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.

Is the first-trimester combined screening result associated with the phenotype of Down syndrome? A population-based cohort study

OBJECTIVE

To investigate if the Down syndrome phenotype differs according to the result of first-trimester combined screening (FTS).

METHOD

We included all Down syndrome cases diagnosed by karyotype in pregnancy or after birth in Denmark during 2005-2018. We compared screen positive (odds ≥1:300) and screen negative (odds <1:300) cases as well as screen result subgroups with respect to anthropometrics, congenital malformations, childhood diseases, and hospitalization.

RESULTS

Absolute measures of fetal and birth anthropometrics were comparable between groups. A prenatal malformation diagnosis was more prevalent among screen positive than screen negative cases. Analyses suggested that this could reflect a detection bias. Cases with a screen result of 1:2-1:10 had a higher probability of being diagnosed with a malformation prenatally and with severe congenital heart disease (CHD) postnatally compared with a result of 1:11-1:300. Screen positive cases more often had non-severe CHD but less often a non-heart malformation compared with screen negative cases, while proportions of severe CHD were similar in these groups. Data on hospitalizations showed inconsistent results.

CONCLUSION

The 1:300 screening threshold had limited or no value in predicting Down syndrome phenotype severity. In contrast, cases with a screen result between 1:2 and 1:10 may represent a more severe phenotype.

Association of first trimester fetal heart rate and nuchal translucency with preterm birth

OBJECTIVE

To evaluate whether first trimester fetal heart rate (FHR) and nuchal translucency (NT) associate with preterm birth (PTB).

METHODS

This was a comparative case-control study of 518 normal pregnancies with no history of PTB, of which 272 delivered at term (TB) and 246 progressed to spontaneous PTB prior to 37, 34, 32, and 28 weeks. Fetal heart rate (FHR) and NT values at the first-trimester scan were compared by means of univariable (Mann-Whitney) and multivariable logistic regression analysis considering hourglass membranes (HM) as the most severe PTB subgroup. Finally, severity trends for both parameters were investigated using correlations with gestational age (GA) at delivery and Kruskal-Walls tests.

RESULTS

Regardless of GA at delivery, pregnancies affected with PTB showed higher FHR and thicker NT at the first trimester scan. The association was confirmed by the multivariable analysis and the severity trends, which paired the highest FHR and NT values with the most severe cases of PTB (p < .001) (p < .0001).

CONCLUSION

Fetuses with subsequent late, early and very early PTB show higher values of NT and FHR at the first-trimester scan.

Predictive values of clinical parameters and biophysical and biochemical markers in the first trimester for the detection of small-for-gestational age fetuses

OBJECTIVES

To evaluate the predictive values of maternal characteristics, biophysical parameters (mean arterial pressure [MAP] and Doppler uterine artery measurements), and biochemical parameters (pregnancy-associated plasma protein A [PAPP-A] and placental growth factor [PlGF]) alone and in association for small-for-gestational age (SGA) fetuses.

METHODS

We performed a retrospective analysis of a prospective observational study that evaluated 615 pregnant women in the first trimester using ultrasonography. For all the women, information regarding clinical and obstetric histories, MAP, and uterine artery mean pulsatility index (UtA-PI), and blood samples for analysis of biochemical markers (PAPP-A and PlGF) were obtained. The patients were grouped according to birth weight as follows: group I (n=571), >10th percentile (control); group II (n=44), <10th percentile; and group III (n=34), <5th percentile. The predictive values of the variables for the detection of SGA fetuses were calculated using a logistic regression model and an analysis of the area under the receiver-operating characteristic curve (AUC).

RESULTS

The sensitivity rates of the maternal characteristics, biophysical markers (MAP and UtA-PI), biochemical markers (PAPP-A and PlGF), and the association between them were: 23.3, 32.5, 25, and 30% respectively, at a false-positive (FP) rate of 10%, in group II and 26.5, 26.5, 23.5, and 23.5%, respectively, at a FP rate of 10% in group III.

CONCLUSIONS

The predictive performances of the combination of maternal characteristics and biophysical and biochemical parameters were unsatisfactory, with a slight improvement in the predictive capacity for SGA fetuses <10th percentile.

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.

Increased nuchal translucency and pregnancy outcomes: experience of Başkent University Ankara Hospital

Objective:

First trimester nuchal translucency (NT) measurement is considered to be an important tool in antenatal follow-up. This study aimed to evaluate the outcomes of pregnancies with increased NT at Başkent University Ankara Hospital between 2004 and 2016.

Materials and Methods:

Patients with NT measurements ≥1.5 multiples of median (MoM) were divided into two groups; group I included increased NT cases without fetal anomalies (either abnormal fetal karyotype or congenital structural anomalies) or loss (intrauterine fetal death), and group II included increased NT cases with fetal anomalies or loss. The groups were compared with each other with respect to maternal demographic features and NT measurements.

Results:

Karyotype analyses were normal in 73.1% of cases with increased NT (57/78). Among those, 21.1% (12/57) had structural anomalies, and to specify, 9.6% (5/52 over 18 weeks) had cardiac anomalies. Although maternal demographic features did not differ significantly, NT measurements, both as millimeters and MoM, were significantly higher in group II (p<0.05). According to the receiver operating characteristic (ROC) curves, the optimal cut-off values for NT measurements for predicting fetal anomalies or loss were 3.05 mm and 2.02 MoM. NT measurement >7 millimeters or NT MoM >4.27 resulted in poor fetal outcomes without exception.

Conclusion:

Higher NT measurements indicate poorer pregnancy outcomes. Our study indicates that fetal echocardiography must be considered for all cases with increased NT.

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.

Effects of fetal gender and low first trimester aneuploidy screening markers on preterm birth

OBJECTIVE

To show the relation between fetal gender and preterm birth (PTB) in low values of first trimester aneuploidy test markers.

MATERIAL AND METHOD

A total of 29,528 patients included the study of them 7382 was PTB and all patients grouped according to fetal gender. Demographic data and perinatal complications were determined. According low PAPP-A MoM (<0.4) and low free BhCG MoM (<0.5) values PTB subgroup relative risks were calculated for each fetal gender.

RESULTS

The PTB rate and birth weight was significantly higher in male gender. At low PAPP-A MoM values Late PTB in male infant (aRR 95% CI 2.028) and late miscarriage (LM) category with low free BhCG MoM values in female infant (aRR 95% CI 0.907) was determined statistically significant.

CONCLUSIONS

Male gender has an effect on PTB rate. İn low values of first trimester aneuploidy test markers late PTB risk is increasing in male gender and also LM risk is decreasing in female gender. Further studies are required in order to determine the relation between PTB and fetal gender and first trimester aneuploidy screening test.

The first trimester aneuploidy biochemical markers in IVF/ICSI patients have no additional benefit compared to spontaneous conceptions in the prediction of pregnancy complications

OBJECTIVES

The aim of this study was to determine if the levels of biochemical aneuploidy markers in in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) pregnancies differ from those in spontaneous pregnancies and to verify if biochemical markers could predict pregnancy outcome in IVF/ICSI gestations.

METHODS

This was a prospective observational study performed in a group of 551 patients who underwent a combined first trimester prenatal screening (ultrasound scan and serum markers). All patients were divided into two groups according to the mode of conception: IVF/ICSI pregnancies (study group) and spontaneous conceptions (control group). The concentrations of first trimester biochemical markers were presented as multiples of median (MoM) and were compared between the study and control groups. Analysed pregnancy complications included: preterm delivery (PTD), small for gestational age (SGA), gestational hypertension (GH), preeclampsia (PE) and gestational diabetes (GDM).

RESULTS

The analysis was performed on 183 IVF/ICSI and 368 spontaneously conceived gestations, with complete data regarding obstetric outcome. There were no significant differences in the concentrations of biochemical markers between the analysed groups. Pregnancy-associated plasma protein-A (PAPP-A) levels were lower in hypertensive than in normotensive patients, although the difference was not significant. Twenty-three patients had GDM (12.5%), 16 had GH or PE (8.7%), SGA was diagnosed in 18 (9.8%) and 25 delivered preterm (13.6%).

CONCLUSIONS

The trend for lower PAPP-A MoM was visible in all affected patients, although the results did not reach statistical significance. The first trimester biochemical markers in assisted reproduction technique (ART) pregnancies do not seem to have additional effect on predicting the risk of pregnancy complications.

First-trimester serum biomarker screening for fetal Down syndrome as a predictor of preterm delivery: a population-based study

Objective: To examine the relationship between the first-trimester serum biomarker levels (pregnancy-associated plasma protein A:PAPP-A; and free beta-human chorionic gonadotropin: b-hCG) and preterm birth; and to create the predictive models for preterm birth in case of strong correlation.Methods: Secondary analysis on a large prospective database of singleton pregnancies undergoing first-trimester serum screening with complete follow-up for pregnancy outcomes. The multiples of medians (MoM) of the biomarkers were compared between the group of term and preterm/early preterm birth. Predictive models were developed based on adjusted MoMs and logistic regression analysis, and then diagnostic performances in predicting preterm birth were assessed.Results: Of 24,611 pregnancies eligible for analysis, 1908 (7.8%) and 500 (2.0%) had preterm and early preterm birth, respectively. Medians MoMs of both biomarkers were significantly lower in preterm and early preterm birth group. The predictive models were constructed. Performance in predicting preterm birth of these models yielded the area-under-ROC-curve of 0.560, 0.652, and 0.653 for b-hCG, PAPP-A, and combined biomarkers, respectively. In predicting early preterm birth, the areas-under-the-curve were found to be 0.551, 0.675, and 0.674 for b-hCG, PAPP-A, and combined biomarkers, respectively.Conclusion: The routine first-trimester serum screening of fetal Down syndrome could also be used as a tool of risk identification of preterm birth. We could take advantage of the screening by incorporating the predictive models into the Down syndrome screening software to report the preterm risk in the same test without extra effort and extra cost.

Placenta Accreta Spectrum: A Review of Pathology, Molecular Biology, and Biomarkers

Background. Placenta accreta spectrum (PAS) is a condition of abnormal placental invasion encompassing placenta accreta, increta, and percreta and is a major cause of severe maternal morbidity and mortality. The diagnosis of a PAS is made on the basis of histopathologic examination and characterised by an absence of decidua and chorionic villi are seen to directly adjacent to myometrial fibres. The underlying molecular biology of PAS is a complex process that requires further research; for ease, we have divided these processes into angiogenesis, proliferation, and inflammation/invasion. A number of diagnostic serum biomarkers have been investigated in PAS, including human chorionic gonadotropin (HCG), pregnancy-associated plasma protein-A (PAPP-A), and alpha-fetoprotein (AFP). They have shown variable reliability and variability of measurement depending on gestational age at sampling. At present, a sensitive serum biomarker for invasive placentation remains elusive. In summary, there are a limited number of studies that have contributed to our understanding of the molecular biology of PAS, and additional biomarkers are needed to aid diagnosis and disease stratification.

Meta-regression analysis to evaluate relationships between maternal blood levels of placentation biomarkers and low delivery weight

BACKGROUND

Caution is required for women at increased risk of low neonatal delivery weight.

OBJECTIVE

To evaluate relationships between maternal placentation biomarkers and the odds of low delivery weight.

SEARCH STRATEGY

Databases including PubMed/MEDLINE were searched up to May 2017 using keywords involving biomarker names and "low birthweight."

SELECTION CRITERIA

English language studies providing true- and false-positive, and true- and false-negative results of low delivery weight classified by maternal blood levels of placentation biomarkers (in units of multiple of the mean [MoM]) were included.

DATA COLLECTION AND ANALYSIS

Coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood placentation biomarkers, and those adjusted for race, sampling period, and/or study quality were calculated.

MAIN RESULTS

Adjusted coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood levels of α-fetoprotein (AFP) and β-human chorionic gonadotropin (β-hCG) were significantly greater than 0 (both P<0.001), whereas that for pregnancy-associated plasma protein A (PAPP-A) was significantly less than 0 (P=0.028). Adjusted models explained the higher proportion of between-study variance better than non-adjusted models.

CONCLUSIONS

Elevated AFP and β-hCG, and reduced PAPP-A in maternal blood were positively associated with odds of low delivery weight.

Maternal Blood Biomarkers of Placentation to Predict Low-Birth-Weight Newborns: A Meta-Analysis

OBJECTIVE

The development of methods for pre-delivery prediction of low-birth-weight newborns would be clinically advantageous because low birth weight contributes to a high infant mortality rate. This study was performed to examine whether maternal blood biomarkers of placentation can be used to predict low-birth-weight newborns.

METHODS

Ten databases, including PubMed/Medline, were searched. Any English language study that provided all of the true- and false-positive and true- and false-negative results of this prediction was included in the analysis. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies. Bivariate diagnostic meta-analysis was performed to construct hierarchical summary receiver operating characteristic curves.

RESULTS

Based on relatively good quality studies, alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), and pregnancy-associated plasma protein A (PAPP-A) (n = 73, 19, and 7, respectively) showed low sensitivity and specificity and low diagnostic odds ratio. The informational usability was categorized as "no exclusion or confirmation" (i.e., positive likelihood ratio <10 and negative likelihood ratio >0.1). The diagnostic accuracy of AFP and hCG or PAPP-A was categorized as low (i.e., 0.5 ≤ area under the curve ≤0.7) or could not be categorized (i.e., area under the curve <0.5).

CONCLUSION

There is no evidence that maternal blood levels of AFP, hCG, or PAPP-A used as a single predictor are useful to predict low-birth-weight newborns.

Prediction of adverse pregnancy outcomes by extreme values of first trimester screening markers

BACKGROUND

To determine the association between extreme values of first trimester markers and adverse pregnancy outcomes.

METHODS

A retrospective cohort study of 916 women who underwent first-trimester combined screening during 2015 was performed. Extreme values of NT, pregnancy-associated plasma protein-A (PAPP-A) and free β-hCG, and their association with adverse pregnancy outcomes were analyzed.

RESULTS

Low PAPP-A (<10th percentile) was associated with an increased risk for preeclampsia (adjusted odds ratio (AOR) 4.13), fetal growth restriction (AOR 3.94) and abruptio placentae (AOR 52.63). Abnormally low or high free β-hCG, high PAPP-A or increased NT was not associated with an increased risk for adverse outcomes.

DISCUSSION

PAPP-A <10th percentile could be associated with an increased risk for adverse outcomes. However, the majority of patients with these events do not have abnormal PAPP-A and few patients with PAPP-A <10th percentile will have an adverse outcome.

Differential performance of first-trimester screening in predicting small-for-gestational-age neonate or fetal growth restriction

OBJECTIVE

To assess the ability of integrated first-trimester screening, combining maternal characteristics and biophysical and biochemical markers, to predict delivery of a small-for-gestational-age (SGA) neonate, and compare this with its ability to predict fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing routine first-trimester screening. SGA was defined as birth weight (BW) < 10^th percentile and FGR was defined as an ultrasound estimated fetal weight < 10^th percentile plus Doppler abnormalities, or BW < 3^rd percentile. Logistic regression-based predictive models were developed for predicting SGA and FGR. Models incorporated the a-priori risk from maternal characteristics, and mean arterial pressure, uterine artery Doppler, placental growth factor and soluble fms-like tyrosine kinase-1.

RESULTS

In total, 9150 births were included. Of these, 979 (10.7%) qualified for a postnatal diagnosis of SGA and 462 (5.0%) for a prenatal diagnosis of FGR. For predicting SGA, the model achieved a detection rate of 35% for a false-positive rate (FPR) of 5% and 42% for a 10% FPR. The model's performance was significantly higher for predicting FGR (P < 0.001), with detection rates of 59% and 67%, for a FPR of 5% and 10%, respectively.

CONCLUSION

The predictive performance of first-trimester screening for cases with growth impairment by a combination of maternal characteristics and biophysical and biochemical markers is improved significantly when a prenatal and strict definition of FGR is used rather than a postnatal definition based on BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester screening with specific algorithms for early- and late-onset fetal growth restriction

OBJECTIVE

To develop optimal first-trimester algorithms for the prediction of early and late fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing first-trimester screening. FGR was defined as an ultrasound estimated fetal weight < 10(th) percentile plus Doppler abnormalities or a birth weight < 3(rd) percentile. Logistic regression-based predictive models were developed for predicting early and late FGR (cut-off: delivery at 34 weeks). The model included the a-priori risk (maternal characteristics), mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1).

RESULTS

Of the 9150 pregnancies included, 462 (5%) fetuses were growth restricted: 59 (0.6%) early and 403 (4.4%) late. Significant contributions to the prediction of early FGR were provided by black ethnicity, chronic hypertension, previous FGR, MAP, UtA-PI, PlGF and sFlt-1. The model achieved an overall detection rate (DR) of 86.4% for a 10% false-positive rate (area under the receiver-operating characteristics curve (AUC): 0.93 (95% CI, 0.87-0.98)). The DR was 94.7% for FGR with pre-eclampsia (PE) (64% of cases) and 71.4% for FGR without PE (36% of cases). For late FGR, significant contributions were provided by chronic hypertension, autoimmune disease, previous FGR, smoking status, nulliparity, MAP, UtA-PI, PlGF and sFlt-1. The model achieved a DR of 65.8% for a 10% false-positive rate (AUC: 0.76 (95% CI, 0.73-0.80)). The DR was 70.2% for FGR with PE (12% of cases) and 63.5% for FGR without PE (88% of cases).

CONCLUSIONS

The optimal screening algorithm was different for early vs late FGR, supporting the concept that screening for FGR is better performed separately for the two clinical forms. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Does increased peripheral C-reactive protein predate the occurrence of a short cervical length?

OBJECTIVE

Shortened cervical length is an important predictor of preterm birth, though the etiology of cervical length variation has not been fully elucidated. Our objective was to evaluate the potential association between peripheral C-reactive protein (CRP), a first trimester peripheral marker of inflammation, and second trimester decreased cervical length.

METHODS

Cases and controls were defined by second trimester cervical length >/<25 mm. CRP concentrations were measured in archived first trimester screen serum via commercial assay. The association between CRP and cervical length was evaluated via Wilcoxon's rank test. Both logistic and linear regressions were performed.

RESULTS

A total of 49 cases were matched to 98 controls. No statistically significant difference in first trimester CRP was demonstrated between cases and controls overall. Among subjects with decreased cervical lengths, however, there was a significant linear association between the degree of shortening and first trimester CRP concentrations (p = 0.022).

CONCLUSION

First trimester CRP was not associated with decreased second trimester cervical length overall. However, the degree of shortening correlated with increased first trimester CRP concentrations in patients with a short cervix. This suggests that systemic inflammation in early pregnancy may underlie variation in second trimester cervical lengths among higher risk individuals.

Association between first-trimester maternal serum pregnancy-associated plasma protein-A and obstetric complications

OBJECTIVE

This study aimed to investigate the relationship between maternal serum pregnancy-associated plasma protein-A (PAPP-A) in the first trimester of pregnancy and the development of preeclampsia (PE), early PE, small-for-gestational age (SGA) fetus and preterm delivery (PD).

METHOD

This is a retrospective study of 12,355 pregnant women that delivered between 2008 and 2011. We define the first, third and fifth percentiles of maternal serum PAPP-A multiples of the median (MoM). The primary outcome measures were the occurrence of PE, early PE (PE requiring delivery before 34 weeks), SGA fetus (birth weight < 5th centile) and PD. The Mann-Whitney U-test and chi-squared test were used to analyze continuous and dichotomous variables, respectively.

RESULTS

Maternal serum PAPP-A was significantly lower in women with PE, early PE, SGA fetus and PD (0.91, 0.74, 0.80 and 0.84 MoM, respectively) than in the study population (0.99 MoM) (p < 0.05). The lower the MoM percentile of PAPP-A, the higher are the odds ratio (OR) to develop PE, early PE, SGA fetus and PD.

CONCLUSIONS

Maternal serum PAPP-A levels are lower in women who develop preeclampsia, those with SGA fetus and those who deliver preterm. However, on its own, maternal serum PAPP-A performs poorly (OR for PE between 1.76 and 2.41 with the lower percentile of PAPP-A) as a screening test for these conditions.

Novel biomarkers for predicting intrauterine growth restriction: a systematic review and meta-analysis

BACKGROUND

Several biomarkers for predicting intrauterine growth restriction (IUGR) have been proposed in recent years. However, the predictive performance of these biomarkers has not been systematically evaluated.

OBJECTIVE

To determine the predictive accuracy of novel biomarkers for IUGR in women with singleton gestations.

SEARCH STRATEGY

Electronic databases, reference list checking and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of novel biomarkers proposed for predicting IUGR.

DATA COLLECTION AND ANALYSIS

Data were extracted on characteristics, quality and predictive accuracy from each study to construct 2×2 tables. Summary receiver operating characteristic curves, sensitivities, specificities and likelihood ratios (LRs) were generated.

MAIN RESULTS

A total of 53 studies, including 39,974 women and evaluating 37 novel biomarkers, fulfilled the inclusion criteria. Overall, the predictive accuracy of angiogenic factors for IUGR was minimal (median pooled positive and negative LRs of 1.7, range 1.0-19.8; and 0.8, range 0.0-1.0, respectively). Two small case-control studies reported high predictive values for placental growth factor and angiopoietin-2 only when IUGR was defined as birthweight centile with clinical or pathological evidence of fetal growth restriction. Biomarkers related to endothelial function/oxidative stress, placental protein/hormone, and others such as serum levels of vitamin D, urinary albumin:creatinine ratio, thyroid function tests and metabolomic profile had low predictive accuracy.

CONCLUSIONS

None of the novel biomarkers evaluated in this review are sufficiently accurate to recommend their use as predictors of IUGR in routine clinical practice. However, the use of biomarkers in combination with biophysical parameters and maternal characteristics could be more useful and merits further research.

Increased nuchal translucency is associated with large for gestational age neonates in singleton pregnancies

OBJECTIVE

To evaluate the correlation between sonographic measurements of nuchal translucency (NT) and neonatal birth weight in non-diabetic population.

METHODS

A retrospective analysis was performed on all singleton term pregnancies delivered at our hospital between 2004 and 2008. Data collected included maternal age, parity, NT measurement, results of glucose challenge test, birth weight, gestational age at delivery, and fetal gender.

RESULTS

The study population comprised of 1649 patients. The mean NT was 1.3 ± 0.5 mm. Male fetuses had a significantly thicker NT (1.3 ± 0.5 vs. 1.2 ± 0.4; P<0.001). NT significantly correlated to birth weight (P=0.002). This correlation was independent of neonatal gender. The median NT in the large for gestational age (LGA) neonates was significantly higher than in the non-LGA neonates (1.4 mm vs. 1.2 mm, P=0.001). Equations for the predicted probability for delivering LGA neonates were derived using either NT alone or in combination with parity. An increase in 0.1 mm in the NT has the odd ratio of 1.042 for delivering an LGA neonate (P=0.02).

CONCLUSIONS

NT correlated with LGA neonates in term non-diabetic patients. This correlation was independent of the neonatal gender. The predictive clinical impact of NT was limited to LGA neonates.

Peripheral biomarkers of endometriosis: a systematic review

BACKGROUND

Endometriosis is estimated to affect 1 in 10 women during the reproductive years. There is often delay in making the diagnosis, mainly due to the non-specific nature of the associated symptoms and the need to verify the disease surgically. A biomarker that is simple to measure could help clinicians to diagnose (or at least exclude) endometriosis; it might also allow the effects of treatment to be monitored. If effective, such a marker or panel of markers could prevent unnecessary diagnostic procedures and/or recognize treatment failure at an early stage.

METHODS

We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature over the last 25 years to assess critically the clinical value of all proposed biomarkers for endometriosis in serum, plasma and urine.

RESULTS

We identified over 100 putative biomarkers in publications that met the selection criteria. We were unable to identify a single biomarker or panel of biomarkers that have unequivocally been shown to be clinically useful.

CONCLUSIONS

Peripheral biomarkers show promise as diagnostic aids, but further research is necessary before they can be recommended in routine clinical care. Panels of markers may allow increased sensitivity and specificity of any diagnostic test.

The origins and evolution of genetic disease risk in modern humans

Patterns and risks of human disease have evolved. In this article, I review evidence regarding the importance of recent adaptive evolution, positive selection, and genomic conflicts in shaping the genetic and phenotypic architectures of polygenic human diseases. Strong recent selection in human populations can create and maintain genetically based disease risk primarily through three processes: increased scope for dysregulation from recent human adaptations, divergent optima generated by intraspecific genomic conflicts, and transient or stable deleterious by-products of positive selection caused by antagonistic pleiotropy, ultimately due to trade-offs at the levels of molecular genetics, development, and physiology. Human disease due to these processes appears to be concentrated in three sets of phenotypes: cognition and emotion, reproductive traits, and life-history traits related to long life-span. Diverse, convergent lines of evidence suggest that a small set of tissues whose pleiotropic patterns of gene function and expression are under especially strong selection-brain, placenta, testis, prostate, breast, and ovary-has mediated a considerable proportion of disease risk in modern humans.

Association of first-trimester low PAPP-A levels with preterm birth

OBJECTIVE

To determine the association of, and predictive ability of, pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotrophin (beta-hCG), and nuchal translucency (NT) with preterm birth (PTB).

METHODS

A 5-year retrospective cohort study of women who underwent first-trimester combined screening was performed. Maternal medical, antepartum, and pregnancy outcome data were obtained. PAPP-A and beta-hCG were converted to multiples of the median (MoM), and primary exposure was defined as < or =10th percentile MoM for PAPP-A. Secondary exposures were defined as > or = 90th percentile MoM for beta-hCG and NT values of > or = 20 and 25 mm. The primary outcome was PTB before 35 weeks and the secondary outcome was PTB before 32 weeks. Univariate, bivariate, multivariate, and receiver-operator analyses were used.

RESULTS

Of the 2231 patients meeting inclusion criteria with complete outcome data available, 222 had a PAPP-A level < or =10th percentile MoM. Abnormally low PAPP-A was associated with an increased risk for PTB < 35 weeks [adjusted odds ratio (aOR) 2.0, 1.0-3.8] and < 32 weeks (aOR 2.7, 1.1-6.4), even after adjusting for prior PTB, tobacco exposure, chronic hypertension, and body mass index. PAPP-A < or =10th percentile was not sufficiently predictive of PTB < 35 weeks (area under curve = 0.63, 95% CI 0.53-0.72). Neither abnormally high beta-hCG nor increased NT was associated with an increased risk for PTB.

CONCLUSIONS

PAPP-A < or =10th percentile is associated with an increased risk for PTB, but is not sufficiently predictive to be used clinically.

The proform of eosinophil major basic protein: a new maternal serum marker for adverse pregnancy outcome

OBJECTIVE

To establish the first trimester serum levels of the proform of eosinophil major basic protein (proMBP) in pregnancies with adverse outcome. Furthermore, to determine the screening performance using proMBP alone and in combination with other first trimester markers.

METHODS

A case-control study was conducted in a primary hospital setting. The proMBP concentration was measured in cases with small-for-gestational age (SGA) (n = 150), spontaneous preterm delivery (n = 88), preeclampsia (n = 40), gestational hypertension (n = 10) and in controls (n = 500). Concentrations were converted to multiples of the median (MoM) in controls and groups were compared using Mann-Whitney U-test. Logistic regression analysis was used to determine significant factors for predicting adverse pregnancy outcome. Screening performance was assessed using receiver operating characteristic curves.

RESULTS

The proMBP median was significantly reduced in pregnancies with SGA (0.81 MoM), spontaneous preterm delivery (0.83 MoM), preeclampsia (0.88 MoM) and gestational hypertension (0.60 MoM). The best screening performance was found for preeclampsia including the covariates proMBP and nulliparity yielding an area under the curve equal to 0.737 (p < 0.0005) and a 75% detection rate for a 30% false positive rate.

CONCLUSION

The proMBP is a novel first trimester serum marker for adverse pregnancy outcome.

Leptin in first trimester pregnancy serum: no reduction associated with small-for-gestational-age infants

Leptin is an adipocytokine that is also synthesized by the placenta. Leptin and its receptor, which is also expressed by the placenta, are believed to play an auto- and paracrine role in trophoblast invasion and placental development. The leptin concentration in first trimester maternal serum and its relation to fetal growth disturbances were examined in this study. The study is a case-control study with 36 small-for-gestational-age (SGA) (<5th percentile) pregnancies and 108 appropriate-for-gestational-age (AGA) (> or =5th percentile) pregnancies. The groups were matched by maternal age, gestational age and body mass index (BMI). All were non-smokers. Leptin was measured in maternal serum in weeks 8-13 and was normalized for BMI with concentrations expressed as multiples of the median for the actual BMI. It was found that maternal serum leptin increased strongly (r = 0.7, P < 10(-4))with maternal BMI. There was no significant difference in maternal serum leptin concentrations between SGA and AGA pregnancies. In conclusion, SGA pregnancies are not associated with a lower maternal serum leptin concentration in first trimester. The maternal serum leptin concentration is largely determined by maternal BMI. Variation in the leptin concentration in maternal serum in first trimester does not seem to be associated with impaired fetal growth.

First-trimester screening markers are altered in pregnancies conceived after IVF/ICSI

OBJECTIVES

To determine the levels of first-trimester screening markers and to assess the false-positive rate for first-trimester combined screening for Down syndrome in a large national population of women pregnant after assisted reproductive technology (ART), in order to decide whether or not to correct risk calculation for mode of conception.

METHODS

A national prospective cohort study of 1000 pregnancies achieved after ART was compared with a control group of 2543 pregnancies conceived spontaneously. All women completed a first-trimester combined screening program. Risk calculation was performed retrospectively based on the screening parameters to avoid bias due to the use of different algorithms of risk calculation.

RESULTS

In chromosomally normal pregnancies conceived after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), the pregnancy-associated plasma protein-A multiples of the median value was significantly decreased when compared with that of pregnancies conceived spontaneously (0.78 and 0.79 vs. 0.98), while there was no difference in the group treated by frozen embryo replacement. There was no difference in the level of free beta-human chorionic gonadotropin between groups. The median nuchal translucency thickness was smaller in the overall ART group compared with controls. The false-positive rate of first-trimester combined screening in the overall ART group, adjusted for maternal age, was significantly higher when compared with controls (9.0% vs. 6.0%).

CONCLUSIONS

It seems advisable to use a population of IVF/ICSI pregnancies to establish median curves for the first-trimester serum screening parameters and perhaps also for nuchal translucency thickness. However, care must be taken, as different ART treatment methods and aspects of medical history seem to alter the screening parameters in different ways.