First-trimester ultrasound and biochemical markers of aneuploidy and the prediction of impending fetal death

The role of second trimester uterine artery Doppler in predicting obstetric and neonatal outcomes in abnormal first trimester maternal serum pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin values

AIM

This study aims to determine whether second-trimester uterine artery (UtA) Doppler combined with first-trimester abnormal pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (β-Hcg) levels predicts adverse obstetric and neonatal outcomes.

MATERIALS AND METHODS

This study of 289 pregnant women included 196 with normal PAPP-A and free β-HCG values (control group) and 93 with abnormal values (study group) in the first-trimester screening test. Second-trimester UtA Doppler sonography was done in these pregnancies. The perinatal prediction and screening potential of UtA Doppler pulsatility index (PI) parameters were examined in the study group.

RESULTS

UtA PI >95 percentile increased birth before the 37th week by 4.46 times, birth before the 34th week by 7.44 times, preeclampsia risk by 3.25 times, fetal growth restriction (FGR) risk by 4.89 times, and neonatal intensive care unit (NICU) admission rates by 3.66 times in the study group (p < 0.05 for all). UtA PI >95 percentile had 49.2% sensitivity and 82.1% specificity for birth before 37 weeks. For birth before 34 weeks, sensitivity was 80.0% and specificity 65.0%. FGR has 70.5% sensitivity and 67.1% specificity. Screening for preeclampsia has 66.6% sensitivity and 61.9% specificity.

CONCLUSION

Adding UtA Doppler in the second trimester to pregnancies with abnormal PAPP-A and/or free β-Hcg values in the first trimester may be a useful screening method for adverse outcomes.

Navigating Uncertain Waters: First-Trimester Screening's Role in Identifying Neonatal Complications

Background: Contemporary diagnostic methods aimed at assessing neonatal outcomes predominantly rely on the medical history of pregnant women. Ideally, universal biomarkers indicating an increased risk of delivering infants in poor clinical condition, with a heightened likelihood of requiring hospitalization in a Neonatal Intensive Care Unit (NICU), would be beneficial for appropriately stratifying pregnant women into a high-risk category. Our study evaluated whether biochemical and ultrasonographical markers universally used in first-trimester screenings for non-heritable chromosomal aberrations could serve this purpose. Methods: This study encompassed 1164 patients who underwent first-trimester screening, including patient history, ultrasound examinations, and biochemical tests for pregnancy-associated plasma protein-A (PAPP-A) and the free beta-HCG subunit (fbHCG), from January 2019 to December 2021. The research concentrated on the correlation between these prenatal test results and neonatal outcomes, particularly Apgar scores, umbilical blood pH levels, and the necessity for NICU admission. Results: In our cohort, neonates scoring lower than 8 on the Apgar scale at birth exhibited lower concentrations of PAPP-A in the first trimester, both in raw and normalized values (PAPP-A MoM 0.93 vs. 1.027, p = 0.032). We also observed a higher pulsatility index in the venous duct in the first trimester in full-term neonates born with <8 points on the Apgar scale. Additionally, newborns born with an umbilical blood pH < 7.2 had lower normalized first-trimester PAPP-A concentrations (0.69 vs. 1.01 MoM, p = 0.04). We also noted that neonates requiring NICU hospitalization post-delivery had lower first-trimester bHCG concentrations (0.93 MoM vs. 1.11 MoM, p = 0.03). However, none of the correlations in our study translated into a robust prognostic ability for predicting dichotomous outcomes. All areas under the curve achieved a value < 0.7. Conclusions: Low concentrations of PAPP-A and free bHCG subunit in the first trimester may be associated with poorer clinical and biochemical conditions in neonates post-delivery. However, the relationship is weak and has limited predictive capability. Further research evaluating these relationships is necessary for the appropriate stratification of pregnant women into high-risk categories for neonatological complications.

The association between human chorionic gonadotropin and adverse pregnancy outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the association between human chorionic gonadotropin and adverse pregnancy outcomes.

DATA SOURCES

Medline, Embase, PubMed, and Cochrane were searched in November 2021 using Medical Subject Headings (MeSH) and relevant key words.

STUDY ELIGIBILITY CRITERIA

This analysis included published full-text studies of pregnant women with serum human chorionic gonadotropin testing between 8 and 28 weeks of gestation, investigating fetal outcomes (fetal death in utero, small for gestational age, preterm birth) or maternal factors (hypertension in pregnancy: preeclampsia, pregnancy-induced hypertension, placental abruption, HELLP syndrome, gestational diabetes mellitus).

METHODS

Studies were extracted using REDCap software. The Newcastle-Ottawa scale was used to assess for risk of bias. Final meta-analyses underwent further quality assessment using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method.

RESULTS

A total of 185 studies were included in the final review, including the outcomes of fetal death in utero (45), small for gestational age (79), preterm delivery (62), hypertension in pregnancy (107), gestational diabetes mellitus (29), placental abruption (17), and HELLP syndrome (2). Data were analyzed separately on the basis of categorical measurement of human chorionic gonadotropin and human chorionic gonadotropin measured on a continuous scale. Eligible studies underwent meta-analysis to generate a pooled odds ratio (categorical human chorionic gonadotropin level) or difference in medians (human chorionic gonadotropin continuous scale) between outcome groups. First-trimester low human chorionic gonadotropin levels were associated with preeclampsia and fetal death in utero, whereas high human chorionic gonadotropin levels were associated with preeclampsia. Second-trimester high human chorionic gonadotropin levels were associated with fetal death in utero and preeclampsia.

CONCLUSION

Human chorionic gonadotropin levels are associated with placenta-mediated adverse pregnancy outcomes. Both high and low human chorionic gonadotropin levels in the first trimester of pregnancy can be early warning signs of adverse outcomes. Further analysis of human chorionic gonadotropin subtypes and pregnancy outcomes is required to determine the diagnostic utility of these findings in reference to specific cutoff values.

A simple scoring system for the prediction of early pregnancy loss developed by following 13,977 infertile patients after in vitro fertilization

A retrospective study was conducted to investigate a convenient simple scoring system for the prediction of early pregnancy loss (EPL) based on simple demographics. A total of 13,977 women undergoing transvaginal ultrasound scans on Days 27-29 after in vitro fertilization-embryo transfer (IVF-ET) from June 2016 and December 2017 were included. The first trimester pregnancy outcome was recorded at 12 weeks of gestation. The areas under the curve of this scoring system were 0.884 (95% confidence interval (CI) 0.870-0.899) and 0.890 (95% CI 0.878-0.903) in the training set and test set, respectively. The score totals ranged from -8 to 14 points. A score of 5 points, which offered the highest predictive accuracy (94.01%) and corresponded to a 30% miscarriage risk, was chosen as the cutoff value, with a sensitivity of 62.84%, specificity of 98.79%, positive predictive value (PPV) of 88.87% and negative predictive value (NPV) of 94.54% for the prediction of EPL in the training set. In the test set, a score of 5 points had a sensitivity of 64.69%, specificity of 98.78%, PPV of 89.87% and NPV of 93.62%, and 93.91% of the cases were correctly predicted. Therefore, the simple scoring system using conventionally collected data can be conveniently used to predict EPL after ET. However, considering the limitations, its predictive value needs to be further verified in future clinical practice.

The impact of preimplantation genetic testing on first- and second-trimester maternal serum analyte levels

OBJECTIVE

To determine whether preimplantation genetic testing (PGT) is associated with a change in maternal serum analyte levels in pregnancies conceived via in vitro fertilization (IVF).

METHODS

Retrospective cohort of singleton and twin IVF pregnancies with available first- or second-trimester serum analyte data from 01/2014 to 09/2019. Multiple of the median (MoM) values for free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A (PAPP-A), alpha-fetoprotein (AFP), inhibin A, and unconjugated estriol, were compared between two groups: pregnancies conceived after transfer of PGT screened euploid embryos vs. those conceived after transfer of untested embryos. Multiple linear regression of log MoM values with F test was performed to adjust for potential confounders.

RESULTS

Nine hundred and sixty-two singleton and 165 twin IVF pregnancies with serum analyte data available for analysis were included. PGT was associated with a higher median first- and second-trimester AFP compared to no PGT in singletons (1.23 MoM vs. 1.13 MoM; parameter estimate [PE] 1.08, 95% CI 1.00-1.17, p= .04, and 1.21 MoM vs. 1.07 MoM; PE 1.07, 95% CI 1.01-1.13, p= .01, respectively). PGT was also associated with a lower median PAPP-A compared to no PGT in twins (0.75 MoM vs. 1.18 MoM, PE 0.74, 95% CI 0.60-0.92, p= .006).

CONCLUSIONS

Our data suggest that PGT is associated with higher maternal serum levels of second-trimester AFP in singleton and lower levels of first-trimester PAPP-A in twin pregnancies conceived via IVF.

Relationship between extreme values of first trimester maternal pregnancy associated plasma Protein-A, free-β-human chorionic gonadotropin, nuchal translucency and adverse pregnancy outcomes

OBJECTIVE

The aim of our study was to investigate the relationship between extreme values of first trimester screening markers and adverse obstetric outcomes.

MATERIALS AND METHODS

Our study was conducted by examining the prenatal and postnatal perinatal records of 786 singleton gestations between the ages of 18-40, who applied to Prof. Dr. Cemil Taşçıoğlu City Hospital outpatient clinics for first-trimester screening for aneuploidy, between January 1, 2017 and December 31, 2019.

RESULTS

The presence of small for gestational age (SGA) was found to be statistically significant for the <5 percentile (<0.37) pregnancy-associated plasma protein A (PAPP-A) group (p = 0.016). For <5 percentile β-hCG group, the presence of gestational diabetes mellitus (GDM), premature rupture of membrane (PROM) and preterm premature rupture of membrane (PPROM) was determined as a statistically significant risk (p = 0.015, p = 0.005, p = 0.02 respectively) In the univariate test, fetal death rate was found to be high for ≥90 percentile at nuchal translucency (NT), but the presence of fetal death was found to be statistically insignificant in logistic regression analysis. (p: 0.057).

CONCLUSION

First trimester screening test can be used in predicting pregnancy complications. In this study we found that serum levels of PAPP-A are associated with developing SGA, while GDM, PROM and PPROM are more common in low serum free β-hCG.

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.

Risk of fetal loss after chorionic villus sampling in twin pregnancy derived from propensity score matching analysis

OBJECTIVE

To estimate the risk of fetal loss associated with chorionic villus sampling (CVS) in twin pregnancy, using propensity score analysis.

METHODS

This was a multicenter cohort study of women with twin pregnancy undergoing ultrasound examination at 11-13 weeks' gestation, performed in eight fetal medicine units in which the leadership were trained at the Harris Birthright Research Centre for Fetal Medicine in London, UK, and in which the protocols for screening, invasive testing and pregnancy management are similar. The risk of death of at least one fetus was compared between pregnancies that had and those that did not have CVS, after propensity score matching (1:1 ratio). This procedure created two comparable groups by balancing the maternal and pregnancy characteristics that lead to CVS being performed, similar to how randomization operates in a randomized clinical trial.

RESULTS

The study population of 8581 twin pregnancies included 445 that had CVS. Death of one or two fetuses at any stage during pregnancy occurred in 11.5% (51/445) of pregnancies in the CVS group and in 6.3% (515/8136) in the non-CVS group (P < 0.001). The propensity score algorithm matched 258 cases that had CVS with 258 non-CVS cases; there was at least one fetal loss in 29 (11.2%) cases in the CVS group and in 35 (13.6%) cases in the matched non-CVS group (odds ratio (OR), 0.81; 95% CI, 0.48-1.35; P = 0.415). However, there was a significant interaction between the risk of fetal loss after CVS and the background risk of fetal loss; when the background risk was higher, the risk of fetal loss after CVS decreased (OR, 0.46; 95% CI, 0.23-0.90), while, in pregnancies with a lower background risk of fetal loss, the risk of fetal loss after CVS increased (OR, 2.45; 95% CI, 0.95-7.13). The effects were statistically significantly different (P-value of the interaction = 0.005). For a pregnancy in which the background risk of fetal loss was about 6% (the same as in our non-CVS population), there was no change in the risk of fetal loss after CVS, but, when the background risk was more than 6%, the posterior risk was paradoxically reduced, and when the background risk was less than 6%, the posterior risk increased exponentially; for example, if the background risk of fetal loss was 2.0%, the relative risk was 2.8 and the posterior risk was 5.6%.

CONCLUSION

In twin pregnancy, after accounting for the risk factors that lead to both CVS and spontaneous fetal loss and confining the analysis to pregnancies at lower prior risk, CVS seems to increase the risk of fetal loss by about 3.5% above the patient's background risk. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Indications for Outpatient Antenatal Fetal Surveillance: ACOG Committee Opinion, Number 828

ABSTRACT

The purpose of this Committee Opinion is to offer guidance about indications for and timing and frequency of antenatal fetal surveillance in the outpatient setting. Antenatal fetal surveillance is performed to reduce the risk of stillbirth. However, because the pathway that results in increased risk of stillbirth for a given condition may not be known and antenatal fetal surveillance has not been shown to improve perinatal outcomes for all conditions associated with stillbirth, it is challenging to create a prescriptive list of all indications for which antenatal fetal surveillance should be considered. This Committee Opinion provides guidance on and suggests surveillance for conditions for which stillbirth is reported to occur more frequently than 0.8 per 1,000 (the false-negative rate of a biophysical profile) and which are associated with a relative risk or odds ratio for stillbirth of more than 2.0 compared with pregnancies without the condition. Table 1 presents suggestions for the timing and frequency of testing for specific conditions. As with all testing and interventions, shared decision making between the pregnant individual and the clinician is critically important when considering or offering antenatal fetal surveillance for individuals with pregnancies at high risk for stillbirth or with multiple comorbidities that increase the risk of stillbirth. It is important to emphasize that the guidance offered in this Committee Opinion should be construed only as suggestions; this guidance should not be construed as mandates or as all encompassing. Ultimately, individualization about if and when to offer antenatal fetal surveillance is advised.

The Use of Sequential Integrated Screening to Stratify Risk in Monochorionic-Diamniotic Twin Pregnancies

OBJECTIVE

This study aimed to identify differences in sequential integrated screening and early ultrasound markers in monochorionic/diamniotic (MC/DA) pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) and unequal placental sharing (UPS).

STUDY DESIGN

Retrospective cohort study of MC/DA pregnancies evaluated between January 2012 and July 2017 at the University of California San Francisco. MC/DA pregnancies with ultrasound surveillance up to 26 weeks who participated in the California Prenatal Screening Program (CPSP) were included. Pregnancies with structural or genetic anomalies were excluded. UPS was defined as an intertwin growth discordance ≥20%. Intertwin nuchal translucency (NT) discordance was calculated by the absolute value of the difference of the NT of cotwins. Kruskal-Wallis or ANOVA testing was performed where appropriate, and negative binomial regression models were chosen to test for differences in mean biomarker levels by outcome group.

RESULTS

A total of 191 MC/DA pregnancies were included; 85 were affected by TTTS, 35 by UPS, and 71 controls. Significant differences in intertwin NT discordance in pregnancies complicated by TTTS and UPS compared with controls (p = 0.007) were found. TTTS cases had a mean NT discordance greater than two times that of controls (p = 0.04), while UPS cases had a value more than three times greater (p = 0.003). There was a statistically significant difference in mean second trimester human chorionic gonadotropin (hCG) between the cohorts (p = 0.0002) with TTTS cases having a mean second trimester hCG value 1.5 greater than both controls (p < 0.001) and UPS cases (p = 0.001). Analysis showed a significant difference in mean second trimester inhibin between the three cohorts (p = 0.029). Pregnancies complicated by UPS had a mean second trimester inhibin 1.5 times greater than controls (p = 0.010).

CONCLUSION

Our study shows that there are unique differences in early ultrasound and sequential integrated serum markers between MC/DA gestations complicated by TTTS and UPS versus those unaffected.

KEY POINTS

· Differences exist in sequential integrated screening markers in monochorionic-diamniotic twin pregnancies.. · Early risk stratification of monochorionic-diamniotic twin pregnancies may be possible.. · Sequential integrated screening testing can provide useful information to clinicians when evaluating monochorionic-diamnitoic twin pregnancies..

New approach for estimating risk of miscarriage after chorionic villus sampling

OBJECTIVE

To estimate the risk of miscarriage associated with chorionic villus sampling (CVS).

METHODS

This was a retrospective cohort study of women attending for routine ultrasound examination at 11 + 0 to 13 + 6 weeks' gestation at one of eight fetal-medicine units in Spain, Belgium and Bulgaria, between July 2007 and June 2018. Two populations were included: (1) all singleton pregnancies undergoing first-trimester assessment at Hospital Clínico Universitario Virgen de la Arrixaca in Murcia, Spain, that did not have CVS (non-CVS group); and (2) all singleton pregnancies that underwent CVS following first-trimester assessment at one of the eight participating centers (CVS group). We excluded pregnancies diagnosed with genetic anomalies or major fetal defects before or after birth, those that resulted in termination and those that underwent amniocentesis later in pregnancy. We used propensity score (PS) matching analysis to estimate the association between CVS and miscarriage. We compared the risk of miscarriage of the CVS and non-CVS groups after PS matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that are associated with CVS, in a similar way to that in which randomization operates in a randomized clinical trial.

RESULTS

The study population consisted of 22 250 pregnancies in the non-CVS group and 3613 in the CVS group. The incidence of miscarriage in the CVS group (2.1%; 77/3613) was significantly higher than that in the non-CVS group (0.9% (207/22 250); P < 0.0001). The PS algorithm matched 2122 CVS with 2122 non-CVS cases, of which 40 (1.9%) and 55 (2.6%) pregnancies in the CVS and non-CVS groups, respectively, resulted in a miscarriage (odds ratio (OR), 0.72 (95% CI, 0.48-1.10); P = 0.146). We found a significant interaction between the risk of miscarriage following CVS and the risk of aneuploidy, suggesting that the effect of CVS on the risk of miscarriage differs depending on background characteristics. Specifically, when the risk of aneuploidy is low, the risk of miscarriage after CVS increases (OR, 2.87 (95% CI, 1.13-7.30)) and when the aneuploidy risk is high, the risk of miscarriage after CVS is paradoxically reduced (OR, 0.47 (95% CI, 0.28-0.76)), presumably owing to prenatal diagnosis and termination of pregnancies with major aneuploidies that would otherwise have resulted in spontaneous miscarriage. For example, in a patient in whom the risk of aneuploidy is 1 in 1000 (0.1%), the risk of miscarriage after CVS will increase to 0.3% (0.2 percentage points higher).

CONCLUSIONS

The risk of miscarriage in women undergoing CVS is about 1% higher than that in women who do not have CVS, although this excess risk is not solely attributed to the invasive procedure but, to some extent, to the demographic and pregnancy characteristics of the patients. After accounting for these risk factors and confining the analysis to low-risk pregnancies, CVS seems to increase the risk of miscarriage by about three times above the patient's background risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors for miscarriage, the risk of miscarriage after CVS remains low and similar to, or slightly higher than, that in the general population. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Predictive value of pregnancy-associated plasma protein-A in relation to fetal loss: A systematic review and meta-analysis

Background

For a woman with bleeding and threatened abortion, ultrasound scan is done to confirm the viability of the fetus; however, 10-15% of the embryos are eventually aborted. Distinguishing between women with good and poor prognosis can be a helpful approach.

Objective

This study aimed to review the predictive value of Pregnancy-associated Plasma Protein A (PAPP-A) in relation to the diagnosis of fetal loss.

Materials and Methods

The articles published in multiple databases including Web of Science, PubMed, MEDLINE, Scopus, and Persian databases such as ISC, Magiran, and IranMedx were searched for articles published until May 2019. MeSH terms was used for searching the databases including fetal loss OR pregnancy loss OR abortion OR miscarriage with the following word using AND; Pregnancy-Associated Plasma Protein-A OR PAPP-A. Two reviewers extracted data and recorded them in a pre-defined form and assessed the quality of articles using the Newcastle-Ottawa tool. Meta-analysis was done using the Comprehensive Meta-Analysis/2.0 software and MetaDisc.

Results

A total number of 16 studies were eligible for the qualitative data synthesis, out of which 8 studies were included in the meta-analysis. All studies had high and medium quality. The forest plot analysis showed a sensitivity of 57% (95% CI: 53-63%), a specificity of 83% (95% CI: 80-85%), a positive likelihood ratio of 3.52 (95% CI: 2.44-5.07), a negative likelihood ratio of 0.54 (95% CI: 0.37-0.79), and a diagnostic odds ratio of 6.95 (95% CI: 3.58-13.50).

Conclusion

PAPP-A cannot be recommended on a routine basis for predicting fetal loss and still further research with a combination of other biomarkers is required.

Elevated maternal serum-free β-human chorionic gonadotropin (β-hCG) and reduced risk of spontaneous preterm delivery. J Matern Fetal Neonatal Med 2018;32:3191-3196. [PMID: 29642747 DOI: 10.1080/14767058.2018.1459554]

Objective: To evaluate the relationship between first and second trimester maternal serum-free β-hCG and the risk of spontaneous preterm delivery (PTD). Study design: This was a case-control study of women evaluated and delivered at our institution from 2011 to 2015. Spontaneous PTD was defined as delivery before 37 weeks due to spontaneous preterm labor or premature rupture of membranes. Patient with multifetal gestation and those with medically indicated term or PTD were excluded. Results: Of 877 women meeting the inclusion criteria, 173 delivered preterm and 704 delivered at term, and 8.1% had high free β-hCG in one or both trimesters. High maternal first and/or second trimester free β-hCG (≥95th percentile) was associated with lower rates of PTD. Thirty-two women with high free β-hCG in both first and second trimesters delivered at term. Gestational age at delivery and birth weights were lower in women who did not have high free β-hCG in any trimester. Low free β-hCG (≤5th percentile) in either trimester was not associated with an increased or decreased likelihood of PTD. Logistic regression demonstrated an independent association of high free β-hCG (≥95th percentile) with a reduced likelihood of PTD. Stratified analysis revealed a stronger impact of this association in women with no prior history of PTD. Conclusions: High free β-hCG, in the absence of risk factors for medically indicated PTD, is associated with a reduced likelihood of spontaneous PTD and may represent a marker indicating lower risk.

Fetal loss following invasive prenatal testing: a comparison of transabdominal chorionic villus sampling, transcervical chorionic villus sampling and amniocentesis

OBJECTIVE

The aim of this study was to compare transabdominal chorionic villus sampling, transcervical chorionic villus sampling and amniocentesis with respect to their total fetal loss rates.

METHODS

We retrospectively evaluated procedures of invasive prenatal testing performed during a 14-year period (2001-2014) including 936 amniocentesis procedures and 1051 chorionic villus samplings, of which 405 cases were executed transabdominally and 646 transcervically. Only singleton pregnancies before 24 weeks and 0 days of gestation where the pregnancy outcome was known were included. Fetal loss was defined as an abortion occurring either before 24 weeks and 0 days of gestation or <2 weeks after the procedure.

RESULTS

The total fetal loss rates were determined to be 1.73% for transabdominal chorionic villus sampling, 2.01% for transcervical chorionic villus sampling and 1.18% for amniocentesis. No statistically noticeable differences between the total fetal loss rates of all three procedures were found (P=0.399).

CONCLUSION

Our study has shown that chorionic villus sampling (either transabdominal or transcervical) and amniocentesis are equal methods for invasive prenatal testing with respect to their abortion risk.

Prediction of stillbirth from biochemical and biophysical markers at 11-13 weeks

OBJECTIVES

To develop a model for the prediction of stillbirth that is based on a combination of maternal characteristics and medical history with first-trimester biochemical and biophysical markers and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and unexplained causes.

METHODS

This was a prospective screening study of 76 897 singleton pregnancies, including 76 629 live births and 268 (0.35%) antepartum stillbirths; 157 (59%) were secondary to impaired placentation and 111 (41%) were due to other or unexplained causes. Multivariable logistic regression analysis was used to determine if there was a significant contribution to prediction of stillbirth from the maternal factor-derived a-priori risk, fetal nuchal translucency thickness, ductus venosus pulsatility index for veins (DV-PIV), uterine artery pulsatility index (UtA-PI) and maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A (PAPP-A). The significant contributors were used to derive a model for first-trimester prediction of stillbirth.

RESULTS

Significant contribution to prediction of stillbirth was provided by maternal factors, PAPP-A, UtA-PI and DV-PIV. A model combining these variables predicted 40% of all stillbirths and 55% of those due to impaired placentation, at a false-positive rate of 10%. Within the impaired-placentation group, the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (64% vs 42%).

CONCLUSIONS

A model based on maternal factors and first-trimester biomarkers can potentially predict more than half of subsequent stillbirths that occur due to impaired placentation. The extent to which such stillbirths could be prevented remains to be determined. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Maternal Serum Analytes as Predictors of Fetal Growth Restriction with Different Degrees of Placental Vascular Dysfunction

Abnormal levels of maternal serum analytes have been associated with fetal growth restriction (FGR) and preeclampsia secondary to placental vascular dysfunction. Accurately identifying the FGR fetuses at highest risk for adverse outcomes remains challenging. Placental function can be assessed by Doppler analysis of the maternal and fetal circulation. Although the combination of multiple abnormal maternal serum analytes and abnormal Doppler findings is strongly associated with adverse outcomes, the predictive value remains too low to be used as a screening test in a low-risk population. Stratification of cases based on the severity of Doppler abnormalities may improve predictive models.

Risk of fetal loss associated with invasive testing following combined first-trimester screening for Down syndrome: a national cohort of 147,987 singleton pregnancies

OBJECTIVE

To assess prospectively the risk of fetal loss associated with chorionic villus sampling (CVS) and amniocentesis (AC) following combined first-trimester screening (cFTS) for Down syndrome.

METHODS

This was a nationwide population-based study (Danish Fetal Medicine Database, 2008-2010) including 147,987 women with singleton pregnancy who underwent cFTS. Propensity score stratification was used to assess the risk of fetal loss with and without invasive testing. Analyses were performed between 3 and 21 days after cFTS for CVS and between 28 and 42 days after cFTS for AC. Results are reported as average risk differences with 95% CIs.

RESULTS

The risks of miscarriage and stillbirth were not higher in women exposed to CVS or AC compared with unexposed women, independent of the analysis time-point. The average effect of CVS on risk of miscarriage was -0.08% (95% CI, -0.64; 0.47) at 3 days and -0.21% (95% CI, -0.58; 0.15) at 21 days after cFTS, while the effect on risk of stillbirth was -0.18% (95% CI, -0.50; 0.13) at 3 days and -0.27% (95% CI, -0.58; 0.04) at 21 days after cFTS. Regarding the effect of AC on risk of miscarriage, the analysis at 28 days after cFTS showed an average effect of 0.56% (95% CI, -0.21; 1.33), while the effect on risk of stillbirth was 0.09% (95% CI, -0.39; 0.58) at 42 days after cFTS.

CONCLUSION

Neither CVS nor AC was associated with increased risk of miscarriage or stillbirth. These findings indicate that the procedure-related risk of CVS and AC is very low.

Macrophage colony-stimulating factor (M-CSF) in first trimester maternal serum: correlation with pathologic pregnancy outcome

PURPOSE

To determine correlations between macrophage colony-stimulating factor (MCSF) levels in maternal blood during first trimester screening with respect to normal and pathological pregnancies.

METHODS

This was a prospective single centre study. First trimester screening was performed according to FMF London certificates. Nuchal translucency, PAPP-A and free β-HCG were obtained as well as M-CSF serum levels in maternal blood. Fetal karyotyping was achieved by chorionic villi sampling.

RESULTS

125 patients were enrolled in this study. 21 pregnancies had confirmed aberrant karyotypes. Trisomy 21 cases showed significantly elevated M-CSF levels of 270 ± 91 pg/ml (p = 0.032), whereas cases of trisomy 13 (183 ± 68 pg/ml) and trisomy 18 (143 ± 40 pg/ml) had low M-CSF levels. Furthermore M-CSF levels tended to be low in preterm deliveries, placental insufficiency and nicotine consumption. In cases with gestational diabetes M-CSF tended to be elevated. Furthermore we found a positive correlation between high free β-human chorionic gonadotropin (hcg) and MCSF values. There was no correlation between pregnancy associated plasma protein (PAPP-A) and M-CSF.

CONCLUSIONS

M-CSF is a cytokine promoting placental growth and differentiation. M-CSF is known to be involved in the process of implantation in pregnancy. The role of M-CSF with respect to disturbed pregnancy outcomes such as placental insufficiency in normal or aberrant karyotypes, for example, is yet subject to further research.

Prediction of Preeclampsia by First Trimester Combined Test and Simple Complete Blood Count Parameters

INTRODUCTION

Preeclampsia is a serious disease which may result in maternal and neonatal mortality and morbidity. Improving the outcome for preeclampsia necessitates early prediction of the disease to identify women at high risk. Measuring blood cell subtype ratios, such as the neutrophil to lymphocyte (NLR) and platelet to lymphocyte (PLR) ratios, might provide prognostic and diagnostic clues to diseases.

AIM

To investigate hematological changes in early pregnancy, using simple complete blood count (CBC) and blood concentrations of beta-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A) to determine whether these measures are of any value in the prediction and early diagnosis of preeclampsia.

MATERIALS AND METHODS

Six hundred fourteen consecutive pregnant women with preeclampsia (288 with mild disease and 326 with severe disease) and 320 uncomplicated pregnant women were included in the study. Blood samples for routine CBC and first trimester screen, which combines PAPP-A and free β-hCG blood concentrations, were analyzed.

RESULTS

The NLR values were significantly higher in the severe preeclampsia group compared with the control group (p<0.001). We also confirmed that levels of PAPP-A were lower in patients who developed preeclampsia.

CONCLUSION

Because measuring CBC parameters, particularly NLR, is fast and easily applicable, they may be used to predict preeclampsia.

Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis

OBJECTIVES

To estimate procedure-related risks of miscarriage following amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and a meta-analysis.

METHODS

A search of MEDLINE, EMBASE, CINHAL and The Cochrane Library (2000-2014) was performed to review relevant citations reporting procedure-related complications of amniocentesis and CVS. Only studies reporting data on more than 1000 procedures were included in this review to minimize the effect of bias from smaller studies. Heterogeneity between studies was estimated using Cochran's Q, the I(2) statistic and Egger bias. Meta-analysis of proportions was used to derive weighted pooled estimates for the risk of miscarriage before 24 weeks' gestation. Incidence-rate difference meta-analysis was used to estimate pooled procedure-related risks.

RESULTS

The weighted pooled risks of miscarriage following invasive procedures were estimated from analysis of controlled studies including 324 losses in 42 716 women who underwent amniocentesis and 207 losses in 8899 women who underwent CVS. The risk of miscarriage prior to 24 weeks in women who underwent amniocentesis and CVS was 0.81% (95% CI, 0.58-1.08%) and 2.18% (95% CI, 1.61-2.82%), respectively. The background rates of miscarriage in women from the control group that did not undergo any procedures were 0.67% (95% CI, 0.46-0.91%) for amniocentesis and 1.79% (95% CI, 0.61-3.58%) for CVS. The weighted pooled procedure-related risks of miscarriage for amniocentesis and CVS were 0.11% (95% CI, -0.04 to 0.26%) and 0.22% (95% CI, -0.71 to 1.16%), respectively.

CONCLUSION

The procedure-related risks of miscarriage following amniocentesis and CVS are much lower than are currently quoted.

First- and second-trimester tests to predict stillbirth in unselected pregnant women: a systematic review and meta-analysis

BACKGROUND

Several biophysical and biochemical tests have been proposed to predict stillbirth but their predictive ability remains unclear.

OBJECTIVE

To assess the accuracy of tests performed during the first and/or second trimester of pregnancy to predict stillbirth in unselected women with singleton, structurally and chromosomally normal fetuses through use of formal methods for systematic reviews and meta-analytic techniques.

SEARCH STRATEGY

Electronic databases, bibliographies and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the predictive accuracy for stillbirth of tests performed during the first two trimesters of pregnancy.

DATA COLLECTION AND ANALYSIS

Two reviewers selected studies, assessed risk of bias and extracted data. Summary receiver operating characteristic curves, pooled sensitivities, specificities and likelihood ratios (LRs) were generated. Data were synthesised separately for stillbirth as a sole category and for specific stillbirth categories.

MAIN RESULTS

Seventy-one studies, evaluating 16 single and five combined tests, met the inclusion criteria. A uterine artery pulsatility index >90th centile during the second trimester and low levels of pregnancy-associated plasma protein A (PAPP-A) during the first trimester had a moderate to high predictive accuracy for stillbirth related to placental abruption, small-for-gestational-age or pre-eclampsia (positive and negative LRs from 6.3 to 14.1, and from 0.1 to 0.4, respectively). All biophysical and biochemical tests assessed had a low predictive accuracy for stillbirth as a sole category.

CONCLUSIONS

Currently, there is no clinically useful first-trimester or second-trimester test to predict stillbirth as a sole category. Uterine artery pulsatility index and maternal serum PAPP-A levels appeared to be good predictors of stillbirth related to placental dysfunction disorders.

First-trimester screening biochemical markers (free beta-subunit human chorionic gonadotropin, pregnancy-associated plasma protein-A) and risk of early fetal loss

AIM

The aim of this work was to assess the risk of early fetal loss (first trimester of pregnancy, 8-13 weeks of gestation) using the results of first-trimester screening (FTS) biochemical markers independently and combined.

METHODS

FTS results of 152 women who suffered early fetal loss were compared to a control group of 150 women with normal pregnancy outcomes. FTS biochemical markers were measured with a Delfia Xpress 6000 analyzer and biochemical risks for Down's and Edward's syndromes were calculated using Prenatal-Lifecycle version 3.0 software. Marker levels were standardized by calculating the gestational-specific multiple of the medians (MoM), further adjusted by maternal age, maternal weight, cigarette consumption and pre-existing type 1 diabetes mellitus. Receiver-operator curves were built to evaluate each marker and its combination.

RESULTS

Our results show that values of biochemical risk of t21 of more than 1 in 310 have a poor sensitivity to predict early fetal loss (31.4%) with a positive predictive value (PPV) for fetal loss of 67.7%. Values of pregnancy-associated plasma protein A (PAPP-A) MoM of less than 0.48 show a sensitivity of 62.1% and a PPV of 84.5% for early fetal loss; whereas for free β-human chorionic gonadotropin, values of MoM of less than 0.44 have a sensitivity of 66.4% with a PPV of 85.3%. A novel algorithm, consisting in the multiplication of both markers, shows for values of less than 0.48 a sensitivity of 83.1%, a specificity of 78.7% and a PPV of 77.1%.

CONCLUSION

Combined analysis of PAPP-A and free β-hCG appears to be a potential candidate to predict early fetal loss.

Maternal Serum Screening Markers and Adverse Outcome: A New Perspective

There have been a number of studies evaluating the association of aneuploidy serum markers with adverse pregnancy outcome. More recently, the development of potential treatments for these adverse outcomes as well as the introduction of cell-free fetal DNA (cffDNA) screening for aneuploidy necessitates a re-evaluation of the benefit of serum markers in the identification of adverse outcomes. Analysis of the literature indicates that the serum markers tend to perform better in identifying pregnancies at risk for the more severe but less frequent form of individual pregnancy complications rather than the more frequent but milder forms of the condition. As a result, studies which evaluate the association of biomarkers with a broad definition of a given condition may underestimate the ability of such markers to identify pregnancies that are destined to develop the more severe form of the condition. Consideration of general population screening using cffDNA solely must be weighed against the fact that traditional screening using serum markers enables detection of severe pregnancy complications, not detectable with cffDNA, of which many may be amenable to treatment options.

Differences in IGF axis-related proteins in amniotic fluid of trisomy 21 and trisomy 18 using a multiple reaction monitoring approach

OBJECTIVE

Trisomy 21 and trisomy 18 are the two most common chromosomal anomalies in live births. To find new biomarkers for aneuploidies and pathogenesis of fetal malformations, we measured insulin-like growth factor (IGF) axis-related proteins in amniotic fluid (AF) of pregnant women carrying trisomies 21 or 18 affected fetuses using multiple reaction monitoring (MRM) approach.

METHOD

Eighty-five AF samples from pregnant women carrying either trisomy 21, trisomy 18, or normal fetuses were collected. IGF axis-related proteins in AF after serial treatments were quantitated with MRM method. The differential protein levels were also confirmed by western blot in AF without any treatment.

RESULTS

The IGF type I receptor and pregnancy-associated plasma protein-A in AF of trisomy 21 (1.35 ± 0.32 and 13.36 ± 3.64 µg/mg protein) and trisomy 18 (1.39 ± 0.40 and 12.80 ± 1.84 µg/mg protein) were decreased versus normal controls (2.16 ± 0.59 and 23.77 ± 6.18 µg/mg protein). IGF binding protein 5 was reduced in trisomy 18 (1.47 ± 0.33 vs 2.36 ± 0.77 µg/mg protein). These alterations were confirmed by western blot. The other proteins showed no significant difference between the three groups.

CONCLUSION

Our data suggested that MRM can provide a powerful platform for the identification of biomarkers in AF that have crucial developmental effects in the aneuploid fetus.

Low pregnancy associated plasma protein-A in the 1st trimester: is it a predictor of poor perinatal outcome?

The objective of the study was to examine the predictive value of pregnancy associated plasma protein-A (PAPP-A) as a marker of poor pregnancy outcome. Databases at the University Hospital Lewisham, were used retrospectively to identify singleton pregnancies, which underwent 1st trimester combined screening between July 2008 and April 2010 and were found to have PAPP-A levels ≤ 0.4 MoM. The perinatal courses of these pregnancies (n = 315) were evaluated for signs of adverse perinatal outcome and compared with a matched control group of pregnancies (n = 330) with normal PAPP-A levels. Results showed that women with low serum PAPP-A were at increased risk of adverse pregnancy outcome compared with the control group (OR 2.4, p = 000.1). They were also more likely to suffer fetal loss (OR 6.2, p = 0.001) in the form of miscarriage (OR 2.7, p = 0.110) and stillbirth (OR 2.4, p = 0.001). It was concluded that serum PAPP-A is a marker for poor pregnancy outcome and women with low serum PAPP-A levels would benefit from increased monitoring of their pregnancies.

Variation of papp-a level in the first trimester of pregnancy and its clinical outcome

INTRODUCTION

Abnormalities in maternal serum marker levels and fetal measurements obtained during the first trimester screening can be a marker not only for certain chromosomal disorders and anomalies in the fetus but also for specific pregnancy complications. In particular, low maternal serum pregnancy-associated plasma protein-A (PAPP-A), at 11-13 weeks of gestation, is associated with stillbirth, infant death, intrauterine growth restriction, preterm birth, and pre-eclampsia in chromosomally normal fetuses, while a raised nuchal translucency is associated with specific structural abnormalities and genetic syndromes. We have studied the serum Papp-A level in 560 pregnant patients (11-13 weeks gestation) registered at Bharati Hospital and Research Centre, Pune. All patients undergoing testing were followed till the delivery and their neonatal outcome was also taken into consideration.

AIMS AND OBJECTIVES

Our aim is to study the pregnancy outcome in relation to the variations of Papp-A level in the first trimester of pregnancy.

MATERIALS AND METHODS

Every patient visiting the antenatal OPD was counseled for testing of First Trimester Screening to assess fetal well-being. Patients who were registered for delivery at our hospital were taken into the trial. Blood samples were taken at 11-13 weeks of pregnancy and sent to the PerkinElmer lab for analysis. Results were expressed in Multiple of Median and patients having MOM value less than 0.5 were carefully observed till the delivery, and a thorough neonatal examination was done by a pediatrician.

OBSERVATIONS

524 patients were included in the trial out of which 452 patients were found to have a normal Papp-A level of >0.5 MOM. All these patients were followed further during the antenatal period where 18 patients developed preterm labor and few patients developed pregnancy-induced hypertension. The obstetric outcome of patients with a normal Papp-A level was fairly uneventful as compared to others with a low Papp-A level.

CONCLUSIONS

Though Papp-A level in the first trimester of pregnancy (11-13 weeks) is an important predictor of future obstetric outcome, it has poor positive predictive value. Patients having a Papp-A level less than 0.5 MOM have a high risk for preterm delivery, fetal growth restriction, and stillbirths along with increased incidence of hypertensive disorders of pregnancy. A low Papp-A level is a useful indicator of risk of preterm delivery and future chance of development of pregnancy-induced hypertension.

Perinatal outcomes in euploid pregnancies with 'double-positive' first trimester prenatal screening for trisomy 18 and 21

OBJECTIVE

The objective of this study was to investigate whether women who screened positive for both trisomy 18 (T18) and trisomy 21 (T21) yet had euploid karyotypes were at increased risk for adverse pregnancy outcomes.

STUDY DESIGN

This was a retrospective cohort study of women who had first trimester aneuploidy screening. Double-positive subjects had risks greater than screening cutoffs for T21 and T18 and confirmed euploid karyotypes. Singleton subjects were matched 1:2 by maternal age to controls with normal screening. Perinatal outcomes were investigated using t-tests and χ(2)-tests; statistical significance was set at P<0.05.

RESULT

Of 9733 women who had first trimester screening, 33 euploid pregnancies screened positive for both T21 and T18. Compared with controls, these study subjects were more likely to have abnormalities identified by prenatal ultrasounds, including renal, fetal membrane and fluid, as well as multiple anomalies (P=0.01). In addition, double-positive subjects had a lower mean gestational age at birth (P=0.02) and lower mean birth weight (P=0.03) than controls. Maternal outcomes were not significantly different.

CONCLUSION

Pregnancies with double false-positive first trimester aneuploidy screening were associated with pregnancy/fetal abnormalities.

Abnormal analyte preeclampsia: do the second-trimester maternal serum analytes help differentiate preeclampsia subtypes?

OBJECTIVE

To determine if serum screen analytes identify preeclamptic patients at risk for small-for-gestational age newborns, maternal laboratory abnormalities and preterm delivery (<37 weeks gestation).

STUDY DESIGN

Using a retrospective cohort of 102 preeclamptic patients, associations between serum screen analytes and newborn birth-weight percentile, gestational age (GA) at delivery and maternal pre-delivery laboratory abnormalities were evaluated using correlation coefficients and local polynomial regression.

RESULT

Inhibin-A and maternal serum alpha fetoprotein were inversely correlated with newborn birth-weight percentile (-0.27, P=0.006; -0.35, P=0.00004) and delivery GA (r=-0.42, P<0.0001; r=-0.26, P=0.008) and positively correlated with pre-delivery aspartate aminotransferase (r=0.22, P=0.03; r=0.21, P=0.04) and lactate dehydrogenase (r=0.33, P=0.0007; r=0.29, P=0.004). A positive correlation was noted between both second-trimester beta human chorionic gonadotropin and estriol and maternal pre-delivery creatinine (0.28, P=0.004; 0.4, P<0.0001, respectively). Hundred percent of patients with ≥ 2 abnormal analytes delivered before 37 weeks gestation.

CONCLUSION

Preeclamptic patients with abnormal serum screen analytes are more likely to have small-for-gestational age newborns, deliver preterm and have pre-delivery laboratory abnormalities.

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.

Pregnancy-associated plasma protein A levels and neonatal complications in post-date pregnancies

OBJECTIVES

To assess the association between serum pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotropin (free β-hCG) in the first trimester and perinatal complications in post-date pregnancies.

METHODS

A total of 4948 women, who delivered after 40 gestational weeks, were included. Labour was not induced routinely until 42 weeks. Serum levels of PAPP-A and free β-hCG were determined at the first-trimester screening for Down syndrome. Neonatal complications were obtained from specific registration forms filled out by senior neonatologists.

RESULTS

In post-date pregnancies, PAPP-A < 0.4 multiples of the median was associated with Apgar score of less than 7 at 5 min (ORadj 5.4, 95% CI 2.0-14.3), admission to the neonatal intensive care unit (ORadj 1.5, 95% CI 1.0-2.3) and newborn hypoglycaemia (ORadj 3.4, 95% CI 1.8-6.4). In small for gestation (SGA) neonates, the risk of hypoglycaemia was further increased (OR 14.6, 95% CI 3.4-58.0). Similar analyses were made with free β-hCG, but no statistically significant associations were found.

CONCLUSIONS

Low first-trimester serum PAPP-A was associated with increased neonatal morbidity in post-date pregnancies, particularly in newborns with SGA. Thus, PAPP-A may qualify the timing of induction of labour in these pregnancies.

Management of abnormal serum markers in the absence of aneuploidy or neural tube defects

OBJECTIVE

Few guidelines address the management of pregnancies complicated by abnormal maternal serum analytes (MSAs) in the absence of aneuploidy or neural tube defects (NTDs). Our objective was to gather preliminary data regarding current opinions and management strategies among perinatologists in the US.

METHODS

This survey of Maternal Fetal Medicine (MFM) physicians and fellows used a secure electronic web-based data capture tool.

RESULTS

A total of 545 potential participants were contacted, and 136 (25%) responded. The majority were experienced academic physicians with robust practices. Nearly all (97.7%) respondents reported a belief in an association between abnormal MSAs and adverse pregnancy outcomes other than aneuploidy or NTDs. Plasma protein A (PAPP-A) and α-fetoprotein (AFP) were most often chosen as markers demonstrating a strong association with adverse outcomes. Most (86.9%) respondents acknowledged that abnormal MSAs influenced their counseling approach, and the majority (80.1%) offered additional ultrasound examinations. Nearly half started at 28 weeks and almost one-third at 32 weeks. Respondents acknowledging a relevant protocol in their hospital or practice were more likely to offer additional antenatal testing (p = 0.01).

CONCLUSIONS

Although most perinatologists were in agreement regarding the association of MSAs with adverse pregnancy outcomes, a lack of consensus exists regarding management strategies.

The role of serum markers and uterine artery Doppler in identifying at-risk pregnancies

Measures of placental dysfunction, including maternal serum analytes and Doppler studies, have been linked to adverse pregnancy outcomes, although the predictive ability of any single one is poor. Improved knowledge of the multifactorial nature of many of the adverse outcomes of pregnancy has sparked interest in the use of multi-parameter models that combine maternal serum analytes with measures of placental structure and blood flow. The combination of various first-trimester and second-trimester analytes and uterine artery Doppler screening show promise as potential screening tools, but large prospective studies are needed to further define their role in clinical practice.

PAPP-A and free β-hCG measured prior to 10 weeks is associated with preterm delivery and small-for-gestational-age infants

OBJECTIVE

To evaluate whether measuring pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotrophin (β-hCG) before 10 weeks of gestation affect the association between these biomarkers and adverse pregnancy outcomes.

METHODS

Singleton pregnant women (9450) who attended the prenatal screening program, Aarhus University Hospital, Denmark, were included. Maternal serum levels of PAPP-A and free β-hCG were measured between week 8 and 13 weeks and 6 days. The risk of preterm delivery (<37 weeks) and small for gestational age (SGA) (<the fifth centile) was evaluated in relation to PAPP-A and free β-hCG < 0.4 multiples of the median, stratified according to early (<10 weeks) or late (≥ 10 weeks) biochemical testing.

RESULTS

A stronger association between low PAPP-A and SGA was found with early serum sampling compared to late, but the difference was not statistically significant [odds ratio (OR) 3.2 vs 1.8; P value = 0.11]. This difference did not apply to PAPP-A and preterm delivery. For free β-hCG, a stronger association with preterm delivery was found with early testing (OR 1.9 vs 1.1; P value = 0.31), whereas this difference was not found regarding SGA.

CONCLUSION

Biochemical testing before 10 weeks does not affect the association between low PAPP-A and free β-hCG and adverse pregnancy outcomes. Whether the association is actually stronger with early testing, requires further study.

Maternal-placental insulin-like growth factor (IGF) signaling and its importance to normal embryo-fetal development

As background for an antibody-based therapeutic program against the IGF receptor, we undertook a review of available information on the early pregnancy-specific regulation and localization of IGFs, IGF-binding proteins (BPs), IGFBP-specific proteases, and the type 1 IGF receptor relative to placental maintenance, function of placental nutrient transporters, placental cellular differentiation/turnover/apoptosis, and critical hormone signaling needed to maintain pregnancy. Possible adverse outcomes of altered IGF signaling include prenatal loss, fetal growth retardation, and maldevelopment are also discussed. It appears that the IGF axes in both the conceptus and mother are important for normal embryo-fetal growth. Thus, all molecules (i.e., both small and large) that disrupt the IGF axis could be expected to have some degree of fetal consequences.

Early vaginal bleeding has no impact on markers used in first trimester aneuploidy screening

OBJECTIVE

To assess the impact of early vaginal bleeding on the levels of markers used in first trimester screening for aneuploidy.

METHODS

A retrospective analysis was carried out on the free beta human chorionic gonadotrophin (beta-hCG) and pregnancy associated plasma protein-A (PAPP-A) levels and nuchal translucency thickness in 49 653 women with a normal singleton fetus who had first trimester combined screening for Down Syndrome in three centres. Median MoMs and the distribution of log MoMs of the two markers were compared in two groups-7470 women who self-reported vaginal bleeding and 42 183 women who reported no vaginal bleeding at any stage prior to the screening test.

RESULTS

The overall median MoM free beta-hCG and that in the bleeding and non-bleeding group were 0.9854, 1.0012 and 0.9832, and for PAPP-A were 1.0407, 1.0413 and 1.037. There was no significant difference between the bleeding and non-bleeding group by median test (p = 0.080) or by t-test comparing log MoMs (p = 0.1305) for free beta-hCG and for PAPP-A with median test (p = 0.5071) or by t-test comparing log MoMs (p = 0.1740). For delta nuchal translucency (NT) there was also no significant difference between the bleeding and non-bleeding group (p = 0.055).

CONCLUSION

Vaginal bleeding has little or no impact on first trimester marker levels and no correction is necessary.

Record linkage to obtain birth outcomes for the evaluation of screening biomarkers in pregnancy: a feasibility study

Background

Linking population health data to pathology data is a new approach for the evaluation of predictive tests that is potentially more efficient, feasible and efficacious than current methods. Studies evaluating the use of first trimester maternal serum levels as predictors of complications in pregnancy have mostly relied on resource intensive methods such as prospective data collection or retrospective chart review. The aim of this pilot study is to demonstrate that record-linkage between a pathology database and routinely collected population health data sets provides follow-up on patient outcomes that is as effective as more traditional and resource-intensive methods. As a specific example, we evaluate maternal serum levels of PAPP-A and free β-hCG as predictors of adverse pregnancy outcomes, and compare our results with those of prospective studies.

Methods

Maternal serum levels of PAPP-A and free β-hCG for 1882 women randomly selected from a pathology database in New South Wales (NSW) were linked to routinely collected birth and hospital databases. Crude relative risks were calculated to investigate the association between low levels (multiples of the median ≤ 5^th percentile) of PAPP-A or free β-hCG and the outcomes of preterm delivery (<37 weeks), small for gestational age (<10^th percentile), fetal loss and stillbirth.

Results

Using only full name, sex and date of birth for record linkage, pregnancy outcomes were available for 1681 (89.3%) of women included in the study. Low levels of PAPP-A had a stronger association with adverse pregnancy outcomes than a low level of free β-hCG which is consistent with results in published studies. The relative risk of having a preterm birth with a low maternal serum PAPP-A level was 3.44 (95% CI 1.96–6.10) and a low free β-hCG level was 1.31 (95% CI 0.55–6.16).

Conclusion

This study provides data to support the use of record linkage for outcome ascertainment in studies evaluating predictive tests. Linkage proportions are likely to increase if more personal identifiers are available. This method of follow-up is a cost-efficient technique and can now be applied to a larger cohort of women.

Role of uterine artery Doppler in interpreting low PAPP-A values in first-trimester screening for Down syndrome in pregnancies at high risk of impaired placentation

OBJECTIVES

Low maternal serum levels of pregnancy-associated plasma protein-A (PAPP-A) are associated with both increased risk of aneuploidies and impaired trophoblastic invasion, while high uterine artery (UtA) resistance is associated with impaired trophoblastic invasion but not with an increased risk of aneuploidies. The aim of this study was to determine whether high UtA resistance plays a role in explaining low PAPP-A levels in the absence of aneuploidies.

METHODS

This was a prospective study of 116 singleton pregnancies at high risk for impaired placentation (having at least one major risk factor: prior history of pre-eclampsia, pregestational diabetes mellitus, chronic hypertension, chronic kidney disease, body mass index >30, autoimmune disorder, thrombophilia or recurrent pregnancy loss), booked for routine assessment of risk for aneuploidies by means of the first-trimester combined screening test (nuchal translucency thickness (NT) + PAPP-A + beta-human chorionic gonadotropin (beta-hCG)). Measurement of NT and the mean UtA pulsatility index (PI) were carried out at the 11 to 13 + 6-week scan. All values were calculated in multiples of the median (MoM) adjusted for gestational age. A cut-off risk of 1/270 at time of sampling was adopted to differentiate high- from low-risk groups for trisomy 21.

RESULTS

There were 108 patients deemed to be at low risk for trisomy 21 and eight at high risk. None had chromosomal defects, giving a false-positive rate for trisomy 21 of 6.9%. The greatest differences between patients at low risk and those at high risk for trisomy 21 were found in their PAPP-A (0.98 vs. 0.38 MoM, P < 0.01) and beta-hCG (1.09 vs. 1.77 MoM, P = 0.04) values. Greater NT thickness (1.02 vs. 0.90 MoM) and higher mean UtA-PI (1.05 vs. 0.96 MoM) were recorded in the high-risk group, although the differences did not reach statistical significance (P = 0.19 and 0.40, respectively). After log-transformation there were no significant correlations between mean UtA-PI and NT and between mean UtA-PI and beta-hCG. There was a significant negative linear correlation between mean UtA-PI and PAPP-A (r = -0.331; P < 0.01). After adjusting the PAPP-A values by UtA-PI, the false-positive rate for trisomy 21 decreased to 2.6%.

CONCLUSION

Mean UtA-PI at the 11 to 13 + 6-week scan may be an effect-modifier variable for PAPP-A that should be taken into account in the first-trimester combined screening for aneuploidies, at least in pregnancies at high risk for impaired placentation.