Chorionic gonadotropin concentration in early human pregnancy: comparison of specific and nonspecific assays

Cryopreserved embryo transfers suggest that endometrial receptivity may contribute to reduced success rates of later developing embryos

OBJECTIVE

To evaluate viability and implantation potential of cryopreserved blastocysts according to the day of blastocyst expansion and cryopreservation.

DESIGN

Retrospective study.

SETTING

Private ART center.

PATIENT(S)

Three hundred and seventy-five patients undergoing embryo transfer with cryopreserved blastocysts.

INTERVENTION(S)

Blastocyst cryopreservation on day 5, 6, or 7 after oocyte retrieval according to the day of blastocyst expansion and subsequent embryo transfer.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (PR) per embryo transfer.

RESULT(S)

Clinical PRs were similar between blastocysts cryopreserved on day 5 and blastocysts cryopreserved on day 6 (32% vs. 28%). The clinical PR was lower for blastocysts cryopreserved on day 7 (15%), but this difference was not statistically significant after accounting for the number of embryos per transfer (P=.15).

CONCLUSION(S)

Viability and implantation potential are similar for day 5 and day 6 blastocyst cryopreservation. Viability may be reduced for blastocysts cryopreserved on day 7, but not to the extent suggested by reports of fresh transfers. These results suggest that reduced success rates associated with fresh transfers of later developing blastocysts may be the result of asynchrony with endometrial receptivity instead of poorer embryo quality.

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

OBJECTIVES

Current testing to determine a failing pregnancy requires two separate clinic visits to measure the hCG doubling rate. Diagnosing a failing pregnancy is often done in emergency departments where simplified and accelerated testing methods are needed. Here, we investigated hyperglycosylated hCG (hCG-H) for predicting pregnancy failure.

DESIGN AND METHODS

We studied two independent sets of patient samples collected in the early weeks of gestation. One set was urine samples, and the other was serum samples. In all cases, hCG and hCG-H were measured using automated chemiluminescence immunoassays. Concentrations of hCG and hCG-H were plotted on a scattergram, and levels in failing pregnancies were compared to those in continuing pregnancies.

RESULTS

Data indicated that a threshold level of hCG-H (13 microg/L) in both serum and urine samples defined the concentration below where pregnancies were likely to fail. This cut-off corresponded to 73% detection of failures at a 2.9% false positive rate using serum and 75% detection at a 15% false positive rate using urine. Using an hCG cut-off that corresponded to the same false positive rates, hCG detected only 42% of failures using serum and 43% of failures using urine.

CONCLUSIONS

Our data indicate that hCG-H provides a much more accurate single test than hCG for assessing pregnancy outcome. Compatible with the use of serum or urine samples, a single hCG-H test might provide simpler, faster, and more accurate results for predicting the progress of a pregnancy than standard hCG testing.

Endometrial markers of uterine receptivity utilizing the donor oocyte model

BACKGROUND

Ethical constraints limit the ability to study peri-implantation phase human endometrium. In this study, the donor oocyte model was used to study candidate endometrial markers of uterine receptivity.

METHODS

Archived, paraffin-embedded tissue obtained by endometrial biopsy during cycle days 21-23 of patients undergoing 'mock' hormonal treatment cycles were evaluated by standard histological criteria and immunohistochemical staining for alpha v beta 3 integrin and glycodelin. All of these patients (n = 101) had undergone a donor oocyte embryo transfer cycle utilizing the exact same hormonal protocol.

RESULTS

Histological evaluation revealed 62 (61.3%) in-phase, 34 (33.7%) dyssynchronous, 2 (2.0%) immature and 3 (3.0%) advanced endometria. The clinical outcomes of patients with either in-phase or dyssynchronous endometria were similar. Very strong correlations were noted between endometrial glandular dating and either alpha v beta 3 integrin or glycodelin immunostaining intensity (P < 0.001 for both). Glycodelin and alpha v beta 3 integrin immunostaining intensities were also highly correlated with each other (P < 0.001).

CONCLUSIONS

Throughout the time period corresponding to the putative window of maximal endometrial receptivity (cycle days 21-23) a dynamic process was observed in exogenous hormonal replacement cycles characterized by a rapid histological advancement of endometrial glandular elements as well as progressive alpha v beta 3 integrin and glycodelin expression.

Human chorionic gonadotropin hormone prevents wasting syndrome and death in HIV-1 transgenic mice

At birth, transgenic mice, homozygous for the HIV-1 provirus pNL4-3, deleted in gag/pol, are normal in appearance and weight. Within several days after birth, the pups develop a syndrome characterized by dry, scaly, hyperkeratotic skin, growth failure, and death. The possibility that the homozygous embryos are being protected during gestation by a maternal factor led us to treat the newborn animals with various pregnancy-related hormones including human chorionic gonadotropin (hCG), estrogen, progesterone, and dexamethasone. Treatment with hCG prevented death, led to normal growth, and markedly reduced skin lesions. In contrast to the skin of the untreated homozygous pups, which expressed high levels of HIV mRNA and proteins (i.e., gp120 and Nef), the skin of the hCG-treated pups showed a marked reduction in both HIV mRNA and proteins. Discontinuation of hCG resulted in the reappearance of HIV transcripts and proteins, skin lesions, and growth failure resulting in death. In addition, HIV transcripts and proteins were reduced significantly in heterozygous mothers during pregnancy, but reappeared after parturition. Similarly, hCG treatment resulted in a decrease of HIV proteins in the skin of nonpregnant heterozygous transgenic mice. These findings suggest that the inhibiting effect of hCG on HIV expression may be clinically useful in the treatment of HIV infections, and may be responsible, during pregnancy, for the low transmission of HIV from infected mothers to their offspring.

The impact of embryonic development and endometrial maturity on the timing of implantation

OBJECTIVE

To gain insight into the peri-implantation period in the human and to answer the question whether timing of nidation is dependent on the stage of embryonic development, endometrial maturation, or a possible dialogue between the two.

DESIGN

Seventy-five women underwent embryo transfer (ET) throughout 93 cycles. Thirty-three ETs resulted in viable pregnancies and deliveries. These pregnancy cycles were used for embryonic signal detection. Embryos of identical age were transferred onto hormonally and histologically defined endometria of different maturational stages (days 15 to 19). Human chorionic gonadotropin (hCG) was measured by a hypersensitive chemiluminescence assay in maternal serum every 1 to 5 days to detect the first embryonic signal.

RESULTS

Individual linear regressions of hCG versus embryonic age and endometrial maturation were performed on 33 viable pregnancy cycles (r2 = 90.5% to 99.9%, P less than 0.02 to 0.002). First signal detection was restricted to an embryonic age of 7.1 +/- 0.28 (mean +/- SD) days (range 6.6 to 7.4) irrespective of endometrial maturation. The pattern of hCG detection was triphasic, described by a sigmoidal curve with the maximal slope corresponding to an hCG doubling time of 15.9 hours. Embryo transfers on cycle day 19 had a steeper slope of hCG detection than days 15 and 16 (P less than 0.05).

CONCLUSIONS

First embryonic signal detection (presumed window of implantation) extends between cycle days 20 and 24. Implantation is dependent on embryonic age and is independent of endometrial maturation within this window. The timing and sigmoidal pattern of hCG detection coincides with structural changes of the implantation bed. The steeper slope of late ETs may represent a compensatory mechanism for late maternal recognition of pregnancy for corpus luteum rescue.

The efficiency of human reproduction after in vitro fertilization and embryo transfer

Two hundred ninety-seven nonpregnant patients were used to study the possibility of early transient implantation as a parameter of the efficiency of in vitro fertilization (IVF) procedures. Ten patients without embryo transfer (ET) were used as controls. The luteal estradiol, progesterone, and human chorionic gonadotropin were measured by radioimmunoassay (RIA). In 31 cases, a transient elevation of hCG occurred after complete serum clearance of exogenous hCG, suggesting that the transient increase in hCG was of embryonic origin. In addition, five patients were found to have prolonged clearance of hCG, which was due not to individual variation in clearance, but to a minimal production of hCG by trophoblastic tissue. These data suggest that implantations occurred in 12.1% of our so-called "nonpregnant" patients.

A possible mechanism of action of danazol and an ethinylestradiol/norgestrel combination used as postcoital contraceptive agents

Twenty-seven women requesting postcoital contraception were randomly allocated to take an ethinylestradiol/dl-norgestrel combination or danazol. Urine specimens were assayed for luteinising hormone (LH) and pregnanediol-3-glucuronide (P3G) levels from the day of the postcoital treatment to the next period. In addition, the urine samples of these recruits and 12 additional women were assayed for the Beta-subunit of human chorionic gonadotropin (B-hCG). A consistent pattern of alteration in urinary steroids was lacking, indicating a heterogeneous effect on ovarian function. There was no evidence of early pregnancy in successfully treated cases. We suggest that the main mechanism of action of these drugs is at the endometrial level.

Comparison of the analytical characteristics and clinical usefulness in tumour monitoring of fifteen hCG(-beta) immunoassay kits

Fifteen immunoassay kits for serum hCG(-beta) measurements have been compared for their analytical characteristics and clinical usefulness in tumour monitoring. Three out of 13 radioimmunoassays and two sandwich hCG immunoassays represent the 'one-component' techniques for intact hCG detection since they are based on antiserum raised against intact hCG. Within this group, method-comparison slopes ranged between 0 X 149 and 0 X 374. The remaining 10 radioimmunoassays all apply antiserum against hCG-beta and are designated 'two (or more)-component' assays since they detect both intact hCG and the free beta-subunit ('total hCG'). For this reason these assays are of potential value for tumour monitoring. Additional criteria for this are: (1) the expression of assay results in terms of 1st IRP-hCG instead of the unstructured use of the 2nd IS or the 1st IRP-hCG-beta; (2) documentation of cross-reactivities especially for the free beta-subunits of hCG and hLH which are almost completely lacking; (3) establishment of the minimum detectable dose in the presence of normo-to-hypergonadotrophic hLH levels in serum (the 'clinical sensitivity') to allow the follow-up of tumour regression especially in the low-dose region. Method-comparison analysis for these assays revealed regression slopes between 0 X 001 and 0 X 873.

Dramatic increase of placental protein 5 levels following injection of small doses of heparin

In the course of an investigation on the effects of thyroid releasing hormone in pregnant women we noted a dramatic increase in the levels of placental protein 5 (PP5) in maternal blood. This increase ranged from 10 times to over 40 times the basal levels. Further study showed that the rise was associated with the use of heparin to maintain the patency of the cannula through which the samples were collected. Furthermore, the phenomenon appeared to be systemic rather than local, and may well be due to a direct effect of heparin on PP5 secretion by the placenta.

Monitoring early production of chorionic gonadotrophin (HCG) following in vitro fertilization and embryo transfer

A rapid, sensitive assay was developed for monitoring HCG production and applied to serum and urine collection between days 4 and 20 after OPU in 55 patients treated by ovarian hyperstimulation and IVF. Eleven ongoing pregnancies, 2 ectopic pregnancies and 1 clinical abortion resulted. The earliest detection of a rise in HCG was on day 7 after OPU. The HCG values showed that trophoblastic tissue functioned transiently in another 11 patients and probably in another 5. Thus evidence for functioning trophoblastic tissue was obtained in a total of 30 patients (55%). These findings are important for the further improvement of IVF. No antibodies to administered HCG were detected.

Placental proteins (human chorionic gonadotropin, human placental lactogen, pregnancy-specific beta 1-glycoprotein, and placental protein 5) in seminal plasma of normal men and patients with infertility

Placental proteins, including human chorionic gonadotropin (hCG), human placental lactogen (hPL), pregnancy-specific beta 1-glycoprotein (SP1), and placental protein 5 (PP5) have been detected in human seminal plasma of 20 normal men and 42 patients with infertility. Levels of hPL, SP1, and PP5 were similar in these groups. There were significantly higher levels of hCG in subjects with normal sperm counts than in those with oligospermia or azoospermia. The levels of PP5 in seminal plasma showed an association with sperm motility, suggesting that PP5 may have a significant biologic function in the maintenance of sperm motility.

Plasma concentrations of human chorionic gonadotropin from the time of implantation until the second week of pregnancy

A systematic study of the daily concentrations of human chorionic gonadotropin (hCG) in maternal circulation following the time of probable implantation in 19 normal pregnancies was carried out. With the use of a specific antiserum to hCG beta-subunit, significant increases in circulating hCG were observed by day 8 following the luteinizing hormone (LH) peak in 5.3% of cycles. by day 9 in 15.8%, by day 10 in 53.2%, and by day 11 in 100% of the cycles resulting in a normal pregnancy. After an initial rapid rise, mean plasma concentrations rose exponentially, with a doubling time of 1.3 days, to reach concentrations between 50 and 250 IU/l at the time of the first missed period. The time of detection of hCG was in close agreement with the anticipated time for this event estimated from morphologic studies. In three abnormal pregnancies, all of which ended in spontaneous abortion, hCG concentrations became progressively more abnormal from within 2 to 5 days of the appearance of this hormone in maternal plasma. Despite this, actual abortion did not occur for several days, or in one case for several weeks, after the divergence of hCG concentration from the normal range.