The concentration of 13,14-dihydro-15-keto prostaglandin F2 alpha and prostaglandin E2 in peritoneal fluid of infertile patients with and without endometriosis

Obstetrical Complications in Women with Endometriosis: A Cohort Study in Japan

Background

Endometriosis, which occurs in approximately 10% of women of reproductive age, is defined as the presence of endometrial tissue outside the uterus. Women with endometriosis are more likely to have difficulty conceiving and tend to receive infertility treatment, including assisted reproductive technology (ART) therapy. There has not yet been a prospective cohort study examining the effects of endometriosis on pregnancy outcome in pregnant Japanese women.

Methodology

This was a prospective cohort study of the incidence of obstetrical complications in women with endometriosis using data of the Japan Environment & Children’s Study (JECS). Included in this study were 9,186 pregnant women in the JECS with or without a history of endometriosis who gave birth or stillbirth or whose pregnancy was terminated with abortion between February and December 2011.

Main Outcome Measures

The effects of endometriosis on pregnancy outcome.

Results

Of the 9,186 pregnant women in the JECS, 4,119 (44.8%) had obstetrical complications; 330 participants reported a diagnosis of endometriosis before pregnancy, and these women were at higher risk for complications of pregnancy than those without a history of endometriosis (odds ratio (OR) = 1.50; 95% confidence interval (CI) 1.20 to 1.87). Logistic regression analyses showed that the adjusted OR for obstetrical complications of pregnant women who conceived naturally and had a history of endometriosis was 1.45 (CI 1.11 to 1.90). Among pregnant women with endometriosis, the ORs of preterm premature rupture of the membranes (PROM) and placenta previa were significantly higher compared with women never diagnosed with endometriosis who conceived naturally or conceived after infertility treatment, except for ART therapy (OR 2.14, CI 1.03–4.45 and OR 3.37, CI 1.32–8.65).

Conclusions

This study showed that endometriosis significantly increased the incidence of preterm PROM and placenta previa after adjusting for confounding of the data by ART therapy.

Pathophysiology. The biologic principles of disease

Endometriosis, although associated with a large variety of symptoms, primarily produces pain and infertility; however, the strong correlation with these disorders, along with basic questions as to why endometriosis develops, when does it become a disease status, and why it's associated with symptoms such as pain or infertility, are still not well understood. A better understanding of the relationship between disease and symptoms of endometriosis must be acquired if effective progress in the treatment of pain and infertility related to endometriosis is to be made.

Endometrial leukocyte subpopulations in women with endometriosis

The aim of this study was to investigate whether the endometrium of women with endometriosis differs immunologically from the endometrium of normal fertile women. Endometrial biopsies were obtained from 18 normal fertile women who were requesting sterilisation or reversal of sterilisation and 21 infertile women who had laparoscopically diagnosed pelvic endometriosis. The endometrial biopsies were obtained from both groups during the either early, mid or late luteal phase of the menstrual cycle. A panel of 11 monoclonal antibodies and immuno-histochemical techniques were employed to characterise the endometrial stromal leukocytes in frozen sections. Image analysis was used for semi quantitation of leukocytes. In both groups, the number of endometrial granulated lymphocytes (CD56+ CD38+ cells) and macrophages (CD68+ cells) increased significantly between the early and late luteal phase of the menstrual cycle. Compared with fertile controls, women with endometriosis had fewer T-suppressor/cytotoxic (CD8+) cells and endometrial granulated lymphocytes but more T-helper/inducer (CD4+) cells, CD68+ cells and CD16+ cells. None of these differences reached a statistically significant level. This study has shown that the endometrial lymphoid tissue of women with endometriosis does not differ qualitatively or quantitively from that of normal fertile controls. However, functional differences of endometrial leukocytes between the two groups cannot be excluded.

Endometriosis-associated infertility

Despite intense clinical interest and increasingly sophisticated diagnostic techniques, we know surprisingly little of the relationship between endometriosis and infertility or the mechanism of infertility in these couples. No therapy specifically directed toward the ectopic endometrial implants, medical or surgical, has been demonstrated to improve the likelihood of pregnancy for couples with endometriosis-associated infertility. This is consistent with the observation that, in the absence of mechanical distortion of the pelvic viscera, no therapy directed against the implants improves the likelihood of pregnancy in these couples. The reason for this lack of progress is most probably that the mechanism of infertility in these couples remains to be determined. At present, it would be more accurate to say that these couples have unexplained infertility. The most promising therapeutic approach is to treat women with endometriosis-associated infertility with a non-specific cycle fecundity enhancing technique. Typically this is one of the newer assisted reproductive technologies such as controlled ovarian hyperstimulation with intrauterine insemination of capacitated sperm. Since the fecundity of many of the women with endometriosis in the later reproductive years is rapidly declining, this may represent their most cost-effective option for establishing a pregnancy. Only with further effort directed towards determining the mechanisms of infertility in these couples will a more effective therapy be forthcoming.

The effect of preovulatory peritoneal fluid from cases of endometriosis on murine in vitro fertilization, embryo development, oviduct transport, and implantation

OBJECTIVE

The null hypothesis of our study is that the success of in vitro and in vivo murine fertilization and embryo development is not decreased by gamete exposure to peritoneal fluid from superovulated patients with endometriosis.

STUDY DESIGN

A murine in vitro fertilization model was used to test the effects of endometriosis versus nonendometriosis peritoneal fluid at concentrations of 1%, 5%, and 10% versus an unsupplemented control. Fertilization and blastocyst formation were compared by analysis of variance. In a second experiment superovulated mice were given intraperitoneal injections of endometriosis or nonendometriosis fluid or saline solution 8 hours after human chorionic gonadotropin and then mated. Some mice were killed 3 days after coitus to assess embryo number, cleavage stage, and uterine versus tubal position by means of analysis of variance and covariance with repeated measures. Others were killed 12 days after coitus with the mean number of implantations per animal between groups compared by Student's t test.

RESULTS

In vitro fertilization rates decreased as peritoneal fluid concentration increased in both the endometriosis (65%, 43%, 33%) and nonendometriosis (65%, 52%, 35%) groups at 1%, 5%, and 10% peritoneal fluid concentration, respectively. Mice receiving intraperitoneal endometriosis or nonendometriosis fluid or saline solution injections showed no differences in embryo number, cleavage, uterine versus tubal position, or mean implantation number.

CONCLUSION

Peritoneal fluid from superovulated patients had no differentially negative effect when compared with the effect of nonendometriosis peritoneal fluid on murine in vitro or in vivo fertilization and embryo development, tubal embryo transport, or implantation.

Menstrual symptoms in women with pelvic endometriosis

OBJECTIVE

To investigate menstrual symptoms in relation to pelvic pathology.

DESIGN

A prospective questionnaire-based study.

SETTING

Aberdeen Royal Infirmary, Scotland.

SUBJECTS

1250 questionnaires were sent out prior to planned admission and 1200 women (96%) brought the completed questionnaires. They comprised 598 women undergoing laparoscopic sterilization, 312 having laparoscopy because of infertility, 156 having laparoscopy because of chronic pelvic pain and 134 women undergoing abdominal hysterectomy for dysfunctional uterine bleeding.

MAIN OUTCOME MEASURES

The occurrence of dysmenorrhoea, menorrhagia, menstrual regularity, premenstrual spotting, deep dyspareunia and pelvic pain in women with either endometriosis and post infective pelvic adhesions or a normal pelvis.

RESULTS

Menorrhagia, menstrual irregularity and premenstrual spotting occurred with equal frequency in all groups. Deep dyspareunia, pain after intercourse and recurrent pain unrelated to menstruation or coitus was more common in women with endometriosis and those with post infective pelvic adhesions than in those with a normal pelvis. Dysmenorrhoea appears to be more prevalent among women having endometriosis.

CONCLUSIONS

Menstrual symptoms, while raising a high index of suspicion for endometriosis, are not entirely reliable as indicators of disease. Dysmenorrhoea is the most common reported symptom in endometriosis sufferers. Diagnostic laparoscopy should be considered before institution of treatment in women complaining of pelvic pain and menstrual symptoms.

Endometriosis and infertility

The relationship of endometriosis, the most common benign gynaecological disease during reproductive life, to infertility is generally ill understood. The association between infertility and minimal to mild endometriosis, when no anatomical defect is evident, may be explained by the following possible mechanisms: alternations in peritoneal fluid (macrophages - immunoglobulins, Interleukin-1, protease inhibitors, prostanoids, an ovum capture inhibitor), ovulatory dysfunctions (anovulation, LUF syndrome), luteal phase defect, disturbed implantation, and spontaneous abortion. These possibilities are discussed. The latest prospective controlled studies offer strong evidence that endometriosis per se is not a direct cause of infertility. On the other hand, the disease usually deteriorates if not treated, and therefore medical or surgical interventions are often needed when expectant treatment or other infertility therapies, e.g., ovulation induction, fail to result in pregnancy. Women with minimal to mild endometriosis only should be diagnosed as having unexplained infertility, which today may be treated by in vitro fertilization.

Prostaglandin and leukotriene concentration of the peritoneal fluid of endometriosis and other gynecologic disorders in the secretory phase

In order to investigate whether prostanoids are involved in the pathophysiology of endometriosis, prostaglandin and leukotriene concentrations in peritoneal fluid were measured in adenomyosis, ovarian chocolate cyst and uterine leiomyoma. In the secretory phase, there was no significant difference in 6-keto PGF1 alpha concentration in peritoneal fluid between the adenomyosis group and the leiomyoma group. TXB2 concentration did not significantly differ in the three study groups. Leukotriene C4 level in the adenomyosis group was significantly higher than that of leiomyoma in the secretory phase. Leukotriene B4 could not be detected by our assay system. Our results suggest that leukotriene C4 is possibly involved in the pathophysiology of endometriosis.

Peritoneal fluid eicosanoids in chronic pelvic pain

Products of the cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism were estimated in the cul-de-sac fluid from patients with endometriosis, pelvic adhesions and normal laparoscopic examinations, with and without chronic pelvic pain. No correlation between the symptoms, underlying diagnoses, and the concentrations of eicosanoids were observed.

The association of anovulation and endometriosis in the infertile female

Ninety-six infertile patients with endometriosis were studied and their endometriosis staged according to the Revised American Fertility Society Classification. Anovulation was detected in 19% of the 32 patients with Stage 1 disease but in only 3% in the remaining 64 patients with Stage II, III and IV disease. These results show that contrary to traditional belief, anovulation does occur in a significant number of patients with endometriosis, especially in minimal or mild disease.

[Early forms of ovarian cancer--are there borderline tumors?]

The early development of ovarian cancer remains unclear. Inclusion cysts or papillary excrescences of the germinal epithelium probably play a role. After a preinvasive stage, these lesions undergo secondary malignant transformation. The issue of borderline tumors is made complicated by diagnostic imprecision and by the fact that the peritoneal epithelium can develop autonomous tumors that look like metastases.

Effect of ovarian endometriosis on ovulation in rabbits

To study the relationship between endometriosis and ovulatory dysfunction, we induced ovarian endometriosis in the rabbit model Adipose tissue was placed in the contralateral ovary as a control. Ovulation was induced with human chorionic gonadotropin, and ovulation points were counted before and after induction of endometriosis. Periovarian adhesions were graded, and ovaries were histologically examined. A significant decrease in the number of ovulation points was observed in ovaries with endometrial tissue (p = 0.001) but not in ovaries that contained adipose tissue (p = 0.095). Periovarian adhesions decreased the number of ovulation points (p less than 0.01) in ovaries that contained adipose or endometrial tissues. Multivariate analysis demonstrated that an increase in adhesion severity was correlated with a decrease in the number of ovulation points (p less than 0.05), but endometrial tissue was not (p = 0.45). We conclude that, in the rabbit model, minimal ovarian endometriosis impairs ovulation primarily through a mechanism related to periovarian adhesions.

Limited hormonal responsiveness of ectopic endometrium: histologic correlation with intrauterine endometrium

In order to assess the hormonal responsiveness of ectopic endometrium, 438 unselected endometrial implants and corresponding intrauterine endometrium from 196 patients were evaluated and classified by standard endometrial dating criteria. Only 13% of the endometrial implants were histologically synchronous with the corresponding intrauterine endometrium. Both proliferative and secretory implants were present in relatively constant proportions throughout the menstrual cycle, demonstrating a lack of correlation with cyclic endogenous hormones. A significant percentage (range, 25% to 49%) of endometrial implants displayed some form of local hemorrhage irrespective of the menstrual cycle timing. Sixty percent of the patients had evidence of hemorrhage in at least one implant. In women receiving hormonal therapy at the time of surgery, the proportion of endometrial implants that were histologically in concert with the corresponding endometrium ranged from 0% to 33%. In early pregnancy and menopause, 50% and 31% of endometrial implants were histologically similar, respectively. These data indicate that the hormonal responsiveness of endometrial implants is unpredictable and inconsistent.

Peritoneal fluid environment and infertility

The PF environment is one that hosts the processes of ovulation, gamete transportation, fertilization, and early embryonic development. The cellular and acellular constituents of this dynamic fluid are in a constant interactive state, being influenced by the physiologic events of the menstrual cycle and pelvic disease processes; these constituents probably influence disease manifestation and reproduction. The importance of understanding this zone of early reproductive life has been now recognized. We hope that future investigations will define the exact role(s) of known components and some yet-to-be defined substances of PF in disease processes that affect reproductive function. With better understanding of normal and abnormal events in this pelvic microenvironment, we can develop rationales for novel treatment modalities.

Cul-de-sac fluid in women with endometriosis: fluid volume, protein and prostanoid concentration during the periovulatory period--days 13 to 18

Cul-de-sac fluid from women with histologically confirmed endometriosis (n = 45) or from infertile women without evidence of endometriosis (n = 28) was collected at the time of laparoscopy during the periovulatory period (days 13 to 18). This fluid was analyzed for prostaglandin E2 (PGE2), prostaglandin F2a (PGF2a), 13,14-dihydro-15 keto-PGF2a (PGFM), and thromboxane B2 (TXB2) by radioimmunoassay (RIA). Protein content of the fluid also was determined. No difference (P greater than 0.05) in cul-de-sac fluid volume was found between women with and without endometriosis, nor were differences detected in the level of any of the prostanoids measured in fluid from infertile control patients compared with those with endometriosis. This was true regardless of whether the prostanoids were expressed as a concentration, total amount in fluid, or as a ratio of prostanoid to protein content. The present study does not support the theory that cul-de-sac fluid prostanoids provide a useful diagnostic index of endometriosis.

A factor inhibiting ovum capture by the oviductal fimbriae present in endometriosis peritoneal fluid

The cumulus-fimbria interaction was investigated in vitro with endometriosis peritoneal fluid (PF). On the oviductal fimbria of the golden hamster, incubated with endometriosis and nonendometriosis PF and culture medium 199 contained 4% bovine serum albumin (control), was placed the mouse oocyte-cumulus complex at 5-minute intervals for 60 to 70 minutes. Incubation periods until the loss of fimbrial capability of ovum capture (ovum capturability disappearance time [OCDT] ) were 23.3 +/- 2.7 (standard error of the mean), 51.7 +/- 2.9, and 61.3 +/- 0.9 minutes with endometriosis, nonendometriosis PF, and control, respectively. OCDT was significantly decreased with cell-free and ultrafiltrated endometriosis PF containing a molecular size greater than 100,000 (26.0 +/- 2.8 and 26.1 +/- 2.5 minutes, respectively). A factor inhibiting fimbrial capability of ovum capture is present in endometriosis PF.

Endometriosis: a reappraisal of pathogenesis and treatment

The enigmatic disease of endometriosis continues to baffle both the scientist and the clinician. An encompassing theory of pathogenesis has failed to emerge from contemporary understanding of the immunologic manifestations, the hormonal aberrations, or the evasive infertility associated with endometriosis. Similarly unsettling is the failure of medical or conservative surgical maneuvers to eradicate endometriosis in a manner commensurate with castration. It is hoped that further insight into these areas of research will resolve both of these dilemmas.

Etiology of infertility in monkeys with endometriosis: measurement of peritoneal fluid prostaglandins

To study the relationship between peritoneal fluid prostaglandins and infertility associated with endometriosis, we autografted endometrial or adipose tissue to the pelvic peritoneum in 21 monkeys. Peritoneal washings were collected prior to tissue transplantation and during a subsequent laparotomy performed for biopsy of the implants. Monkeys were mated and peritoneal washings were collected during three subsequent cycles. The content of prostaglandin F2 alpha (PGF2 alpha) in adipose tissue autografts was significantly less (p less than 0.05) than in endometrial tissue autografts. The PGF2 alpha concentration in peritoneal fluid increased significantly (p less than 0.05) only in monkeys that developed moderate or severe endometriosis. Prostaglandin E levels in tissue autografts or peritoneal fluid were similar in all animals. Infertility in monkeys with endometriosis was associated with luteinized unruptured follicles, luteal phase defects, and pelvic adhesions. Although PGF2 alpha concentrations in peritoneal washings obtained during these cycles were increased in comparison with those of ovulatory cycles, the difference was not significant. A relationship between spontaneous abortion and prostaglandin concentrations in peritoneal fluid was not established.

Peritoneal fluid prostaglandins and prostanoids in women with endometriosis, chronic pelvic inflammatory disease, and pelvic pain

Peritoneal fluid obtained at laparoscopy from 49 women was measured for its content of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-keto-prostaglandin F1 alpha (6-KF), and thromboxane B2 (TxB2) by specific radioimmunoassays. In normal women (n = 10), the concentrations of prostaglandins in peritoneal fluid were (mean +/- SE): PGE2 = 0.79 +/- 0.26, PGF2 alpha = 0.60 +/- 0.18, 6-KF = 0.48 +/- 0.19, and TxB2 = 0.23 +/- 0.09 ng/ml; in women with endometriosis (n = 16): PGE2 = 1.43 +/- 0.72, PGF2 alpha = 1.52 +/- 0.59, 6-KF = 3.32 +/- 0.71, and TxB2 = 1.14 +/- 0.69 ng/ml; in women with chronic pelvic inflammatory disease and/or obstructed tubes (n = 19): PGE2 = 1.94 +/- 1.04, PGF2 alpha = 1.20 +/- 0.61, 6-KF = 1.55 +/- 0.40, and TxB2 = 0.64 +/- 0.24 ng/ml; in women with pelvic pain without any visible pathologic condition (n = 4): PGE2 = 1.11 +/- 0.66, PGF2 alpha = 0.73 +/- 0.55, 6-KF = 1.35 +/- 0.35, and TxB2 = 0.39 +/- 0.17. The mean volumes of peritoneal fluid recovered were 10 to 16 ml and were not significantly different between the groups. Except for a significantly elevated concentration of 6-KF in the peritoneal fluid of women with endometriosis compared to normal women (p = less than 0.02), the prostaglandins measured did not differ significantly between the groups of women studied. The possible significance of elevated 6-KF in the peritoneal fluid of women with endometriosis is discussed.

Follicular fluid prostaglandins in endometriosis and ovarian hyperstimulation

To study the presence of prostaglandin F2 alpha (PGF2 alpha), prostacyclin (PGI2), and thromboxane A2 (TxA2) in the human ovary, follicular fluid samples were collected with puncture at laparoscopy in 17 women with pelvic endometriosis, 17 women with tubal occlusion and healthy ovaries, and 5 women with tubal occlusion and induced ovarian hyperstimulation between menstrual cycle days 8 and 18. The concentrations of the metabolites of PGF2 alpha, PGI2, and TxA2, i.e., 13,14-dihydro-15-keto PGF2 alpha (M-PGF2 alpha), 6-keto PGF1 alpha, and TxB2, respectively, were measured with radioimmunoassays. Each prostanoid was detected in follicular fluid, but their concentrations were unrelated to the menstrual cycle day at collection. Moreover, these concentrations were similar in various groups of patients. The data suggest that the human ovary produces PGF2 alpha, PGI2, and TxA2 in vivo and that these prostanoids, as measured from follicular fluid, may not be of primary significance in ovulation or endometriosis.

The prostanoid content in peritoneal fluid and plasma of women with endometriosis

Peritoneal fluid and plasma collected at laparoscopy in women with and without endometriosis were evaluated for prostanoid content. 6-Keto-prostaglandin F1 alpha (6-keto-F1 alpha), thromboxane B2 (TxB2), 15-keto- 13, 14-dihydroprostaglandin F2 alpha (PGFM), prostaglandin F (PGF) and prostaglandin E (PGE) were assayed in peritoneal fluid, with 6-keto-F1 alpha, TxB2, and PGFM being studied in plasma. The concentrations of these prostanoids in women with endometriosis were not significantly different from the concentrations in the disease-free group, nor was a significant difference seen in any of the prostanoids studied in relationship to the severity of the endometriosis. The results suggest that routine study of prostanoid levels in patients with endometriosis may not be of a diagnostic or prognostic value.