Trimester Screening Research Articles

VP30.10: Nuchal translucency: is pure mid‐sagittal section required in era of NIPT?

Difference in nuchal translucency and T21 risk calculation between mid-sagittal section and mid-sagittal section also showing maxilla and nasal bone. We evaluate fetus (n = 1242) with CRL was 65 to 84 mms. 2D sections were obtained of NT in mid-sagittal plane as per FMF criteria (maxilla not to be seen) and about 5-degree oblique plane where maxilla along with nasal bone are visible in midsagittal plane were documented. NT was measured by auto NT calculation in GE Voluson E10. Risk for Down syndrome was calculated in Astraia gmbh FMF approved software. We were able to get NT section in 98% and 96% in section showing NB, Maxilla and NT. There was a fixed error of NT of 0.2 mm between both sections. Mid sagittal section as per FMF was lower. Risk for T21 was not showing significant difference. When mother was less than 35 years, calculated risk difference was < 4%. When mother was above 35 years' risk varied up to 6%. As per new algorithm by FMF, NIPT is recommended when risk is intermediate between 1:10 to 1:3000. More than 97% of patients did not shifted from low, intermediate or high-risk group without change in clinical manage. Ease of following fewer rigid criteria will increase the NT users and will be beneficial to society, where less professionals are available who can perform first trimester screening. If NT as per FMF criteria is difficult to be obtained, one can consider NT at a mid-sagittal section where NT and NB are seen with maxilla. It will not make a significant difference in risk calculation for Trisomy 21. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

OC10.05: *Increased nuchal translucency in congenital heart defects: associations with mortality

The objective was to investigate if increased NT was associated with increased mortality in children with CHD. In a nationwide cohort using population-based registries, 5,633 liveborn children in Denmark with a pre or postnatal diagnosis of CHD from 2008-2018 (0.7%) were identified. Children with lack of data on first trimester screening, chromosomal abnormalities or no match between registries were excluded. Increased NT was defined as NT > 3.5 mm or NT > 1.5 Multiples of Median (MoM). Proportions were compared using chi-squared test with a significance level of 0.05. Of 4,469 children with CHD eventually included in the cohort, 754 (17%) had complex CHD and 3,715 (83%) simple CHD. Of these, 239 (5.3%) had an NT >1.5 MoM, and 57 (1.3%) an NT >3.5 mm. Mortality was higher in CHD with NT >1.5 MoM than NT <1.5 MoM (3.3% vs. 1.5%, p = 0.03). Mortality was increased for simple CHD when NT was >1.5 MoM (2.3% vs 0.6%, p = 0.01). Amongst simple CHD undergoing surgery a significantly higher mortality was found in the group with NT >1.5 MoM (8.6% vs 2.5%, p = 0.04). Complex CHD was more frequent in the group of NT >1.5 MoM than NT <1.5 MoM (27% vs. 16%, p < 0.01), but NT >1.5 MoM was not associated with higher mortality (6.1% vs. 5.8%, p = 0.93) Amongst complex CHD undergoing surgery there was no difference in mortality between NT >1.5 MoM and NT <1.5 MoM (4.3% vs. 7.5%, p = 0.44). Due to limited numbers the association to mortality in the group with NT >3.5 mm could not be assessed. Confounding birth variables: gestational age, birthweight, small for gestational age, preterm birth, pre-eclampsia, placental weight, maternal smoking, maternal BMI, beta-HcG, and PAPP-A were equally distributed between NT >1.5 and <1.5 MoM. In children born with CHD, an increased NT was associated with increased mortality. The association was primarily evident in infants with simple CHD. Increased NT could possibly be an independent predictor of increased mortality in children with CHD.

VP28.05: Predicting chromosomal abnormalities through first trimester screening and nuchal translucency: experience of a tertiary centre

VP28.05: Predicting chromosomal abnormalities through first trimester screening and nuchal translucency: experience of a tertiary centre

OC07.06: Pregnancy outcomes following multicentre clinical implementation of routine first trimester screening for preterm pre‐eclampsia in Australia

OC07.06: Pregnancy outcomes following multicentre clinical implementation of routine first trimester screening for preterm pre‐eclampsia in Australia

VP18.10: What is the benefit of using an ultrasound checklist during a second trimester screening exam?

VP18.10: What is the benefit of using an ultrasound checklist during a second trimester screening exam?

Karyotype analysis of amniotic fluid cells and report of chromosomal abnormalities in 15,401 cases of Iranian women

The aim of present study was to assess the karyotypes of amniotic fluid cells and find the frequency of chromosomal abnormalities and their significance in clinical setting. A total of 15,401 pregnant women were assessed from March 2016 to May 2019, and 14,968 amniotic fluid samples were successfully cultured. These fetuses were grouped according to different indications including advanced maternal age, abnormal nuchal translucency (NT) values, positive first/second trimester screening results, high risk NIPT results, very low PAPP-A and free β-hCG multiples of the normal median (MoM) results, abnormal ultrasound findings or previous history of chromosomal abnormalities. Results indicated the presence of normal karyotype in 90.2% (13,497/14,968) of fetuses. Totally, 46.4% (6945/14,968) of fetuses were 46,XX and 43.8% (6552/14,968) had 46,XY chromosome pattern. A total of 1077 abnormal karyotypes were found among 14,968 fetuses, thus the rate of abnormal fetuses was calculated to be 7.2% (1072/14,968). Meanwhile, a total of 394 cases (2.8%) had a normal polymorphism in their karyotype. In other words, abnormal karyotypes were detected in one of 13.9 cases of patients underwent amniocentesis. Down syndrome, Edward’s syndrome, abnormal mosaicisms and Patau’s syndrome were detected in 4.4% (659/14,968), 0.57% (85/14,968), 0.49% (74/14,968) and 0.24% (36/14,968) of cases, respectively. Sex chromosomal abnormalities including Klinefelter syndrome, Turner syndrome and 47,XXX karyotype were detected in 64 cases (0.43%). In this article, the rates of chromosomal abnormalities are compared between different groups of patients based on the advanced maternal age, abnormal NT values, very low PAPP-A and free β-hCG MoMs results, and positive FTS results. The current investigation provides insight into the most appropriate indications for amniocentesis in Iran.

SY10-3. Complement Activation and Regulation in Preeclampsia and HELLP Syndrome

To evaluate the potential of maternal serum placental growth factor (PlGF) as a marker for Trisomy 21 in Chinese pregnant women.Serum samples were collected and stored from 600 women who have a viable singleton pregnancy and underwent first trimester screening for Trisomy 21 between 2011 and 2014. Serum concentration of PlGF was measured using the automated time-solved immunofluorometric assay and expressed as Multiples of the expected median (MoM) from the 600 women available stored serum samples (558 Euploidy and 42 Trisomy 21). The levels of PlGF MoM were compared between Trisomy 21 cases and Euploid pregnancies. Expected median PlGF levels in Chinese were also compared to that published for Caucasians. Multivariate Gaussian modeling was performed to predict detection and false-positive rates.In euploid pregnancies the concentrations of PlGF increased with Crown Rump Length(CRL) and decreased with maternal weight. The overall median MoM of PlGF in Chinese was higher than that of Caucasian. The median PlGF level was 0.63 MoM in the cases and 1.00 MoM in the controls (p < 0.0001). The prediction of Trisomy 21 has been slightly improved by the addition of PlGF to the standard screening test in China. The detection rate of screening after adding PlGF data was increased from 93.4% to 94.6% at a false-positive rate of 3% and the false positive rate decreased from 0.23% to 0.17% for a detection rate of 80%.The median PlGF concentrations in Chinese is higher than those of Caucasians. Results suggest adding PlGF may substantially improve the performance of current first trimester screening strategy for Trisomy 21 in Chinese pregnant women.

Pentalogy of Cantrell: An extremely rare congenital anomaly diagnosis in the first trimester screening

Pentaloy of cantrell is a rare congenital syndrome characterised by varying degrees of midline thoracoabdominal wall defect resulting from defective development in the septum transversum. Ectopia cordis, defined as a developmental defect in which the heart is abnormally located partially or totally outside the thorax, is in some cases a part of this syndrome. A 29-year-old pregnant woman gravida: 1 para: 0 was referred to our service for fetal posture anomaly at 12 +4 week of gestation. Ultrasonographic examination revealed ectopia cordis, omphalocle and a diaphragmatic defect. Medical pregnancy termination was indicated. Incidence of the PC varies from 5.5 to 7.9 per million live births. The etiology of PC is unknown. Most cases are sporadic, and no recurrences have been reported. The constellation of defects observed in pentalogy of cantrell is thought to result from the abnormalities in the differentiation of the intraembryonic mesoderm at approximately 14 to 18 days after conception. Sternal defects include bifid sternum (26%), absent xiphoid (10%) and absent lower 2/3 of sternum (9%). Anterior abdominal wall defect is mostly an omphalocele (63%). A ventral retrosternal defect of the diaphragm occurs in 91% of the cases. With prenatal ultrasonography, PC can usually be diagnosed as early as 10 weeks of pregnancy. In conclusion, early diagnosis is feasible in the first trimester if ectopia cordis and omphalocele exist. Development in ultrasound technology provides us better visualization and early diagnosis. Termination is the choice of treatment. Early diagnosis gives us a chance to reduce maternal morbidity and mortality related to termination.

Depression Screening During Pregnancy: Compliance and Effectiveness in a Military Population.

Perinatal and postpartum depression are common, affecting 13% to 24% of pregnant women through the first year postpartum. Depression screening is recommended by the American College of Obstetrics and Gynecology as an effective and low-cost intervention to improve patient outcomes; however, no nationwide screening rate is reported in the literature. This study was designed to assess the rate and effectiveness of screening in a major military medical center. Institutional review board (IRB) approval was obtained before beginning the study. The facility where this study was performed has a universal depression screening policy in which all patients should be screened using the Edinburgh Postnatal Depression Scale (EPDS) at the initial obstetric visit, the 28-week visit, and the postpartum visit. The EPDS scores and demographic data were collected by chart review of patients seen between May 2015 and April 2017. Ninety-six percent of patients completed EPDS at their first appointment with a mean score of 3.8. At 28 weeks, 60% of patients were screened with a mean score of 3.8, and at the postpartum appointment, 84% were screened with a mean score of 3.5. Veterans Affairs (VA) patients and dependent daughters had significantly higher EPDS scores than active duty women and dependent wives (mean 7.91, 5.78, 3.19, 3.70, P < .0001). Eight-eight percent of patients with scores of ≥12 were offered the appropriate treatment. First trimester screening rates are excellent; however, 28-week and postpartum screening rates need improvement. Standardization of clinic screening procedures may be necessary to increase the screening rates. Veterans Affairs patients and dependent daughters have a higher-than-average risk for depression and should be monitored closely. This study demonstrates that a universal postpartum depression screening program is an important part of obstetric care.

The importance of first trimester screening of cranial posterior fossa in predicting posterior fossa malformations which may be identified in the following weeks of gestation.

We aimed to investigate the value of posterior fossa ultrasonography measurements in predicting fetal posterior fossa anomaly at 11-14 weeks of gestation. The study was performed at Zeynep Kamil Women and Children's Diseases Training and Research Hospital. Measurements were made in two groups: the control group consisted of 328 fetuses with normal postnatal outcome and the study group consisted of 22 fetuses with enlarged 4th ventricle. In the study group, we questioned the value of intracranial translucency (IT) and brainstem (BS) measurements and the BS/brainstem-to-occipital bone (BSOB) ratio in order to predict possible posterior fossa anomalies that may be identified in advanced gestational weeks. The differences of ultrasonographic measurements between groups with p < 0.05 were considered statistically significant. IT value, BSOB value, and BS/BSOB ratio were determined as ultrasonographic variables in predicting normal development of the fetal posterior fossa, with cutoff values of 2.7, 5.1, and 0.3. Negative predictive values of these three measurements for posterior fossa abnormalities were 100%. There was no statistically significant difference between the three variables for other diagnostic accuracy values (specifities and positive predictive values) (p > 0.05). IT, BSOB, and BS/BSOB ratio can be used as ultrasonographic markers to predict the normal development of the fetal posterior fossa.

Predictive Role of First-trimester ELABELA Levels for Late-onset Preeclampsia.

To determine the predictive role of first trimester maternal serum ELABELA (ELA) levels in late-onset preeclampsia (PE). Comparative descriptive study. Department of Obstetrics and Gynecology, Bursa Yüksek İhtisas Training and Research Hospital, Bursa, Turkey between January and September 2019. A total of 600 pregnant women, whose maternal serum samples were collected through the first trimester screening test, were recruited. Twenty-three patients with late-onset PE group and 47 without PE group were included. All participants in whom maternal serum samples were collected between 11th and 14th weeks of pregnancy were followed until delivery. Median ELA level was 654.53 [217.67-870.20] pg/mL in the PE group and 645.80 [367.25-1833.17] pg/mL in the control group, indicating no significant difference between the groups (p=0.408). There was a statistically significant difference between the two groups in terms of frequency of history of hypertension, intrauterine growth restriction (IUGR) and acute fetal distress (AFD), (p=0.003, p=0.016, and p=0.005, respectively). Three patients had preterm delivery in the PE group which was non-significant, while seven patients had gestational diabetes mellitus in PE group that was significantly higher compared to controls (p<0.001). Only ELA level in the first trimester of pregnancy may not be of much value in predicting late-onset PE. Key Words: ELABELA, Preeclampsia, Late-onset, Predictive marker.

Association between low first trimester maternal serum PAPP-A levels and presence of unilateral or bilateral uterine artery diastolic notches

Objective Uterine artery impedance is known to have an effect on first trimester aneuploidy screening biomarkers. In this study we aim to compare first trimester screening parameters in women with and without uterine artery diastolic notches. Methods This retrospective case control study was conducted in a single tertiary center by obtaining medical records of women that admitted for first trimester pregnancy follow-up. Singleton pregnancies without structural anomalies, chromosomal anomalies and obstetric complications were included in the study. 268 women with first trimester unilateral uterine artery diastolic notches are constituted study group 1, 149 women with bilateral uterine artery diastolic notches constituted study group 2. 200 women were randomly selected as control group. Results Significantly decreased PAPP-A levels were found in both study groups. PAPP-A levels were even lower in women with bilateral notches in comparison to unilateral notches. Fetal birth weights and gestational ages at birth were also found significantly lower in study groups. Beta human chorionic gonadotropin levels and nuchal translucency measurements were found similar. Prevalence of false positive first trimester aneuploidy screening test results were significantly higher in women with bilateral uterine artery diastolic notches. Conclusion Presence of first trimester uterine artery diastolic notches, particularly the presence of bilateral diastolic notches, is related with decreased PAPP-A levels in first trimester aneuploidy screening and lead to higher false positive rates in first trimester aneuploidy screening and consequently more unnecessary invasive procedures.

Reducing the Risk of Preterm Preeclampsia: Comparison of Two First Trimester Screening and Treatment Strategies in a Single Centre in Switzerland.

Introduction First trimester screening for preeclampsia (PE) is based on the combined risks model. Recent trials demonstrate that variations in multiple of the medians (MoMs) of the screening markers influence the performance of the algorithm in different populations. The aim of this study is to compare the performance of the algorithm in two cohorts with different prevention strategies. Material and Methods All first trimester screening tests performed between January 2014 and April 2020 were included. Up to June 2017 pregnancies with a risk > 1 : 200 for early-onset PE (eoPE) were considered at risk and received 100 mg of aspirin (strategy A). From July 2017 onwards, pregnancies with a risk > 1 : 100 for preterm PE (pPE) received 150 mg of aspirin (strategy B). We compared the screen positive rates (SPR) and incidence of PE between the two screening approaches. Statistical analysis were performed with Graphpad 8.0. Results 3552 pregnancies were included; 1577 pregnancies were screened according to strategy A, 1975 pregnancies according to strategy B. The screen positive rate (SPR) for strategy A and B was 8.9 and 16.9% respectively (p < 0.0001) while the incidence of PE was 1.41 and 1.84% respectively (p = ns). Conclusion With a SPR of less than 10% we achieved a remarkably low rate of PE in our population, no further reduction in PE could be achieved by an increase in the SPR and LDA-prescription during the second screening period. The cut-off to define a pregnancy at risk for PE should be tailored to keep the SPR below 10% to avoid unnecessary treatment with aspirin.

Twin chorionicity and zygosity both vary with maternal age.

To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age. We reviewed all twin pregnancies undergoing first trimester screening (FTS) with nuchal translucency from April 2009 to December 2012 with sonographic determination of chorionicity. Cases were linked to newborn screening (NBS) results and zygosity estimated based on rates of fetal sex discordance. The ratio of DC to MC placentation by maternal age was calculated. We identified 11,351 twin pregnancies with FTS and documented chorionicity. Among these, 7,861 (64.2%) had linked data on FTS and NBS to allow estimation of zygosity based on neonatal sex. Of these, 1,464 (18.6%) were MC and 6,406 (81.4%) DC. The MC twin rate remained constant while the DC twin rate increased with maternal age until 40y. At < 20y, 55% of twin pregnancies were monozygotic (MZ), as compared to 29% at ≥ 40y. Of MZ twins, 38% were DC at < 20y, while 53% were DC at ≥ 40y. Our data suggest a relationship of both zygosity and chorionicity with maternal age. DZ twinning increased with maternal age, while among MZ twins, the proportion that were DC also increased with maternal age.

First trimester screening with biochemical markers and ultrasound in relation to non-invasive prenatal testing (NIPT).

Non-invasive prenatal testing (NIPT) is often erroneously received as a diagnostic procedure due to its high discriminatory power in the field of fetal trisomy 21 diagnosis (wording: "NIPT replaces amniocentesis"). Already a look at the methodology of NIPT (statistical gene dose comparison of a primarily maternofetal DNA mixture information at selected sites of the genome) easily reveals that NIPT cannot match the gold standard offered by cytogenetic and molecular genetic analysis procedures from the matrix of the entire human genome (origin: vital fetal cells), neither in diagnostic breadth nor in diagnostic depth. In fact, NIPT in fetal medicine in its current stage of development is a selective genetic search procedure, which can be applied in primary (without indication) or secondary (indication-related) screening. Thus, NIPT competes with established search procedures for this field. Here, the combined nuchal translucency (NT) test according to Nicolaides has become the worldwide standard since 2000. The strength of this procedure is its broad predictive power: NT addresses not only the area of genetics, but also the statistically 10 times more frequent structural fetal defects. Thus, NIPT and NT have large overlaps with each other in the field of classical cytogenetics, with slightly different weighting in the fine consideration. However, NIPT without a systematic accompanying ultrasound examination would mean a step back to the prenatal care level of the 1980s. In this respect, additional fine ultrasound should always be required in the professional application of NIPT. NIPT can thus complement NT in wide areas, but not completely replace it.

Cost-Benefit Analysis of Down Syndrome Screening in Iran

Background: Down syndrome (DS) screening has been integrated into prenatal care programs in Iran. Objectives: Using cost-benefit analysis (CBA) method, this study aimed to evaluate the economic aspects of combined first trimester screening in Iran. Methods: The population of this descriptive cross-sectional study included all pregnant women in Tehran, Iran. A decision tree model was used to determine the costs and benefits of diagnosing and averting a DS fetus through screening. Direct and indirect costs of diagnosis and the incremental living costs of DS children in 2019 were calculated from societal perspective and compared with each other. Results: The cost of identifying a fetus with DS in Iran is approximately equal to 611 million Tomans (about 25,000 USD), and the incremental living cost of DS children (benefits) was about 34 million Tomans (about 2,270 USD). The net monetary benefit was negative due to the lower incremental living cost of a DS child than the cost of finding the affected fetus. Conclusions: The result of this study showed the screening tests for DS needs revision and consideration in Iran, and due to the high cost of screening, coverage with insurance organization is necessary.

Preeclampsia prediction –First trimester screening markers

Preeclampsia is a multi-system disorder manifested primarily by hypertension and proteinuria during second half of pregnancy. It is a major cause of maternal morbidity and mortality worldwide. Despite decades of research into the condition, the ability of clinicians to predict preeclampsia prior to the onset of symptoms has not improved significantly. In this review we will look at potential biomarkers for early prediction and diagnosis of preeclampsia. To evaluate the efficacy of different biochemical and biophysical markers in the early weeks of gestation as screening tools for early prediction of preeclampsia. This hospital-based prospective observational study conducted on 52 pregnant women, at less than 13 weeks of gestation were recruited. Maternal urine microalbumin, urinary albumin to creatinine ratio, and USG uterine artery PI levels were analyzed among the pregnant women who subsequently developed PE and compare with those who did not develop PE. Methods used for the detection of markers are: immunoturbidimetric method for urine albumin, modified kinetic Jaffe reaction without deproteinization for Urine creatinine and Uterine artery Doppler velocimetry was done by PHILIPS HD11XE transabdominal ultrasound machine using a 4-6 MHz probe with the same sonographer. In the present study, spot urine microalbumin and spot urine albumin to creatinine ratio (UACR) at 11-13 were significantly higher in women who developed PE subsequently when compared to nonpreeclamptic women.(P&amp;#60;0.0001). The mean levels of 1st and 2nd-trimester uterine artery PI significantly high in women who subsequently developed PE when compared to those who did not develop preeclampsia (P&amp;#60;0.0001). Study results showed a strong association between gestational age at delivery and neonatal outcome (neonatal birth weight and APGAR) with preeclampsia. The maternal urine microalbumin, albumin to creatinine ratio, and uterine artery PI found to have good sensitivity and specificity for early prediction of PE. Study concluded that the women who are prone to develop PE subsequently, had high levels of MAP, UAPI, microalbuminuria and urine albumin to creatinine ratio than the normotensive women. In our setting, MAP, UAPI, microalbuminuria, and UACR markers appeared to be better screening modalities. The combination of biochemical markers with the biophysical markers, demographic characteristics, and other novel markers will establish the effective screening models for early prediction of PE. Early identification of high-risk cases will offer an opportunity for prophylactic therapy, such as Low- dose Aspirin in selected groups of high-risk women screened in the first trimester, thus improving the maternal and perinatal outcome.

Universal HbA1c screening and gestational diabetes: a comparison with clinical risk factors

Background Screening strategies for gestational diabetes mellitus (GDM), particularly early GDM, have traditionally relied upon the use of clinical risk factors (CRFs). Although commonly used in nonpregnant patients, HbA1c screening is not widely used despite reports of abnormal HbA1c values being predictive of GDM development. The aims of this study are to assess the utility of universal HbA1c screening in predicting GDM and to compare universal screening to targeted CRF-based screening for the diagnosis of GDM. Study design This is a retrospective cohort study of patients undergoing universal HbA1c screening at ≤16 completed weeks gestation with a singleton pregnancy between December 2016 and April 2018 at a single urban tertiary care center. Patients with preexisting diabetes (HbA1c ≥6.5%) or patients who did not have glucose tolerance testing were excluded. Patients with HbA1c 5.7–6.4% underwent early two-step GDM screening. Positive screens were diagnosed with early GDM. Normal early screeners underwent repeat 3rd trimester screening. Clinical risk factors for early GDM screening at our institution prior to universal screening were history of GDM, body mass index (BMI) ≥40 kg/m2, prior macrosomia (birth weight ≥4000 g) or stillbirth, and polycystic ovary syndrome. Multivariable regression was performed to assess the relationship between HbA1c and GDM. The predictive ability of universal HbA1c screening compared to that of CRFs was evaluated by testing for differences in the area under the curve (AUC) of receiver operating curves (ROCs). Results One thousand nine hundred and fifteen patients met inclusion criteria. Two hundred and thirty-one (12.1%) patients had an elevated HbA1c ≥5.7%. Patients with elevated HbA1c were more likely to be older, Black, or obese compared with patients with normal HbA1c values. After adjusting for Black race, BMI, age, and public insurance, the odds of GDM development are 3.50 (95%CI 2.26–5.39) times higher among patients with HbA1c ≥5.7% compared to those with a normal HbA1c. Clinical risk factors for early glucose screening were present in 33% of patients with an elevated HbA1c. The AUC of CRF screening and HbA1c ≥5.7% was 0.72 and 0.75, respectively (p= .07), after controlling for Black race, BMI, maternal age, and insurance. Conclusions An elevated HbA1c is associated with an increased risk of GDM. Universal HbA1c screening performs as favorably as CRF based screening for the prediction of GDM.

Clinical implementation of pre-eclampsia screening in the first trimester of pregnancy.

Early identification of preeclampia in the first trimester of pregnancy represents one of the major challenges of modern fetal medicine. The primary aim of our study was to evaluate the effectiveness of implementation of preeclampsia screening in Tuscany, Italy. The secondary aim was to evaluate pregnancy/neonatal outcome in the positive screening group compared with the negative screening group. Retrospective study including singleton pregnancies undergoing screening for preeclampsia. The screening test was a multiparametric algorithm based on maternal history, biochemical and biophysical parameters (Fetal Medicine Foundation algorithm). The overall performance of the test was calculated, in terms of sensitivity, specificity, positive and negative predictive value and in relation to gestational age at onset (primary aim). Pregnancy and neonatal outcomes were then compared between the positive and negative population at preeclampsia screening test (secondary aim). Of the 5719 patients enrolled, 4797 were included in the analysis. The sensitivity for early onset of preeclampsia (≤34weeks) was 0.75 (CI:0.41-0.93) and specificity 0.93 (CI:0.92-0.94) for a false positive rate of 7%. The population that tested positive for preeclampsia screening showed a higher incidence of deliveries at lower gestational ages (p<0.001), preeclampsia onset despite prophylaxis with aspirin (p<0.001), emergency caesarean section (p<0.001), low fetal birth weight (p<0.001) and neonatal admission in intensive care unit (p<0.001). Our data confirm the validity of first trimester screening test in identifying a category of patients at greatest risk for preeclampsia even in the presence of a post-test pharmacological prophylaxis.

A Rare Case of Hemoglobin Bart’s Hydrops Fetalis due to Uniparental Disomy of Chromosome 16

Hemoglobin (Hb) Bart’s hydrops fetalis is the most severe form of alpha-thalassemia and is usually inherited in an autosomal recessive manner. We report a case of Hb Bart’s hydrops fetalis due to uniparental disomy of chromosome 16. Antenatal screening showed a low maternal mean corpuscular volume (MCV), while paternal MCV was normal. The fetus was found to have a thickened nuchal translucency during first trimester screening for Down’s syndrome. Mid-trimester fetal anomaly ultrasound scan showed fetal cardiomegaly with pericardial effusion, scalp edema, ascites and an elevated middle cerebral arterial peak systolic velocity (MCA PSV). Multiplex polymerase chain reaction (PCR) on DNA from amniocentesis showed that the fetus was homozygous for South East Asian (SEA) type 2 alpha-globin gene deletion. Chromosome microarray (CMA) showed two regions of absence of heterozygosity (AOH) on the terminal p and q arm of chromosome 16. The rare occurrence of Hb Bart’s hydrops fetalis caused by maternal uniparental disomy should be considered in cases of fetal hydrops even in cases where paternal MCV is normal. J Med Cases. 2021;12(7):275-279 doi: https://doi.org/10.14740/jmc3693