Second-trimester prediction of severe placental complications in women with combined elevations in alpha-fetoprotein and human chorionic gonadotrophin

Relationship between increased maternal serum free human chorionic gonadotropin levels in the second trimester and adverse pregnancy outcomes: a retrospective cohort study

BACKGROUND

A retrospective cohort study was conducted to collect the data of pregnant women who received hospital delivery in Hangzhou Women's Hospital from January 2018 to December 2020, and who participated in the second trimester (15-20+6 weeks) of free beta human chorionic gonadotropin (free β-hCG). And the study was conducted to explore the relationship between maternal serum free β-hCG and adverse pregnancy outcomes (APO).

METHODS

We retrospectively analyzed the clinical data of 1,978 women in the elevated maternal serum free β-hCG group (free β-hCG ≥ 2.50 multiples of the median, MoM) and 20,767 women in the normal group (0.25 MoM ≤ free β-hCG < 2.50 MoM) from a total of 22,745 singleton pregnancies, and modified Poisson regression analysis was used to calculate risk ratios (RRs) and 95% confidence intervals (CI) of the two groups.

RESULTS

The gravidity and parity in the elevated free β-hCG group were lower, and the differences between the groups were statistically significant (all, P < 0.05). The risks of polyhydramnios, preeclampsia, and hyperlipidemia, were increased in women with elevated free β-hCG levels (RRs: 1.996, 95% CI: 1.322-3.014; 1.469, 95% CI: 1.130-1.911 and 1.257, 95% CI: 1.029-1.535, respectively, all P < 0.05), intrauterine growth restriction (IUGR) and female infants were also likely to happen (RRs = 1.641, 95% CI: 1.103-2.443 and 1.101, 95% CI: 1.011-1.198, both P < 0.05). Additionally, there was an association between elevated AFP and free β-hCG levels in second-trimester (RR = 1.211, 95% CI: 1.121-1.307, P < 0.001).

CONCLUSIONS

APOs, such as polyhydramnios, preeclampsia, and hyperlipidemia, were increased risks of elevated free β-hCG levels, IUGR and female infants were also likely to happen. Furthermore, there was an association between elevated AFP levels and elevated free β-hCG levels in second-trimester. We recommend prenatal monitoring according to the elevated maternal serum free β-hCG level and the occurrence of APO.

Maternal First-Trimester Alpha-Fetoprotein and Placenta-Mediated Pregnancy Complications

BACKGROUND

Maternal serum markers used for trisomy 21 screening are associated with placenta-mediated complications. Recently, there has been a transition from the traditional first-trimester screening (FTS) that included PAPP-A (pregnancy-associated plasma protein-A) and beta-hCG (human chorionic gonadotropin), to the enhanced FTS test, which added first-trimester AFP (alpha-fetoprotein) and PlGF (placental growth factor). However, whether elevated first-trimester AFP has a similar association with placenta-mediated complications to that observed for elevated second-trimester AFP remains unclear. Our objective was to estimate the association of first-trimester AFP with placenta-mediated complications and compare it with the corresponding associations of second-trimester AFP and other first-trimester serum markers.

METHODS

Retrospective population-based cohort study of women who underwent trisomy 21 screening in Ontario, Canada (2013-2019). The association of first-trimester AFP with placenta-mediated complications was estimated and compared with that of the traditional serum markers. The primary outcome was a composite of stillbirth or preterm placental complications (preeclampsia, birthweight less than third centile, or placental abruption).

RESULTS

A total of 244 990 and 96 167 women underwent FTS and enhanced FTS test screening, respectively. All markers were associated with the primary outcome, but the association for elevated first-trimester AFP (adjusted relative risk [aRR], 1.57 [95% CI, 1.37-1.81]) was weaker than that observed for low PAPP-A (aRR, 2.48 [95% CI, 2.2-2.8]), low PlGF (aRR, 2.28 [95% CI, 1.97-2.64]), and elevated second-trimester AFP (aRR, 1.97 [95% CI, 1.81-2.15]). When the models were adjusted for all 4 enhanced FTS test markers, elevated first-trimester AFP was no longer associated with the primary outcome (aRR, 0.77 [95% CI, 0.58-1.02]).

CONCLUSIONS

Unlike second-trimester AFP, elevated first-trimester AFP is not an independent risk factor for placenta-mediated complications.

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.

Frequency and clinical manifestation of prenatal cytogenetic diagnosis of chromosomal polymorphisms in Northeast China

OBJECTIVE

To retrospectively analyze the incidence of chromosomal polymorphisms in prenatal cytogenetic diagnostic cases and the effect of the clinical manifestation of these fetuses.

MATERIALS AND METHODS

490 fetuses with chromosomal polymorphisms among 9996 pregnant women who underwent prenatal cytogenetic diagnosis were included in this study and were set as group 1. Other 500 pregnant women, whose fetuses were with normal karyotypes, were randomly selected from the remaining pregnant women and set as group 2. Clinical information and outcomes and maternal serum screening results of group 1 were compared with group 2.

RESULTS

The frequency of fetal chromosomal polymorphism was 4.90% (490/9996). The most common variants observed were 1/9/16 qh± (2.27%, 227/9996), followed by inv(9) (0.90%, 90/9996). 94.62% (264/279) of fetal chromosomal variants were inherited from parents. No statistical difference was found in clinical information and outcomes and maternal serum screening results between group 1 and group 2.

CONCLUSION

The fetus with chromosomal polymorphism has no impact on serum markers of second trimester screening and does not play an important role for the clinical outcome of the current pregnancy either, whether it is inherited from the parents or a de novo mutation.

Screening for fetal growth restriction and placental insufficiency

Fetal growth restriction (FGR) continues to be a leading cause of preventable stillbirth and poor neurodevelopmental outcomes in offspring, and furthermore is strongly associated with the obstetrical complications of iatrogenic preterm birth and pre-eclampsia. The terms small for gestational age (SGA) and FGR have, for too long, been considered equivalent and therefore used interchangeably. However, the delivery of improved clinical outcomes requires that clinicians effectively distinguish fetuses that are pathologically growth-restricted from those that are constitutively small. A greater understanding of the multifactorial pathogenesis of both early- and late-onset FGR, especially the role of underlying placental pathologies, may offer insight into targeted treatment strategies that preserve placental function. The new maternal blood biomarker placenta growth factor offers much potential in this context. This review highlights new approaches to effective screening for FGR based on a comprehensive review of: etiology, diagnosis, antenatal surveillance and management. Recent advances in novel imaging methods provide the basis for stepwise multi-parametric testing that may deliver cost-effective screening within existing antenatal care systems.

A placenta clinic approach to the diagnosis and management of fetal growth restriction

Effective detection and management of fetal growth restriction is relevant to all obstetric care providers. Models of best practice to care for these patients and their families continue to evolve. Since much of the disease burden in fetal growth restriction originates in the placenta, the concept of a multidisciplinary placenta clinic program, managed primarily within a maternal-fetal medicine division, has gained popularity. In this context, fetal growth restriction is merely one of many placenta-related disorders that can benefit from an interdisciplinary approach, incorporating expertise from specialist perinatal ultrasound and magnetic resonance imaging, reproductive genetics, neonatal pediatrics, internal medicine subspecialties, perinatal pathology, and nursing. The accurate diagnosis and prognosis for women with fetal growth restriction is established by comprehensive clinical review and detailed sonographic evaluation of the fetus, combined with uterine artery Doppler and morphologic assessment of the placenta. Diagnostic accuracy for placenta-mediated fetal growth restriction may be enhanced by quantification of maternal serum biomarkers including placenta growth factor alone or combined with soluble fms-like tyrosine kinase-1. Uterine artery Doppler is typically abnormal in most instances of early-onset fetal growth restriction and is associated with coexistent preeclampsia and underlying maternal vascular malperfusion pathology of the placenta. By contrast, rare but potentially more serious underlying placental diagnoses, such as massive perivillous fibrinoid deposition, chronic histiocytic intervillositis, or fetal thrombotic vasculopathy, may be associated with normal uterine artery Doppler waveforms. Despite minor variations in placental size, shape, and cord insertion, placental function remains, largely normal in the general population. Consequently, morphologic assessment of the placenta is not currently incorporated into current screening programs for placental complications. However, placental ultrasound can be diagnostic in the context of fetal growth restriction, for example in Breus' mole and triploidy, which in turn may enhance diagnosis and management. Several examples are illustrated in our figures and supplementary videos. Recent advances in the ability of multiparameter screening and intervention programs to reduce the risk of severe preeclampsia will likely increase efforts to deliver similar improvements for women at risk of fetal growth restriction. Placental pathology is important because the underlying pathologies associated with fetal growth restriction have a wide range of recurrence risks. Rare conditions such as massive perivillous fibrinoid deposition or chronic histolytic intervillositis may recur in >50% of subsequent pregnancies. Postpartum care in a placenta-focused program can provide effective counseling for modifiable maternal risk factors, and can assist in planning future pregnancy care based on the pathologic basis of fetal growth restriction.

Pathophysiology of placental-derived fetal growth restriction

Placental-related fetal growth restriction arises primarily due to deficient remodeling of the uterine spiral arteries supplying the placenta during early pregnancy. The resultant malperfusion induces cell stress within the placental tissues, leading to selective suppression of protein synthesis and reduced cell proliferation. These effects are compounded in more severe cases by increased infarction and fibrin deposition. Consequently, there is a reduction in villous volume and surface area for maternal-fetal exchange. Extensive dysregulation of imprinted and nonimprinted gene expression occurs, affecting placental transport, endocrine, metabolic, and immune functions. Secondary changes involving dedifferentiation of smooth muscle cells surrounding the fetal arteries within placental stem villi correlate with absent or reversed end-diastolic umbilical artery blood flow, and with a reduction in birthweight. Many of the morphological changes, principally the intraplacental vascular lesions, can be imaged using ultrasound or magnetic resonance imaging scanning, enabling their development and progression to be followed in vivo. The changes are more severe in cases of growth restriction associated with preeclampsia compared to those with growth restriction alone, consistent with the greater degree of maternal vasculopathy reported in the former and more extensive macroscopic placental damage including infarcts, extensive fibrin deposition and microscopic villous developmental defects, atherosis of the spiral arteries, and noninfectious villitis. The higher level of stress may activate proinflammatory and apoptotic pathways within the syncytiotrophoblast, releasing factors that cause the maternal endothelial cell activation that distinguishes between the 2 conditions. Congenital anomalies of the umbilical cord and placental shape are the only placental-related conditions that are not associated with maldevelopment of the uteroplacental circulation, and their impact on fetal growth is limited.

Physiology of Alpha-Fetoprotein as a Biomarker for Perinatal Distress: Relevance to Adverse Pregnancy Outcome

The many physiologic roles of human alpha-fetoprotein (HAFP) and its correlation with perinatal distress/pregnancy outcome are rarely addressed together in the biomedical literature, even though HAFP has long been used as a biomarker for fetal birth defects. Although the well being of the fetus can be monitored by the measurement of gestational age–dependent HAFP in biologic fluid levels (serum, amniotic fluid, urine, and vaginal fluids) throughout pregnancy, the majority of clinical reports reflect largely second trimester and (less likely) first trimester testing due to regulatory clinical restrictions. However, reports of third-trimester and pregnancy term measurement of HAFP levels performed in clinical research and/or investigational settings have gradually increased over the years and have expanded our base knowledge of AFP-associated pregnancy disorders during these stages. The different structural forms of HAFP (isoforms, epitopes, molecular variants, etc.) detected in the various biologic fluid compartments have been limited by antibody recognition of specific epitopic sites developed by the kit manufacturers based on antibody specificity, sensitivity, and precision. Concomitantly, the advances in elucidating the various biologic actions of AFP are opening new vistas toward understanding the physiologic roles of AFP during pregnancy. The present review surveys HAFP as a biomarker for fetal distress during the perinatal period in view of its structural and functional properties. An attempt is then made to relate the AFP fluid levels to adverse pregnancy complications and outcomes. Hence, the present review was divided into two major sections: (I) AFP structure and function considerations and (II) the relationship of AFP levels to the distressed fetus during the third trimester and at term.

Maternal Serum Analytes as Predictors of Fetal Growth Restriction with Different Degrees of Placental Vascular Dysfunction

Abnormal levels of maternal serum analytes have been associated with fetal growth restriction (FGR) and preeclampsia secondary to placental vascular dysfunction. Accurately identifying the FGR fetuses at highest risk for adverse outcomes remains challenging. Placental function can be assessed by Doppler analysis of the maternal and fetal circulation. Although the combination of multiple abnormal maternal serum analytes and abnormal Doppler findings is strongly associated with adverse outcomes, the predictive value remains too low to be used as a screening test in a low-risk population. Stratification of cases based on the severity of Doppler abnormalities may improve predictive models.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Placental hyperinflation and the risk of adverse perinatal outcome

OBJECTIVES

To determine the pathological basis and clinical associations of excessively thick placentae observed at second-trimester ultrasound examination.

METHODS

In a retrospective cohort of 19 singleton high-risk second-trimester pregnancies noted to have a placental length-to-maximum thickness ratio ≤ 2.0, maximum sonographic placental thickness was correlated with clinical outcome, maximum placental thickness after delivery and placental pathological findings. Results were compared with those of an intermediate group of 21 high-risk pregnancies with normal placental dimensions and a control group of 18 low-risk pregnancies also with normal placental dimensions. Increased maximum placental thickness (> 28 mm) and abnormal placental deflation following delivery (pathology - sonography difference in maximum placental thickness < -2 mm) were defined by the upper and lower quartile values, respectively, in the control group.

RESULTS

The study group exhibited significantly more adverse outcomes and gross pathological placental features compared with both intermediate and control groups. Despite increased sonographic maximum placental thickness in the study group (median, 55 (range, 40-75) mm compared with both the intermediate group (median, 27 (range, 22-41) mm, P < 0.0001) and the control group (median 26 (range, 23-36) mm, P < 0.0001)), all three groups had similar maximal placental thickness following delivery (study group: median, 24 (range, 10-50) mm vs intermediate group: median, 27 (range, 15-40) mm, P = 0.82 and vs control group: median, 28.5 (range, 18-44), P = 0.42). Pathology-sonography difference in maximum placental thickness in the study group (median, -30 (range, -42 to 0) mm) was significantly greater than that in either the intermediate (median, -2 (range, -11 to 9) mm, P < 0.0001) or the control (median, 1.5 (range, -10 to 18) mm, P < 0.0001) group and was significantly associated with abnormal development of the gas-exchanging placental villi (distal villous hypoplasia) (P = 0.0001).

CONCLUSIONS

Increased second-trimester sonographic maximum placental thickness represents a pathological finding associated with severe adverse perinatal outcome. This observation is due to overinflation of the intervillous space by maternal blood rather than to adaptive formation of functional placental tissue.

2D-Ultrasound and endocrinologic evaluation of placentation in early pregnancy and its relationship to fetal birthweight in normal pregnancies and pre-eclampsia

OBJECTIVES

To study the relationships between 2D ultrasound measurements of placentation and maternal serum (MS) levels of PAPP-A, inhibin A and fβhCG in early pregnancy and subsequent fetal growth in pregnancies with a normal and abnormal outcome.

STUDY DESIGN

Prospective population-based cohort study of 301 pregnancies with a normal outcome, 18 with a pregnancy complicated by pre-term delivery (PTD) and 14 with subsequent pre-eclampsia (PE).

MAIN OUTCOME MEASURES

Basal placental surface area, placental thickness, ellipsivity and volume; MS PAPP-A and fβhCG at 11-13 + 6 weeks, MS inhibin A at 15-22 weeks and birthweight centile at delivery.

RESULTS

In the normal group, the basal surface area showed a significantly (P < 0.001) positive correlation with placental thickness and placental ellipsivity. With the exception of placental ellipsivity, all other placental ultrasound parameters were significantly related with birthweight centile. Inhibin A showed a significant (P < 0.005) correlation with birthweight centiles. The basal plate surface area and MS PAPP-A were significantly (P < 0.01 and P < 0.001, respectively) lower and MS inhibin A significantly (P < 0.01) higher in PE than in controls. No changes were found in pregnancies complicated by PTD.

CONCLUSION

The basal plate surface area at 11-14 weeks reflects indirectly normal and abnormal placentation and development of the definitive placenta. Combined with MS PAPP-A and/or inhibin A levels this parameter could be useful in identifying from the end of the first trimester, pregnancies subsequently complicated with PE.

Mid-trimester maternal serum HCG and alpha fetal protein levels: clinical significance and prediction of adverse pregnancy outcome

CONTEXT

Maternal serum human Chorionic Gonadotropin (hCG) and Alpha Fetal Protein (AFP) were originally introduced to detect trisomy 21 and neural tube defects. However, in the absence of aneuploidy or neural tube defects, mid-trimester maternal serum hCG and/or maternal serum AFP associated with adverse pregnancy outcomes. Pregnancies with unexplained mid-trimester elevation in maternal serum hCG and/or maternal serum AFP, are at increased risk for pregnancy complications resulting from placental insufficiency.

EVIDENCE ACQUISITION

Mid-trimester maternal serum hCG>2.5 MoM associated with an increased risk for pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, intrauterine growth restriction (IUGR), preterm delivery and intrauterine fetal death(IUFD). Mid-trimester maternal serum AFP levels >2.5 MoM are thought to reflect a defect in placentation and associated with an increased risk for pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, IUGR, preterm delivery and IUFD.

RESULTS

Combined mid-trimester elevation in maternal serum hCG and AFP levels suggest a more complex type of placental pathology. They have stronger association with pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, IUGR, preterm delivery and IUFD.

CONCLUSIONS

Mid-trimester maternal serum hCG or AFP levels alone cannot detect all pregnant women with increased risk to develop pregnancy complications. Multiparameter testing of placental function in mid-trimester (maternal serum hCG and AFP screening, uterine artery Doppler and placental morphology) may allow us to identify women with increased risk to develop severe placental insufficiency and pregnancy complications. However, future prospective studies are needed to confirm the prognostic significance of multiparameter testing of placental function in mid-trimester.

Screening for pre-eclampsia: a systematic review of tests combining uterine artery Doppler with other markers

AIMS

To perform a systematic review of screening for pre-eclampsia (PE) with the combination of uterine artery Doppler (UAD), maternal history, mean arterial pressure and/or maternal serum markers.

METHODS

We identified eligible studies through a search of Medline, and, for each included study, we assessed the risk of bias and extracted relevant data. We reported the performance of screening tests according to the target population (low- or high-risk), the trimester of screening (first and/or second) and the subset of PE screened for (early and late).

RESULTS

Several tests provided moderate or convincing prediction of early PE, but screening for late PE was poor. Although UAD is more accurate in the second trimester, we found encouraging results for first-trimester screening when it was combined with other markers. Performance of screening was consistently lower in populations with risk factors for PE in the maternal history.

CONCLUSIONS

We present encouraging results for the prediction of early PE, even in the first trimester of pregnancy. The different performance of tests in screening for early vs. late PE, and of low- vs. high-risk populations, supports the concept that PE is a heterogeneous disease.

High-risk pregnancy and neonatal complications in the DNA repair and transcription disorder trichothiodystrophy: report of 27 affected pregnancies

OBJECTIVE

To identify the frequency of pregnancy and neonatal complications in pregnancies carrying fetuses affected with trichothiodystrophy (TTD).

METHODS

We identified pregnancy and neonatal complications and serum screening results from mothers of TTD patients in a DNA repair diseases study from 2001 to 2011.

RESULTS

Pregnancy reports of 27 TTD patients and their 23 mothers were evaluated and 81% of the pregnancies had complications: 56% had preterm delivery, 30% had preeclampsia, 19% had placental abnormalities, 11% had HELLP syndrome, and 4% had an emergency c-section for fetal distress, while 44% had two or more complications. Only 19% of the pregnancies delivered at term without complications. Eight of the ten pregnancies tested had abnormal multiple marker results including elevated levels of human chorionic gonadotrophin. Eighty-five percent of the neonates had complications: 70% were low birth weight (<2500 g), 35% had birth weight < 10 centile for gestational age, 70% had NICU admission, 67% had a collodion membrane, and 31% of the 16 males had cryptorchidism. Cataracts were present in 54% of the TTD patients examined.

CONCLUSION

TTD is a multisystem disease that predisposes mothers of affected patients to substantial risks for pregnancy complications and TTD neonates have a high incidence of multiple abnormalities.

Antithrombotic therapy for improving maternal or infant health outcomes in women considered at risk of placental dysfunction

BACKGROUND

Pregnancy complications such as pre-eclampsia and eclampsia, intrauterine growth restriction and placental abruption are thought to have a common origin related to abnormalities in the development and function of the placenta.

OBJECTIVES

To compare, using the best available evidence, the benefits and harms of antenatal antithrombotic therapy to improve maternal or infant health outcomes in women considered at risk of placental dysfunction, when compared with other treatments, placebo or no treatment.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010).

SELECTION CRITERIA

Randomised controlled trials comparing antenatal antithrombotic therapy (either alone or in combination with other agents) with placebo or no treatment, or any other treatment in the antenatal period to improve maternal or infant health outcomes in women considered at risk of placental dysfunction.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated trials under consideration for appropriateness for inclusion and methodological quality without consideration of their results according to the prestated eligibility criteria. We used a fixed-effect meta-analysis for combining study data if the trials were judged to be sufficiently similar. We investigated heterogeneity by calculating I(2) statistic, and if this indicated a high level of heterogeneity among the trials included we used a random-effects model.

MAIN RESULTS

Our search strategy identified 14 reports of 10 studies for consideration, of which five met the inclusion criteria, involving 484 women. Four studies compared heparin (alone or in combination with dipyridamole) with no treatment; and one compared trapidil (triazolopyrimidine). While there were no statistically significant differences identified for the primary outcomes following heparin treatment, it was associated with a reduction in the risk of pre-eclampsia, eclampsia, and infant birthweight less than the 10th centile for gestational age.

AUTHORS' CONCLUSIONS

The review identified no significant differences for the primary outcomes perinatal mortality, preterm birth less than 34 weeks' gestation, and childhood neurodevelopmental handicap, although the number of studies and participants was small. While treatment with heparin appears promising with a reduction in pre-eclampsia, eclampsia, and infant birthweight less than the 10th centile for gestational age, the number of studies and participants included was small, and to date important information about serious adverse infant and long-term childhood outcomes is unavailable. Further research is required.

Risk factors and prediction of preeclampsia

Inadequate trophoblast invasion of the spiral arteries in early pregnancy, an increased inflammatory response and changes in the immune answer to paternal antigens are considered aetiological factors in preeclampsia. Searching for factors related to these angiogenic, anti-angiogenic, immunologic and inflammatory mechanisms may provide methods to determine which patient will develop preeclampsia predating the onset of the clinical manifestations of the disease. Screening for preeclampsia in the first trimester has had Limited success. Currently, maternal characteristics, clinical history, maternal serum biochemistry and uterine artery Doppler sonography before 14 weeks are being investigated. Preeclampsia in a previous pregnancy is still the strongest predictor. In the second trimester, uterine artery Doppler has a detection rate around 60% but also a high false positive rate of 25%. First trimester uterine artery Doppler studies have high sensitivity but poor specificity with a high false positive rate. Combination of first trimester uterine artery Doppler with patient characteristics and maternal serum biochemistry, specifically placental protein 13 holds promise but further evaluation is needed. Maternal serum markers including inhibin A, activin A, soluble FMS-Like tyrosine kinase 1, endoglin, pregnancy associated plasma protein A and others, when used alone have proved poor predictors of preeclampsia. Most studies have been performed by a limited group of researchers in a population with a high risk and no validation studies of any method in other populations are available. Results are difficult to compare due to differences in methodology, and differences in the end point studied.There are still no good methods of preventing preeclampsia once a high risk has been determined.

Placental size and the prediction of severe early-onset intrauterine growth restriction in women with low pregnancy-associated plasma protein-A

OBJECTIVES

Screening studies for trisomy 21 demonstrate that low maternal serum pregnancy-associated plasma protein-A (PAPP-A) at 11-13 weeks' gestation is associated with stillbirth, intrauterine growth restriction (IUGR) and pre-eclampsia in chromosomally normal fetuses. However, the strength of these associations is too weak to justify screening for these placental insufficiency syndromes. Our objective was to evaluate placental size and uterine artery (UtA) Doppler imaging as second-stage screening tests for women with low PAPP-A.

METHODS

We prospectively studied 90 normal singleton pregnancies with first-trimester PAPP-A </= 0.30 multiples of the median. Maternal serum alpha-fetoprotein (AFP) at 15-18 weeks' gestation, and second-trimester placental size and UtA Doppler indices were assessed as predictors of pregnancy outcome.

RESULTS

The risks of IUGR, preterm delivery before 32 weeks' gestation and stillbirth were significantly associated with small placental size (relative risk (RR), 3.96; 95% CI, 2.21-5.98; RR, 3.96; 95% CI, 2.21-5.98; and RR, 6.44, 95% CI, 2.74-14.54, respectively) and elevated AFP (RR, 3.67; 95% CI, 1.78-7.71; RR, 2.48; 95% CI, 1.23-4.94; and RR, 5.14; 95% CI, 1.66-16.85, respectively), but not with abnormal UtA Doppler indices. The combination of elevated AFP and small placental size further increased the risk of IUGR (RR, 4.88; 95% CI, 2.88-5.31), delivery before 32 weeks' gestation (RR, 4.25; 95% CI, 2.38-4.98) and stillbirth (RR, 7.44; 95% CI, 3.04-3.75).

CONCLUSIONS

Small placental size and elevated AFP, but not UtA Doppler indices, identify women with low PAPP-A at high risk of IUGR, extreme preterm delivery and stillbirth. These additional screening tests may directly improve perinatal outcomes in women with low PAPP-A.

Obstetrical complications associated with abnormal maternal serum markers analytes

OBJECTIVE

To review the obstetrical outcomes associated with abnormally elevated or decreased level of one or more of the most frequently measured maternal serum marker analytes used in screening for aneuploidy. To provide guidance to facilitate the management of pregnancies that have abnormal levels of one of more markers and to assess the usefulness of these markers as a screening test.

OPTIONS

Perinatal outcomes associated with abnormal levels of maternal serum markers analytes are compared with the outcomes of pregnancies with normal levels of the same analytes or the general population.

EVIDENCE

The Cochrane Library and Medline were searched for English-language articles published from 1966 to February 2007, relating to maternal serum markers and perinatal outcomes. Search terms included PAPP-A (pregnancy associated plasma protein A), AFP (alphafetoprotein), hCG (human chorionic gonadotropin), estriol, unconjugated estriol, inhibin, inhibin-A, maternal serum screen, triple marker screen, quadruple screen, integrated prenatal screen, first trimester screen, and combined prenatal screen. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key individual studies on which the recommendations are based are referenced. Supporting data for each recommendation are summarized with evaluative comments and references. The evidence was evaluated using the guidelines developed by the Canadian Task Force on Preventive Health Care.

VALUES

The evidence collected was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada.

BENEFITS, HARMS, AND COSTS

The benefit expected from this guideline is to facilitate early detection of potential adverse pregnancy outcomes when risks are identified at the time of a maternal serum screen. It will help further stratification of risk and provide options for pregnancy management to minimize the impact of pregnancy complications. The potential harms resulting from such practice are associated with the so called false positive (i.e., uncomplicated pregnancies labelled at increased risk for adverse perinatal outcomes), the potential stress associated with such a label, and the investigations performed for surveillance in this situation. No cost-benefit analysis is available to assess costs and savings associated with this guideline. SUMMARY STATEMENTS: 1. An unexplained level of a maternal serum marker analyte is defined as an abnormal level after confirmation of gestational age by ultrasound and exclusion of maternal, fetal, or placental causes for the abnormal level. (III) 2. Abnormally elevated levels of serum markers are associated with adverse pregnancy outcomes in twin pregnancies, after correction for the number of fetuses. Spontaneous or planned mutifetal reductions may result in abnormal elevations of serum markers. (II-2) RECOMMENDATIONS: 1. In the first trimester, an unexplained low PAPP-A (< 0.4 MoM) and/or a low hCG (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) In the second trimester, an unexplained elevation of maternal serum AFP (> 2.5 MoM), hCG (> 3.0 MoM), and/or inhibin-A (> or =2.0 MoM) or a decreased level of maternal serum AFP (< 0.25 MoM) and/or unconjugated estriol (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) 2. Pregnant woman with an unexplained elevated PAPP-A or hCG in the first trimester and an unexplained low hCG or inhibin-A and an unexplained elevated unconjugated estriol in the second trimester should receive normal antenatal care, as this pattern of analytes is not associated with adverse perinatal outcomes. (II-2A) 3. The combination of second or third trimester placenta previa and an unexplained elevated maternal serum AFP should increase the index of suspicion for placenta accreta, increta, or percreta. (II-2B) An assessment (ultrasound, MRI) of the placental-uterine interface should be performed. Abnormal invasion should be strongly suspected, and the planning of delivery location and technique should be done accordingly. (III-C) 4. A prenatal consultation with the medical genetics department is recommended for low unconjugated estriol levels (<0.3 MoM), as this analyte pattern can be associated with genetic conditions. (II-2B) 5. The clinical management protocol for identification of potential adverse obstetrical outcomes should be guided by one or more abnormal maternal serum marker analyte value rather than the false positive screening results for the trisomy 21 and/or the trisomy 18 screen. (II-2B) 6. Pregnant woman who are undergoing renal dialysis or who have had a renal transplant should be offered maternal serum screening, but interpretation of the result is difficult as the level of serum hCG is not reliable. (II-2A) 7. Abnormal maternal uterine artery Doppler in association with elevated maternal serum AFP, hCG, or inhibin-A or decreased PAPP-A identifies a group of women at greater risk of IUGR and gestational hypertension with proteinuria. Uterine artery Doppler measurements may be used in the evaluation of an unexplained abnormal level of either of these markers. (II-2B) 8. Further research is recommended to identify the best protocol for pregnancy management and surveillance in women identified at increased risk of adverse pregnancy outcomes based on an abnormality of a maternal serum screening analyte. (III-A) 9. In the absence of evidence supporting any specific surveillance protocol, an obstetrician should be consulted in order to establish a fetal surveillance plan specific to the increased obstetrical risks (maternal and fetal) identified. This plan may include enhanced patient education on signs and symptoms of the most common complications, increased frequency of antenatal visits, increased ultrasound (fetal growth, amniotic fluid levels), and fetal surveillance (biophysical profile, arterial and venous Doppler), and cervical length assessment. (III-A) 10. Limited information suggests that, in women with elevated hCG in the second trimester and/or abnormal uterine artery Doppler (at 22-24 weeks), low-dose aspirin (60-81 mg daily) is associated with higher birthweight and lower incidence of gestational hypertension with proteinuria. This therapy may be used in women who are at risk. (II-2B) 11. Further studies are recommended in order to assess the benefits of low-dose aspirin, low molecular weight heparin, or other therapeutic options in pregnancies determined to be at increased risk on the basis of an abnormal maternal serum screening analyte. (III-A) 12. Multiple maternal serum markers screening should not be used at present as a population-based screening method for adverse pregnancy outcomes (such as preeclampsia, placental abruption, and stillbirth) outside an established research protocol, as sensitivity is low, false positive rates are high, and no management protocol has been shown to clearly improve outcomes. (II-2D) When maternal serum screening is performed for the usual clinical indication (fetal aneuploidy and/or neural tube defect), abnormal analyte results can be utilized for the identification of pregnancies at risk and to direct their clinical management. (II-2B) Further studies are recommended to determine the optimal screening method for poor maternal and/or perinatal outcomes. (III-A).

Determinants of adverse perinatal outcome in high-risk women with abnormal uterine artery Doppler images

OBJECTIVE

The purpose of this study was to evaluate the prognostic role of placental ultrasound imaging at 19-23 weeks of gestation in clinically high-risk women with abnormal uterine artery Doppler (UTAD).

STUDY DESIGN

Placentas of 60 women with abnormal UTAD were examined at 19-23 weeks of gestation for shape and texture abnormalities. Findings were correlated with clinical outcomes (preterm delivery at <32 weeks of gestation; birth weight <10th percentile [small for gestational age]; preeclampsia/hemolysis, elevated liver enzymes, low platelets; early-onset intrauterine growth restriction with abnormal umbilical artery Doppler; and intrauterine fetal death) and maternal serum screening data. Placental disease was reviewed by 2 perinatal pathologists.

RESULTS

Women with abnormal placental shape at 19-23 weeks of gestation (n = 28) had higher odds of intrauterine fetal death (odds ratio, 4.5; 95% CI, 1.3-15.6), delivery at <32 weeks of gestation (odds ratio, 4.7; 95% CI, 1.6-14.1]), and intrauterine growth restriction (odds ratio, 4.7; 95% CI, 1.4-15.1]) than did the women with a normal placental shape. Thirty-two of 41 placentas (74%) weighed <10th percentile, and 36 of 43 placentas (83%) had ischemic-thrombotic pathologic condition. There was no association between abnormal placental shape at 19-23 weeks of gestation and placental weight, but 5 of 6 placentas that were <10 cm long were <10th percentile for weight at delivery. There was a poor correlation between measures of ultrasound texture at 19-23 weeks of gestation and the presence of specific lesions at delivery.

CONCLUSION

Combined abnormal UTAD and placental dysmorphologic condition before fetal viability identifies a subset of women who are at risk of adverse outcomes. Placental size is critical in the determination of the outcome in this situation because of the very high prevalence of destructive lesions, although present methods of placental imaging have significant limitations.

Uterine artery Doppler in the prediction of adverse pregnancy outcome

PURPOSE OF REVIEW

To review publications, published during the past year, that have examined uterine artery Doppler findings in women with adverse pregnancy outcome.

RECENT FINDINGS

Almost two-thirds of stillbirths that occur in the early preterm period (up to 32 weeks) can be predicted by uterine artery Doppler at 23 weeks. First trimester screening studies have shown that an abnormal result increases the risk of subsequent fetal growth restriction, and such women are at particularly high risk when indices remain abnormal in the second trimester. Studies combining uterine artery Doppler with maternal serum markers have demonstrated that measurement of first-trimester maternal serum pregnancy-associated plasma protein A and free beta human chorionic gonadotrophin improve sensitivities of second-trimester Doppler. As these are frequently measured in Down syndrome screening and they lend themselves in screening for pre-eclampsia. Women with abnormal first and second-trimester serum markers constitute a high-risk group. Maternal serum placental protein 13 remains a promising method for early screening, although a recent study suggests lower sensitivities than initially reported.

SUMMARY

Uterine artery Doppler screening identifies women at high risk for developing adverse pregnancy outcomes. Detection rates may be increased and false positive rates reduced by combination with maternal characteristics or serum markers.

Ultrasound detection of placental insufficiency in women with 'unexplained' abnormal maternal serum screening results

Serious placental insufficiency results in perinatal death or preterm birth from ischemic-thrombotic pathology, a process which has its origins in placental maldevelopment in the first trimester. A proportion of at-risk pregnancies may be identified from abnormalities in first or second trimester serum screening data, uterine artery Doppler waveforms or placental shape and texture at the time of the 18-20-week anatomical examination. In combination, these tests may be capable of recognizing a subset of at-risk pregnancies with 50% positive predictive values. Early recognition before fetal viability affords opportunities to direct women to regional perinatal care centres for enhanced maternal-fetal surveillance, corticosteroids to enhance fetal lung maturation, prophylactic measures to prevent pre-eclampsia and optimal decision making around the time of delivery. The creation of regional screening programs to use screening data with a placental focus is likely to be cost-effective, because existing patterns of care are utilized. More importantly, this strategy can direct women to participate in clinical research programs designed to reduce morbidity and mortality from this common group of conditions.