A new contingent screening strategy increased detection rate of trisomy 21 in the first trimester

BACKGROUND

Although the traditional contingent screening strategy is effective, there are still undetected low-risk trisomy 21. This study aims to define appropriate cut-off values of serum biochemical markers at low-risk and develop a strategy for sequential prenatal testing associated with first-trimester screening to increase the detection rate of trisomy 21.

METHODS

This was a 9-year retrospective analysis of singleton pregnant women who underwent serum biochemical screening or combined first-trimester screening (CFTS) in the first trimester. For the low-risk group, the cut-off values of the serum biochemical markers were adjusted to determine the appropriate detection efficiency. Gravidas with abnormal serum biochemical markers at low-risk were advised to undergo further non-invasive prenatal screening (NIPS), whereas others continued with routine prenatal care.

RESULTS

When cut-off values of free beta subunit of human chorionic gonadotropin (free β-hCG) multiples of the median (MoM) or pregnancy-associated plasma protein A (PAPP-A) MoM were defined with ≥ 2.75 or ≤ 0.5, 7.72% (2,194/28,405) in the serum biochemical screening group and 12.36% (4,005/32,403) in CFTS group could be detected as abnormal results for further NIPS. Finally, 55.56% (5/9) and 85.71% (6/7) of trisomy 21 cases with false-negative results were detected, and the overall detection rate for trisomy 21 was improved by 10.64% (5/47) and 12.77% (6/47), respectively.

CONCLUSIONS

The new contingent screening strategy can increase the detection rate of trisomy 21 compared with the traditional contingent screening strategy.

Evaluation of the Relationship between Pregnancy-Associated Plasma Protein A (PAPP-A) and Pregnancy Outcomes

Background

In the current study, we aimed to evaluate the association between pregnancy-related plasma protein-A (PAPP-A) levels measured in the first trimester and pregnancy outcomes.

Materials and Methods

This is a descriptive-analytical study that was performed in 2019--2021 on 1061 pregnant women in their first trimester. Demographic and basic information of all women were collected. These data included age, weight, parity, and date of delivery. Then the quantity of PAPP-A was recorded in three groups including less than 0.5 MOM, 0.5 to 2.5 MOM, and more than 2.5 MOM.

Results

Data of 1061 women were analyzed. 900 women (84.8%) had term delivery and 155 women (14.6%) had pre-term deliveries. PAPP-A levels were normal in 83.4% of women. BMI and number of pregnancies had significant relationships with PAPP-A (p < 0.001, P = 0.03 respectively). The mean BMI in mothers with PAPP-A higher than 2.5 was significantly more than mothers with normal or lower PAPP-A levels (26.2 ± 31, P = 0.04). The frequency of term labor in mothers with normal PAPP-A was higher than other mothers (86.3%, P = 0.04). The frequency of preeclampsia in recent pregnancies in mothers with normal PAPP-A was significantly lower than other mothers (p < 0.001) and the frequency of abortions in recent pregnancies in mothers with PAPP-A less than 0.5 was significantly higher than mothers with normal or elevated PAPP-A (p < 0.001).

Conclusion

Mothers with low PAPP-A levels are more likely to have poor pregnancy outcomes such as abortion, pre-term labor, and preeclampsia.

Importance of Low Pregnancy Associated Plasma Protein-A (PAPP-A) Levels During the First Trimester as a Predicting Factor for Adverse Pregnancy Outcomes: A Prospective Cohort Study of 2636 Pregnant Women

OBJECTIVES

The aim of this study is to investigate the predictive value of low levels of pregnancy associated plasma protein-A (PAPP-A) during the first trimester on adverse pregnancy outcomes, namely pregnancy induced hypertension (PIH), preeclampsia (PE), intrauterine growth restriction (IUGR), and fetal loss.

METHODS

This is a prospective cohort study including 2636 women with singleton pregnancies that attended the Prenatal Diagnosis Unit of the First Department of Obstetrics and Gynecology of National and Kapodistrian University of Athens in "Alexandra Hospital" between 2017 and 2019 for the first trimester combined screening routine scan. The study population was divided into two groups according to their PAPP-A levels. The cut-off value of the PAPP-A level was defined as the 0.4 multiple of median (MoM) which is in correspondence with the fifth centile. The women were followed-up prospectively until delivery and the primary outcome measures were the incidence of PIH, PE, IUGR (<10th centile), and fetal loss.  Results: PAPP-A levels of ≤0.4 MoM were associated with increased maternal body mass index (BMI), increased uterine arteries pulsatility index (PI), and lower birth weight. Women with PAPP-A levels ≤0.4 MoM were more likely to develop PE (2.3% vs. 0.2%, p<0.001), PE or PIH (2.3% vs. 0.4%, p=0.003), IUGR (2.3% vs. 0.4%, p=0.003), and combined adverse outcome (25.5% vs. 1.9%, p<0.001) compared to women with PAPP-A>0.4 MoM.

CONCLUSIONS

This study confirms that among women with PAPP-A levels ≤0.4 MoM in the first trimester, there are increased odds for PE or PIH, IUGR, and combined composite pregnancy outcome.

First trimester low maternal serum pregnancy associated plasma protein-A (PAPP-A) as a screening method for adverse pregnancy outcomes

OBJECTIVES

To evaluate different cut-off values of first trimester pregnancy associated plasma protein-A (PAPP-A) in screening for adverse pregnancy outcomes in a retrospective cohort study.

METHODS

During the study period of 1.1.2014-31.12.2018, total of 23,482 women with singleton pregnancies participated in first trimester combined screening for chromosomal abnormalities. Maternal serum PAPP-A multiple of medians (MoM) levels were measured, and study population was divided into three study groups of PAPP-A ≤0.40 (n=1,030), ≤0.35 (n=630) and ≤0.30 (n=363) MoM.

RESULTS

Small for gestational age (SGA), preterm birth (PTB) and composite outcome (SGA, hypertensive disorder of pregnancy (HDP) and/or PTB) were more frequent in all three PAPP-A MoM study groups and pre-eclampsia in ≤0.40 and ≤0.35 study groups than in their control groups (p < 0.05). The odds ratio (OR) for SGA varied from 3.7 to 5.4 and sensitivity and specificity from 6.9 to 13.8% and from 95.9 to 98.6%, between study groups. Using PAPP-A ≤0.30 MoM as a screening cut-off instead of PAPP-A ≤0.40 MoM, resulted in approximately 50% reduction in screening detection of SGA and PTB.

CONCLUSIONS

PAPP-A ≤0.40 MoM should be considered as a primary screening cut-off for adverse pregnancy outcomes as approximately 23% will develop either SGA, HDP or PTB. It seems to be the best cut-off to screen for SGA.

The expression of pregnancy-associated plasma protein-A (PAPP-A) in human blastocoel fluid-conditioned media: a proof of concept study

Purpose

The aim of this study was to determine if pregnancy-associated plasma protein-A (PAPP-A), typically measured in maternal serum and a potential predictor of adverse maternal and fetal outcomes such as spontaneous miscarriage, pre-eclampsia, and stillbirth, is expressed in blastocoel fluid–conditioned media (BFCM) at the embryonic blastocyst stage.

Design

This is an in vitro study.

Methods

BFCM samples from trophectoderm-tested euploid blastocysts (n = 80) from in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) patients were analyzed for PAPP-A mRNA. BFCM was obtained from blastocyst stage embryos in 20 uL drops. Blastocysts underwent trophectoderm biopsy for preimplantation genetic testing for aneuploidy prior to blastocyst vitrification and BFCM collection for snap freezing. cfDNA was synthesized using BFCM collected from 80 individual euploid blastocysts. Next, real-time qPCR was performed to detect expression of PAPP-A with GAPDH for normalization of expression in each sample.

Results

PAPP-A mRNA was detected in 45 of 80 BFCM samples (56.3%), with varying levels of expression across samples.

Conclusion

Our study demonstrates the expression of PAPP-A in BFCM. To our knowledge, this is the first study to report detection of PAPP-A mRNA in BFCM. Further studies are required and underway to investigate a greater number of BFCM samples as well as the possible correlation of PAPP-A expression with pregnancy outcomes of transferred euploid blastocysts. If found to predict IVF and obstetric outcomes, PAPP-A may provide additional information along with embryonic euploidy for the selection of the optimal blastocyst for embryo transfer.

Serum Inhibin-A and PAPP-A2 in the prediction of pre-eclampsia during the first and second trimesters in high-risk women

OBJECTIVES

Maternal serum inhibin-A, pregnancy associated plasma protein-A (PAPP-A) and PAPP-A2 together with placental growth factor (PlGF), maternal risk factors and uterine artery pulsatility index (UtA PI) were analysed to study their ability to predict pre-eclampsia (PE).

STUDY DESIGN

Serial serum samples for the nested case-control study were collected prospectively at 12-14, 18-20 and 26-28 weeks of gestation from 11 women who later developed early-onset PE (EO PE, diagnosis < 34 + 0 weeks of gestation), 34 women who developed late-onset PE (LO PE, diagnosis ≥ 34 + 0 weeks) and 89 controls.

MAIN OUTCOME MEASURES

Gestational age -adjusted multiples of the median (MoM) values were calculated for biomarker concentrations. Multivariate regression analyses were performed to combine first trimester biomarkers, previously reported results on PlGF, maternal risk factors and UtA PI. Area under curve (AUC) values and 95% confidence intervals (CIs) for the prediction of PE and its subtypes were calculated.

RESULTS

A high first trimester inhibin-A predicted PE (AUC 0.618, 95%CI, 0.513-0.724), whereas PAPP-A and PlGF predicted only EO PE (0.701, 0.562-0.840 and 0.798, 0.686-0.909, respectively). At 26-28 weeks PAPP-A2 and inhibin-A predicted all PE subtypes. In the multivariate setting inhibin-A combined with maternal pre-pregnancy body mass index, prior PE and mean UtA PI predicted PE (0.811,0.726-0.896) and LO PE (0.824, 0.733-0.914).

CONCLUSIONS

At first trimester inhibin-A show potential ability to predict not only EO PE but also LO PE whereas PlGF and PAPP-A predict only EO PE. At late second trimester inhibin-A and PAPP-A2 might be useful for short-term prediction of PE.

Can first trimester pregnancy-associated plasma protein-A predict the surfactant needs of preterm neonates?

BACKGROUND

Low values of pregnancy associated plasma protein A (PAPP-A), have been shown to be associated with some poor gestational outcomes, especially those related to placental deficiency such as pre-eclampsia and fetal growth restriction as well as preterm labor. The aim of this study was to compare first trimester PAPP-A MoM values with the surfactant needs of newborns of pregnant women who had a preterm delivery.

METHODS

This study included 216 pregnant women who had a preterm delivery, who were found to be in the low-risk group based on their aneuploidy screening. The women were separated into two groups based on the surfactant receipts of their newborns. A record was made of the obstetric history, birth characteristics of the preterm infants, and whether or not there was a need for surfactant.

RESULTS

A comparison of the PAPP-A values of the two groups revealed that the group that received surfactant had statistically significantly lower PAPP-A values (t(-3.97) = 0.203, p <  0.001). When the cut-off value of PAPP-A was taken as 1 MoM and the gestational age was analyzed together with the birth weight, PAPP-A alone was found to be a significant independent variable for the prediction of respiratory distress syndrome (RDS) (p = 0.031; OR:8.2 (1.2-55.6)).

CONCLUSIONS

The result of this study demonstrated that PAPP-A MoM values may be significant in predicting the need for surfactant in RDS, which is a frequently seen condition in the neonatal period.

Chronic Intervillositis of Unknown Etiology: Development of a Grading and Scoring System That Is Strongly Associated With Poor Perinatal Outcomes

Chronic intervillositis of unknown etiology (CIUE) is a rare placental disease characterized by intervillous infiltration of maternal macrophages and associated with poor pregnancy outcomes and a high risk of recurrence in subsequent pregnancies. Its pathophysiology remains unclear and prognostic factors have not yet been established. In addition, clear relationships between the histologic extent of lesions and the severity of perinatal outcomes have not been demonstrated. Our objectives were to validate a CIUE classification system based on the gradation of macrophagic infiltration of the intervillous space, and to attempt to correlate these results with perinatal outcomes. For this multicenter retrospective study, 3 pathologists reviewed all cases diagnosed with "intervillositis" between 1997 and 2018. Confirmed CIUE cases were semiquantitatively graded based on the percentage of macrophagic infiltrate in the intervillous space: grade 1 (5% to 10%), grade 2 (10% to 50%), and grade 3 (>50%). Multiple pregnancies and pregnancies with medical follow-up completed outside of the study centers were excluded. In total, 122 cases of CIUE in 102 patients were included in the study. Microscopic classification based on one criterion was easy to perform, and interobserver correlation was good. Grade 3 infiltration was strongly associated with poor perinatal outcomes and fetal growth restriction (P<0.0001). After delivery, only 16.1% of newborns from the grade 3 CIUE group were alive, compared with 59% from the grade 2 and 86.5% from the grade 1 group (P=0.0002). Recurrence risk was associated with CIUE gradation of the index case (P=0.004), with 95% of recurrent CIUE cases being from patients with grades 2 and 3 CIUE. In this study, conducted with the largest CIUE cohort to date, a classification based only on the degree of macrophagic infiltration of the intervillous space was validated, and this classification was shown to be strongly associated with poor perinatal outcomes and risk of recurrence.

Pregnancy associated plasma protein A: An indicator of adverse obstetric outcomes in a South India population

Objective

First trimester aneuploidy screening (FTAS) has become an integral part of antenatal care in most of centers in India. The serum markers used for FTAS are pregnancy-associated plasma protein A (PAPP-A) and beta human chorionic gonadotropin. In the present study, we aimed to assess the role of PAPP-A in specific adverse fetal maternal events. To analyze pregnancy outcomes with low maternal PAPP-A (≤5^th percentile) at the FTAS screening test in southern India, and them compared with a control group of >5^th percentile value.

Materials and Methods

A total of 1800 consecutive pregnancies in the first trimester were followed up with PAPP-A levels. The study group consisted 108 subjects, which was compared with a matched control group of 288 subjects. The outcomes considered were spontaneous abortions, fetal anomalies, preterm delivery (PTD), hypertension in pregnancy, intrauterine growth restriction, gestational diabetes, mode of delivery, and birthweight.

Results

For our grouped data, the 5^th percentile value for PAPP-A was 0.49 multiple of medians, (incidence-6%). The incidence of fetal major anomalies was higher in the study group [odds ratio (OR): 1.87]. The incidence of minor anomalies, gestational diabetes, and hypertensive disorders was higher in the study group but not statistically significant. The total rate of PTDs (OR:2.1), small-for-gestation-age fetuses (OR:2.3), and low birthweight babies (OR- 2.12) was significantly higher in the study group. We found positive likelihood ratio of 1.4 for PTD, 2 for <5^th percentile birthweight, and 1.7 for <10^th centile birthweight.

Conclusion

Low PAPP-A pregnancies are at risk of various obstetric complications. Hence, such a pregnancy should have closer surveillance. Further research work on intervention strategy is needed.

Whole-exome sequencing for diagnosis of Peters-plus syndrome after prenatal diagnosis of recurrent low PAPP-A and multiple fetal anomalies in two consecutive pregnancies

 We report a case of two consecutive pregnancies in the same couple presenting with very low pregnancy-associated plasma protein A (PAPP-A), with both pregnancies affected by multiple anomalies of a similar phenotype identified during mid-trimester ultrasound, and eventual diagnosis of Peters-plus syndrome. This case is important in expanding the differential for very low PAPP-A. It also demonstrates the diagnostic value of whole-exome sequencing (WES) after prenatal diagnosis of recurrent fetal ultrasonographic findings. The importance and complexity of providing patient education to enable informed consent for next generation sequencing technologies is discussed.

Whole-exome sequencing for diagnosis of Peters-plus syndrome after prenatal diagnosis of recurrent low PAPP-A and multiple fetal anomalies in two consecutive pregnancies

 We report a case of two consecutive pregnancies in the same couple presenting with very low pregnancy-associated plasma protein A (PAPP-A), with both pregnancies affected by multiple anomalies of a similar phenotype identified during mid-trimester ultrasound, and eventual diagnosis of Peters-plus syndrome. This case is important in expanding the differential for very low PAPP-A. It also demonstrates the diagnostic value of whole-exome sequencing (WES) after prenatal diagnosis of recurrent fetal ultrasonographic findings. The importance and complexity of providing patient education to enable informed consent for next generation sequencing technologies is discussed.

High risk in the first-trimester combined screening: Long-term outcomes of the children

OBJECTIVE

To bring new accuracy to the prognosis of outcomes of euploid fetuses with an extremely high risk in the first-trimester combined screening when compared to the low-risk group.

STUDY DESIGN

The data included pregnancies with a trisomy 21 risk ≥ 1:50 in the combined first-trimester screening but normal fetal chromosomes. The control group had a risk value ≤ 1:300. Miscarriage, termination of pregnancy, stillbirth, premature delivery, and delivery of an unhealthy child were considered adverse outcomes. The impact of each component in the combined first-trimester screening was analyzed separately. Statistical comparisons were made by using the chi-square test, Fisher-Freeman-Halton test, Mann-Whitney test or t-test.

RESULTS

The study comprised 483 women (161 cases and 322 controls). The mean follow-up time of children born alive was 61.4 months. An adverse outcome was detected in 11.8% of the cases and in 5.9% of the controls. After adjusting the values of mother´s age, parity, and smoking habit the odds ratio for an adverse outcome was 2.1 (95% CI: 1.0-4.5, p = 0.05) for cases. When evaluating the effect of 1 SD increase in MOM of PAPP-A or 1 SD decrease in MOM of NT or β-hCG to any adverse outcome, 1 SD increase in PAPP-A MOM decreased the risk of adverse outcome by OR 0.48 (95% CI: 0.3 - 0.8, p = 0.05) while the others were not significant.

CONCLUSION

Euploid fetuses with a high risk in the combined first-trimester screening have a twofold risk for adverse outcomes when compared to those with a low risk.