Modulation of human chorionic gonadotrophin bioactivity during the first trimester of pregnancy

The objective of this study was to evaluate the bioactivity of human chorionic gonadotrophin (HCG) during first trimester pregnancy. This was done by means of a retrospective analysis of sera from patients with first trimester normal intrauterine and ectopic pregnancies. Serum samples were obtained from 38 women with amenorrhoea of <10 weeks. From these, 19 had a normal intrauterine pregnancy (IUP) and 19 an ectopic pregnancy (EP). Cases were allocated to either low serum immunoreactive HCG (HCGi), intermediate HCGi or high HCGi concentrations (HCGi <5000 mUI/ml, between 5000 and 40,000 mIU/ml and >40,000 mIU/ml respectively). HCGi and oestradiol were measured by enzyme immunoassays and bioactive HCG by the mouse Leydig cell bioassay. All results were analysed by analysis of variance and unpaired Student's t-test. There was a significant difference between bioactive to immunoreactive HCG ratios (b/i ratio) between the subgroups of low, intermediate and high HCGi concentrations. Lower b/i ratios were found when HCGi concentrations were high (HCG b/i mean +/- SEM: high subgroup, 0.33 +/- 0.07 versus low subgroup: 1.50 +/- 0.12; P < 0.0001). Furthermore, the b/i ratios were inversely correlated with oestradiol (P < 0.0001) and HCGi (P < 0.0001) concentrations but not with gestational age. There was no difference in the b/i ratios when comparing IUP with EP. It is concluded that, in first trimester pregnancies, there is a likely modulation of HCG bioactivity which is inversely correlated with HCGi and oestradiol concentration. The underlying mechanisms and their physiological relevance remain to be elucidated.      

Trophoblast tissue culture of human intrauterine and ectopic pregnancies and treatment with methotrexate.

The application of drugs for conservative treatment of patients with ectopic pregnancy has been used worldwide for several years. In-vitro studies, however, are very few. We therefore examined the effects of methotrexate on trophoblast tissue cultures derived from intrauterine and ectopic pregnancies. Methotrexate was administered either 12 h or 6 days after initiation of the culture. Human chorionic gonadotrophin (HCG) levels were measured in the culture medium. All cultures showed secretion of HCG within the first 16 days. Methotrexate concentrations less than 3.8 x 10(-4) mol/l had no effect on HCG secretion. Cultures of ectopic pregnancies required a concentration about 10x higher to induce an equivalent reduction of HCG levels compared to intrauterine pregnancies. A few intrauterine and ectopic pregnancies showed no reduction of HCG values after treatment. These results suggest that data obtained from studies on intrauterine pregnancies may not be transferable to ectopic pregnancies in all instances. In some regimens approximately 8 days are required before the effect becomes measurable. In combination with our clinical data, we therefore recommend not to repeat a methotrexate dose too early in treatment of patients with ectopic pregnancies. The possibility that non-responding patients could exist should be kept in mind.     

Preliminary results on the role of embryonic human chorionic gonadotrophin in corpus luteum rescue during early pregnancy and the relationship to abortion and ectopic pregnancy.

The precise mechanisms by which corpus luteum (CL) function is modulated during early pregnancy are not known. Evidence in failed pregnancies (ectopic, abortions), shows that factors other than human chorionic gonadotrophin (HCG) could be involved in its regulation. The objective of this study was to investigate the dynamics of beta-HCG, progesterone and oestradiol production in early pregnancy and its relation to embryonic quality and topographic localization. Plasma concentrations of progesterone, oestradiol and beta-HCG were studied between days +12 and +21 after an in-vitro fertilization (IVF) embryo transfer in 11 intrauterine pregnancies, 10 intrauterine abortions and seven tubal pregnancies. Tubal pregnancies and abortions were grouped according to doubling time (DT) of HCG. Results showed that oestradiol concentrations were apparently reduced in both ectopic pregnancies and abortions compared with normal pregnancies. The fall in oestradiol concentrations was seen in ectopic pregnancies with an abnormal DT for HCG and in all abortions. When the ectopic pregnancy had a normal DT, oestradiol and progesterone concentrations were normal. In abortions, the fall in oestradiol and progesterone concentrations was less influenced by the DT of HCG. These findings suggest that corpus luteum function depends on an adequate DT of HCG more than an absolute value, and with normal trophoblastic tissue the site of implantation does not affect CL function.     

Serum HCG 12 days after embryo transfer in predicting pregnancy outcome

BACKGROUND: Assisted reproduction treatment (ART) entails a risk of ectopic pregnancy and early pregnancy loss. Serum HCG has been found to be predictive of pregnancy outcome. Our aim was to assess the clinical value of a single early HCG assay in ART pregnancies taking into account the aetiology and treatment of infertility. METHODS: During 1994-1999, we studied 774 embryo transfer cycles resulting in pregnancy defined as a serum HCG concentration of > or =5 IU/l on day 12 following embryo transfer. The treatment included IVF in 518, ICSI in 119, and frozen embryo transfer in 137 cycles. Serum HCG concentrations were measured by fluoroimmunometric assay. Pregnancies were classified as viable (live fetus at > or =22 weeks gestation) or non-viable (biochemical pregnancy, miscarriage, ectopic pregnancy and molar pregnancy). Data on the outcomes were retrospectively retrieved from the records. RESULTS: The median HCG concentration was 126 IU/l in viable pregnancies and 31 IU/l in non-viable pregnancies (P < 0.0001). The median HCG concentration was 115 IU/l in singleton pregnancies and 201 IU/l in multiple pregnancies (P < 0.0001). Male factor infertility was associated with viable pregnancies (P = 0.004) and tubal factor with non-viable pregnancies (P = 0.003); the lowest HCG level (88 IU/l) was observed in subjects with both male factor infertility and ICSI treatment (P = 0.001). An HCG value of 76 IU/l emerged as the most suitable cut-off point to predict viable pregnancy. Probabilities of each type of outcome related to the HCG level are given. CONCLUSIONS: A single HCG reading on day 12 after embryo transfer helps to plan the subsequent follow-up. Male factor infertility and ICSI are associated with relatively low HCG values in viable pregnancies.     

Improved sensitivity and specificity of a single measurement of serum progesterone over serial quantitative beta-human chorionic gonadotrophin in screening for ectopic pregnancy.

The sensitivity and specificity of a single serum progesterone measurement was compared against two beta-human chorionic gonadotrophin (HCG) measurements 48 h apart in screening for abnormal pregnancy, i.e. ectopic pregnancy, completed or incomplete abortion. Of 1120 patients in the first trimester presenting with a positive urinary pregnancy test, 116/1120 (10.4%) had an ectopic pregnancy, 755/1120 (67.4%) had ultrasonographically confirmed intra-uterine pregnancies, and 249/1120 (22.2%) had abnormal intra-uterine pregnancies documented as complete, incomplete or missed abortions. Of the ectopic pregnancies, 113/116 (97.4%) had a serum progesterone level less than 25 ng/ml while 516/755 (68.3%) viable intra-uterine pregnancies had a serum progesterone level greater than or equal to ng/ml. Of the 1120 patients screened, 402 (35.9%) had both a serum progesterone and two HCG measurements and were eligible for inclusion in this study. Setting a cut-off of 25 ng/ml, the sensitivity and specificity of a single serum progesterone measurement was then compared against two serial HCG measurements, utilizing receiver operating characteristic curves. This analysis demonstrated that a single serum progesterone measurement was significantly more sensitive (P less than 0.05) than two HCG measurements in screening for an abnormal pregnancy. In some patients, a single serum progesterone makes possible the diagnosis of ectopic pregnancy 2 days earlier than two HCG determinations because a second blood sample was not required. We conclude that a single serum progesterone measurement should be added to serial HCG determinations as a standard diagnostic screening test for ectopic pregnancy.     

Intact HCG, free HCG beta subunit and HCG beta core fragment: longitudinal patterns in urine during early pregnancy

BACKGROUND: Detecting and monitoring early pregnancy depend on the measurement of HCG. Little is known about how production of various forms of HCG may evolve over the earliest weeks of pregnancy, particularly in naturally conceived pregnancies. METHODS: We describe the daily excretion of three urinary HCG analytes during the first 6 weeks post-conception in 37 naturally conceived pregnancies ending in singleton birth. We assayed daily first morning urine samples for intact HCG, free beta subunit and beta?core fragment, plus the combined measurement of these HCG forms. We calculated doubling times for each analyte and the inter- and intra-subject day-to-day variation. RESULTS: Intact HCG and the free beta subunit were initially the predominant forms of HCG, with the beta core fragment emerging as the predominant form in the fifth week after conception. Intact HCG and the free beta subunit showed the most day-to-day variability, and were transiently undetectable even 10 days after detection of pregnancy. The most stable estimate of doubling time was provided by the combined measurement of all these forms. CONCLUSIONS: Although intact HCG is usually regarded as the main analyte for detection and monitoring of early pregnancy, it can fluctuate markedly during early pregnancy. This variability could affect pregnancy test results based on early pregnancy urine, and may distort estimates of doubling time. Assays that combine several forms of HCG may be more reliable.     

Human chorionic gonadotrophin concentrations in early pregnancy after in-vitro fertilization.

There is increased risk of early pregnancy loss after assisted reproduction. In this study the use of serum human chorionic gonadotrophin (HCG) concentrations on day 12 after in-vitro fertilization (IVF) and embryo transfer was evaluated to predict pregnancy outcome. A total of 417 IVF pregnancies were included. Early pregnancy loss was defined as biochemical pregnancies, ectopic pregnancies and first trimester abortions. Vital pregnancies were defined as delivered singletons, multiple pregnancies and second trimester abortions. On the post embryo transfer day 12, the mean HCG concentration of the vital pregnancy group was significantly higher than in early pregnancy loss outcomes (P < 0.00001). Receiver operating characteristic (ROC) curve analysis was performed to evaluate the cut-off value of HCG giving maximal sensitivity and specificity in order to discriminate early pregnancy losses from vital pregnancies. A patient with a HCG value higher than the calculated cut-off value (55 IU/l) had a 90% chance of having a vital pregnancy after IVF and embryo transfer. It can be concluded that a discriminatory HCG value on day 12 after IVF and embryo transfer cycles may be useful in predicting pregnancy outcome and may guide clinicians in identifying those pregnancies at risk for adverse outcomes and instituting more intensive surveillance in this population.     

天花粉宫腔注射联合米非司酮治疗异位妊娠的临床研究

目的探讨结晶天花粉蛋白注射液宫腔注射联合米非司酮治疗未破裂异位妊娠的临床效果.方法对58例未破裂异位妊娠患者随机分为两组,治疗组和对照组,治疗组:30例采用结晶天花粉蛋白注射液宫腔注射,米非司酮50mg,2/d,口服,连服3d.对照组:氨甲蝶呤(MTX),25mg,1/隔日,肌注,共5次.定时监测血、尿HCG、B超,比较两组治疗效果及尿HCG转阴天数.结果两组间有效率无显著统计学差异(P＞0.05),两组尿HCG转阴的平均天数有显著性差异(P＜0.01),治疗组明显缩短.结论结晶天花粉注射宫腔注射联合米非司酮治疗异位妊娠,疗效好、无明显副作用,可作为保守异位妊娠的首选治疗方案.     

Are pregnancy-associated plasma protein-A (PAPP-A) and CA 125 measurements after IVF-ET possible predictors of early pregnancy wastage?

Pregnancy-associated plasma protein-A (PAPP-A), a macromolecular glycoprotein of placental origin, was reported to be depressed in established ectopic pregnancies. CA 125 is a known marker for ovarian cancer found to be elevated during the first trimester of pregnancy and in women with pelvic inflammatory disease. The present study investigated the usefulness of these parameters to predict the outcome of pregnancy in asymptomatic patients with a positive pregnancy test after in-vitro fertilization and embryo transfer (IVF-ET). Blood samples (n = 159) were obtained at different periods of time post-ET from 39 women, 21 of whom experienced a normal pregnancy, 12 had an intrauterine abortion and six had an ectopic pregnancy. PAPP-A and CA 125 were measured by radioimmunoassays. From day 30 onwards in normal pregnancies, PAPP-A was significantly increased over non-pregnant controls. In the spontaneous abortion group, the levels of PAPP-A were significantly lower than in normal pregnancy but higher than in non-pregnant controls. In ectopic pregnancy, PAPP-A remained at the level of non-pregnant controls throughout the entire observation period. CA 125 was significantly increased in all types of pregnancy. However, in two cases of hyperstimulation followed by a normal pregnancy and in four cases of ectopic pregnancy with signs of peritoneal irritation (hydrosalpinx, ruptured ectopic or salpingitis) the levels of CA 125 were 15-50 times higher than in normal pregnancies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of serum human chorionic gonadotrophin levels in normal singleton, multiple and abnormal pregnancies.

Some researchers claim that first trimester beta-human chorionic gonadotrophin (beta HCG) levels have a constant doubling time; others suggest doubling time increases as pregnancy progresses. This study was designed to settle the debate by analysing a large series of serial serum beta HCG determinations from 143 pregnant women whose day of ovulation was precisely determined. Regression analysis was used to evaluate linear and quadratic models for the relationship of HCG with time in normal pregnancies. Doubling times were calculated for three time periods: 10-20 days post-ovulation (period 1); 21-30 days post-ovulation (period 2); greater than 30 days post-ovulation (period 3). Analysis of variance was used to compare the mean doubling time by time period and type of pregnancy (single, multiple, spontaneous abortion and ectopic). The analysis showed that a quadratic model best described the pattern of HCG rise in early normal pregnancy. Furthermore, for normal pregnancies, the mean doubling time increased significantly with advancing gestational age between time periods 1 and 2 and between periods 2 and 3. The mean doubling time was the same for single and multiple pregnancies. The doubling time was prolonged with ectopic pregnancy in period 1; and for aborters reaching ultrasound at 8 weeks, the doubling time was normal in period 1 but prolonged in period 2. Careful observation of the doubling time may aid clinicians in the detection of abnormal pregnancies.     

Single progesterone assay for early recognition of abnormal pregnancy

Serum progesterone and human chorionic gonadotrophin (HCG) were analysed using a time-resolved fluoroimmunoassay in an unselected group made up of 158 women with clinical suspicions of abnormal early gestation. Only cases in which endovaginal sonography had failed to localize the pregnancy were included. A single HCG determination had no diagnostic value. On the other hand, a critical progesterone level of 30 nM was determined below which no viable intrauterine pregnancies were found. Eighty-eight per cent of the ectopic pregnancies (n = 97) and 83% of the spontaneous abortions had progesterone levels below this limit. The discriminatory efficacy of one single progesterone determination was independent of the actual HCG level and serial determinations of progesterone did not increase the discriminatory power.     

Pregnancy-associated plasma protein A in pregnancy-related gynaecologic emergency

Serum concentrations of pregnancy-associated plasma protein A (PAPP-A) were measured in patients with pregnancy-related gynaecologic emergencies including ectopic pregnancy (n = 124) and intrauterine abortion (n = 40). The results were compared with those in normal pregnancy (n = 136) and non-pregnant women (n = 460). In ectopic pregnancy and intrauterine abortion, the PAPP-A levels were lower than in normal pregnancy. In patients with a pregnancy-related gynaecologic emergency PAPP-A was undetectable in 82% of the ectopic pregnancies and in 55% of the intrauterine abortions. Considering the frequency of ectopic pregnancy (35.8%) and intrauterine abortion (52.3%) among all patients with pregnancy-related disorders, the likelihood that a pregnant patient with undectable PAPP-A has an ectopic pregnancy is 30%, and intrauterine abortion is 29%. These results indicate that although PAPP-A levels in ectopic pregnancy and intrauterine abortion are lower than in normal pregnancy, PAPP-A measurement cannot be used to distinguish between ectopic pregnancy and intrauterine abortion.     

ROC曲线对妊娠结局预测模式的评价

目的通过监测正常早孕、自然流产与异位妊娠妇女血清绒毛膜促性腺激素(β-HCG)及孕酮(P)水平,建立正常早孕、自然流产与异位妊娠的妊娠结局预测模式,并利用ROC曲线评价其预测妊娠结局的能力。方法选择正常早期单胎妊娠对照组191例,自然流产患者150例、异位妊娠患者204例。用电发光免疫法测血清β-HCG及P水平,建立单独β-HCG、P以及β-HCG和P联合积分预测模式。结果正常早孕组孕龄血清β-HCG平均值为(7812.52±3599.29)IU/L,P平均值为(35.27±12.91)nmol/L;自然流产组血清β-HCG平均值为(1298.07±1808.83)IU/L,P平均值为(6.66±4.42)nmol/L;异位妊娠组β-HCG平均值为(2118.23±2905.75)IU/L,P平均值为(6.37±5.58)nmol/L;自然流产组血清β-HCG及P水平明显低于正常早孕对照组,独立样本t检验t=21.75,P=0.000(95%CI:5925.31-7103.79)及t=28.49,P=0.000(95%CI:26.52-30.46),差异有显著性意义;异位妊娠组血清β-HCG及P水平明显低于正常早孕对照组,独立样本t检验t=17.25,P=0.000(95%CI:5045.02-6﹤343.57)及t=28.32,P=0.000(95%CI:26.79-30.79),差异有显著性意义;自然流产组与异位妊娠组血清β-HCG差异有显著性意义,t=-3.27,P=0.001(P<0.05),两组P水平差异无统计学意义,t=0.57,P=0.57(P>0.05);通过ROC曲线分析血清β-HCG、P水平及联合积分预测妊娠结局的能力,曲线下面积分别为0.879、0.973、0.984,(P值均<0.05),95%CI分别为(0.845-0.913)、(0.959-0.986)、(0.973-0.994)。结论单独P较β-HCG水平具有更好的预测非正常妊娠的能力;联合积分预测妊娠结局的能力最强;单独P和联合积分与单独β-HCG预测妊娠结局的能力的差异有统计学意义,但二者的差异无统计学意义;随妊娠时间的延长,正常早孕β-HCG水平有迅速增加的趋势,异位妊娠有缓慢增加的趋势,而自然流产则有降低趋势;P水平不能有效区分自然流产与异位妊娠。     

Distinction between early normal intrauterine pregnancies and pathological pregnancies by means of a logistic model.

The probability of an unclear very early pregnancy being a normal intrauterine pregnancy was estimated using a logistic model. Five diagnostic measures of prognostic value were identified in the model: (i) daily change in human chorionic gonadotrophin (HCG), (ii) results of transvaginal ultrasound, (iii) vaginal bleeding, (iv) serum progesterone level and (v) risk score for ectopic pregnancy. With the use of this model, the probability of a normal intrauterine pregnancy has been estimated as 96.7%.     

Placental protein 14 in human in-vitro fertilization early pregnancies.

Placental protein 14 (PP14) and human chorionic gonadotrophin (HCG) were analysed in patients participating in an in-vitro fertilization-embryo transfer programme which did not include any kind of luteal support. Women with normal pregnancies, spontaneous abortions, ectopic pregnancies, biochemical pregnancies and non-pregnant women were compared. A combination of HCG and PP14 analyses distinguished between normal and abnormal implantation as early as 15 days after oocyte retrieval. The product of HCG (IU/l) and PP14 (micrograms/l) concentrations differed significantly between normal pregnancy, spontaneous abortion and ectopic pregnancy (P = 0.0248). It is concluded that both endometrial (PP14) and trophoblastic (HCG) markers, when used in combination, exhibit changes in abnormal implantation which may be clinically useful.     

Pregnancy: Heterotopic pregnancies after in-vitro fertilization and embryo transfer

A total of 20 cases of heterotopic pregnancy were encounteredamong 2650 clinical pregnancies (0.75%) resulting from in-vitrofertilization/embryo transfer at Bourn Hall Clinic (Cambridge,UK) during the period July 1984-July 1993. The aetiology ofheterotopic pregnancy in the series is multifactorial, withtubal damage as the main factor. Transvaginal ultrasonographyshowed a high sensitivity for making correct diagnoses of heterotopicpregnancies compared with transabdominal ultrasonography (93.3versus 50.0%). The mean plasma human chorionic gonadotrophin(HCG) concentration on day 13 after embryo transfer was similarto those of uncomplicated intrauterine pregnancies and hencewas of no diagnostic value. The serial plasma HCG concentrationsof patients who delivered were significantly higher than forthose who aborted their intrauterine pregnancies (P < 0.01),although the sample of data available was too small to makefirm inferences. It does appear that serial HCG concentrationsmay have a predictive value of fair accuracy regarding the outcomeof the intrauterine pregnancy in heterotopic pregnancies. Theclinical presentations of the 20 cases at first examinationwere quite variable, with 45% (9/20) of patients asymptomatic.Tubal pregnancy in one patient resolved spontaneously, two caseswere treated by an injection of potassium chloride into thegestational sac and the remaining 17 cases were treated by salpingectomy.In 10 patients the intrauterine pregnancy resulted in live birthand the remaining 10 patients aborted spontaneously.     

Pregnancy: Corpus luteum failure in ectopic pregnancy

The endocrinology of ectopic pregnancy was studied in orderto investigate the origin of the discordance in the circulatingamounts of human chorionic gonadotrophin (HCG) and those ofoestradiol and progesterone. Serial maternal blood samples wereobtained at 4–9 weeks gestation from 93 patients who becamepregnant following in-vitro fertilization and embryo transferincluding 10 ectopic, 21 anembryonic and 62 normal singletonpregnancies. The samples were analysed for HCG, Schwangerschaftprotein-1 (SP-1), pregnancy-associated plasma protein-A (PAPP-A),progesterone and oestradiol. In ectopic pregnancies, concentrationsof all substances analysed were significantly reduced comparedto singleton pregnancies from 5 weeks gestation (P < 0.05–0.001)but they were not significantly different from those of anembryonicpregnancies. In ectopic pregnancies, associations were foundbetween the concentration of both HCG and SP-1 and those ofprogesterone and oestradiol. No associations were found betweenPAPP-A and any other substances analysed. This may be due toinsensitivity of the PAPP-A assay; alternatively PAPP-A concentrationsmay be differentially reduced in ectopic pregnancy. These findingssuggest that progesterone and oestradiol are derived from thecorpus luteum in early ectopic pregnancy but that the corpusluteum fails rapidly and the dominant source of both hormonesbecomes the trophoblast as early as 5 weeks.     

Rapid diagnosis of early ectopic pregnancy in an emergency gynaecology service--are measurements of progesterone, intact and free {beta} human chorionic gonadotrophin helpful?

The clinical usefulness of measuring serum concentrations ofprogesterone, human chorionic gonadotrophin (HCG) and the free-subunit of HCG in distinguishing between early viable and non-viablepregnancy, before an accurate ultrasound diagnosis is possible,was evaluated in a prospective study of patients presentingto our emergency gynaecology service with a clinical suspicionof ectopic pregnancy. Patients were selected on the basis ofinitial HCG concentrations; samples with HCG 25–10 000IU/I were later analysed for progesterone and free HCG. Of the181 patients studied, 38 (21%) had an ectopic pregnancy, 108(60%) had a spontaneous abortion and 35 (19%) had a viable intra-uterinepregnancy. Concentrations of HCG and free HCG in the group withviable pregnancies were significantly higher than in the groupwith ectopic pregnancy (P < 0.001) and than those destinedto miscarry (P < 0.01). Progesterone concentrations werealso significantly higher in the viable versus the ectopic andthe spontaneous abortion groups (P < 0.001 in each case).Despite these highly significant differences there was a degreeof overlap such that it was impossible to devise a cut-off levelfor any hormone analysed, either singly or in combination, whichwould offer a clinically useful predictor of outcome.     

Rare association of ovarian implantation site for patients with heterotopic and with primary ectopic pregnancies after ICSI and blastocyst transfer

Two cases of patients with ruptured ovarian pregnancies (P1 = ovarian heterotopic and P2 = primary ovarian ectopic) after intracytoplasmic sperm injection and blastocyst transfer are presented. Laparoscopy was performed on day 40 and day 27 after transfer in cases P1 and P2 respectively. In both cases the ectopic pregnancies were located on the left ovary and were successfully removed by laparoscopy preserving the ovaries. In case P1 the intrauterine pregnancy was not affected. A healthy boy was born after 37 weeks of pregnancy. In this way, potential fertility of the patients and the intrauterine pregnancy were maintained. These cases occurred during a series of blastocyst transfers in which 129 pregnancies were obtained. There were no cases of ovarian ectopic/heterotopic pregnancies from January 1996 to September 1999 in 814 pregnancies obtained from day 2 or day 3 embryo transfers. Because the ovarian ectopic pregnancies occurred in patients with day 5 embryo transfer who otherwise did not have any predisposing factors for ectopic pregnancy, it is advisable to conduct a large scale analysis of future data about the possible association between blastocyst-stage embryo transfer and the somewhat higher risk of unexpected complications of clinical outcome.