Applicability of first-trimester combined screening for fetal trisomy 21 in a resource-limited setting in mainland China

Associated congenital heart disease with Hirschsprung's disease: a retrospective cohort study on 2,174 children

Objective

To examine the incidence and phenotypes of congenital heart disease (CHD) in a large cohort of patients with Hirschsprung's disease (HSCR).

Study design

Retrospective data review of children with HSCR between 2003 and 2020 was conducted at the Provincial Key Laboratory for Structural Birth Defects in Guangzhou, Guangdong, China. HSCR was confirmed by pathological diagnosis. CHD was defined as a gross structural abnormality of the heart or intrathoracic great vessels that is of functional significance.

Results

A total of 2,174 HSCR patients (84.7% males) were studied and 306 of them underwent echocardiography. Overall, 27 children (1.2%) had associated CHD. Among them, CHDs mostly presented as atrial and ventricular septal defects (n = 5 and 12 respectively) and patent ductus arteriosus (n = 4). Three patients (1.4‰) presented as a severe CHD including complete atrioventricular canal, congenitally corrected transposition of the great arteries and double-outlet of right ventricle. Among 14 patients carrying a chromosomal abnormality, CHD was detected in 4 infants (28.6%), all being mild forms of septal defects.

Conclusions

Some new and severe types of CHD were found in patients with HSCR. Patients with syndromic features had higher incidence of CHD.

The role of serum markers PAPP-A β-hCG, AFP, and uE3 in predicting the risk of preeclampsia in early, middle, and late pregnancy

BACKGROUND: Preeclampsia (PE) has adverse effects on pregnant women, fetuses, and newborns [1], and accounts for 3%–10% of pregnancy-related diseases globally. OBJECTIVE: This study aimed to screen a series of prenatal markers (pregnancy-associated plasma protein [PAPP-A], β-human chorionic gonadotropin [β-hCG], alpha fetoprotein [AFP], and estriol [uE3]) to establish a risk model and evaluate the diagnostic values of the markers for predicting PE. METHODS: Sixty-five pregnant women were enrolled in this study. They were divided into two groups containing healthy pregnant women (n= 51, the non-PE group) and pregnant women with PE (n= 14, the PE group). According to the stage of pregnancy, the pregnant women in each group were divided into early, middle, and late pregnancy groups for statistical analysis. The levels of PAPPA-A β-hCG, AFP, and uE3 were compared among these groups. Then, a risk model was established, and PE was diagnosed using receiver operating characteristic (ROC) curve results. RESULTS: In the early pregnancy group, the differences in the levels of PAPP-A, AFP, and uE3 between the PE and non-PE groups were statistically significant (P< 0.001, P= 0.029, and P= 0.033, respectively), while the difference in the single remaining marker was not statistically significant. A ROC curve analysis revealed that in early pregnancy, the sensitivity and specificity of PAPP-A were 76.5% and 71.4%, respectively, and the sensitivity and specificity of β-hCG were 82.4% and 57.1%, respectively. The sensitivity and specificity of the combination of the two markers for diagnosing PE were 86.3% and 57.1%, respectively. CONCLUSION: This study demonstrated that the combination of PAPP-A and β-hCG has diagnostic value for PE in pregnant women. Accordingly, we should formulate innovative PE screening strategies to target the prevention of PE and create important conditions for predictive and preventive personalized medical treatments.

A Risk Model for Predicting Fetuses with Trisomy 21 Using Alpha-Fetoprotein Variants L2 Combined with Maternal Serum Biomarkers in Early Pregnancy

To establish a risk prediction model and the clinical value of trisomy 21 using alpha-fetoprotein variants L2 (AFP-L2) combined with maternal serum biomarkers and nuchal translucency (NT) thickness in early pregnancy. A retrospective case–control study was conducted. The subjects were divided into the case group (n = 40) or the control group (n = 40). An enzyme-linked immunosorbent assay was used to measure the maternal serum AFP-L2 level in both groups. The AFP-L2 single-index or multi-index combined risk model was used to predict the efficiency of trisomy 21. The best cut-off value and area under the curve (AUC) were determined to evaluate the predictive efficacy of different risk models constructed by AFP-L2. The maternal serum AFP-L2 level in the case group was 1.59 (0.61–3.61) Multiple of medium (MoM), which was higher than 1.00 (0.39–2.12) MoM in the control group (P < 0.001). The free beta-human chorionic gonadotropin (free β-hCG) level and NT in the case group were significantly higher than those in the control group (P < 0.001). The pregnancy-associated plasma protein A (PAPP-A) level in the case group was lower than that in the control group (P < 0.001). The AUC of AFP-L2 in predicting trisomy 21 was 0.797. After considering the maternal serum AFP-L2 level, the AUC, detection rate (DR), positive predictive value (PPV), negative predictive value (NPV), falsepositive rate (FPR), false negative rate (FNR), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were significantly improved. In this study, PAPP-A + free β-hCG + NT + AFP-L2 and PAPP-A + free β-hCG + AFP-L2 increased the integrated discrimination improvement (IDI) and net classification improvement (NRI) of predicting fetuses with trisomy 21 (1.10% and 5.27%; 11.07% and 2.78%)  (1.10% and 5.27%; 11.07% and 2.78%), respectively, after considering the maternal serum AFP-L2 level. The maternal serum AFP-L2 level in early pregnancy had high sensitivity and specificity, and it was a good biomarker to predict fetuses with trisomy 21.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Associations between Human Chorionic Gonadotropin, Maternal Free Thyroxine, and Gestational Diabetes Mellitus

Background: Human chorionic gonadotropin (hCG) is a marker of placental function, which also stimulates the maternal thyroid gland. Maternal thyroid function can be associated with the pathophysiology of gestational diabetes mellitus (GDM). We aimed to study whether there is an association of hCG concentrations in early pregnancy with GDM and whether it is mediated through maternal thyroid hormones. Methods: This study included 18,683 pregnant women presenting at a tertiary hospital in Shanghai, China, between January 2015 and December 2016. GDM was diagnosed using a 2-hour, 75-g, oral glucose tolerance test (OGTT) according to the American Diabetes Association guidelines. Multivariable logistic or linear regression models were used to identify associations, adjusting for maternal age, education level, family history of diabetes, parity, fetal sex, thyroperoxidase antibody (TPOAb) status, and prepregnancy body-mass index. Results: Higher hCG concentrations were associated with a lower plasma glucose level during the OGTT, but not with fasting plasma glucose or hemoglobin A1c concentrations tested during early pregnancy. hCG in early pregnancy was negatively associated with GDM risk (p = 0.027). Mediation analysis identified that an estimated 21.4% of the association of hCG-associated GDM risk was mediated through changes in free thyroxine (fT4) concentrations (p < 0.05). In the sensitivity analysis restricted to TPOAb-positive women, hCG was not associated with GDM (p = 0.452). Conclusions: Higher hCG levels in early pregnancy are associated with a lower risk of GDM. Maternal fT4 may act as an important mediator in this association.

A risk model of prenatal screening markers in first trimester for predicting hypertensive disorders of pregnancy

Background

We aimed to construct a risk model to assess the diagnostic value of predicting hypertensive disorders of pregnancy (HDPs) by screening a range of prenatal markers, including pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotropin (free β-hCG), and fetal nuchal translucency (NT).

Method

We analyzed 902 women, classified into four groups: healthy gravidas (n = 680, controls), gravidas with gestational hypertension (n = 61; GH), gravidas with preeclampsia (n = 90; PE), and gravidas with severe preeclampsia (n = 71, SPE). We then compared the multiple of median (MoM) of PAPP-A, free β-hCG, and NT. A risk model was constructed and receiver operating characteristic curve (ROC) analysis was used to diagnose HDPs.

Results

Levels of PAPP-A and free β-hCG levels in the GH, PE, and SPE groups were significantly lower than those in the control group (χ ² = 7.522, P = 0.001; χ ² = 17.775, P < 0.001). NT did not differ significantly when compared across all four groups (χ ² = 1.592, P > 0.05). When the cut-off values for PAPP-A and free β-hCG were 0.795 MoM and 1.185 MoM, the corresponding sensitivities and specificities were 0.514 and 0.635, and 0.734 and 0.450, respectively. The best risk calculation featured PAPP-A, free β-hCG, and NT; this model exhibited the highest diagnostic value in the SPE group, followed by the GH group and then the PE group.

Conclusion

The use of prenatal screening markers during early pregnancy can identify fetal aneuploidy and can also predict HDPs. The development of innovative screening strategies for gravidas and the targeted prevention of HDPs in high-risk gravidas are essential for perinatal care and early intervention, thus creating significant opportunities for predictive and preventive personalized medicine. In our study, we found that the combination of a series of prenatal screening markers in early pregnancy is better than a single marker; our data clearly demonstrate the diagnostic value of combining PAPP-A, free β-hCG, and NT for patients with SPE.

A Retrospective Analysis Of Different Contingent Screening Models For Fetal Down Syndrome In Southwestern China

To discuss combinations of traditional screening and noninvasive prenatal screening (NIPS) and to compare which traditional screening is the most suitable first-line screening approach to NIPS, pregnant women were recruited in this retrospective observational study. Pregnant women underwent one of four traditional screening tests. The 9 contingent models were combined by high risk cut-offs of 1:50, 1:100, 1:270 and intermediate risk cut-offs of 1:1000, 1:1500, 1:2000. We analyzed cost and performance of various screening models with contingent screening of different risk cut-offs. Compared with other screening tests, combined first-trimester screening (CFTS) had the lowest proportion of high risk (≥1:270) with the highest detection rate (DR) (78.79%) and the lowest proportion of intermediate risk (1:271~1:1000). When intermediate risk was 1:51 ~1:1500, CFTS as first-line screening had the lowest cost with DR of 93.94%. Other screening tests as the first-line screening with intermediate risk of 1:51~1:1000 had the lowest cost, there DR were 90.91%, 84.62%, 91.67%, respectively. Our study demonstrated if only one traditional screening was allowed to screen pregnant women, CFTS was recommended as the first choice. According to local health and economic conditions, adopting appropriate traditional screening with suitable cut-offs as first-line screening will contributed to a cost-effective screening model.

Targeted capture enrichment followed by NGS: development and validation of a single comprehensive NIPT for chromosomal aneuploidies, microdeletion syndromes and monogenic diseases

Background

Non-invasive prenatal testing (NIPT) has been widely adopted for the detection of fetal aneuploidies and microdeletion syndromes, nevertheless, limited clinical utilization has been reported for the non-invasive prenatal screening of monogenic diseases. In this study, we present the development and validation of a single comprehensive NIPT for prenatal screening of chromosomal aneuploidies, microdeletions and 50 autosomal recessive disorders associated with severe or moderate clinical phenotype.

Results

We employed a targeted capture enrichment technology powered by custom TArget Capture Sequences (TACS) and multi-engine bioinformatics analysis pipeline to develop and validate a novel NIPT test. This test was validated using 2033 cell-fee DNA (cfDNA) samples from maternal plasma of pregnant women referred for NIPT and paternal genomic DNA. Additionally, 200 amniotic fluid and CVS samples were used for validation purposes. All NIPT samples were correctly classified exhibiting 100% sensitivity (CI 89.7–100%) and 100% specificity (CI 99.8–100%) for chromosomal aneuploidies and microdeletions. Furthermore, 613 targeted causative mutations, of which 87 were unique, corresponding to 21 monogenic diseases, were identified. For the validation of the assay for prenatal diagnosis purposes, all aneuploidies, microdeletions and point mutations were correctly detected in all 200 amniotic fluid and CVS samples.

Conclusions

We present a NIPT for aneuploidies, microdeletions, and monogenic disorders. To our knowledge this is the first time that such a comprehensive NIPT is available for clinical implementation.

Prenatal diagnosis and socioeconomic status in the non-invasive prenatal testing era: A population-based study

BACKGROUND

Advances in technology can bring great benefits to human health, but their implementation may be influenced by socioeconomic factors, particularly in the field of prenatal screening for Down syndrome.

AIM

To analyse screening test indications for, and diagnostic yield of, invasive prenatal diagnostic testing (PNDx) according to socioeconomic status.

METHODS

Retrospective analysis of population-based data on PNDx and karyotype results for 2014-2015 in the Australian state of Victoria. Women having PNDx < 25 weeks due to combined first trimester screening (CFTS), second trimester serum screening (STSS), or noninvasive prenatal testing (NIPT) results were included. PNDx data were analysed by indication and maternal Index of Relative Socio-economic Advantage and Disadvantage (IRSAD), the latter determined by postcode.

RESULTS

There were 145 206 births in 2014-2015; 1906 women underwent PNDx for the indication of CFTS (70.1%), NIPT (17.8%) or STSS (12.0%). Covariates positively associated with NIPT-indicated PNDx, compared with CFTS-indicated testing, were residence in a region of socioeconomic advantage, metropolitan status and maternal age. Women from the most advantaged regions had higher adjusted odds ratios (aOR) of NIPT-indicated testing compared with women from disadvantaged regions (aOR 5.72, 95% CI: 2.95-11.09). The diagnostic yield of PNDx increased with socioeconomic region, from 14% in the lowest IRSAD quintile to 31.2% in the highest (P < 0.0001).

CONCLUSION

Population-based data reveal significant disparities in screening indications for PNDx and hence, in diagnostic yield, according to socioeconomic region. This finding may have ethical and policy implications for prenatal screening in Australia.