A single serum test for measuring early pregnancy outcome with high predictive value

Early detection of pregnancy after IVF and embryo transfer with hyperglycosylated HCG versus Elecsys HCG+β assay

RESEARCH QUESTION

Is measurement of hyperglycosylated HCG (hHCG) superior to beta-HCG (HCG+β) for early pregnancy detection after IVF and embryo transfer?

DESIGN

Blood samples were collected on day 4 (+1), 7 (+1) and 11 (+2) after embryo transfer from women aged 18-45 years undergoing first or second fresh or frozen IVF embryo transfer cycles. Biochemical pregnancy was assessed on-site by HCG determination on day 11; clinical pregnancy was assessed by ultrasound on day 21 (+4/-3). Serum hHCG (immunochemiluminometric assay) and HCG+β (Elecsys® HCG+β assay) concentrations were measured. Performance of hHCG and HCG+β for predicting pregnancy was evaluated and cut-offs selected.

RESULTS

In total, 155 women were enrolled and underwent IVF and embryo transfer. Area under the curve (AUC) (95% CI) on day 4 was not significantly different for hHCG (AUC 0.88; 95% CI 0.83 to 0.94) and HCG+β (AUC 0.90; 95% CI 0.84 to 0.95), as was predictive performance on day 7 and 11, with higher AUC estimates compared with day 4. Applying cut-offs derived according to Youden's index on day 4 (hHCG, 100 pg/ml; HCG+β, 1.30 mIU/ml), both biomarkers demonstrated high negative predictive values for ruling out pregnancy (hHCG, 83.8%; HCG+β, 82.8%) and high positive predictive values for ruling in pregnancy (hHCG, 89.0%; HCG+β, 84.9%) on day 21. Diagnostic performance improved from day 4 to day 11.

CONCLUSIONS

Predictive performance for early pregnancy post-IVF embryo transfer of day-5 blastocysts was not significantly different for hHCG and HCG+β; hHCG superiority over HCG+β was not shown.

Unbalanced human embryos secrete more hyperglycosylated human chorionic gonadotrophin (hCG-H) than balanced ones

PURPOSE

The aim of this study was to compare the levels of hyperglycosylated human chorionic gonadotropin (hCG-H) secreted from balanced and unbalanced human embryos.

METHODS

Single-step culture media samples from 155 good quality embryos, derived from 90 good prognosis patients undergoing intracytoplasmic sperm injection (ICSI), were collected on the fifth day of embryo cultivation. All embryos were tested by next-generation sequencing (NGS) technique. The hCG-H levels in the culture media were evaluated by ELISA kit (Cusabio Biotech, CBS-E15803h) according to the manufacturer's instructions. Statistical analysis was performed using SPSS v.21 (IBM Corp., Armonk, NY, USA).

RESULTS

The NGS analysis revealed that 36% of the embryos (n = 56) were balanced, and 64% of the embryos were unbalanced (n = 99). The presence of hCG-H was confirmed in all embryo culture media samples but was absent in the negative control. In addition, hCG-H concentration was significantly higher in the culture media from unbalanced embryos compared with the balanced ones (0.72 ± 0.30 mIU/ml vs. 0.62 ± 0.12 mIU/ml, p = 0.02, respectively). Furthermore, the mean levels of hCG-H were significantly increased in the samples from embryos with multiple abnormalities. Finally, the highest levels of hCG-H were expressed from embryos with monosomy of chromosome 11 (1.28 ± 0.04 mIU/ml) and those with trisomies of chromosomes 21 (2.23 mIU/ml) and 4 (1.02 ± 0.35 mIU/ml).

CONCLUSION

Our results suggest that chromosomal aberrations in human embryos are associated with an increased secretion of hCG-H. However, hCG-H concentration in embryo culture media as a single biomarker is not sufficient for an accurate selection of balanced embryos.

Hyperglycosylated human chorionic gonadotropin as a predictor of ongoing pregnancy

BACKGROUND

Hyperglycosylated human chorionic gonadotropin, the predominant human chorionic gonadotropin variant secreted following implantation, is associated with trophoblast invasion.

OBJECTIVE

To determine whether the initial serum hyperglycosylated human chorionic gonadotropin differs between ongoing and failed pregnancies, and to compare it to total serum human chorionic gonadotropin as a predictor of ongoing pregnancy.

MATERIALS AND METHODS

Women undergoing fresh/frozen in vitro fertilization cycles at a university-based infertility clinic with an autologous day 5 single embryo transfer resulting in serum human chorionic gonadotropin >3 mIU/mL (n = 115) were included. Human chorionic gonadotropin was measured 11 days after embryo transfer in a single laboratory (coefficient of variation <6%). Surplus frozen serum (-80^oC) was shipped to Quest Laboratories for measurement of hyperglycosylated human chorionic gonadotropin (coefficient of variation <9.1%). Linear regression analyses adjusted for oocyte age a priori were used to compare human chorionic gonadotropin and hyperglycosylated human chorionic gonadotropin in ongoing pregnancies (>8 weeks of gestation) and failed pregnancies (clinical pregnancy loss, biochemical and ectopic pregnancies).

RESULTS

A total of 85 pregnancies (73.9%) were ongoing. Hyperglycosylated human chorionic gonadotropin and human chorionic gonadotropin values were highly correlated (Pearson correlation coefficient 92.14, P < .0001), and mean values of both were positively correlated with blastocyst expansion score (P value test for trend < .0004). Mean human chorionic gonadotropin and hyperglycosylated human chorionic gonadotropin were significantly higher in ongoing vs failed pregnancies. Among ongoing pregnancies vs clinical losses, mean hyperglycosylated human chorionic gonadotropin, but not human chorionic gonadotropin, was significantly higher (19.0 vs 12.2 ng/mL, β -8.1, 95% confidence interval -13.0 to -3.2), and hyperglycosylated human chorionic gonadotropin comprised a higher proportion of total human chorionic gonadotropin (4.6% vs 4.1%; risk ratio, 0.79; 95% confidence interval, 0.66-0.94).

CONCLUSION

Measured 11 days after single blastocyst transfer, hyperglycosylated human chorionic gonadotropin and human chorionic gonadotropin values were highly correlated, but only mean hyperglycosylated human chorionic gonadotropin and its ratio to total human chorionic gonadotropin were significantly higher in ongoing pregnancies vs clinical pregnancy losses. Further evaluation of hyperglycosylated human chorionic gonadotropin, including in multiple embryo transfers and multiple pregnancy, and using serial measurements, is required.

The Establishment of an HE4-CLIA Method and the Combined Analysis of HE4 and CA125 in Ovarian Cancer

BACKGROUND

The human epididymal secretory protein 4 (HE4) is a novel, verified biomarker for the early diagnosis of ovarian cancer.

METHODS

Magnetic beads were coated with capture antibodies and were used with acridinium ester labeled detection antibodies in a sandwich-type immunoassay. The patient's HE4 serum levels were measured simultaneously with the chemiluminescence immunoassay (CLIA) kit we developed and electrochemiluminescence immunoassay (ECLIA) kit from Roche (Mannheim, Germany). CA125 was also detected by time-resolved fluoroimmunoassay. The diagnostic value was analyzed.

RESULTS

The assay demonstrated a linear range from 2.5 to 2,000 pmol/l, with an analytical sensitivity of 2.5 pmol/l. The reproducibility, recovery, and specificity of the immunoassay were demonstrated to be acceptable. Compared with the ECLIA kit from Roche in 124 serum samples (40 patients with ovarian cancer, 35 patients with benign gynecological diseases, and 49 health controls), there is a satisfied correlation coefficient of 0.875. The area under the receiver-operating curve (ROC-AUC) was 0.903 (95% CI was 0.839-0.966, P < 0.001) for HE4, 0.787 (95% CI was 0.694-0.879, P < 0.001) for CA125, and 0.914 (95% CI was 0.866-0.962, P < 0.001) for combined analysis of HE4 and CA125.

CONCLUSIONS

A quantitative method (HE4-CLIA) for detecting HE4 in serum was successfully established. Preliminary clinical sample analysis showed HE4-CLIA has a certain clinical value in the screening and diagnosis of ovarian cancer. Moreover, in distinguishing benign from malignant ovarian lesions, HE4 has higher demonstrated accuracy than CA125.

Hyperglycosylated human chorionic gonadotropin as an early predictor of pregnancy outcomes after in vitro fertilization

OBJECTIVE

To determine whether serum hyperglycosylated human chorionic gonadotropin (hhCG) measured as early as 9 days after egg retrieval can predict ongoing pregnancies after in vitro fertilization and fresh embryo transfer (IVF-ET).

DESIGN

Cohort

SETTING

Academic assisted reproduction center.

PATIENT(S)

Consecutive patients undergoing IVF-ET INTERVENTION(S): Serum hhCG and hCG levels measured 9 (D9) and 16 (D16) days after egg retrieval

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy beyond 9 weeks of gestation.

RESULT(S)

Ongoing pregnancy (62 of 112 participants) was associated with higher D9 levels of hhCG and hCG. However, hhCG was detectable in all D9 OP samples, while hCG was detectable in only 22%. A D9 hhCG level of >110 pg/mL was 96% specific for an ongoing pregnancy, yielding a positive predictive value of 94%. Compared with the D9 hCG levels, hhCG was more sensitive and had a larger area under the curve (0.87 vs. 0.67, respectively). The diagnostic test characteristics were similar between the D16 hhCG and hCG levels.

CONCLUSION(S)

In patients undergoing assisted reproduction, a test to detect pregnancy early and predict outcomes is highly desirable, and hhCG is detectable in serum 9 days after egg retrieval IVF-ET cycles. In this early assessment, hhCG was superior to traditional hCG and highly predictive of ongoing pregnancies.

Human chorionic gonadotropin (hCG) in the secretome of cultured embryos: hyperglycosylated hCG and hCG-free beta subunit are potential markers for infertility management and treatment

Human chorionic gonadotropin (hCG) is produced by trophoblast cells throughout pregnancy, and gene expression studies have indicated that hCG-beta subunit (hCGβ) expression is active at the 2 blastomere stage. Here, we investigated the qualitative hCG output of developing embryos in culture and hCG isoforms expressed in the secretome as a novel sensitive method for detecting hCG. Culture media was collected from the culture plates of 118 embryos in culture (including controls and embryos at different stages of culture) from 16 patients undergoing routine fertility treatment. The hCGβ was detectable in media from 2 pronuclear (2PN) stage embryos through to the blastocyst stage. The hCGβ was absent in 1PN and arrested embryos as well as all media controls. Prior to hatching, hyperglycosylated hCG (hCGh) was observed selectively in 3PN embryos, but after hatching, along with hCG, became the dominant hCG molecule observed. We have reported at the 2PN stage the earliest evidence of hCGβ expression in embryos. There is a suggestion this may be indicative of quality in early embryos, and hCGh seen at the pronuclear stage may suggest triploid abnormality. The dominance of hCG, and hCGh expression, seen after blastocyst hatching may be indicative of potential implantation success. Thus, hCG isoforms have potential roles as biomarkers of embryo viability for embryo/blastocyst transfer.

Biomarkers for ectopic pregnancy and pregnancy of unknown location

Early pregnancy failure is the most common complication of pregnancy, and 1% to 2% of all pregnancies will be ectopic. As one of the leading causes of maternal morbidity and mortality, diagnosing ectopic pregnancy and determining the fate of a pregnancy of unknown location are of great clinical concern. Several serum and plasma biomarkers for ectopic pregnancy have been investigated independently and in combination. The following is a review of the state of biomarker discovery and development for ectopic pregnancy and pregnancy of unknown location.

The sensitivity and specificity of hyperglycosylated hCG (hhCG) levels to reliably diagnose clinical IVF pregnancies at 6 days following embryo transfer

Objective

To determine the sensitivity and specificity of hyperglycosylated hCG (hhCG) measurements for the diagnosis of clinical pregnancies in the IVF setting and how soon post embryo transfer (ET) a pregnancy can be detected using an ultrasensitive (hhCG) assay. To determine if a single, early hhCG measurement can discriminate between biochemical and clinical pregnancies.

Design

A 4 center prospective blinded clinical trial was performed with patients undergoing IVF-ET. Patients had blood drawn and submitted for hhCG analysis on the day of ET and at days 4, 6, 8, and 12 thereafter. First morning urines were collected and submitted for hhCG analysis on days 0, 4, 6, 8, 10 and 12.

Setting

Fertility Centers

Outcome Measures

Clinical pregnancies were defined as an ultrasound study demonstrating a gestational sac and/or heart beat at appropriate gestational ages.

Results

Fifty-six of 58 enrolled patients completed the study. There were 25 clinical and 6 biochemical pregnancies. For blastocyst transfers, a single serum or urine hhCG measurement identified pregnancies (both biochemical and clinical) at 6 days post ET with 100% sensitivity and specificity. There were 6 biochemical pregnancies, all following blastocyst transfers. All of these pregnancies were identified by lower values.

hCG, five independent molecules

INTRODUCTION

The hCG amino acid sequence supports 5 glycoproteins. All are called hCG forms. This review examines all 5 molecules, the hormone as produced by the placental syncytiotrophoblast cells, the sulfated hormone produced by the pituitary gonadotrope cells, the hyperglycosylated hCG autocrine made by placental cytotrophoblast cells, and the autocrine cancer promoters hyperglycosylated hCG, hCGß and hyperglycosylated hCGß as made by all malignancies. This review examines all the molecules and multiple proven functions, ranging from evolution to cancer promotion to hormone action.

RESULTS AND DISCUSSION

hCG forms are critical super-growth factors in humans, with an exceptional wide range of functions.

Recurrent miscarriage and hCG supplementation: a review and metaanalysis

Human chorionic gonadotropin (hCG) has been used to prevent subsequent miscarriages after previous recurrent miscarriages. In addition to the luteotrophic effects, hCG has uterine immune and autocrine actions. hCG also affects cytokine expression. A Cochrane database systematic review has indicated that hCG seems to prevent further miscarriages, (OR for miscarriage = 0.26, 95% CI 0.14-0.52). However, the trials in the Cochrane database were not matched for the number of miscarriages, 1°, 2° or 3° aborter status, maternal age, etc. and no account was made for chromosomally abnormal pregnancies. All of these impact on the subsequent prognosis and may confound the results. The previous trials in the literature all assessed urinary (u-hCG) rather than recombinant hCG (r-hCG), raising the question whether the effect on pregnancy outcome is due to hCG itself, or other urinary proteins present in u-hCG. A new trial is indicated in which r-hCG is compared to u-hCG and the most effective compared to placebo. Treatment and placebos arms should be stratified for the prognostic factors above and the results corrected for fetal chromosomal aberrations. Until such a trial is carried out, the use of hCG supplementation is empiric.

Human chorionic gonadotropin and associated molecules

When considering human chorionic gonadotropin (hCG) and hCG tests, it is important to realize that it is not a single biological molecule. The regular form of hCG produced by differentiated syncytotrophoblast cells (regular hCG) is a hormone made with the primary function of maintaining the myometrial and decidual spiral arteries and the vascular supply of the placenta during the full course of pregnancy. Hyperglycosylated hCG (hCG with double-size O-linked oligosaccharides) is made by undifferentiated cytotrophoblast cells. This is an autocrine hormone with separate functions, it maintains invasion as in implantation of pregnancy and malignancy in gestational trophoblastic diseases. A hyperglycosylated free beta-subunit is produced by a high proportion of all malignancies. This functions as an autocrine hormone to promote the growth and invasion of the malignancy. It is important to realize when ordering an hCG test what you are measuring and whether the test ordered will detect appropriately these three variant of hCG as well as their degradation products. Most automated commercial laboratory tests, point-of-care test and over-the-counter tests are limited in what is detected, focusing only on regular hCG. This is in part due to the US FDA, who only consider hCG as a pregnancy test, and to whom only detection of regular hCG is critical. This may be a cause of test errors since primarily hyperglycosylated hCG is produced in early pregnancy, choriocarcinoma and germ cell testicular malignancies, and only free beta-subunit may be produced in other germ cell malignancies (all applications for hCG test). The exceptions are the older style hCGbeta radioimmunoassay and the Siemen's Immulite platform hCG test which detect all variant and their degradation product appropriately. Regardless of test specificity limitations, assays for hCG variants are widely used clinically in pregnancy detection, early pregnancy detection, prediction of spontaneously aborting and ectopic pregnancies and prediction of trisomy pregnancies. hCG tests are essential in managing gestational trophoblastic diseases, whether hydatidiform mole, invasive mole or choriocarcinoma, and are very useful in management of testicular malignancies and other germ cell malignancies.

New discoveries on the biology and detection of human chorionic gonadotropin

Human chorionic gonadotropin (hCG) is a glycoprotein hormone comprising 2 subunits, alpha and beta joined non covalently. While similar in structure to luteinizing hormone (LH), hCG exists in multiple hormonal and non-endocrine agents, rather than as a single molecule like LH and the other glycoprotein hormones. These are regular hCG, hyperglycosylated hCG and the free beta-subunit of hyperglycosylated hCG. For 88 years regular hCG has been known as a promoter of corpus luteal progesterone production, even though this function only explains 3 weeks of a full gestations production of regular hCG. Research in recent years has explained the full gestational production by demonstration of critical functions in trophoblast differentiation and in fetal nutrition through myometrial spiral artery angiogenesis. While regular hCG is made by fused villous syncytiotrophoblast cells, extravillous invasive cytotrophoblast cells make the variant hyperglycosylated hCG. This variant is an autocrine factor, acting on extravillous invasive cytotrophoblast cells to initiate and control invasion as occurs at implantation of pregnancy and the establishment of hemochorial placentation, and malignancy as occurs in invasive hydatidiform mole and choriocarcinoma. Hyperglycosylated hCG inhibits apoptosis in extravillous invasive cytotrophoblast cells promoting cell invasion, growth and malignancy. Other non-trophoblastic malignancies retro-differentiate and produce a hyperglycosylated free beta-subunit of hCG (hCG free beta). This has been shown to be an autocrine factor antagonizing apoptosis furthering cancer cell growth and malignancy. New applications have been demonstrated for total hCG measurements and detection of the 3 hCG variants in pregnancy detection, monitoring pregnancy outcome, determining risk for Down syndrome fetus, predicting preeclampsia, detecting pituitary hCG, detecting and managing gestational trophoblastic diseases, diagnosing quiescent gestational trophoblastic disease, diagnosing placental site trophoblastic tumor, managing testicular germ cell malignancies, and monitoring other human malignancies. There are very few molecules with such wide and varying functions as regular hCG and its variants, and very few tests with such a wide spectrum of clinical applications as total hCG.

The normal variabilities of the menstrual cycle

OBJECTIVE

To address conflicts in the normal variabilities of the menstrual cycle using the newest generation test methods and to establish normal ranges for use in clinical practice.

DESIGN

Daily urine samples were collected from 167 women eager to achieve pregnancy. Samples were tested prospectively for LH and total hCG. A total of 458 nongestational and 111 gestational menstrual cycles were evaluated.

SETTING

Division of Women's Health Research, University of New Mexico.

PATIENT(S)

One hundred sixty-seven women desiring pregnancy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Levels of hCG and LH.

RESULT(S)

Menstrual cycles were 27.7 +/- 2.4 days in length. The LH peak indicated the onset of the presumed ovulatory window, which occurs at 14.7 +/- 2.4 days. Implantation (first day of sensitive detection of hCG) occurred in gestational menstrual cycles at 24.6 +/- 3.1 days, or 4.3 +/- 2.2 days before missing the expected onset of menses.

CONCLUSION(S)

Our data confirm epidemiological studies on menstrual cycle length and variability and hormonal studies on timing of the ovulatory window and its variability. They dispute, however, the published data on the timing and variance of implantation. As shown, implantation is limited to a 10-day interval culminating in the day of the expected onset of menses. Reference range data provide guidelines for differentiating normal and problem menstrual cycles.

Hyperglycosylated human chorionic gonadotropin and the source of pregnancy failures

OBJECTIVE

To investigate the proportion of hyperglycosylated human chorionic gonadotropin (hCG-H) produced at the time of implantation as a predictor of pregnancy success.

DESIGN

Measuring daily urine hCG and hCG-H on the day of implantation. The time of implantation was assumed to be the first day of hCG detection (total hCG >1 mIU/mL).

SETTING

Urine samples were collected at volunteers' homes throughout city of Albuquerque.

PATIENT(S)

110 women attempting to conceive spontaneously; 62 achieved pregnancies (42 to term and 20 failed).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Measurements of the total hCG and hCG-H, and calculations of the proportion of hCG-H.

RESULT(S)

In all 42 term pregnancies, the proportion of hCG-H on the day of implantation was >50%. This was also true for 7 of the 20 failures. Statistically significant lower proportions of hCG-H (<50%) were observed in 13 of 20 pregnancies that eventually failed. The predictive values of proportion of hCG-H, concentration of hCG-H, total hCG, and regular hCG alone for detecting failures were 100%, 59%, 41%, and 21%, respectively.

CONCLUSION(S)

Hyperglycosylated is produced by cytotrophoblast cells in early pregnancy at the time of implantation. Effective proportions of hCG-H (>50%) are required for successful growth and invasion by cytotrophoblasts at the time of implantation. Low proportions of hCG-H at implantation predict failure and are likely to be the root of many pregnancy failures. The 7 of 20 failures with normal proportions of hCG-H were likely due to genetic, immune, or maternal causes. Measurement of a proportion of hCG-H <50% on the day of implantation absolutely indicates a failing pregnancy.

Hyperglycosylated hCG

Hyperglycosylated hCG (hCG-H) is a glycosylation variant of the hormone hCG. Here we review all that is known about this independently functioning molecule. As discussed, it is a very different molecule to the hormone hCG. First, hCG-H is produced by cytotrophoblast cells while regular hCG is made in syncytiotrophoblast cell. Second, it is an autocrine acting directly on the cells which produce it, while regular hCG is an endocrine acting on maternal corpus luteal cells. Third, hCG-H has minimal biological activity in promoting progesterone production compared to regular hCG. Fourth, hCG-H functions unlike regular hCG as an invasion promoter, whether invasion as in choriocarcinoma and testicular germ cell malignancies, or as in implantation of pregnancy. These functions seemingly occur through action on cytotrophoblast cell TGFbeta receptors. Fifth, hCG-H is an essential component for successful human implantation to prevent early pregnancy loss and spontaneous abortion. Sixth, hCG-H is critical for promoting the midtrimester hemochorial implantation, and for preventing preeclampsia. Seventh, measurements of hCG-H have advantages over measurements of regular hCG or total hCG, in detecting pregnancy, pregnancy outcome (failing or term pregnancy), predicting preeclampsia in pregnancy, or as a tumor marker for gestational trophoblastic diseases.

Hyperglycosylated hCG: a variant with separate biological functions to regular hCG

Hyperglycosylated hCG (hCG-H) is an over-glycosylated variant of hCG. While regular hCG is produced by differentiated syncytotrophoblast cells, hCG-H is independently secreted by stem cytotrophoblast cells. hCG-H has an independent function to regular hCG. It is the direct promoter of trophoblast invasion and malignancy. Invasion as in implantation of pregnancy and malignancy as in choriocarcinoma. Neither will occur in the absence of hCG-H. hCG-H measurements have multiple functions. Primarily or exclusively hCG-H is produced at the time of implantation of pregnancy and in the 2 weeks that follows. As such, a good pregnancy test should measure regular hCG and hCG-H equally. This is not commonly the case. Most tests poorly detect hCG-H. New pregnancy tests are needed, including those that measure only hCG-H. Considering that hCG-H is critical for implantation, hCG-H is also invaluable for determining pregnancy outcome and detecting failures. It makes a considerable more accurate test for detecting pregnancy failures and ectopic pregnancies than regular hCG. Down syndrome pregnancies are marked by poor trophoblast differentiation. As such, they are very well marked by using a combination of hCG-H measurements and other screening tests. hCG-H is also an absolute tumor marker for malignant or invasive gestational trophoblastic disease, it can discriminate active and inactive (quiescent) disease, and the need for chemotherapy.