictive values (NPVs and PPVs) were evaluated for their value in determining whether hospital admission was required. Non-parametric tests were applied for statistical analysis; p < 0.05 was considered significant. Results—near delivery, all the pro-and anti-angiogenic markers provided diagnostic (ROC = 1.00) accuracy for the early (<34 wks) group of FGR. Diagnostic or near diagnostic (ROC = 0.95) accuracy was achieved by all marker for early PE + FGR but lower accuracy was achieved for early PE. For all cases, all markers, especially PlGF reached diagnostic or near diagnostic accuracy for FGR and PE + FGR. At this accuracy level, they can contribute to the clinical management of FGR, and PE + FGR. All the markers were less accurate for all PE cases. The use of published cutoffs was adequate for clinical management of FGR, whether early or for all cases, using an NPV > 90%. For PE + FGR, the PPV value approached 100%, especially for early cases, and can thus be implemented in clinical management. Neither NPV nor PPV were high enough for managing all cases of PE. There was no added value in measuring the PlGF/(sFlt-1 + sEng) ratio. Conclusion—This is the first study on a Slovenian population. It shows that near-delivery angiogenic biomarkers tests may be useful for confirming the diseases in cases where there is a diagnostic doubt. However, the clinical use of the biomarkers needs to be weighed against resources available and degree of certainty of the diagnosis made with and without them for managing suspected FGR and PE + FGR requiring delivery <34 wks, where they are very accurate, and furthermore in the management of all cases of FGR and FGR+PE. The markers were less accurate for the clinical diagnosis of PE.