DIAGNOSIS OF GENITAL Chlamydia trachomatis infections is important, because untreated infections in women may have great impact on public health, both on an individual level and on the community level. A variety of methods for detecting chlamydial infection exist.1 Previously, diagnosis by culture was “the gold standard.” Within the last few years, methods that use amplification of nucleic acids have been introduced. Polymerase chain reaction (PCR) and ligase chain reaction using primers specific for the endogenous plasmid are very sensitive methods.2–4 In female sexually transmitted disease (STD) populations, the prevalence of C. trachomatis infection has been reported to be as much as 27.1%,5 whereas in women from the general population, it has ranged from 4.5% to 9.2%.2,3,6,7 Within the last decade, the prevalence has shown a decreasing trend, most likely because of increased screening and treatment.8 Until recently, risk factors for C. trachomatis have mostly been examined using nonamplification detection methods. The objective of this study is to investigate the prevalence of and the risk factors for genital C. trachomatis in cervical scrapes as detected by PCR in a random sample of younger Danish women from the general population. From May 1991 to January 1993, a population-based cohort of 11,088 women (aged 20-29 years) was established with the purpose of studying risk factors for cervical neoplasia with emphasis on human papillomavirus (HPV) infection. Enrollment and data collection procedures are described elsewhere.9 Briefly, all participants were personally interviewed and had a gynecologic examination in which material for HPV and C. trachomatis testing were collected. A sample of 525 women was randomly chosen from the cohort. They were all tested for genital infection with C. trachomatis. However, the samples from 3 women were not adequate for testing; therefore, the remaining 522 women formed the study population for this article. Cervical swabs from the ectocervix and endocervix were taken using cotton-tipped swabs, which were placed in a tube with 2 ml of Tris HCl-EDTA buffer and kept frozen at −80°C until they were used. After thawing and vigorous vortexing, the swabs were removed. Ten μl of crude cell suspensions of these cervical scrapes were boiled for 10 minutes, chilled on ice, and subsequently used for PCR analyses. To examine whether the samples were suitable for PCR amplification, they were screened by a PCR specific for the human beta-globin gene.3 Subsequently, C. trachomatis PCR was performed as described previously.4 Polymerase chain reaction products were analyzed by a nonradioactive enzyme immunoassay (EIA).10 Dilutions of C. trachomatis serovar L2 DNA were used as positive controls. Cut-off values used in PCR-EIA were OD values corresponding to 0.01 to 0.1 inclusion forming unit (IFU) L2 DNA.4 Our PCR test is slightly more sensitive than the commercially available C. trachomatis detection systems (e.g., Amplicor [Roche Diagnostic Systems, Basel, Switzerland] 1 IFU), and the specificity is similar to those reported for the commercially available tests (>99.5%). Initial evaluation of data included univariate analysis, whereby the association between each variable and outcome was measured by the prevalence odds ratio (POR) and 95% confidence interval (CI). Variables related to having genital C. trachomatis were subsequently evaluated by means of a multiple logistic regression analysis to adjust for potential confounding. The prevalence of C. trachomatis was 6.7% (35/522). Age was a strong determinant for having genital chlamydial infection (Table 1). Women 20 to 22 years of age and 23 to 24 years of age had, respectively, a 5.1 times and 2.6 times higher risk of chlamydial infection than 25- to 29-year-old women (95% CI: 2.0-12.8 and 0.9-7.2, respectively).TABLE 1: Determinants for PCR-Detected Genital Chlamydia trachomatis Among 522 Young Women From CopenhagenLikewise, lifetime number of sex partners was a predictor for genital C. trachomatis. After adjustment, women with five to nine partners were 4.8 times more likely to have chlamydial infection than women with zero to four partners (95% CI: 1.8-12.7). Having had 10 or more sex partners increased the risk 2.8 times, although it was not a significant increase (95% CI: 0.9-8.8). Women who had used a barrier contraceptive method (condom or diaphragm) for ≥5 years had a 60% decreased risk of chlamydial infection compared with women who had never used this method or who had only used it for ≤1 year, although the association was not significant. However, the trend was significant (p < 0.02). No association was observed with the use of oral contraceptives (OC), neither with ever use of OC nor with duration of OC use (data not shown). In the crude analysis, ever pregnant women had a significantly lower risk of C. trachomatis infection than women who had never been pregnant (POR = 0.3; 95% CI: 0.1-0.9). However, after adjustment, the association was no longer significant. We also observed a tendency toward women who reported a history of genital chlamydial infection having a decreased risk of current C. trachomatis detection (POR = 0.4). However, the association did not reach statistical significance. Finally, no significant association with detection of C. trachomatis was observed for smoking, education, and “sexual” variables other than from lifetime number of sex partners (e.g., age at first intercourse and partners before the age of 20 years) (data not shown). The prevalence of genital chlamydial infection in our randomly sampled study group of women from the general population resembles that found by other investigators in population-based studies using PCR and ligase chain reaction.2,3 The determinants for having genital C. trachomatis in our plasmid-PCR-based study are in accordance both with studies using other diagnostic methods5–7 and with the newer PCR-based method.11–14 Younger age, increasing number of sex partners, and increasing years without use of barrier contraception are the major risk factors. The use of OCs as a risk factor for C. trachomatis has been a matter of debate. It has been suggested that OC increases the accessible transitional zone (ectopy), thereby making the cervix more susceptible to infection with C. trachomatis.15 However, another suggested explanation is that the ectopy increases the likelihood of detecting the infection because of more effective sampling in OC users.16 We have used a very sensitive method that might detect C. trachomatis independently of the size of the transitional zone and, therefore, may have overcome the problem of detection-bias. However, to address the effect of OC use more accurately, an analysis including the timing of OC use in relation to the occurrence of C. trachomatis infection is needed. Studies have indicated that pregnant women have an increased risk of genital C. trachomatis.17 This has been attributed to increased hormonal levels and lowered immunity during pregnancy. In the current study, ever pregnant women had a decreased risk (although not significant) of current C. trachomatis infection compared with never pregnant women. A similar association has been shown previously regarding another STD (HPV).18 Number of recent partners has been shown to be a good predictor of genital chlamydial infection, and it could be hypothesized that young, ever pregnant women have had a recent period of monogamy in connection with the pregnancy, and likewise, their partners have probably also been monogamous. Therefore, the risk of currently being infected with genital chlamydial infection is decreased. Being a current smoker has been shown to be correlated positively with sexual habits.19 Therefore, it is a variable that has to be taken into account when risk factors for an STD are evaluated to adjust for the possible confounding effect. However, in line with Willmott,19 we found no effect of smoking per se on the risk of currently being infected with C. trachomatis. Immunity against genital C. trachomatis has been much discussed. In the current study, the risk of C. trachomatis infection increased with lifetime number of sexual partners until a certain point, whereafter it leveled off. This could indicate that women with multiple sex partners acquire immunity against chlamydial infection. Like C. trachomatis, HPV is sexually transmitted, and both infections frequently occur in younger populations. Therefore, the risk of repeated infections with HPV or C. trachomatis is much higher than for STDs with a low prevalence. For HPV, it has been shown that repeated exposure can lead to acquired immunity.18,20 The women in the study group were also tested for genital HPV DNA, which was detected by PCR in 15.5% of the women (81/522). In Figure 1, the prevalence of C. trachomatis and HPV according to number of partners is shown. The profiles of the prevalence curves are very similar. For C. trachomatis, we also stratified by age and the profile of the prevalence curve in each age stratum was identical to the one shown in Figure 1. Accordingly, as in the case of HPV, it can be hypothesized that repeated exposure leads to acquired immunity against C. trachomatis. However, for C. trachomatis, several different outer membrane protein genotypes have been identified. Therefore, immunity may be strain specific and/or shortlived. Finally, we found a tendency toward a “protective” effect of former genital chlamydial infection (self-reported). This may also support that immunity against C. trachomatis exists.FIG. 1: Prevalence of genital HPV and C. trachomatis according to lifetime number of sex partners.However, it should be emphasized that our results are based on a small number of infected individuals, and it can not be excluded that the associations are confounded by behavioral changes over time that we could not adjust for. Further investigation of the immune response to evaluate the extent of spontaneous regression of C. trachomatis is needed-ideally in a prospective design.

Sexual behavior has been consistently identified as a major risk factor for cervical cancer. Population-based studies have demonstrated that risk related to sexual activity is mediated by human papillomavirus (HPV) infection. We conducted a case-control study of 199 cases with low-grade squamous intraepithelial lesions or high-grade squamous intraepithelial lesions as defined by cytology and 1000 control women selected from an ongoing prospective cohort study in Copenhagen, Denmark. Furthermore, 131 women with equivocal smears (atypical squamous cells of undetermined significance) were examined as a separate borderline case group. At enrollment, all women had a personal interview and a gynecological examination including cervical swabs for HPV testing and a Pap smear. HPV testing was performed using a combination of general primer 5/6-mediated and type-specific polymerase-chain-reaction-based methods. Cervical HPV infection was by far the most significant risk factor for cervical squamous intraepithelial lesions. The relationship with HPV was observed for all grades, while strength of association was greater for more severe lesions. The importance of the previously identified epidemiological risk factors for cervical neoplasia was also demonstrated. However, most of the effect of these factors could be explained by taking HPV infection into account, except for schooling and smoking. Non-use of barrier contraceptives and smoking were the only significant risk factors in HPV-positive women. In HPV-negative women, a residual effect existed for different measures of sexual activity, and use of oral contraceptives and smoking constituted significant risk determinants Overall, 66% of cases could be attributed to HPV; however, if the results were restricted to histologically confirmed high-grade lesions, the proportion of cases that could be attributed to HPV infection increased to 80%.

The role of smoking and other risk factors for cervical neoplasia was investigated in a population-based case-control study of 586 women with histologically verified cervical squamous-cell carcinoma in sitre (CIS), and 59 women with invasive squamous-celI cervical cancer from Copenhagen. Controls were randomly selected from the general female population using the computerized Danish Central Population Register. After adjustment for a variety of confounding variables, which were all significantly associated with CIS risk and included age, number of partners, proportion of sexually active life without barrier contraceptive use, years with intra-uterine devices, number of births, and age at first episode of genital warts (as a proxy measure for human papillomavirus exposure), current cigarette smoking was found to be significantly associated with CIS [adjusted relative risk (RR) = 2.4; 95% confidence interval (CI): 1.7-3.4]. Ex-smokers had a lower, but still significantly increased risk (RR = 1.6; 95% CI: 1.0-2.7). A dose-response relationship was present, especially for number of cigarettes smoked per day. In contrast, the crude estimates showed a weak association between invasive cervical cancer and smoking, which however disappeared after confounder control. The results of the present study support the hypothesis implicating smoking as a risk factor for CIS.

In a previous study, we have demonstrated that inhibin-production may be associated with improved survival and, also, that tetranectin (TN) is a valuable prognostic marker in ovarian epithelial cancer. We investigated the possible correlation between inhibin, tetranectin, CA-125, ovarian steroid activity and the gonadotropin levels. Preoperative serum levels of the tumor markers inhibin, tetranectin (TN) and CA-125 were measured and related to ovarian steroid function and the pituitary-gonadal axis (gonadotropin levels) in 28 postmenopausal ovarian cancer patients. The following median levels and 95% confidence limits were demonstrated for the tumor markers: Inhibin 0.4 U/l (0.2-0.9), TN 8.9 mg/l (6.8-9.2), CA-125 160 kU/l (75-687). A significant inverse correlation was demonstrated between inhibin and the gonadotropins. The Spearman correlation coefficients showed a highly significant correlation of inhibin with the examined ovarian steroid hormones except DHEAS which also has a suprarenal component. This indicates a synthesis of inhibin and the steroid hormones from the same cell compartment as known from the normal ovary and an apparently intact negative feed back mechanism. Inhibin may be produced in the normal ovary as a defense mechanism against an elevated gonadotropin level and inhibin acts by lowering the gonadotropins or by altering their biological activity. Elevated values of the tumor markers TN and CA-125 due to gonadotropin stimulation could not be demonstrated but a significant inverse correlation between TN and CA-125 was confirmed.

Although many investigations have shown a correlation between elevated gonadotropin levels and ovarian tumors (the gonadotropin theory), the ovarian response to a specific suppression of the gonadotropins has not been elucidated. The ovaries of (C57BL/6J x C3H/HeJ)F1-Wx/Wv mice, which contain 1% of the normal oocyte count at birth, rapidly lose the follicular apparatus and develop a 100% incidence of bilateral complex tubular adenomas from the surface germinal epithelium, which is also the origin of 90% of human ovarian carcinomas. Plasma levels of LH and FSH are known to rise fourfold during the period of tumorigenesis. We compared tumor development in Wx/Wv mice after either injecting a GnRH agonist (3.6 mg slow-release goserelin depot, Zoladex Depot) or administering a sham injection every 28 days from the age of 7 days up to 245 days. All 15 Wx/Wv mice that received sham injections developed bilateral ovarian tubular adenomas from the surface germinal epithelium. In none of the 11 mice receiving the GnRH agonist was any tumor found (p < 0.00005), and a significant suppression of the gonadotropins was demonstrated (p < 0.00005).

The vulvectomy specimens of 78 patients with vulvar squamous cell carcinoma were reviewed and examined for human papillomavirus (HPV) types 6, 11, 16, 18, and 33 by the polymerase chain reaction technique. The tumors were classified as keratinizing squamous cell carcinoma (KSC), as warty carcinoma (WC), and as basaloid carcinoma (BC). DNA of HPV types 16 and 33 was found in 2/51 KSC, in 12/17 WC, and in 10/10 BC. HPV types 6, 11, and 18 were not detected. Patients with WC and BC were younger, and 78% had VIN III lesions adjacent to the carcinoma. Patients with KSC were older and had a high incidence of dystrophic lesions, including lichen sclerosus, adjacent to the tumor. None of the KSC showed adjacent VIN III. In conclusion, vulvar carcinoma segregates into two categories, of which KSC seems to be the classic type, only rarely associated with HPV infection, and mostly affecting older women; WC and BC constitute an HPV-related subgroup of tumors occurring in younger patients and are associated with VIN III lesions from which they may emerge.

OBJECTIVES:To assess the feasibility of a randomised trial of ovarian cancer screening by vaginal ultrasonography.SETTING:A population based study, recruiting a random sample of the female population aged 46 to 65 years living in Copenhagen, Denmark.DESIGN:Randomised controlled trial allocating 50% to the study group having vaginal ultrasonography, and 50% to the control group having no examination. (a) Acceptability of the study was evaluated by the proportion of eligible women willing to participate in the study. (b) The false positive rate was evaluated as the proportion of women without ovarian cancer referred for an operation because of abnormal ovaries detected by ultrasonography.RESULTS:950 (64.3%) of the 1477 eligible women participated in the study. At the first scan abnormal ovaries were detected in 54 of 435 women (12%), significantly more frequently among younger women. Nine women were referred for an operation because of abnormal findings in the ovaries, giving a false positive rate of 2%. Ovarian size and morphology found at operation corresponded with those at ultrasonography; none of them was malignant.CONCLUSIONS:A randomised controlled trial of ovarian cancer screening using vaginal ultrasonography seems acceptable in the general population. The rate of abnormal ovaries at ultrasonography with the cut offs used in this study was quite high. Such a study is, therefore, feasible, but it is proposed that it is carried out in an older age group (50-64 years) and that the cut offs used for ovarian size and morphology are re-evaluated. Second line tests, such as colour Doppler flow, should be considered in order to reduce the false positive rate.

Serum CA 125 levels were evaluated in 71 patients undergoing second-look laparotomy for primary epithelial ovarian cancer. With a cut-off limit of 35 U/ml, 17 of 45 patients with residual disease (38%) were CA 125-positive. All of 26 patients with pathological complete response were marker-negative. Second-look laparotomy may be avoided in a select group of patients with elevated CA 125 values.

The polymerase chain reaction (PCR) was used to detect human papillomavirus (HPV) type 16 DNA in cervical swabs from 37 patients with HPV 16-harboring cervical lesions (15 carcinomas and 22 cervical intraepithelial neoplasias). Primers amplifying a sequence of the human beta-globin genome were used for internal control together with the HPV 16-specific primers. The cell samples were prepared for PCR analysis by two different methods: either by phenol/chloroform extraction or by boiling in the presence of a chelating agent. HPV 16 DNA was found in 27 swabs. The detection rates were identical with both methods of preparation. Four of the 10 false-negative swabs contained too little DNA to permit amplification with the genomic primers. Excluding these insufficient samples, the detection rate was 82%. Reasons for false-negative results may include low cell numbers or failure to obtain cells representative of the underlying lesion. In conclusion, the PCR offers a satisfactory method of HPV detection in cervical swabs. Cell preparation can be restricted to simple boiling with a chelating agent. For optimal results, samples containing less than 2 x 10(4) cells should be discarded, and genomic primers should be used for internal control.

The role of oral contraceptive (OC) use in relation to the risk of cervical neoplasia (squamous cell) was investigated in a population-based case-control study in Denmark of 586 women with histologically verified cervical carcinoma in situ (CIS), 59 women with invasive cervical cancer from Copenhagen, and 614 controls drawn at random from the female population in the study area. Ever use of OCs was associated with an increased crude risk for carcinoma in situ (relative risk [RR] = 1.8, 95 percent confidence interval [CI] = 1.3-2.5). The crude risk in relation to invasive carcinoma was 1.6 (CI = 0.7-3.5). After adjustment for potential confounders (excluding human papillomavirus), the risks were marginally increased, but not statistically significant (CIS: RR = 1.4, CI = 0.9-21: invasive: RR = 1.3, CI = 0.5-3.3). The risk increased with duration of use; compared with never users, the adjusted RR for carcinoma in situ was 1.9 (CI = 1.1-3.1) for women who had used OCs for six to nine years, and 1.7 (CI = 1.0-2.7) for women who used OCs for 10 years or more. This was independent of years since last use since both recent and non-recent long-term users were at an increased risk. This trend in risk with duration did not apply to the same extent to invasive lesions. The observation that the risks related to OC use were found both in women who had ever had a Pap smear and in women who had never been screened previously may speak against detection bias as an important factor.

Paraffin‐embedded sections of vulvar squamous‐cell carcinomas and of normal vulvar tissues were examined for HPV types 6, 11, 16, 18 and 33 by the polymerase chain reaction. Overall, 19 of 62 tumours harboured HPV DNA of types 16, 18 or 33. HPV types 6 and 11 were not detected. HPV DNA was found in 61% of tumours with adjacent intraepithelial neoplasia (VIN III), and in 13% of tumours without associated VIN III. HPV DNA was not detected in any of 101 normal vulvar tissues. HPV DNA was found more often in younger women, in patients with VIN III‐associated tumours, and in those with multicentric anogenital neoplasia. This points to the existence of a subset of vulvar carcinomas preceded by intraepithelial neoplasia, with HPV as a major factor in carcinogenesis. HPV also seems to be an important factor in the development of multiprimaries in these patients. The 2 groups of patients with vulvar carcinoma did not differ with regard to prognosis, as estimated by the risk of recurrence after primary surgery.

Serial estimates of the post-operative hormone levels were made in 15 women subjected to oophorectomy because of ovarian carcinoma. All women were post-menopausal. Pre-operatively, they had significantly lower follicle stimulating hormone (FSH) levels compared with an age-matched control group. Blood samples were collected after a median time of 8 months (139-378 days). After oophorectomy, significantly higher FSH values were found (P = 0.0002), whereas the luteinizing hormone (LH) values were not significantly changed. The inhibin, estradiol and progesterone values were found to be significantly lowered compared with the pre-operative sample. Total and unbound testosterone levels were significantly lower while dehydroepiandrosterone sulphate (DHEAS) and androstenedione levels were unchanged compared with the original sample and compared with controls. Most likely, estradiol and progesterone are produced by the epithelial malignant tumors, as the post-operative values are completely comparable with the primarily included healthy controls. The FSH is suppressed by inhibin and only to a minor degree by the steroid hormones as indicated by the correlation coefficients. Of great interest is the question whether inhibin production is random, or defensive, lowering the gonadotropin levels or influencing tumor growth in some hitherto unknown fashion.

In post-menopausal women with a malignant epithelial ovarian tumor the follicle stimulating hormone (FSH) level was found to be significantly lower compared with healthy controls. We demonstrated immunoreactive (i.r.) inhibin in 20% of controls which was elevated to 60% of women with an ovarian tumor and correlating strongly to FSH in the tumor group (P = 0.0002). Steroid hormone levels were comparable in the two groups. In women with ovarian tumors the survival time for the i.r. inhibin-producing women was found to be 4.6 years compared wirh 0.9 year, or 5.1 times longer than in the non-producing women (P = 0.002). The site of i.r. inhibin production in these post-menopausal women is unknown, but i.r. inhibin production by the developing ovarian tumor or by the post-menopausal ovary may be regarded as a defense mechanism against an elevated gonadotrophin level (the gonadotrophin theory) which would promote further tumor growth. The recent suggestion that the alpha subunit of inhibin is a tumor suppressor gene is consistent with these results. The serum i.r. inhibin or alpha subunit concentrations might be used as an aid to diagnosis or as a prognostic indicator of survival in women with an ovarian carcinoma.

When a significantly lower follicle stimulating hormone (FSH) level was found in patients with epithelial ovarian carcinoma, it was decided to analyze the influence of hormonal factors on prognosis. Thirteen factors were tested for prognostic significance in 35 women with epithelial ovarian carcinoma. Age, FIGO-stage, histopathological grade, residual tumor, treatment, gonadotrophins and steroid hormones were tested. By univariate log-rank testing a significantly shorter survival time was found for patients with ascending FIGO-stage, residual tumor mass, estradiol < 0.10 nmol/l, progesterone < 2.0 nmol/l and DHEAS < 1300 nmol/l. In the Cox model the independently significant prognostic factors found were residual tumor mass (P < 0.001) with a risk estimate of 2.65, progesterone (P < 0.05) with a risk estimate of 0.29 for a progesterone level > 2.0 nmol/l and total testosterone (P < 0.03) with a risk estimate of 0.29 for a total testosterone level > 1.15 nmol/l. The present findings, together with the assumption that an elevated gonadotrophin level may induce ovarian tumor growth (the gonadotrophin theory), earlier findings of estrogen and progesterone receptors in human ovarian cancer, and the in vitro demonstration of gonadotrophin-growth-stimulation of human malignant epithelial tumors, justify a thorough investigation of the interaction between steroid hormones and receptors, gonadotrophins, tumor bulk and survival in future research protocols.

Investigation of the techniques employed in sterilization of women in Denmark in 1990 was undertaken and compared to an equivalent investigation done in 1985. A questionnaire was sent to all hospitals in Denmark, Greenland and the Faroe Islands. Among the departments returning the questionnaire and carrying out sterilization of women in 1990, 29 departments were specialized gynaecological departments, 31 were non-subspecialized surgical departments and five were medical/surgical departments. Laparoscopic sterilization was used in every specialized gynaecological department. The percentage of surgical departments using this method has increased from 41.3 in 1985 to 87.0 in 1990. In 1990, bipolar electrocoagulation and clip-technique were the most frequently employed laparoscopic methods. In 1985 it was bipolar electrocoagulation. Five departments are still using unipolar electrocoagulation. In 1990, hysteroscopy mainly took place in the western part of Denmark.

The incidence of cervical cancer in Greenland is one of the highest in the world. This is in accordance with known epidemiologic risk factors, in particular of sexual lifestyle and tobacco smoking. Yet a recent study of cervical smears from randomly selected Greenlandic women failed to demonstrate any elevated prevalence of human papillomavirus (HPV), of which particularly HPV types 16 and 18 are assumed to play a role in the development of cervical dysplasia and carcinoma. Another oncogenic virus, Epstein-Barr virus (EBV) is known to be widespread in the Greenlandic population and the virus has been reported to infect the female genital tract. We therefore used the polymerase chain reaction to examine paraffin-embedded tissues of cervical carcinomas from 11 indigenous Greenlandic women and, for comparison, also cervical carcinoma tissues from 11 Danish patients, for EBV, HPV 16 and HPV 18 DNA sequences. None of the 22 cervical tissues contained EBV DNA. Six Greenlandic and five Danish carcinomas harbored HPV 16 DNA, and one carcinoma of each group was HPV 18-positive. In conclusion, cervical carcinoma is not associated with EBV infection. Further, the oncogenic HPVs are probably encountered at the same rate in carcinomas from Greenland and from Denmark.

Carbohydrates related to the ABO, Tn, and T blood group systems are markers of cellular differentiation in many epithelial tissues. Using a panel of specific monoclonal antibodies, we have immunohistochemically investigated the expression of mucin-type (type 3 chain ABO-related) antigens in 64 samples of normal cycling endometria of known ABO and Lewis blood type. Tn and T antigens had a highly restricted expression in normal cycling endometrial tissue. The expression of type 3 chain H and A antigens was always compatible with the ABO blood type of the individual and seems to be regulated by the secretor genes, as secretors [Lewis (a-b+)] expressed more A and H type 3 chains than nonsecretors [Lewis (a+b-)]. The expression of type 3 chain H and A, sialyl-Tn and sialyl-T antigens showed cyclic variations in the glandular epithelium of the functionalis, but not of the basalis layer of cycling endometrium. A hormonal regulation of the enzymes involved in blood group-related carbohydrate chain elongation in human endometrium is thus possible and may participate in the specialized secretory process of human cycling endometrium.