A re-evaluation of the influence of maternal insulin-dependent diabetes on fetal nuchal translucency thickness and first-trimester maternal serum biochemical markers of aneuploidy

First trimester combined screening test for aneuploidies in anti-Ro carriers pregnant women

INTRODUCTION

Anti-Ro/SSA and anti-La/SSB antibodies are associated with neonatal lupus and congenital heart block. Controversial results regarding perinatal outcomes are found and less is known about aneuploidy screening. The hypothesis is that the presence of anti-Ro and/or anti-La antibodies influences the levels of PAPP-A and ß-HCG, thus interfering in the calculation of risk of aneuploidies.

MATERIAL AND METHODS

Fifty-five anti-Ro/SSA positive pregnant women were included. The demographic characteristics and laboratory variables were studied. Data concerning chromosomopaties screening were also recorded.

RESULTS

PAPP-A and β-HCG levels were calculated (as well as NT and CRL) and compared with a healthy cohort of 12971 pregnant women. PAPP-A levels in mg/mL were lower significatively. In anti-La/SS-B cohort, significant differences were found in PAPP-A in mg/mL and in MoM. Combined risks for Down syndrome (DS) in both groups were higher but the differences were due to age.

CONCLUSIONS

Serum levels of PAPP-A were significative lower but not confirmed when adjusted to MoM. This will have to be confirmed in studies with a larger number of patients and to check whether there is an impact in the calculation of DS risk or not. They could represent a group of pregnant women with significantly a higher risk of adverse perinatal outcome. Key Points • Pregnant patients with anti-Ro/SS-A ant/or anti-La/SS-B antibodies have low PAPP-A levels compared with pregnant women without antibodies. • PAPP-A levels are used in obstetrics for aneuploidies screening in the first trimester, so in these patients, there could be more false positive screening. • In these findings are verified in trials with a larger number of patients, a correction variable would have to be applied for the aneuploidies screening calculation. • Also, low PAPP-A levels are correlated with poor placentation, that is to say, more risk of miscarriages, small fetus for gestational age, and preeclampsia. This is another topic to take into consideration in this population.

Pregestational diabetes in pregnancy: Complications, management, surveillance, and mechanisms of disease-A review

Diabetes is an increasingly common diagnosis among pregnant women. Pregestational diabetes is associated with an increase in many adverse pregnancy outcomes, which impact both on the woman and her fetus. The models of pregnancy care for women with diabetes are based largely on observational data or consensus opinion. Strategies for aneuploidy screening and monitoring for fetal well-being should be modified in women with diabetes. There is an increasing understanding of the mechanisms by which congenital anomalies and disorders of fetal growth occur, involving epigenetic modifications, changes in gene expression in critical developmental pathways, and oxidative stress. This knowledge may lead to pathways for improved care for these high-risk pregnancies.

Are the first-trimester levels of PAPP-A and fb-hCG predictors for obstetrical complications in diabetic pregnancy?

Objective: To assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (fb-hCG) in cases of diabetic pregnancy, to determine whether these biomarkers can be considered significant predictors for macrosomia, preeclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth in mothers with different types of pregestational diabetes mellitus (DM).Methods: It was a retrospective cohort study. Study groups were presented: type 1 DM (n = 100), type 2 DM (n = 50), and controls (n = 25). At 11 + 0 to 13 + 6 week's gestation, we recorded maternal characteristics and medical history, and performed a combined test for the detection of risk of chromosomal abnormalities. To assess the performance of the markers in the prediction of the main obstetrical complications (PE, IUGR, preterm birth, and macrosomia), receiver-operating characteristic (ROC) curves were produced and area under the curves was calculated.Results: The study has shown that DM is associated with a high rate of perinatal complications: PE, IUGR, macrosomia, and preterm birth. The median level of PAPP-A was significantly lower in case of type 1 DM- 0.89 (inter quartile range (IQR), 0.51-1.1), and type 2 DM-0.88 (IQR, 0.42-1.15) compared to the unaffected group 1.03 (IQR, 0.96-1.12; p = .025). There were no significant differences in the fb-hCG multiples of the normal median (MoM; p = .14) between the diabetic and unaffected groups. More significant results were obtained when calculated by percentile: in diabetic pregnancies, PAPP-A and fb-hCG MoMs values were lower in the 5-10% ranges and higher in the 95% range, compared to the control group. ROC-analysis did not show any significant data that first-trimester PAPP-A and fb-hCG serum levels are predictors for PE, IUGR, macrosomia, and preterm birth.Conclusion: The routine first-trimester serum screening of fetal Down syndrome cannot be used as a tool of risk identification for PE, IUGR, macrosomia, and preterm birth in case of diabetic pregnancy.

Usefulness and reliability of cell free fetal DNA screening for main trisomies in case of atypical profile on first trimester maternal serum screening

Background

Patients with atypical values of HCG and/or PAPP-A are at higher risk of chromosomal abnormality and vascular complications of pregnancy. The performance of cfDNA in this particular population has not yet been evaluated.

Objectives

The primary objective was to evaluate the usefulness and reliability of cfDNA in screening for trisomy 21, 18 and 13 for patients with HCG < 0.25 multiple of median (MoM), HCG > 5.0 MoM and/or PAPP-A < 0.25 MoM, PAPP-A > 2.5 MoM. The secondary objective was to evaluate the contribution of cfDNA assay for the prediction of pregnancy’s vascular complications.

Method

Between June 2016 and July 2017, we analysed a women cohort from all over France who had at least one first trimester serum biomarker outside of normal range, in a retrospective, observational and multicentre study. Patients were included if they had a single pregnancy, normal first trimester ultrasound examination, whatever the result of the combined first trimester screening test was. The cfDNA was analysed by massive parallel sequencing technique. The accuracy of cfDNA assay was evaluated by calculation of sensitivity and specificity, and multivariate regression analysis was used to search for predictive factors for pregnancy’s vascular complications.

Results

Among the 498 patients who underwent a cfDNA assay in this context, twenty-one (4.2%) were excluded because of loss to follow-up. Out of 477, test failure occurred for four patients initially, reduced to two patients (0.4%) after redrawn. CfDNA was positive for Trisomy 21 (n = 19), Trisomy 18 (n = 6) and Trisomy 13 (n = 1) and negative in 449. The sensitivity of cfDNA assay for trisomy 21 screening was 100% (19/19) (IC 95% 82.4–100) and specificity 100% (458/458) (IC 95% 99.2–100). Among the 447 patients included for prediction of vascular complications, there were four cases of pregnancy induced hypertension and 10 cases of preeclampsia, for which no predictive factor was identified. Intra Uterine growth restriction under 5th percentile (n = 44, 9.8%) was significantly associated with a low fetal fraction (OR = 0.87, IC 95% 0.79–0.96, p = 0.006).

Conclusion

cfDNA assay is an effective and reliable tool for women with atypical profile of first trimester serum biomarkers.

The introduction of the absolute risk for the detection of fetal aneuploidies in the first-trimester screening

PURPOSE

Maternal age is a crucial factor in fetal aneuploidy screening, resulting in an increased rate of false-positive cases in older women and false-negative cases in younger women. The absolute risk (AR) is the simplest way to eliminate the background maternal age risk, as it represents the amount of improvement of the combined risk from the maternal background risk. The aim of this work is to assess the performance of the AR in the combined first-trimester screening for aneuploidies.

MATERIALS AND METHODS

A retrospective validation of the AR in the combined first-trimester screening for fetal aneuploidies, in an unselected population at Altamedica Fetal-Maternal Medical Center in Rome, between March 2007 and December 2008.

RESULTS

Of 3845 women included in the study, we had a complete follow-up on 2984. We evaluated that an AR < 3 would individuate 22 of 23 cases of aneuploidy with a detection rate of 95.7% (95%CI 87.3-100), a false-positive rate of 8.7% (95%CI 7.7-9.7) and a false-negative rate of 4.3% (95%CI 0-12.7).

CONCLUSIONS

In our study, the AR ameliorates the detection rate for aneuploidy. Further research and a prospective study on a larger population would help us to improve the AR in detecting most cases of aneuploidy.

Does diurnal variation affect the first trimester fetal aneuploidy screening test biochemical parameters of fetuses with normal nuchal translucency?

OBJECTIVE

The purpose of this study was to investigate the effect of diurnal variation on biochemical results of first trimester aneuploidy screening test.

METHODS

A total of 2725 singleton pregnant female, who had normal fetal nuchal translucency (NT) thickness, were included in the study during this period. Individuals were divided into two groups according to the sampling time (morning group: 09:00-11:00 am and afternoon group: 02:00-04:00 pm). Hormonal parameters (free-beta human chorionic gonadotropin [free β-hCG] and pregnancy-associated plasma protein-A [PAPP-A] multiples of median [MoM] levels) of first trimester (11(+0)-13(+6) weeks) combined aneuploidy screening test were compared between morning and afternoon groups.

RESULTS

PAPP-A MoM levels were significantly lower in the afternoon group when compared to the morning group (p = 0.001), whereas free β-hCG MoM levels were similar in the both groups (p = 0.392). Rate of high risk for Down syndrome (Combine risk >1/300) and amniocentesis ratio were found higher in the afternoon group than morning group, but there were no difference between groups for the number of fetuses with Down syndrome.

CONCLUSION

Receiving the venous blood sample for first trimester aneuploidy screening test in the afternoon causes low PAPP-A MoM levels.

Serum free β-human chorionic gonadotropin in the three trimesters of pregnancy: effects of maternal characteristics and medical history

OBJECTIVE

To define the contribution of maternal variables which influence the measured level of maternal serum free β-human chorionic gonadotropin (β-hCG) in screening for pregnancy complications.

METHODS

Maternal characteristics and medical history were recorded and serum free β-hCG was measured in women with a singleton pregnancy attending for three routine hospital visits at 11 + 0 to 13 + 6, 19 + 0 to 24 + 6 and 30 + 0 to 34 + 6 weeks' gestation. For pregnancies delivering phenotypically normal live births or stillbirths ≥ 24 weeks' gestation, variables from maternal demographic characteristics and medical history that are important in the prediction of free β-hCG were determined from a linear mixed-effects multiple regression.

RESULTS

Serum free β-hCG was measured in 94 985 cases in the first trimester, 7879 in the second trimester and 8424 in the third trimester. Significant independent contributions to serum free β-hCG were provided by gestational age, maternal weight, age and racial origin, cigarette smoking, method of conception, diabetes mellitus and family history of pre-eclampsia (PE) in the mother of the patient. The effects of some variables were similar and those for others differed in each trimester. Random-effects multiple regression analysis was used to define the contribution of maternal variables that influence the measured level of serum free β-hCG and express the values as multiples of the median (MoMs). The model was shown to provide an adequate fit of MoM values for all covariates both in pregnancies that developed PE and in those without this pregnancy complication.

CONCLUSIONS

A model was fitted to express measured serum free β-hCG across the three trimesters of pregnancy as MoMs after adjusting for variables from maternal characteristics and medical history that affect this measurement.

First Trimester Aneuploidy Screening Markers in Women with Pre-Gestational Diabetes Mellitus

OBJECTIVE

To investigate whether maternal serum pregnancy associated plasma protein-A (PAPP-A), total β human chorionic gonadotropin (hCG) levels and nuchal translucency (NT) measurements differ in women with pre-gestational diabetes mellitus (PGDM) compared to non-diabetic controls and to assess whether correction factors are needed for diabetic women in calculation of aneuploidy risks.

STUDY DESIGN

We performed a retrospective study of all women who underwent first trimester aneuploidy screening (11 + 0 to 13 + 6 weeks) from 2005 to 2011. The primary study outcome was the difference in PAPP-A, β-hCG and NT multiples of median between women with PGDM and non-diabetic women.

RESULTS

Of 6741 eligible patients, 103 patients with PGDM were using insulin and 4 patients were using oral hypoglycemic agents; the latter were excluded due to small number. There was 12% reduction of median PAPP-A (p = 0.001) and 18% reduction of median hCG (p = 0.006) in women with PGDM receiving insulin. There was no difference in NT.

CONCLUSIONS

In women with PGDM receiving insulin, PAPP-A and β-hCG levels are significantly lower compared to non-diabetic women. This suggests that when calculating risks for aneuploidy, correction factors should be considered to adjust PAPP-A and β-hCG concentrations to those seen in non-diabetic women.

The association between gestational diabetes mellitus and first trimester aneuploidy screening markers

Objective

To establish whether maternal serum first trimester concentrations of PAPP-A and free hCGβ are altered in pregnancies that subsequently are diagnosed by an oral glucose tolerance test (OGTT) with gestational diabetes mellitus (GDM).

Methods

Over the period 2009 and 2011, the results for women who had first trimester screening for aneuploidy were matched with those having an oral glucose tolerance test at 22–26 weeks for suspected GDM. Free hCGβ, PAPP-A and NT MoMs were compared amongst the group having an OGTT with confirmed GDM and those in which GDM was not confirmed. A second comparison group consisted of all non-aneuploidy singleton pregnancies in which no OGTT was performed.

Results

During the three-year period, 27,660 singleton pregnancies were screened of which 7429 cases had an OGTT of which 870 cases were classed as GDM by WHO criteria. There was a significant 7–9% reduction in both PAPP-A and free hCGβ MoM in the GDM group compared with either the OGTT non-GDM group or the remaining pregnancies with no known risk factors for evidence of GDM. There was no difference in the NT measurements.

Conclusions

First trimester concentrations of PAPP-A and free hCGβ are reduced in pregnancies that subsequently are diagnosed with GDM and may be useful in further screening algorithms for this disorder although the sensitivity alone is quite poor.

Gestational diabetes mellitus: including serum pregnancy-associated plasma protein-A testing in the clinical management of primiparous women? A case-control study

AIMS

To assess pregnancy-associated plasma protein A (PAPP-A) correlation with GDM and its usefulness in predicting GDM in primiparous women.

METHODS

First trimester data related to 307 pregnant women affected by GDM and 366 control pregnant women were retrieved from a computer data base and integrated with ad hoc data. Clinical data were recorded at delivery. A logistic model was used to analyze the association between first trimester data and subsequent clinical outcomes. We derived a risk score using both classical risk factors for GDM and PAPP-A.

RESULTS

Diabetic and control women were significantly different in terms of age (p<0.001), BMI (p<0.001), weight (p<0.001), family history of diabetes (p<0.001), PAPP-A concentration and PAPP-A corrected multiple of the median (MoM) (p<0.001). The ROC-AUC of the clinical risk score was 0.60 (95%CI 0.56-0.64), the adjusted score including PAPP-A MoM was 0.70 (95%CI 0.66-0.74).

CONCLUSIONS

Low PAPP-A was strongly associated with GDM and lower values were found in diabetic women needing insulin therapy. Adding PAPP-A to first trimester screening could improve the prediction of women at high risk who will develop GDM. Further studies are needed to validate the applicability of our findings in different populations and settings.

First-trimester detection of fetal anomalies in pregestational diabetes using nuchal translucency, ductus venosus Doppler, and maternal glycosylated hemoglobin

OBJECTIVE

The frequency of fetal anomalies in women with pregestational diabetes correlates with their glycemic control. This study aimed to assess the predictive performance of first-trimester fetal nuchal translucency (NT), ductus venosus (DV) Doppler, and hemoglobin A1c (HbA1c) to predict fetal anomalies in women with pregestational diabetes.

STUDY DESIGN

This was a prospective observational study of patients undergoing first-trimester NT with DV Doppler. Screening performance was tested for first-trimester parameters to detect fetal anomalies.

RESULTS

Of 293 patients, 17 had fetal anomalies (11 cardiac, 7 major, 3 multisystem). All anomalous fetuses were suspected prenatally. One had NT >95th centile, 2 had reversed DV a-wave, and 13 had HbA1c >7.0%. The HbA1c was the primary determinant of anomalies (r(2), 0.15; P < .001) and >8.35% was the optimal cutoff for prediction of anomalies with an area under the curve of 0.72 (95% confidence interval, 0.57-0.88). Therefore, first-trimester prediction of anomalies was best in women with increased NT or HbA1c >8.3% (sensitivity 70.6%, specificity 77.4%, positive predictive value 16.2%, negative predictive value 97.7%, P < .001).

CONCLUSION

In women with pregestational diabetes and poor glycemic control, an increased NT increases risks for major fetal anomalies. Second-trimester follow-up is required to achieve accurate prenatal diagnosis.

Standardized Procedural Practices of the Ontario Prenatal Screening Program for aneuploidies and open neural tube defects

BACKGROUND/OBJECTIVES

The Ontario Prenatal Screening Program (OPSP) follows internationally recognized standardized procedures for laboratories and genetics clinics. However, it has been found that some procedures are subject to interpretation, so the current procedures are designed to facilitate a unified approach in the interpretation of literature recommendations. In Ontario, the OPSP offers multiple screening modalities with integrated prenatal screening (including both first and second trimester markers) being the most commonly chosen option. Other screening modalities include first trimester screening, second trimester quad screening, serum integrated screening, and NT-Quad.

METHODS

The standardization was based on a literature review and on current practices in Ontario.

RESULTS/DISCUSSION

The main finding of the review was a paucity of published data relating to the procedures and the decision-making processes involved in prenatal screening. The purpose of this publication is to provide the most up-to-date and pertinent information for clinical laboratory professionals involved with prenatal screening for Down syndrome, trisomy 18 and open neural tube defects.

Sonographic evaluation and the pregnancy complicated by diabetes

Sonography is a fundamental tool in the management of pregnancies affected by maternal diabetes. Purposeful use of ultrasound in each trimester provides an invaluable amount of information about the developing fetus including gestational age and growth patterns, anatomical structure and function, assessment of fetal well-being, and prediction of adverse outcome. There are great ongoing research efforts in this field of prenatal diagnosis and management, yet even more are needed.