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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Is There a Relationship Between First-Trimester Aneuploidy Screening Serum Biomarker Values and Nuchal Translucency Measurements and the Development of Retinopathy of Prematurity (ROP) in Premature Infants?

Purpose The purpose of this study is the evaluation of serum biomarker and nuchal translucency (NT) values measured during first-trimester aneuploidy screening in terms of the development of retinopathy of prematurity (ROP) in premature infants and investigation of whether the development of ROP is associated with these parameters. Methods In this retrospective cohort study, 3,750 premature infants who underwent ROP screening from 2016 to 2021 were identified from the hospital medical record system. Among 2,130 premature babies screened for first-trimester aneuploidy, 166 babies whose mothers had single pregnancies were screened by the same method and showed the same clinical course in both eyes were included in the study. The infants were divided into two groups according to the presence of ROP, and those with ROP were further evaluated in two groups according to the presence of proliferation. The groups were compared in terms of the serum values of human chorionic gonadotropin and pregnancy-associated plasma protein A, among aneuploidy screening biomarkers, and NT measurements. Results There was no significant difference in the evaluated serum biomarker values and NT measurements between the ROP and non-ROP groups or between the proliferative ROP, non-proliferative ROP, and non-ROP groups. Conclusion Our results showed that first-trimester aneuploidy screening serum biomarker values and NT measurements were not associated with the development of ROP in premature infants.

The predictive value of maternal serum AFP to PAPP-A or b-hCG ratios in spontaneous preterm birth

The use of the second trimester alpha-fetoprotein (AFP) along with the first trimester pregnancy-associated plasma protein-A (PAPP-A) has been found to be useful in the estimation of unfavourable pregnancy outcome. Our aim in this study was to determine the relationship between maternal PAPP-A and b-hCG and AFP concentrations in spontaneous preterm birth (sPTB). This prospective cohort study included 372 singleton pregnancies with PAPP-A, b-hCG and AFP levels in the first trimester, which were converted to multiples of the median (MoM). The predictive ability of AFP-to-PAPP-A and AFP-to-b-hCG ratios for sPTB was evaluated. The risk for sPTB ≤34 weeks increased in women with AFP-to-PAPP-A ratio >7 (OR 2.9, 95% CI 1.2-6.4). Women with AFP-to-b-hCG ratio >0.6 had a 3.5-fold higher risk for sPTB ≤32 weeks. Increased maternal AFP-to-PAPP-A or AFP-to-b-hCG ratios in the first trimester may help to predict pregnant women at high risk for sPTB, and this may be beneficial in developing management plans.Impact StatementWhat is already known on this subject? There is a synergistic association between the combination of low pregnancy-associated plasma protein-A (PAPP-A) in the first trimester with alpha-fetoprotein (AFP) in the second trimester with subsequent development of PTB. Maternal serum biochemical markers measured as a part of aneuploidy screening are reflective of pregnancy adverse outcomes related with placental insufficiency. PAPP-A and AFP have a low predictive ability to determine women at high risk for preterm birth.What do the results of this study add? Elevated AFP:PAPP-A or AFP:B-HCG ratio in the first trimester is associated with increased risk for sPTB. The ratios of these biochemical markers in the first trimester may be beneficial to identify women at high risk for sPTB.What are the implications of these findings for clinical practice and/or further research? The ratios may predict pregnant women at high risk for sPTB, and such risk may be helpful in the development of a management plan. Incorporation of AFP:PAPP-A or AFP:B-HCG ratios in the first trimester may help to improve the screening efficacies, and provide a simple alternative tool.