Turning the pyramid of prenatal care

Cervical length measurement between 11 and 13 + 6 weeks of pregnancy: Comparison of maternal and ultrasonographic characteristics between term and preterm deliveries

OBJECTIVE

The aim of this study was to evaluate the maternal and ultrasonographic characteristics of pregnant women who underwent cervical length (CL) measurement by transvaginal ultrasound between 11 and 13 + 6 weeks of gestation and who delivered at term or preterm.

METHODS

A retrospective cohort study was carried out between March 2013 and December 2018 by analyzing ultrasound data of singleton pregnant women who underwent CL measurement by transvaginal ultrasound during the first trimester scan. CL was compared between the two groups (full-term and preterm birth [PB]) using Student's t-test.

RESULTS

A total of 5097 pregnant women were enrolled, of whom 5061 (99.3%) had term and 36 (0.7%) had PB < 34 weeks. CL measurements did not differ between the term and preterm groups (36.62 vs. 37.83 mm, p = 0.08). Maternal age showed a significant and linear association with CL (r = 0.034, p = 0.012) and CRL (r = 0.086, p < 0.001). Smoking status was associated with shorter CL (36.64 vs. 35.09 mm, p = 0.003). When we analyzed the CL of the pregnant women in the term and preterm groups, according to the gestational age cut-offs for prematurity (28, 30, 32, and 34 weeks), we found that there was no significant difference between the measurements in all groups (p > 0.05).

CONCLUSION

We observed no significant differences between CL measurements between 11 and 13 + 6 weeks in pregnant women who had preterm and term deliveries. Gestational age and CRL showed a significant and linear association with CL measurement.

Integration of Telehealth in Routine Perinatal Care: A Model of Care for Primary Healthcare Clinics in Saudi Arabia

This study aims to introduce a new model of antenatal/postnatal care that integrates virtual clinics with the current model of care, including a discussion on the current model, pre-existing barriers, and prenatal framework, and the need for transition to telehealth beyond the pandemic. In antenatal primary health care centers, such as King Abdulaziz Medical City (KAMC), low-risk antenatal/postnatal care receives clinical care through complete physical attendance in antenatal/postnatal clinics in primary care clinics for pregnancy follow-up and in tertiary hospitals for fetal ultrasound and invasive procedures if needed. Pregnancy is confirmed through a regular family medicine (FM) clinic where risk assessment through history, physical examination, and investigations are carried out. If the pregnant woman is at low risk, she will be started on folic acid, 1 mg or 5 mg based on the risk assessment (if it was not received before). Pregnant women will be given a telehealth appointment for the lab results. Concomitantly, the pregnant women will receive an appointment in the antenatal clinics, which board-certified family physicians run. High-risk patients will be referred to the hospital for further care. Current postnatal care is delivered through regular booking with the FM clinic through physical attendance sometimes, and virtual care is provided upon physican/patient request. Current care meets the past quality care and patient expectations. However, with the current Saudi Vision 2030 and after the experience with virtual care during the COVID-19 pandemic, the current services need to move a step forward to meet the rapidly developing medical care/needs in Saudi Arabia. Various challenges must be addressed, and new models must be included in clinical care for pregnant and postnatal women. Introducing virtual antenatal/postnatal care to the current care could be a new era in maternity primary health care; this model will move the clinical care provided to pregnant/postnatal women a step forward that meets the excellence of high-quality, evidence-based medical care.

Invasive prenatal diagnosis in the era of cell-free fetal DNA: experience at a single center

BACKGROUND

We aimed to assess procedure-related risk of fetal loss associated with amniocentesis and chorionic villus sampling and compare amniocentesis and chorionic villus sampling with cell-free fetal DNA in identifying chromosomal abnormalities.

METHODS

A retrospective observational study on 4712 women with singleton pregnancy who underwent invasive prenatal diagnosis, from January 2010 to December 2019. Postprocedural miscarriage rate (before 24+0 weeks gestation) was determined for the whole population and for the group of women aged ≥35 years who underwent the procedure for the sole maternal age.

RESULTS

Miscarriage rate following amniocentesis and chorionic villus sampling were 0.50% and 1.25%, respectively. In our population of women undergoing invasive procedure for advanced maternal age cell-free fetal DNA would have identified only the 49 cases of trisomy 21, 13 and 18, whereas the other 21 more subtle chromosomal anomalies, diagnosed by amniocentesis and chorionic villus sampling, would have been missed.

CONCLUSIONS

Patients who opt for cell-free fetal DNA test should be informed of the screening nature of the test and the possibility of false positive results. Invasive prenatal testing has probably lower risks than previously reported and has unquestionable advantages such as the certainty of diagnosis and the ability to detect a higher number of chromosomal abnormalities, when compared with cell-free fetal DNA.

External validation of Fetal Medicine Foundation competing-risks model for midgestation prediction of small-for-gestational-age neonates in Spanish population

OBJECTIVE

To examine the external validity of the new Fetal Medicine Foundation (FMF) competing-risks model for prediction in midgestation of small-for-gestational-age (SGA) neonates.

METHODS

This was a single-center prospective cohort study of 25 484 women with a singleton pregnancy undergoing routine ultrasound examination at 19 + 0 to 23 + 6 weeks' gestation. The FMF competing-risks model for the prediction of SGA combining maternal factors and midgestation estimated fetal weight by ultrasound scan (EFW) and uterine artery pulsatility index (UtA-PI) was used to calculate risks for different cut-offs of birth-weight percentile and gestational age at delivery. The predictive performance was evaluated in terms of discrimination and calibration.

RESULTS

The validation cohort was significantly different in composition compared with the FMF cohort in which the model was developed. In the validation cohort, at a 10% false-positive rate (FPR), maternal factors, EFW and UtA-PI yielded detection rates of 69.6%, 38.7% and 31.7% for SGA < 10th percentile with delivery at < 32, < 37 and ≥ 37 weeks' gestation, respectively. The respective values for SGA < 3rd percentile were 75.7%, 48.2% and 38.1%. Detection rates in the validation cohort were similar to those reported in the FMF study for SGA with delivery at < 32 weeks but lower for SGA with delivery at < 37 and ≥ 37 weeks. Predictive performance in the validation cohort was similar to that reported in a subgroup of the FMF cohort consisting of nulliparous and Caucasian women. Detection rates in the validation cohort at a 15% FPR were 77.4%, 50.0% and 41.5% for SGA < 10th percentile with delivery at < 32, < 37 and ≥ 37 weeks, respectively, which were similar to the respective values reported in the FMF study at a 10% FPR. The model had satisfactory calibration.

CONCLUSION

The new competing-risks model for midgestation prediction of SGA developed by the FMF performs well in a large independent Spanish population. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Is the Biphasic Effect of Diabetes and Obesity on Fetal Growth a Risk Factor for Childhood Obesity?

In pregnancies of women with obesity or diabetes, neonates are often overgrown. Thus, the pregnancy period in these women offers a window of opportunity to reduce childhood obesity by preventing neonatal overgrowth. However, the focus has been almost exclusively on growth in late pregnancy. This perspective article addresses possible growth deviations earlier in pregnancy and their potential contribution to neonatal overgrowth. This narrative review focuses on six large-scale, longitudinal studies that included ∼14,400 pregnant women with at least three measurements of fetal growth. A biphasic pattern in growth deviation, including growth reduction in early pregnancy followed by overgrowth in late pregnancy, was found in fetuses of women with obesity, gestational diabetes mellitus (GDM), or type 1 diabetes compared with lean women and those with normal glucose tolerance. Fetuses of women with these conditions have reduced abdominal circumference (AC) and head circumference (HC) in early pregnancy (observed between 14 and 16 gestational weeks), while later in pregnancy they present the overgrown phenotype with larger AC and HC (from approximately 30 gestational weeks onwards). Fetuses with early-pregnancy growth reduction who end up overgrown presumably have undergone in utero catch-up growth. Similar to postnatal catch-up growth, this may confer a higher risk of obesity in later life. Potential long-term health consequences of early fetal growth reduction followed by in utero catch-up growth need to be explored.

Resistance to Change

Advances in medical technology do not follow a smooth process and are highly variable. Implementation can occasionally be rapid, but often faces varying degrees of resistance resulting at the very least in delayed implementation. Using qualitative comparative analysis, we have evaluated numerous technological advances from the perspective of how they were introduced, implemented, and opposed. Resistance varies from benign - often happening because of inertia or lack of resources to more active forms, including outright opposition using both appropriate and inappropriate methods to resist/delay changes in care. Today, even public health has become politicized, having nothing to do with the underlying science, but having catastrophic results. Two other corroding influences are marketing pressure from the private sector and vested interests in favor of one outcome or another. This also applies to governmental agencies. There are a number of ways in which papers have been buried including putting the thumb on the scale where reviewers can sabotage new ideas. Unless we learn to harness new technologies earlier in their life course and understand how to maneuver around the pillars of obstruction to their implementation, we will not be able to provide medical care at the forefront of technological capabilities.

Improving the interpretation of electronic fetal monitoring: the fetal reserve index

Electronic fetal monitoring, particularly in the form of cardiotocography, forms the centerpiece of labor management. Initially successfully designed for stillbirth prevention, there was hope to also include prediction and prevention of fetal acidosis and its sequelae. With the routine use of electronic fetal monitoring, the cesarean delivery rate increased from <5% in the 1970s to >30% at present. Most at-risk cases produced healthy babies, resulting in part from considerable confusion as to the differences between diagnostic and screening tests. Electronic fetal monitoring is clearly a screening test. Multiple attempts have aimed at enhancing its ability to accurately distinguish babies at risk of in utero injury from those who are not and to do this in a timely manner so that appropriate intervention can be performed. Even key electronic fetal monitoring opinion leaders admit that this goal has yet to be achieved. Our group has developed a modified approach called the "Fetal Reserve Index" that contextualizes the findings of electronic fetal monitoring by formally including the presence of maternal, fetal, and obstetrical risk factors and increased uterine contraction frequencies and breaking up the tracing into 4 quantifiable components (heart rate, variability, decelerations, and accelerations). The result is a quantitative 8-point metric, with each variable being weighted equally in version 1.0. In multiple previously published refereed papers, we have shown that in head-to-head studies comparing the fetal reserve index with the American College of Obstetricians and Gynecologists' fetal heart rate categories, the fetal reserve index more accurately identifies babies born with cerebral palsy and could also reduce the rates of emergency cesarean delivery and vaginal operative deliveries. We found that the fetal reserve index scores and fetal pH and base excess actually begin to fall earlier in the first stage of labor than was commonly appreciated, and the fetal reserve index provides a good surrogate for pH and base excess values. Finally, the last fetal reserve index score before delivery combined with early analysis of neonatal heart rate and acid/base balance shows that the period of risk for neonatal neurologic impairment can continue for the first 30 minutes of life and requires much closer neonatal observation than is currently being done.

First Trimester Ultrasound Detection of Fetal Central Nervous System Anomalies

OBJECTIVE

To evaluate the potential of the first-trimester ultrasound (US) features for the detection of central nervous system (CNS) anomalies. Methods/Methodology: This is a prospective one-center three-year study. Unselected singleton pregnant women were examined using an extended first-trimester anomaly scan (FTAS) that included the CNS assessment: the calvaria shape, the septum (falx cerebri), the aspect of the lateral ventricles, the presence of the third ventricle and aqueduct of Sylvius (AS) and the posterior brain morphometry: the fourth ventricle, namely intracranial translucency (IT), brain stem/brain stem-occipital bone ratio (BS/BSOB) and cisterna magna (CM). The spine and underlying skin were also evaluated. The cases were also followed during the second and third trimesters of pregnancy and at delivery. FTAS efficiency to detect major CNS abnormalities was calculated.

RESULTS

We detected 17 cases with CNS major abnormalities in a population of 1943 first-trimester (FT) fetuses, including spina bifida with myelomeningocele, exencephaly-anencephaly, holoprosencephaly, hydrocephaly, cephalocele and Dandy-Walker malformation. The CNS features in the abnormal group are presented. In the second trimester (ST), we further diagnosed cases of corpus callosum agenesis, cerebellar hypoplasia, vein of Galen aneurysm and fetal infection features (ventriculomegaly, intraventricular bands, intraventricular cyst and hyperechoic foci), all declared normal at the FTAS. During the third trimester (TT) scan we identified a massive fetal cerebral haemorrhage absent at previous investigations. We report a detection rate of 72.7% of fetal brain anomalies in the FT using the proposed CNS parameters. The sensitivity of the examination protocol was 72.7%, and the specificity was 100%.

CONCLUSION

A detailed FT CNS scan is feasible and efficient. The majority of cases of major CNS abnormalities can be detected early in pregnancy. The visualization rates of the CNS parameters in the FT are great with short, if any, additional investigation time. FT cerebral disorders such as haemorrhage or infections were missed in the FT even when an extended evaluation protocol was used.

Diagnostic biomolecules and combination therapy for pre-eclampsia

Pre-eclampsia (PE), associated with placental malperfusion, is the primary reason for maternal and perinatal mortality and morbidity that can cause vascular endothelial injury and multi-organ injury. Despite considerable research efforts, no pharmaceutical has been shown to stop disease progression. If women precisely diagnosed with PE can achieve treatment at early gestation, the maternal and fetal outcomes can be maximally optimized by expectant management. Current diagnostic approaches applying maternal characteristics or biophysical markers, including blood test, urine analysis and biophysical profile, possess limitations in the precise diagnosis of PE. Biochemical factor research associated with PE development has generated ambitious diagnostic targets based on PE pathogenesis and dissecting molecular phenotypes. This review focuses on current developments in biochemical prediction of PE and the corresponding interventions to ameliorate disease progression, aiming to provide references for clinical diagnoses and treatments.

Behavior of the Genetic Markers at Screening during the First Trimester of Pregnancy in Euploid Fetuses

OBJECTIVE

 This study aims to describe the behavior of chromosomopathy screenings in euploid fetuses.

METHODS

 This is a prospective descriptive study with 566 patients at 11 to 14 weeks of gestation. The associations between ultrasound scans and serological variables were studied. For the quantitative variables we used the Spearman test; for the qualitative with quantitative variables the of Mann-Whitney U-test; and for qualitative variables, the X² test was applied. Significance was set at p ≤ 0.05.

RESULTS

 We have found that gestational age has correlation with ductus venosus, nuchal translucency, free fraction of β subunit of human chorionic gonadotropin, pregnancy-associated plasma protein-A and placental growth factor; there is also a correlation between history of miscarriages and nasal bone. Furthermore, we correlated body mass index with nuchal translucency, free fraction of β subunit of human chorionic gonadotropin, and pregnancy-associated plasma protein-A. Maternal age was associated with free fraction of β subunit of human chorionic gonadotropin and pregnancy-associated plasma protein-A.

CONCLUSION

 Our study demonstrates for the first time the behavior of the biochemical and ultrasonographic markers of chromosomopathy screenings during the first trimester in euploid fetuses in Colombia. Our information is consistent with international reference values. Moreover, we have shown the correlation of different variables with maternal characteristics to determine the variables that could help with development of a screening process during the first trimester with high detection rates.

Changing Perspectives of Electronic Fetal Monitoring

The delivery of healthy babies is the primary goal of obstetric care. Many technologies have been developed to reduce both maternal and fetal risks for poor outcomes. For 50 years, electronic fetal monitoring (EFM) has been used extensively in labor attempting to prevent a large proportion of neonatal encephalopathy and cerebral palsy. However, even key opinion leaders admit that EFM has mostly failed to achieve this goal. We believe this situation emanates from a fundamental misunderstanding of differences between screening and diagnostic tests, considerable subjectivity and inter-observer variability in EFM interpretation, failure to address the pathophysiology of fetal compromise, and a tunnel vision focus. To address these suboptimal results, several iterations of increasingly sophisticated analyses have intended to improve the situation. We believe that part of the continuing problem is that the focus of EFM has been too narrow ignoring important contextual issues such as maternal, fetal, and obstetrical risk factors, and increased uterine contraction frequency. All of these can significantly impact the application of EFM to intrapartum care. We have recently developed a new clinical approach, the Fetal Reserve Index (FRI), contextualizing EFM interpretation. Our data suggest the FRI is capable of providing higher accuracy and earlier detection of emerging fetal compromise. Over time, artificial intelligence/machine learning approaches will likely improve measurements and interpretation of FHR characteristics and other relevant variables. Such future developments will allow us to develop more comprehensive models that increase the interpretability and utility of interfaces for clinical decision making during the intrapartum period.

First-Trimester Fetal Hepatic Artery Examination for Adverse Outcome Prediction

Objective: To assess whether there are differences in first-trimester fetal hepatic artery flows depending on pregnancy outcomes. Methods: The prospective study conducted in 2012–2020 included 1841 fetuses from singleton pregnancies assessed during the routine first-trimester ultrasound examination (between 11- and 14-weeks’ gestation). Also, each fetus was examined to determine their hepatic artery flows by measuring the artery’s pulsatility index (HA-PI) and peak systolic velocity (HA-PSV). Results: The fetuses that were classified as belonging to the adverse pregnancy outcome group (those with karyotype abnormalities and congenital heart defects) were characterized by a significantly lower HA-PI and higher HA-PSV compared to normal outcome fetuses. Conclusion: Hepatic artery flow assessment proved to be a very useful tool in predicting adverse pregnancy outcomes, in particular karyotype abnormalities and congenital heart defects.

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.

Impact of introducing cell-free DNA screening into clinical care on first trimester ultrasound

OBJECTIVE

First-trimester ultrasound is an important component of prenatal care. We investigated the impact of introducing cell-free DNA (cfDNA) aneuploidy screening into routine care, on performance of first-trimester ultrasound.

METHODS

Retrospective study of patients who had prenatal care at a tertiary referral center. We compared the performance of any first-trimester ultrasound between three different aneuploidy screening protocols, used consecutively during the study period: (1) combined first-trimester screening (FTS); (2) FTS and cfDNA offered together; (3) patients requested to choose between FTS and cfDNA. Secondary outcomes included performance of nuchal translucency (NT), aneuploidy screens and diagnostic genetic procedures.

RESULTS

The number of patients undergoing first-trimester ultrasound remained similar with the second protocol but decreased in the third (68.7% vs. 40.9%, OR 0.32, 95% CI 0.25-0.4, p < 0.001). Diagnostic procedures decreased between protocol 1 and 2 (7.6% vs. 4.4%, OR 0.59, 95% CI 0.37-0.93, p = 0.02) while NT scans decreased between protocol 2 and 3 (6.8% vs. 1.3%, OR 0.18, 95% CI 0.09-0.4, p < 0.001). The rate of FTS decreased over the study period and less women had cfDNA when they had to choose one method (p < 0.001).

CONCLUSIONS

Introducing cfDNA screening as an alternative to FTS, resulted in fewer patients receiving ultrasound in the first-trimester.

Lower uterine segment scar assessment at 11-14 weeks' gestation to screen for placenta accreta spectrum in women with prior Cesarean delivery

OBJECTIVES

To validate prospectively transvaginal ultrasound assessment of the lower uterine segment (LUS) scar at the time of first-trimester screening in women with previous Cesarean section (CS) and to determine its feasibility and accuracy in stratifying women according to the risk for placenta accreta spectrum (PAS) disorder.

METHODS

Women with a history of CS were recruited between 11 + 0 and 13 + 6 weeks' gestation and underwent LUS scar assessment using transvaginal ultrasound. A standardized midsagittal plane, which included the cervicoisthmic canal (CIC), the uterine scar and the placental site, was obtained. The scar was described in terms of its size (narrow or dehiscent) and its location in relation to the CIC (within or above), with each LUS scar classified into one of four groups based on these features. Placental location was assessed and classified as high- or low-lying. Women were stratified according to the risk of PAS, based on the relationship between the scar location and placental site. Women were considered high risk when the scar was above the CIC and the placenta was low-lying (i.e. when the placenta was overlying an exposed scar) and low risk when the scar was within the CIC and/or the placenta was high. High-risk patients were followed up at 20 weeks and 28-30 weeks for the development of PAS. Maternal demographics, detailed obstetric history and obstetric outcome were collected.

RESULTS

First-trimester transvaginal ultrasound was offered to 535 women with prior CS during the study period. A LUS scar was visualized in 79.9% (401/502) of those who agreed to undergo the examination. At this scan, the LUS scar was above the CIC in 9.0% (36/401) of women, but only 5.7% (23/401) additionally had a low-lying placenta overlying the scar. Of these 23 high-risk women, two were found to have PAS on the mid-trimester screening scan and one was noted to have placental adherence during evacuation following mid-trimester termination of pregnancy. On the first-trimester scan, 94.3% (378/401) of women were at low risk of PAS. This screening protocol yielded a positive likelihood ratio of 21.33 (95% CI, 13.02-34.96), sensitivity of 100% (95% CI, 29.24-100%), specificity of 95.31% (95% CI, 92.39-97.35%), positive predictive value of 16.7% (95% CI, 5.8-39.2%) and negative predictive value of 100% (95% CI, 98.4-100%). On multivariable regression analysis performed to identify confounding variables associated with a LUS scar above the CIC, only maternal body mass index ≥ 30 kg/m² was significant (odds ratio (OR), 2.42 (95% CI, 1.04-5.39); P = 0.03). Although there was a trend towards an increased risk of a LUS scar above the CIC in women with prior elective prelabor CS (OR, 1.72 (95% CI, 0.80-3.68)), this association did not reach statistical significance.

CONCLUSIONS

Routine transvaginal ultrasound assessment of the location of the LUS scar and placenta at the time of first-trimester screening between 11 + 0 and 13 + 6 weeks' gestation in women with prior CS is a feasible and effective tool to identify those at risk of subsequent development of PAS disorder. A finding of placental implantation over an exposed LUS scar seems to be cardinal in predicting the risk of PAS disorder in women with prior CS, with an excellent negative predictive value. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal circulating concentrations of soluble Fas and Elabela in early- and late-onset preeclampsia

OBJECTIVE

The Fas/Fas ligand (FASL) system and Elabela-apelin receptor signaling pathways are implicated in the pathophysiology of preeclampsia. The aim of the current study was to investigate whether a model combining the measurement of sFas and Elabela in the maternal circulation may serve as a clinical biomarker for early- and/or late-onset preeclampsia more effectively than measures of each biomarker individually.

METHODS

Blood samples were collected from 214 women in the following groups: (1) normal pregnancy sampled <34 weeks of gestation (n = 56); (2) patients who developed early-onset preeclampsia (n = 54); (3) normal pregnancy sampled ≥34 weeks of gestation (n = 52); (4) patients who developed late-onset preeclampsia (n = 52). Maternal circulating soluble Fas and Elabela concentrations were determined using sensitive and validated immunoassays. Two sample t-tests, multivariate logistic regression, and receiver operating characteristic curves were used for analyses.

RESULTS

(1) Women with early-onset preeclampsia, and those with late-onset preeclampsia with placental lesions of maternal vascular malperfusion, had increased concentrations of sFas compared to their gestational age-matched normal controls; (2) women with late-onset preeclampsia, but not those with early-onset preeclampsia, had increased concentrations of Elabela compared to their gestational age-matched counterparts; and (3) an increase in both Elabela and sFas concentrations was more strongly associated with late-onset preeclampsia than early-onset preeclampsia relative to models including either of the markers alone.

CONCLUSIONS

A combined model of maternal sFas and Elabela concentrations provides a stronger association with late-onset preeclampsia than either protein alone. This finding demonstrates the possibility to improve the classification of late-onset preeclampsia by combining the results of both molecular biomarkers.

Prediction of preeclampsia throughout gestation with maternal characteristics and biophysical and biochemical markers: a longitudinal study

BACKGROUND

The current approach to predict preeclampsia combines maternal risk factors and evidence from biophysical markers (mean arterial pressure, Doppler velocimetry of the uterine arteries) and maternal blood proteins (placental growth factor, soluble vascular endothelial growth factor receptor-1, pregnancy-associated plasma protein A). Such models require the transformation of biomarker data into multiples of the mean values by using population- and site-specific models. Previous studies have focused on a narrow window in gestation and have not included the maternal blood concentration of soluble endoglin, an important antiangiogenic factor up-regulated in preeclampsia.

OBJECTIVE

This study aimed (1) to develop models for the calculation of multiples of the mean values for mean arterial pressure and biochemical markers; (2) to build and assess the predictive models for preeclampsia based on maternal risk factors, the biophysical (mean arterial pressure) and biochemical (placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin) markers collected throughout pregnancy; and (3) to evaluate how prediction accuracy is affected by the presence of chronic hypertension and gestational age.

STUDY DESIGN

This longitudinal case-cohort study included 1150 pregnant women: women without preeclampsia with (n=49) and without chronic hypertension (n=871) and those who developed preeclampsia (n=166) or superimposed preeclampsia (n=64). Mean arterial pressure and immunoassay-based maternal plasma placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin concentrations were available throughout pregnancy (median of 5 observations per patient). A prior-risk model for preeclampsia was established by using Poisson regression based on maternal characteristics and obstetrical history. Next, multiple regression was used to fit biophysical and biochemical marker data as a function of maternal characteristics by using data collected at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, and observed values were converted into multiples of the mean values. Then, multivariable prediction models for preeclampsia were fit based on the biomarker multiples of the mean data and prior-risk estimates. Separate models were derived for overall, preterm, and term preeclampsia, which were evaluated by receiver operating characteristic curves and sensitivity at fixed false-positive rates.

RESULTS

(1) The inclusion of soluble endoglin in prediction models for all preeclampsia, together with the prior-risk estimates, mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1, increased the sensitivity (at a fixed false-positive rate of 10%) for early prediction of superimposed preeclampsia, with the largest increase (from 44% to 54%) noted at 20 to 23⁺⁶ weeks (McNemar test, P<.05); (2) combined evidence from prior-risk estimates and biomarkers predicted preterm preeclampsia with a sensitivity (false-positive rate, 10%) of 55%, 48%, 62%, 72%, and 84% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, and 28 to 31⁺⁶ week intervals, respectively; (3) the sensitivity for term preeclampsia (false-positive rate, 10%) was 36%, 36%, 41%, 43%, 39%, and 51% at 8 to 15⁺⁶, 16 to 19⁺⁶, 20 to 23⁺⁶, 24 to 27⁺⁶, 28 to 31⁺⁶, and 32 to 36⁺⁶ week intervals, respectively; (4) the detection rate for superimposed preeclampsia among women with chronic hypertension was similar to that in women without chronic hypertension, especially earlier in pregnancy, reaching at most 54% at 20 to 23⁺⁶ weeks (false-positive rate, 10%); and (5) prediction models performed comparably to the Fetal Medicine Foundation calculators when the same maternal risk factors and biomarkers (mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1 multiples of the mean values) were used as input.

CONCLUSION

We introduced prediction models for preeclampsia throughout pregnancy. These models can be useful to identify women at risk during the first trimester who could benefit from aspirin treatment or later in pregnancy to inform patient management. Relative to prediction performance at 8 to 15⁺⁶ weeks, there was a substantial improvement in the detection rate for preterm and term preeclampsia by using data collected after 20 and 32 weeks' gestation, respectively. The inclusion of plasma soluble endoglin improves the early prediction of superimposed preeclampsia, which may be valuable when Doppler velocimetry of the uterine arteries is not available.

Every Mother and Every Fetus Matters: A Positive Pregnant Test = Multiple Offerings of Reproductive Risk Screening for personal, family, and specific obstetrical-fetal conditions

Structured OBJECTIVE: The requirement and need for a focused 'pregnant person -centered' antenatal care process with time for informed consent and shared decision making are important for optimal antenatal care. This commentary focuses on the evidenced -based screening test options and timing as part of the overall 'pregnant person-centered' preconception and antenatal care journey.

METHODS

A structured quality improvement (QI) review (Squire 2.0) was undertaken to examine the appropriate reproductive screening process in the periods of preconception and during pregnancy.

RESULTS

First, evaluated the broader antenatal care structure which, second, enabled the directed reproductive risk screening processes to be offered within an informed consent process. Four international pre-conception and antenatal evidenced-based consensus would routinely offer specific gestational age reproductive risk screening elements: totaling 21 screening elements (preconception 3; 1st trimester 9; 2nd trimester 3; 3rd trimester 4; intrapartum 1; postpartum 1).

CONCLUSION

The best evidenced-based opportunity for comprehensive and collaborative antenatal care with appropriate screening elements requires: single national access healthcare system; expert evidenced-based guideline creation; collaborative maternity care providers based for risk assessment, triage, and management; pregnant person (women) centered care model of maternity care; clearly identified evidenced-based gestational age directed screening elements; international pre-conception and antenatal guideline consensus.

Prediction of pre-eclampsia

Pre-eclampsia is a leading cause of neonatal and maternal mortality and morbidity that complicates approximately 2-8% of all pregnancies worldwide. The precise cause of pre-eclampsia is not completely understood, with several environmental, genetic, and maternal factors involved in its pathogenesis and pathophysiology. An accurate predictor of pre-eclampsia will facilitate early recognition, close surveillance according to the individual risk and early intervention, and reduce the negative consequences of the disorder. Current evidence shows that no single test predicts pre-eclampsia with sufficient accuracy to be clinically useful. A combination of markers into multiparametric models may provide a more useful and feasible predictive tool for pre-eclampsia screening in the routine care setting than a test of either component alone. This review presents a summary of the current advances on prediction of pre-eclampsia, highlighting their performance and applicability. Key priorities when conducting research on predicting pre-eclampsia are also analyzed.

Diagnosis and Management of Cesarean Scar Pregnancy and Placenta Accreta Spectrum: Case Series and Review of the Literature

With an increased cesarean delivery rate, the incidence of abnormal placentation is steadily rising, and it is estimated to be around 1.7 per 1000 pregnancies for cesarean scar pregnancy and 1 per 500 pregnancies for placenta accreta spectrum disorder. Current evidence considers cesarean scar pregnancy and placenta accreta spectrum as being the same condition, with different aspects, of the same spectrum, having higher risks with advancing gestation. We present 7 cases, diagnosed and managed in our hospital, at different gestational ages. Early diagnosis is essential for appropriate counseling and subsequent management, and an ultrasound examination is the reference standard for diagnosis. Screening for an abnormally implanted placenta in the first trimester of pregnancy might improve the perinatal outcome and reduce maternal morbidity and mortality.

Stratification of pregnancy care based on risk of pre-eclampsia derived from biophysical and biochemical markers at 19-24 weeks' gestation

OBJECTIVE

We have proposed previously that all pregnant women should have assessment of risk for pre-eclampsia (PE) at 20 and 36 weeks' gestation and that the 20-week assessment should be used to define subgroups requiring additional monitoring and reassessment at 28 and 32 weeks. The objective of this study was to examine the potential improvement in screening at 19-24 weeks' gestation for PE with delivery at < 28, < 32, < 36 and ≥ 36 weeks' gestation by the addition of serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) to the combination of maternal demographic characteristics and medical history, uterine artery pulsatility index (UtA-PI) and mean arterial pressure (MAP).

METHODS

This was a prospective, non-intervention study in women attending for an ultrasound scan at 19-24 weeks as part of routine pregnancy care. Patient-specific risks of delivery with PE at < 36 weeks' gestation were calculated using the competing-risks model to combine the prior distribution of gestational age at delivery with PE, obtained from maternal characteristics and medical history, with multiples of the median values of UtA-PI, MAP, PlGF and sFlt-1. Different risk cut-offs were used to vary the proportion of the population stratified into each of four risk categories (very high risk, high risk, intermediate risk and low risk) with the intention of detecting about 80%, 85%, 90% and 95% of cases of delivery with PE at < 28, < 32 and < 36 weeks' gestation. The performance of screening was assessed by plotting the detection rate against the screen-positive rate and calculating the areas under these curves, and by the proportion stratified into a given group for fixed detection rates. Model-based estimates of screening performance for these various combinations of markers were also produced.

RESULTS

In the study population of 37 886 singleton pregnancies, there were 1130 (3.0%) that subsequently developed PE, including 160 (0.4%) that delivered at < 36 weeks' gestation. In both the modeled and empirical results, there was incremental improvement in the performance of screening with the addition of PlGF and sFlt-1 to the combination of maternal factors, UtA-PI and MAP. If the objective of screening was to identify about 90% of cases of PE with delivery at < 28, < 32 and < 36 weeks and the method of screening was a combination of maternal factors, UtA-PI and MAP, the respective screen-positive rates would be 3.1%, 8.5% and 19.1%. The respective values for screening by maternal factors, UtA-PI, MAP and PlGF were 0.2%, 0.7% and 10.6%, and for screening by maternal factors, UtA-PI, MAP, PlGF and sFlt-1 they were 0.1%, 0.4% and 9.5%. The empirical results were consistent with the modeled results. There was good agreement between the predicted risk and the observed incidence of PE at < 36 weeks' gestation for all three strategies of screening. Prediction of PE at ≥ 36 weeks was poor for all three screening methods, with the detection rate, at a 10% screen-positive rate, ranging from 33.2% to 38.4%.

CONCLUSIONS

The performance of screening at 19-24 weeks' gestation for PE with delivery at < 28, < 32 and < 36 weeks' gestation achieved by a combination of maternal demographic characteristics and medical history, UtA-PI and MAP is improved by the addition of serum PlGF and sFlt-1. The performance of screening for PE at ≥ 36 weeks' gestation is poor irrespective of the method of screening at 19-24 weeks. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal growth restriction: underdiagnosed condition with non-optimal screening

BACKGROUND

Fetal Growth restriction (FGR) is the pathological failure of a fetus to reach its biologically determined growth potential. Detection of FGR fetuses is a universally agreed key objective of antenatal care. Antenatal detection of FGR has undeniable benefits, juggling between intensive fetal surveillance and optimized timing of delivery; it reduces adverse perinatal outcomes by up to four-fold. However, FGR is still widely underdiagnosed. We aimed to identify the prevalence of FGR diagnosis in our wards and study the impact of the 2013 published French guidelines on the detection rate of FGR. The secondary objective aimed to highlight the factors of suboptimal screening in the population of non-diagnosed FGR fetuses and emphasize the screening method that led to antenatal diagnosis of FGR.

MATERIALS AND METHODS

We conducted a retrospective study at a single tertiary maternity center in Lyon-France, the Femme Mère Enfant Hospital, including the exhaustive population of FGR born after 24 + 0 weeks of gestation from 1 January 2011 to 31 December 2017. FGR was defined combining the neonatal and antenatal consensus-based definitions for early and late FGR in absence of congenital anomalies, excluding small for gestational age fetuses. For all FGR fetuses, we compared the antenatal detection rate of FGR during 2011-2013 to 2015-2017, since the French guidelines were published in December 2013. When FGR fetuses underwent an antenatal diagnosis of FGR, we retrospectively collected the characteristics that led to the diagnosis. When fetuses were not diagnosed as FGR, we retrospectively reviewed the implementation of the recommended screening method, enabling to evaluate whether screening was optimal or not. Statistical analysis was performed in July 2018, and statistical significance was regarded as a p-value <.05.

RESULTS

Over the seven-year period, and among 31,052 newborns, 1020 (3.3%) infants were identified as FGR and met the inclusion criteria. The detection rate of FGR was similar before and after publication of the French Guidelines related to FGR in 2013. Indeed, 50.8% (201/395) FGR were diagnosed between 2011 and 2013 versus 52.6% (245/465) between 2015 and 2017 (p = .59). In the population of non-diagnosed FGR infants, screening was suboptimal in 80%. Symphysis-fundal height (SFH) was not measured in 10.7%, with no difference before and after 2014 (7.3 versus 11.8% p = .11). Ultrasound examination for fetal biometry had not been prescribed in spite of abnormal SFH in 47.7% of undiagnosed FGR infants. Diagnosis has been missed in 11.5% of infants because of misinterpretation of the estimated fetal weight's centile.

CONCLUSION

FGR is widely underdiagnosed. However, the limited performances can partially be explained by the regular misuse of screening method in clinical practice. Despite the systematic third trimester ultrasound screening, the detection rate of FGR was similar to the one reported in the medical literature. The timing of routine third trimester ultrasound in low-risk women may be rethought.

Stratification of pregnancy care based on risk of pre-eclampsia derived from uterine artery Doppler at 19-24 weeks' gestation

OBJECTIVES

There were two objectives of this study. First, to examine the value of uterine artery pulsatility index (UtA-PI) at 19-24 weeks' gestation in the prediction of subsequent development of pre-eclampsia (PE) and to compare the performance of screening between the use of, first, fixed cut-offs of UtA-PI, second, percentile cut-offs of UtA-PI adjusted for gestational age, third, a competing-risks model combining maternal demographic characteristics and medical history with UtA-PI, and, fourth, a competing-risks model combining maternal factors with UtA-PI and mean arterial pressure (MAP). Second, to stratify pregnancy care based on the estimated risk of PE at 19-24 weeks' gestation from UtA-PI and combinations of maternal factors with UtA-PI and MAP.

METHODS

This was a prospective, non-intervention study in women attending for an ultrasound scan at 19-24 weeks as part of routine pregnancy care. Patient-specific risks of delivery with PE at < 36 weeks' gestation were calculated using the competing-risks model to combine the prior distribution of the gestational age at delivery with PE, obtained from maternal characteristics and medical history, with multiples of the median (MoM) values of UtA-PI and MAP. Different risk cut-offs were used to vary the proportion of the population stratified into each risk category (very high risk, high risk, intermediate risk and low risk) with the intention of detecting about 80%, 85%, 90% and 95% of cases of delivery with PE at < 28, < 32 and < 36 weeks' gestation. We also examined the performance of screening by maternal factors and UtA-PI MoM, fixed cut-offs of UtA-PI and percentile cut-offs of UtA-PI adjusted for gestational age. Calibration for risks for PE < 36 weeks' gestation by the combination of maternal factors, UtA-PI MoM and MAP MoM was assessed by plotting the observed incidence of PE against the predicted incidence. Additionally, we developed reference ranges of transabdominal and transvaginal measurement of UtA-PI according to gestational age.

RESULTS

In the study population of 96 678 singleton pregnancies, there were 2866 (3.0%) that subsequently developed PE, including 467 (0.5%) that delivered at < 36 weeks' gestation. If the objective of screening was to identify about 90% of cases of delivery with PE at < 28, < 32 and < 36 weeks and the method of screening was a combination of maternal factors, UtA-PI MoM and MAP MoM, the proportion of the population stratified into very high-risk, high-risk, intermediate-risk and low-risk groups would be 2.4%, 3.9%, 17.8% and 75.9%, respectively; the respective values were 6.0%, 3.0%, 21.0% and 70.0% if screening was by maternal factors and UtA-PI MoM, 5.7%, 7.5%, 49.8% and 37.0% if screening was by fixed cut-offs of UtA-PI and 6.9%, 5.2%, 49.0% and 38.9% if screening was by percentile cut-offs of UtA-PI. In the validation of the prediction model based on a combination of maternal factors and MoM values of UtA-PI and MAP, calibration plots demonstrated good agreement between the predicted risk and the observed incidence of PE.

CONCLUSIONS

All pregnant women should have screening for PE at 20 and 36 weeks' gestation. The findings at 20 weeks can be used to identify the subgroups that require additional monitoring and reassessment at 28 and 32 weeks. The performance of screening by a combination of maternal factors and MoM values of UtA-PI and MAP at 19-24 weeks for delivery with PE at < 28, < 32 and < 36 weeks' gestation is superior to that of screening by a combination of maternal factors and UtA-PI MoM, by fixed cut-offs of UtA-PI or by percentile cut-offs of UtA-PI. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Understanding False Negative in Prenatal Testing

A false negative can happen in many kinds of medical tests, regardless of whether they are screening or diagnostic in nature. However, it inevitably poses serious concerns especially in a prenatal setting because its sequelae can mark the birth of an affected child beyond expectation. False negatives are not a new thing because of emerging new tests in the field of reproductive, especially prenatal, genetics but has occurred throughout the evolution of prenatal screening and diagnosis programs. In this paper we aim to discuss the basic differences between screening and diagnosis, the trade-offs and the choices, and also shed light on the crucial points clinicians need to know and be aware of so that a quality service can be provided in a coherent and sensible way to patients so that vital issues related to a false negative result can be appropriately comprehended by all parties.

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

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

A hierarchical procedure to select intrauterine and extrauterine factors for methodological validation of preterm birth risk estimation

Background

Etiopathogenesis of preterm birth (PTB) is multifactorial, with a universe of risk factors interplaying between the mother and the environment. It is of utmost importance to identify the most informative factors in order to estimate the degree of PTB risk and trace an individualized profile. The aims of the present study were: 1) to identify all acknowledged risk factors for PTB and to select the most informative ones for defining an accurate model of risk prediction; 2) to verify predictive accuracy of the model and 3) to identify group profiles according to the degree of PTB risk based on the most informative factors.

Methods

The Maternal Frailty Inventory (MaFra) was created based on a systematic review of the literature including 174 identified intrauterine (IU) and extrauterine (EU) factors. A sample of 111 pregnant women previously categorized in low or high risk for PTB below 37 weeks, according to ACOG guidelines, underwent the MaFra Inventory. First, univariate logistic regression enabled p-value ordering and the Akaike Information Criterion (AIC) selected the model including the most informative MaFra factors. Second, random forest classifier verified the overall predictive accuracy of the model. Third, fuzzy c-means clustering assigned group membership based on the most informative MaFra factors.

Results

The most informative and parsimonious model selected through AIC included Placenta Previa, Pregnancy Induced Hypertension, Antibiotics, Cervix Length, Physical Exercise, Fetal Growth, Maternal Anxiety, Preeclampsia, Antihypertensives. The random forest classifier including only the most informative IU and EU factors achieved an overall accuracy of 81.08% and an AUC of 0.8122. The cluster analysis identified three groups of typical pregnant women, profiled on the basis of the most informative IU and EU risk factors from a lower to a higher degree of PTB risk, which paralleled time of birth delivery.

Conclusions

This study establishes a generalized methodology for building-up an evidence-based holistic risk assessment for PTB to be used in clinical practice. Relevant and essential factors were selected and were able to provide an accurate estimation of degree of PTB risk based on the most informative constellation of IU and EU factors.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12884-021-03654-3).

The reduced use of invasive procedures leads to a change of frequencies of prenatally detected chromosomal aberrations: population data from the years 2012-2016

OBJECTIVE

The aim of the study was to analyze the results of screening for chromosomal aberrations in a population with a high rate of first-trimester screening and low rate of cell-free DNA testing.

METHODS

The data were obtained from the National Registry of Congenital Anomalies of the Czech Republic. We calculated and compared the proportion of autosomal trisomies (Down, Edwards, and Patau syndrome) and of other chromosomal aberrations identified during prenatal diagnostics.

RESULTS

We identified 3009 prenatally diagnosed cases of chromosomal aberrations in the 2012-2016 period. The number of major autosomal trisomies has increased from 329 cases (30.86 per 10,000 live births) in 2012 to 423 cases (37.41) in 2016 (p = 0.014). The numbers of other aberrations decreased from 246 cases (23.07 per 10,000) in 2012 to 217 cases (19.19) in 2016 (p = 0.017). The usage of invasive diagnostic procedures decreased from 1099.54 in 2012 to 622.73 in 2016 (per 10,000 live births).

CONCLUSIONS

Our population-based study confirmed a decrease in prenatal detection of nonmajor chromosomal aberrations wherein a decrease of invasive testing occurred. With the introduction of cell-free DNA testing, further decrease of invasive procedures and detection of nonmajor aberrations may be expected.

First trimester biomarkers for prediction of gestational diabetes mellitus

PURPOSE

To develop a first trimester prediction model for gestational diabetes mellitus (GDM) using obesity, placental, and inflammatory biomarkers.

METHODS

We used a first trimester dataset of the ASPRE study to evaluate clinical and biochemical biomarkers. All biomarkers levels (except insulin) were transformed to gestational week-specific medians (MoMs), adjusted for maternal body mass index (BMI), maternal age, and parity. The MoM values of each biomarker in the GDM and normal groups were compared and used for the development of a prediction model assessed by area under the curve (AUC).

RESULTS

The study included 185 normal and 20 GDM cases. In the GDM group, compared to the normal group BMI and insulin (P = 0.003) were higher (both P < 0.003). The MoM values of uterine artery pulsatility index (UtA-PI) and soluble (s)CD163 were higher (both P < 0.01) while pregnancy associated plasma protein A (PAPP-A), placental protein 13 (PP13), and tumor-necrosis factor alpha (TNFα) were lower (all P < 0.005). There was no significant difference between the groups in placental growth factor, interleukin 6, leptin, peptide YY, or soluble mannose receptor (sMR/CD206). In screening for GDM in obese women the combination of high BMI, insulin, sCD163, and TNFα yielded an AUC of 0.95, with detection rate of 89% at 10% false positive rate (FPR). In non-obese women, the combination of sCD163, TNFα, PP13 and PAPP-A yielded an AUC of 0.94 with detection rate of 83% at 10% FPR.

CONCLUSION

A new model for first trimester prediction of the risk to develop GDM was developed that warrants further validation.

Early prediction of placenta accreta spectrum in women with prior cesarean delivery using transvaginal ultrasound at 11 to 14 weeks

BACKGROUND

There is a growing body of evidence that sonographic signs of placenta accreta spectrum can be observed in the first trimester of pregnancy. The most significant marker is placental location next to or in the scar niche in women with a prior cesarean delivery.

OBJECTIVE

This study aimed to assess the performance of transvaginal ultrasound in the early prediction of placenta accreta spectrum in women with a prior cesarean delivery.

STUDY DESIGN

This was a retrospective cohort of women with a history of cesarean delivery who had transvaginal ultrasound at 11 to 14 weeks' gestation between September 2016 and May 2018. Ultrasound reports were reviewed and graded for suspicion of placenta accreta spectrum as follows: Grade 0 (no suspicion) if the placenta is not next to the scar; Grade 1 (intermediate suspicion) if the placenta is next or on the scar; Grade 2 (high suspicion) if the placenta was inside the scar niche. In addition, all images were reviewed and graded by trained specialists blinded to the outcome. The primary outcome was a histologic diagnosis of placenta accreta spectrum. Sensitivity, specificity, positive predictive value, and negative predictive value of first-trimester transvaginal ultrasound to detect placenta accreta spectrum were assessed.

RESULTS

In this study, 467 patients were included, and 8 (1.7%) had placenta accreta spectrum at delivery. Using the original report, 442 patients (94.6%) were Grade 0, 20 (4.3%) Grade 1, and 5 (1.1%) Grade 2. The revised grading had 456 patients (97.6%) with Grade 0, 5 (1.1%) with Grade 1, and 6 (1.3%) with Grade 2. Patients with Grade 2 yielded a sensitivity of 62.5% (95% confidence interval, 24.5-91.5), specificity of 100% (95% confidence interval, 99.2-100.0), positive predictive value of 100% (95% confidence interval, 97.0-100.0), and negative predictive value of 99.4% (95% confidence interval, 98.4-99.7). Any sonographic suspicion of placenta accreta spectrum (Grade 1 or Grade 2) had a sensitivity of 75% (95% confidence interval, 34.9-96.8), specificity of 95.9% (95% confidence interval, 93.6-97.5), positive predictive value of 24% (95% confidence interval, 14.8-36.4), and negative predictive value of 99.6% (95% confidence interval, 98.5-99.9). The blinded image review yielded a better specificity (99.1% vs 95.9%; P=.001) and a positive predictive value (63.6% vs 24%; P=.02) with similar sensitivity (87.5% vs 75%; P=.52) and negative predictive value (99.8% vs 99.6%; P=.55).

CONCLUSION

Transvaginal ultrasound between 11 and 14 weeks' gestation in women a with prior cesarean delivery can identify at least 3 of 4 cases of placenta accreta spectrum. A finding of placental implantation within the scar niche has high positive predictive value for placenta accreta spectrum. Prospective studies are needed to assess routine screening for placenta accreta spectrum at 11 to 14 weeks' gestation in women with a prior cesarean delivery.

Clinical and Economic Evaluation after Adopting Contingent Cell-Free DNA Screening for Fetal Trisomies in South Spain

INTRODUCTION

Contingent cell-free (cf) DNA screening on the basis of the first-trimester combined test (FCT) results has emerged as a cost-effective strategy for screening of trisomy 21 (T21).

OBJECTIVES

To assess performance, patients' uptake, and cost of contingent cfDNA screening and to compare them with those of the established FCT.

METHODS

This is a prospective cohort study including all singleton pregnancies attending to their FCT for screening of T21 at 2 university hospitals in South Spain. When the FCT risk was ≥1:50, there were major fetal malformations, or the nuchal translucency was ≥3.5 mm, women were recommended invasive testing (IT); if the risk was between 1:50 and 1:270, women were recommended cfDNA testing; and for risks bellow 1:270, no further testing was recommended. Detection rate (DR), false-positive rate (FPR), patients' uptake, and associated costs were evaluated.

RESULTS

We analyzed 10,541 women, including 46 T21 cases. DR of our contingent strategy was 89.1% (41/46) at 1.4% (146/10,541) FPR. Uptake of cfDNA testing was 91.2% (340/373), and overall IT rate was 2.0%. The total cost of our strategy was €1,462,895.7, similar to €1,446,525.7 had cfDNA testing not been available.

CONCLUSIONS

Contingent cfDNA screening shows high DR, low IT rate, and high uptake at a similar cost than traditional screening.

IVF/ICSI treatment and the risk of iatrogenic preterm birth in singleton pregnancies: systematic review and meta-analysis of cohort studies

Objectives: Preterm birth (PTB) is more frequent among in vitro fertilization (IVF) as compared to natural conception and recent research in this group describes an increase of its spontaneous etiology. However, clear description and quantification of iatrogenic preterm birth (IPTB) was not determined in IVF/ICSI (intra-cytoplasmic sperm injection) conceptions. This study quantifies the risk of IPTB in singleton pregnancies resulting from IVF/ICSI as compared to spontaneous conceptions (SCs).Methods: Web-based databases search (PubMed/Medline, Scopus, Web of Science) from inception up to January 2019 looking for cohort studies comparing the risk of IPTB in singleton pregnancies obtained with IVF/ICSI (intervention group) or SC (control group). Only studies with clear distinction of spontaneous and indicated PTB were included. Primary outcome was IPTB before 37 weeks of gestation, defined as indicated delivery for any medical recommendation. All pertinent secondary outcomes were also included: IPTB <34/32/28 weeks, abnormal cardiotocography (CTG), abruptio, placenta previa, pre-eclampsia, fetal growth restriction, any other available indication to IPTB. A meta-analysis calculated the pooled odds ratio (OR) for IPTB in IVF/ICSI and SC, using random effects model. Sensitivity analysis for study quality, methodology of case counting, use of cryotransfer, and secondary analyses for available indications of IPTB were also performed. Prospero RN: CRD42019117672.Results: Pooled crude analysis showed a sample size of 9590 births with significant increase in IPTB <37 weeks in IVF/ICSI pregnancies (nine studies, pooled proportion IPTB IVF/ICSI 4.73% vs. SC 1.81%; OR = 2.47; 95% CI: 1.46-4.18; I² = 67%). Pooled analysis was impossible for most secondary outcomes due to lack of available data and failed to show statistical significance for abnormal CTG. The risk for IPTB due to abruptio placentae or placenta previa was significantly increased in IVF/ICSI pregnancies (two studies, 561 pregnancies; pooled proportion IPTB IVF/ICSI 2.12% vs. SC 1.06%; OR = 5.41; 95% CI: 1.26-23.25; I²: 0%).Conclusion: The risk of IPTB <37 weeks in singleton pregnancies achieved after IVF/ICSI is significantly greater than that occurring in SC. This is likely due to a multifactorial etiology, in which placental diseases are included. Full etiologic understanding of this association needs further clarification.Summary: The risk of IPTB below 37 weeks in singleton pregnancies achieved after IVF/ICSI is more than double than that occurring in natural conception.

"Mom, I'm Pregnant": The Adolescent Pregnancy Reveal

The pregnancy reveal is conventionally a celebratory occasion, but for a pregnant adolescent, sharing news of a pregnancy, particularly with parents, can be a daunting prospect. Nonetheless, given the importance of social support to pregnant and parenting adolescents' success, the pregnancy reveal is an important step toward making healthy pregnancy decisions. Drawing on data from 27 in-depth interviews with young parents in Texas who were peer educators in an adolescent pregnancy prevention program, we find that adolescents often delay telling parents about a pregnancy. The complex decision-making process they undergo as they consider how and from whom to seek help can be drawn out, sometimes well into the second trimester, potentially delaying prenatal care and other steps necessary for a healthy pregnancy. This finding suggests that the delay and its consequences warrant further research and may have implications for parents' and practitioners' conversations with adolescents about sexual and reproductive health.

Pre-eclampsia screening in the first trimester - preemptive action to prevent the peril

Pre-eclampsia complicating 2-5% of pregnancies is an obstetrical syndrome associated with deleterious short-and long-term consequences to the gravid women, the fetus and the neonate. Majority of the obstetrical complications occur in early pre-eclampsia (requiring delivery <34 weeks). The risk factor based approach recommended by the professional organizations for pre-eclampsia screening has shown suboptimal clinical performance. The combined multimarker screening for pre-eclampsia encompassing documentation of maternal medical history, measurement of mean arterial pressure, estimation of the maternal serum levels of placental growth factor, pregnancy associated plasma protein-A, and recording the Uterine artery mean pulsatility index, performed in the first trimester between 11 and 13 + 6 weeks has proven to be an effective screening strategy. The a-priori risk is determined by multivariate analysis of the factors from history, while the other parameters are converted to log 10 transformed multiple of median values. Bayes' theorem is used to calculate the final risk. The above model has shown to detect 77% of preterm pre-eclampsia (<37 weeks), 96% of early preterm pre-eclampsia (<34 weeks), 38% of term pre-eclampsia and 54% of all pre-eclampsia, at a false positive rate of 10%. Uterine artery Doppler is key to pre-eclampsia screening. Currently a risk of >1:100 for pre-eclampsia developing before 37 weeks (preterm pre-eclampsia) is regarded as screen positive. Aspirin at a dose of 150 mg at bedtime given to screen positive subjects is associated with a significant reduction of preterm pre-eclampsia and early pre-eclampsia. The intervention is now supported by a well conducted randomized trial and metanalysis data. Aspirin acts by diminishing stores of constitutive cyclooxygenase enzyme in the non-nucleated platelets without disturbing systemic prostaglandin production. Selective use of aspirin in screen positive women is associated with a very low incidence of adverse maternal, fetal and neonatal side effects. The screening protocol can be applied to twin pregnancies albeit minor differences. Hence, screening for pre-eclampsia in first trimester, which is now endorsed by the federation of international obstetrical and gynecological societies, should be offered universally to all women at 11 to 13 + 6 weeks of gestation, followed by the administration of aspirin and serial maternal-fetal surveillance in the screen positive woman.

Systematic review of the measurement properties of indices of prenatal care utilization

Background

An accurate assessment of the adequacy of prenatal care utilization is critical to inform the relationship between prenatal care and pregnancy outcomes. This systematic review critically appraises the evidence on measurement properties of prenatal care utilization indices and provides recommendations about which index is the most useful for this purpose.

Methods

MEDLINE, EMBASE, CINAHL, and Web of Science were systematically searched from database inception to October 2018 using keywords related to indices of prenatal care utilization. No language restrictions were imposed. Studies were included if they evaluated the reliability, validity, or responsiveness of at least one index of adequacy of prenatal care utilization. We used the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. We conducted an evidence synthesis using predefined criteria to appraise the measurement properties of the indices.

Results

From 2664 studies initially screened, 13 unique studies evaluated the measurement properties of at least one index of prenatal care utilization. Most of the indices of adequacy of prenatal care currently used in research and clinical practice have been evaluated for at least some form of reliability and/or validity. Evidence about the responsiveness to change of these indices is absent from these evaluations. The Adequacy Perinatal Care Utilization Index (APNCUI) and the Kessner Index are supported by moderate evidence regarding their reliability, predictive and concurrent validity.

Conclusion

The scientific literature has not comprehensively reported the measurement properties of commonly used indices of prenatal care utilization, and there is insufficient research to inform the choice of the best index. Lack of strong evidence about which index is the best to measure prenatal care utilization has important implications for tracking health care utilization and for formulating prenatal care recommendations.

Soluble urokinase plasminogen activator receptor (suPAR) as a biomarker of early pregnancy location and viability compared with hCG, progesterone and estradiol

A circulating biomarker of early pregnancy outcome independent of ultrasonography and gestational age is a coveted goal. This study evaluated soluble urokinase plasminogen activator receptor (suPAR), a well-described marker of inflammation and immunological activation, for this purpose, and compared it with established early pregnancy biomarkers of the luteoplacental phase: progesterone, estradiol and hCG. We merged data from two prospective first trimester cohorts to conduct a case-control study comparing these analytes in women who had either a live birth, a miscarriage or an ectopic pregnancy. The ability to predict pregnancy location and viability was assessed by areas under the receiver operating characteristic curves (AUC). Comparing women irrespective of gestational age with a live birth, miscarriage or ectopic pregnancy showed significantly lower suPAR values in the latter group (2.4 vs. 2.4 vs. 2.0 μg/L, p = 0.032, respectively), as were all other analytes. Before 6 weeks' gestation, suPAR was significantly inferior to progesterone, estradiol and hCG in pregnancy location and viability prediction (in 124 pregnancies, suPAR AUC_location = 0.69 [CI: 0.54-0.83] and AUC_viability = 0.58 [CI: 0.48-0.69], while progesterone AUC_location = 0.95 [CI: 0.87-1.00] and AUC_viability = 0.84 [CI: 0.75-0.92]). After 6 weeks' gestation, suPAR prediction improved but was inferior to hCG, progesterone and estradiol (in 188 pregnanices, suPAR AUC_location = 0.71 [CI: 0.63-0.78] and AUC_viability = 0.70 [CI: 0.63-0.78] compared with hCG AUC_location = 0.96 [CI: 0.93-0.99] and AUC_viability = 0.96 [CI: 0.93-0.98]). Collectively, suPAR is less useful as a predictor of early pregnancy outcome than hCG, progesterone and estradol.

Mean arterial blood pressure: potential predictive tool for preeclampsia in a cohort of healthy nulliparous pregnant women

Background

Prediction of preeclampsia is a challenge to overcome. The vast majority of prospective studies in large general obstetric populations have failed in the purpose of obtain a useful and effective model of prediction, sometimes based on complex tools unavaible in areas where the incidence of preeclampsia is the highest. The goal of this study was to assess mean arterial blood pressure (MAP) levels at 19–21, 27–29 and 37–39 weeks of gestation and performance of screening by MAP for the prediction of preeclampsia in a Brazilian cohort of healthy nulliparous pregnant women.

Methods

This was a cohort approach to a secondary analysis of the Preterm SAMBA study. Mean arterial blood pressure was evaluated at three different time periods during pregnancy. Groups with early-onset preeclampsia, late-onset preeclampsia and normotension were compared. Increments in mean arterial blood pressure between 20 and 27 weeks and 20 and 37 weeks of gestation were also calculated for the three groups studied. The accuracy of mean arterial blood pressure in the prediction of preeclampsia was determined by ROC curves.

Results

Of the 1373 participants enrolled, complete data were available for 1165. The incidence of preeclampsia was 7.5%. Women with early-onset preeclampsia had higher mean arterial blood pressure levels at 20 weeks of gestation, compared to the normotensive group. Women with late-onset preeclampsia had higher mean arterial blood pressure levels at 37 weeks of gestation, than the normotensive groups and higher increases in this marker between 20 and 37 weeks of gestation. Based on ROC curves, the predictive performance of mean arterial blood pressure was higher at 37 weeks of gestation, with an area under the curve of 0.771.

Conclusion

As an isolated marker for the prediction of preeclampsia, the performance of mean arterial blood pressure was low in a healthy nulliparous pregnant women group. Considering that early-onset preeclampsia cases had higher mean arterial blood pressure levels at 20 weeks of gestation, future studies with larger cohorts that combine multiple markers are needed for the development of a preeclampsia prediction model.

Prediction of Preterm Birth by Maternal Characteristics and Medical History in the Brazilian Population

Objectives

The aim of this study was to assess the performance of a previously published algorithm for first-trimester prediction of spontaneous preterm birth (PTB) in a cohort of Brazilian women.

Methods

This was a retrospective cohort study of women undergoing routine antenatal care. Maternal characteristics and medical history were obtained. The data were inserted in the Fetal Medicine Foundation (FMF) online calculator to estimate the individual risk of PTB. Univariate and multivariate logistic regression analyses were performed to determine the effects of maternal characteristics on the occurrence of PTB. A receiver-operating characteristics (ROC) curve was used to determine the detection rates and false-positive rates of the FMF algorithm in predicting PTB <34 weeks of gestation in our population.

Results

In total, 1,323 women were included. Of those, 23 (1.7%) had a spontaneous PTB before 34 weeks of gestation, 87 (6.6%) had a preterm birth between 34 and 37 weeks, and 1,197 (91.7%) had a term delivery. Smoking and a previous history of recurrent PTB between 16 and 30 weeks of gestation without prior term pregnancy were significantly more common among women who delivered before 34 weeks of gestation compared to those who delivered at term were (39.1% vs. 12.0%, p = 0.001 and 8.7% vs. 0%, p < 0.001, respectively). Smoking and history of spontaneous PTB remained significantly associated with spontaneous PTB in the multivariate logistic regression analysis. Significant prediction of PTB <34 weeks of gestation was provided by the FMF algorithm (area under the ROC curve 0.67, 95% CI 0.56–0.78, p = 0.005), but the detection rates for fixed false-positive rates of 10% and 20% were poor (26.1% and 34.8%, respectively).

Conclusions

Maternal characteristics and history in the first trimester can significantly predict the occurrence of spontaneous delivery before 34 weeks of gestation. Although the predictive algorithm performed similarly to previously published data, the detection rates are poor and research on new biomarkers to improve its performance is needed.

Cell-Free Fetal DNA in the Early and Late First Trimester

OBJECTIVE

The aim of this work was to investigate the association between maternal and fetal characteristics and the fetal fraction at 8-14 weeks' gestation, with emphasis on the change in the fetal fraction upon repeat sampling.

METHOD

One sample for cell-free DNA (cfDNA) testing was collected at the same time as the biochemical markers for combined first trimester screening (visit 1) and another at the nuchal translucency scan (visit 2). Chromosome-selective cfDNA analysis was performed on frozen plasma.

RESULTS

Overall, 321 women were included at visit 1, and 307 had a repeat blood sampling. A fetal fraction was obtained in 532 samples (238 samples with repeat fetal fraction). The fetal fraction decreased with maternal BMI (p < 0.001), was lower in Asian women (p = 0.03), and increased with β-hCG levels (p < 0.001) and gestational age (p = 0.04). Before 10 weeks' gestation, the fetal fraction was lower (p = 0.02), as was the probability of a sufficient fetal fraction (p = 0.03) after adjustment for maternal BMI. Asian women had a higher increase in fetal fraction upon repeat sampling (p < 0.001).

CONCLUSION

Before 10 weeks' gestation, the fetal fraction is significantly lower but seems to increase more rapidly compared to later gestations. Presently, combined first trimester screening with cfDNA testing should not include samples before 10 weeks' gestation.

Fetal Growth Restriction Prediction: How to Move beyond

The actual burden and future burden of the small-for-gestational-age (SGA) babies turn their screening in pregnancy a question of major concern for clinicians and policymakers. Half of stillbirths are due to growth restriction in utero, and possibly, a quarter of livebirths of low- and middle-income countries are SGA. Growing body of evidence shows their higher risk of adverse outcomes at any period of life, including increased rates of neurologic delay, noncommunicable chronic diseases (central obesity and metabolic syndrome), and mortality. Although there is no consensus regarding its definition, birthweight centile threshold, or follow-up, we believe birthweight <10th centile is the most suitable cutoff for clinical and epidemiological purposes. Maternal clinical factors have modest predictive accuracy; being born SGA appears to be of transgenerational heredity. Addition of ultrasound parameters improves prediction models, especially using estimated fetal weight and abdominal circumference in the 3rd trimester of pregnancy. Placental growth factor levels are decreased in SGA pregnancies, and it is the most promising biomarker in differentiating angiogenesis-related SGA from other causes. Unfortunately, however, only few societies recommend universal screening. SGA evaluation is the first step of a multidimensional approach, which includes adequate management and long-term follow-up of these newborns. Apart from only meliorating perinatal outcomes, we hypothesize SGA screening is a key for socioeconomic progress.

Early prediction of preeclampsia and small-for-gestational-age via multi-marker model in Chinese pregnancies: a prospective screening study

BACKGROUND

Recent evidence suggests early screening of preeclampsia and small-for-gestational-age (SGA) would benefit pregnancies followed by subsequent prophylactic use of aspirin. Multi-marker models have shown capability of predicting preeclampsia and SGA in first trimester. Yet the clinical feasibility of combined screening model for Chinese pregnancies has not been fully assessed. The aim of this study is to evaluate the applicability of a multi-marker screening model to the prediction of preeclampsia and SGA in first trimester particularly among Chinese population.

METHODS

Three thousand two hundred seventy pregnancies meeting the inclusion criteria took first-trimester screening of preeclampsia and SGA. A prior risk based on maternal characteristics was evaluated, and a posterior risk was assessed by combining prior risk with multiple of median (MoM) values of mean arterial pressure (MAP), serum placental growth factor (PLGF) and pregnancy associated plasma protein A (PAPP-A). Both risks were calculated by Preeclampsia PREDICTOR™ software, Perkin Elmer. Screening performance of prior and posterior risks for early and late preeclampsia by using PREDICTOR software was shown by Receiver Operating Characteristics (ROC) curves. The estimation of detection rates and false positive rates of delivery with both preeclampsia and SGA was made.

RESULTS

Eight cases developed early preeclampsia (0.24%) and 35 were diagnosed as late preeclampsia (1.07%). Five with early preeclampsia and ten with late preeclampsia later delivered SGA newborns (0.46%); 84 without preeclampsia gave birth to the SGAs (2.57%). According to ROC curves, posterior risks performed better than prior risks in terms of preeclampsia, especially in early preeclampsia. At 10% false positive rate, detection rates of early and late preeclampsia were 87.50 and 48.57%, detection rates of early and late SGA were 41.67 and 28.00%, respectively. For SGA, detection rates in cases with preeclampsia were much higher than those in absence of it.

CONCLUSIONS

This study demonstrates that combined screening model could be useful for predicting early preeclampsia in Chinese pregnancies. Furthermore, the performance of SGA screening by same protocol is strongly associated with preeclampsia.

National Analysis of Risk Assessment Content in Prenatal Records Across Canada

Each Canadian province/territory has a distinct prenatal record form to guide maternity health care. Because there is no national oversight of these forms, little is known about how they compare regarding content on risk assessment for adverse perinatal outcomes. We cataloged and compared the risk factors that are captured on prenatal record forms across Canada. Nine out of 12 records included risk sections, with an average of 35 risk items. We identified 100 prenatal risk factors and categorized them as medical (73%), lifestyle (11%), psychosocial (11%), or personal (5%). Where present, clinical definitions for risk factors often varied. The substantial differences in risk assessment content in the prenatal record forms may contribute to differences in health care quality among provinces. The development of standardized national guidelines for prenatal risk assessment may be a valuable goal.

The outcome of structural heart defects diagnosed in the first trimester of pregnancy

PURPOSE

We present the results of a detailed protocol of fetal heart examination in the first trimester, in a fetal medicine unit in Romania.

METHODS

Since October 2009, in Filantropia Hospital in Bucharest, we have systematically assessed pregnancies at 11-14 weeks to screen for aneuploidies and for major fetal structural defects. The fetal anatomy examination protocol included the detailed assessment of the fetal heart. This was performed using the same principles as for the second trimester examination, in the entire cohort.

RESULTS

Our population consisted of 7693 patients and 7816 embryos. The protocol for the ultrasound evaluation of the fetal heart was completed for 7597 embryos (97.2%). The outcome is known for 6912 cases (90.9%). We diagnosed 39 heart defects - 30 in the first trimester, seven in the second trimester, two postnatally. Twenty of the 39 heart defects were isolated cardiac malformations. Twelve of the isolated heart defects were diagnosed in the first trimester. The sensitivity of the first trimester ultrasound in identifying major heart defects was 76.92%. The overall survival in cases of isolated congenital heart disease diagnosed in the first trimester was significantly lower than the survival in the cases diagnosed in the second trimester.

CONCLUSIONS

Many (76.92%) of the significant heart defects can be diagnosed by ultrasound examination, in the first trimester. Our study is an argument for developing the multidisciplinary approach needed for the management of early detected structural heart disease.

Prediction of small for gestational age neonates: screening by maternal factors, fetal biometry, and biomarkers at 35-37 weeks' gestation

BACKGROUND

Small for gestational age (SGA) neonates are at increased risk for perinatal mortality and morbidity; however, the risks can be substantially reduced if the condition is identified prenatally, because in such cases close monitoring and appropriate timing of delivery and prompt neonatal care can be undertaken. The traditional approach of identifying pregnancies with SGA fetuses is maternal abdominal palpation and serial measurements of symphysial-fundal height, but the detection rate of this approach is less than 30%. A higher performance of screening for SGA is achieved by sonographic fetal biometry during the third trimester; screening at 30-34 weeks' gestation identifies about 80% of SGA neonates delivering preterm but only 50% of those delivering at term, at a screen-positive rate of 10%. There is some evidence that routine ultrasound examination at 36 weeks' gestation is more effective than that at 32 weeks in predicting birth of SGA neonates.

OBJECTIVE

To investigate the potential value of maternal characteristics and medical history, sonographically estimated fetal weight (EFW) and biomarkers of impaired placentation at 35⁺⁰- 36⁺⁶ weeks' gestation in the prediction of delivery of SGA neonates.

MATERIALS AND METHODS

A dataset of 19,209 singleton pregnancies undergoing screening at 35⁺⁰-36⁺⁶ weeks' gestation was divided into a training set and a validation set. The training dataset was used to develop models from multivariable logistic regression analysis to determine whether the addition of uterine artery pulsatility index (UtA-PI), umbilical artery PI (UA-PI), fetal middle cerebral artery PI (MCA-PI), maternal serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFLT) would improve the performance of maternal factors and EFW in the prediction of delivery of SGA neonates. The models were then tested in the validation dataset to assess performance of screening.

RESULTS

First, in the training dataset, in the SGA group, compared to those with birthweight in ≥10th percentile, the median multiple of the median (MoM) values of PlGF and MCA-PI were reduced, whereas UtA-PI, UA-PI, and sFLT were increased. Second, multivariable regression analysis demonstrated that in the prediction of SGA in <10th percentile there were significant contributions from maternal factors, EFW Z-score, UtA-PI MoM, MCA-PI MoM, and PlGF MoM. Third, in the validation dataset, prediction of 90% of SGA neonates delivering within 2 weeks of assessment was achieved by a screen-positive rate of 67% (95% confidence interval [CI], 64-70%) in screening by maternal factors, 23% (95% CI, 20-26%) by maternal factors, and EFW and 21% (95% CI, 19-24%) by the addition of biomarkers. Fourth, prediction of 90% of SGA neonates delivering at any stage after assessment was achieved by a screen-positive rate of 66% (95% CI, 65-67%) in screening by maternal factors, 32% (95% CI, 31-33%) by maternal factors and EFW and 30% (95% CI, 29-31%) by the addition of biomarkers.

CONCLUSION

The addition of biomarkers of impaired placentation only marginally improves the predictive performance for delivery of SGA neonates achieved by maternal factors and fetal biometry at 35⁺⁰-36⁺⁶ weeks' gestation.

Prediction of small-for-gestational-age neonates at 35-37 weeks' gestation: contribution of maternal factors and growth velocity between 20 and 36 weeks

OBJECTIVES

To evaluate the performance of ultrasonographic estimated fetal weight (EFW) at 35 + 0 to 36 + 6 weeks' gestation in the prediction of delivery of a small-for-gestational-age (SGA) neonate and assess the additive value of, first, maternal risk factors and, second, fetal growth velocity between 20 and 36 weeks' gestation in improving such prediction.

METHODS

This was a prospective study of 44 043 singleton pregnancies undergoing routine ultrasound examination at 19 + 0 to 23 + 6 and at 35 + 0 to 36 + 6 weeks' gestation. Multivariable logistic regression analysis was used to determine whether addition of maternal risk factors and growth velocity, the latter defined as the difference in EFW Z-score or fetal abdominal circumference (AC) Z-score between the third- and second-trimester scans divided by the time interval between the scans, improved the performance of EFW Z-score at 35 + 0 to 36 + 6 weeks in the prediction of delivery of a SGA neonate with birth weight < 10^th and < 3^rd percentiles within 2 weeks and at any stage after assessment.

RESULTS

Screening by EFW Z-score at 35 + 0 to 36 + 6 weeks' gestation predicted 63.4% (95% CI, 62.0-64.7%) of neonates with birth weight < 10^th percentile and 74.2% (95% CI, 72.2-76.1%) of neonates with birth weight < 3^rd percentile born at any stage after assessment, at a screen-positive rate of 10%. The respective values for SGA neonates born within 2 weeks after assessment were 76.8% (95% CI, 74.4-79.0%) and 81.3% (95% CI, 78.2-84.0%). For a desired 90% detection rate of SGA neonate delivered at any stage after assessment, the necessary screen-positive rate would be 33.7% for SGA < 10^th percentile and 24.4% for SGA < 3^rd percentile. Multivariable logistic regression analysis demonstrated that, in the prediction of a SGA neonate with birth weight < 10^th and < 3^rd percentiles, there was a significant contribution from EFW Z-score at 35 + 0 to 36 + 6 weeks' gestation, maternal risk factors and AC growth velocity, but not EFW growth velocity. However, the area under the receiver-operating characteristics curve for prediction of delivery of a SGA neonate by screening with maternal risk factors and EFW Z-score was not improved by addition of AC growth velocity.

CONCLUSION

Screening for SGA neonates by EFW at 35 + 0 to 36 + 6 weeks' gestation and use of the 10^th percentile as the cut-off predicts 63% of affected neonates. Prediction of 90% of SGA neonates necessitates classification of about 35% of the population as being screen positive. The predictive performance of EFW is not improved by addition of estimated growth velocity between the second and third trimesters of pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.