The measurement of CA 125 and placental protein 14 in uterine flushings in women with recurrent miscarriage; relation to endometrial morphology

Mediation by hormone concentrations on the associations between repeated measures of phthalate mixture exposure and timing of delivery

BACKGROUND

Phthalates are used in the manufacturing of consumer products, resulting in ubiquitous human exposure to phthalate mixtures. Previous work has suggested that phthalates display endocrine-disrupting capabilities, and exposure is associated with early delivery.

OBJECTIVE

To assess mediating effects of hormone concentrations on associations between phthalate mixtures and preterm birth (PTB).

METHODS

Repeated urinary phthalates and serum hormones were measured among 1011 women in the PROTECT Puerto Rico birth cohort from 2011-2019. We utilized ridge regression to create phthalate environmental risk scores (ERS), which represent weighted summaries of total phthalate exposure. Mediation analyses were conducted on a subset of 705 women. We additionally conducted fetal sex-specific analyses.

RESULTS

Free thyroxine (FT4) mediated 9.6% of the association between high molecular weight (HMW) ERS at 18 weeks and reduced gestational age at delivery (95%CI:1.07-29.9). Progesterone at 26 weeks mediated 21.1% and 16.2% of the association between HMW ERS at 18 and 22 weeks, and spontaneous PTB, respectively. Among male fetuses, corticotropin releasing hormone (CRH) at 18 weeks mediated 28.2% of the association between low molecular weight ERS and spontaneous PTB.

SIGNIFICANCE

We provide introductory evidence of hormone disruption on the causal pathway between phthalate exposure and early delivery. We also show differences by fetal sex, but larger sample size is necessary to validate our findings.

IMPACT STATEMENT

This study provides introductory evidence that an alteration of hormone concentrations occurs on the causal pathway between gestational phthalate mixture exposure and subsequent PTB. In addition to the novel application of repeated biomarker measurements and mixtures methods in causal mediation analyses, we also explored differences between classes of phthalate compounds and between fetal sexes. We show that differential endocrine pathways may be disrupted with exposures to low versus HMW phthalate compounds, and that pregnancies with a male fetus may be more susceptible to endocrine disruption than those with a female fetus.

Glucose/insulin metabolism and vitamin D in women with recurrent pregnancy loss

OBJECTIVE

Glucose/insulin metabolism has been related to recurrent pregnancy loss (RPL) through mechanisms not really clarified. Also, vitamin D deficiency seems to be associated to RPL. The purpose of our study was to evaluate the correlation between glucose/insulin metabolism parameters and vitamin D levels in women with history of RPL.

STUDY DESIGN

Observational retrospective study on RPL women. The correlation among vitamin D levels and fasting glucose (FG), fasting insulin (FI), Homeostatic model assessment of insulin resistance (HOMA-IR) index, area under glucose curve (AUC-Glyc) and area under insulin curve (AUC-Ins), was evaluated.

RESULTS

One-hundred and twenty-seven RPL women were classified into three subgroups (0-1-2) according to the levels of FI. We found a statistically significant linear Pearson correlation between FI and HOMA-IR (r = .840; P = .001). An, inverse, but non-significant correlation both between vitamin D and FI (R = -.202, ns) and vitamin D levels and AUC-Ins (R = -.288, ns) was observed. The variables vitamin D, HOMA-IR and AUC-Ins were statistically significant in the considered subgroups (Vitamin D: ANOVA + Bonferroni test: 0 vs. 1; P = .001; 0 vs. 2; P = .010; 1 vs. 2; P = .657; HOMA-IR: ANOVA + Bonferroni test: 0 vs. 1; P = .014; 0 vs. 2; P = .001; 1 vs. 2; P = .001; AUC-Ins: ANOVA + Bonferroni test: 0 vs. 1; P = .010; 0 vs. 2; P = .206; 1 vs. 2; P = .980).

CONCLUSIONS

Vitamin D might play additional roles in the pathogenesis of RPL, beyond its well known immunomodulatory role.

Evidence from three cohort studies on the expression of MUC16 around the time of implantation suggests it is an inhibitor of implantation

PURPOSE

To examine the expression of MUC16 in the endometrium peri-implantation period in three different cohort studies.

METHODS

This was a retrospective observational cohort study. A total of 245 participants were recruited in three separate cohort studies: (1) women with recurrent miscarriage (n = 50) and fertile controls (n = 29); (2) women who had high (n = 20) or normal (n = 20) progesterone on the day of hCG trigger in ovarian stimulation cycle for IVF; and (3) women who did (n = 95) or did not (n = 31) conceive following frozen embryo transfer in HRT cycles. All subjects had archived endometrial samples precisely taken on LH+7 in natural cycles, or hCG+6 in ovarian stimulation cycles, or P+5 in HRT cycles. The H-score (median, range) of MUC16 in the luminal epithelium and glandular epithelium was determined by using immunohistochemistry.

RESULTS

The median (range) of H-score of MUC16 in the luminal epithelium (1) in women with recurrent pregnancy loss was 23.7 (0-300), which was significantly (P < 0.05) lower than that of 118.4 (7.7-300) in fertile controls; (2) in women with elevated progesterone on the day of hCG administration (147.8, 18.0-230.1), significantly (P < 0.05) higher than that of women with normal progesterone (61.0, 2.3-205.3); (3) in women who conceived (23.1, 0-250.3), significantly (P < 0.001) lower than that in women who did not conceive (58.4, 0-300).

CONCLUSION

The expression of MUC16 in all three cohort studies is consistent with it being an inhibitor of implantation.

The role of glycans in immune evasion: the human fetoembryonic defence system hypothesis revisited

Emerging data suggest that mechanisms to evade the human immune system may be shared by the conceptus, tumour cells, persistent pathogens and viruses. It is therefore timely to revisit the human fetoembryonic defense system (Hu-FEDS) hypothesis that was proposed in two papers in the 1990s. The initial paper suggested that glycoconjugates expressed in the human reproductive system inhibited immune responses directed against gametes and the developing human by employing their carbohydrate sequences as functional groups. These glycoconjugates were proposed to block specific binding interactions and interact with lectins linked to signal transduction pathways that modulated immune cell functions. The second article suggested that aggressive tumour cells and persistent pathogens (HIV, H. pylori, schistosomes) either mimicked or acquired the same carbohydrate functional groups employed in this system to evade immune responses. This subterfuge enabled these pathogens and tumour cells to couple their survival to the human reproductive imperative. The Hu-FEDS model has been repeatedly tested since its inception. Data relevant to this model have also been obtained in other studies. Herein, the Hu-FEDS hypothesis is revisited in the context of these more recent findings. Far more supportive evidence for this model now exists than when it was first proposed, and many of the original predictions have been validated. This type of subterfuge by pathogens and tumour cells likely applies to all sexually reproducing metazoans that must protect their gametes from immune responses. Intervention in these pathological states will likely remain problematic until this system of immune evasion is fully understood and appreciated.

Manifestations of immune tolerance in the human female reproductive tract

Like other mucosal surfaces (e.g., the gastrointestinal tract, the respiratory tract), the human female reproductive tract acts as an initial barrier to foreign antigens. In this role, the epithelial surface and subepithelial immune cells must balance protection against pathogenic insults against harmful inflammatory reactions and acceptance of particular foreign antigens. Two common examples of these acceptable foreign antigens are the fetal allograft and human semen/sperm. Both are purposely deposited into the female genital tract and appropriate immunologic response to these non-self antigens is essential to the survival of the species. In light of the weight of this task, it is not surprising that multiple, redundant and overlapping mechanisms are involved. For instance, cells at the immunologic interface between self (female reproductive tract epithelium) and non-self (placental trophoblast cells or human sperm) express glycosylation patterns that mimic those on many metastatic cancer cells and successful pathogens. The cytokine/chemokine milieu at this interface is altered through endocrine and immunologic mechanisms to favor tolerance of non-self. The “foreign” cells themselves also play an integral role in their own immunologic acceptance, since sperm and placental trophoblast cells are unusual and unique in their antigen presenting molecule expression patterns. Here, we will discuss these and other mechanisms that allow the human female reproductive tract to perform this delicate and indispensible balancing act.

Is metformin a primary ovulatory agent in patients with polycystic ovary syndrome?

Insulin resistance is an important pathophysiological feature of the polycystic ovary syndrome (PCOS). Insulin resistance and its compensatory hyperinsulinemia contribute to the anovulation, hyperandrogenism, infertility and early pregnancy loss suffered by women with PCOS. Current evidence supports the role of metformin in the treatment of anovulation in PCOS, both in monotherapy and concomitantly with clomiphene in clomiphene-resistant patients. In addition, novel evidence suggests that insulin sensitizers may also play a role in reducing the risk of early pregnancy loss. The insulin-sensitizing agents available commercially include metformin, rosiglitazone and pioglitazone. Compared with the thiozolidinediones, metformin is the agent that has been most frequently studied in PCOS, and has the most favorable pregnancy safety profile. In conclusion, there is strong evidence supporting the use of metformin as a primary ovulatory agent in women with PCOS.

A baboon model for endometriosis: implications for fertility

Endometriosis is one of the most common causes of chronic pelvic pain and infertility in women in the reproductive age group. Although the existence of this disease has been known for over 100 years our current knowledge of its pathogenesis and the pathophysiology of its related infertility remains unclear. Several reasons contribute to our lack of knowledge, the most critical being the difficulty in carrying out objective long-term studies in women. Thus, we and others have developed a model of this disease in the non-human primate, the baboon (Papio anubis). Intraperitoneal inoculation of autologous menstrual endometrium results in the development of endometriotic lesions with gross morphological characteristics similar to those seen in the human. Multiple factors have been implicated in endometriosis-associated infertility. We have described aberrant levels of factors involved in multiple pathways important in the establishment of pregnancy, in the endometrium of baboons induced with endometriosis. Specifically, we have observed dysregulation of proteins involved in invasion, angiogenesis, methylation, cell growth, immunomodulation, and steroid hormone action. These data suggest that, in an induced model of endometriosis in the baboon, an increased angiogenic capacity, decreased apoptotic potential, progesterone resistance, estrogen hyper-responsiveness, and an inability to respond appropriately to embryonic signals contribute to the reduced fecundity associated with this disease.

Recurrent miscarriage: pathophysiology and outcome

PURPOSE OF REVIEW

This article reviews new concepts in the aetiology of recurrent miscarriage, presents new outcome data and evaluates new modalities of treatment for unexplained recurrent miscarriage.

RECENT FINDINGS

Preimplantation genetic diagnosis has been considered an option for couples who have structural chromosomal abnormalities or unexplained recurrent miscarriage. The association between thrombophilias and adverse pregnancy outcome is further reviewed. In relation to this, there is increasing support for the use of thromboprophylaxis in improving pregnancy outcome in women with inherited thrombophilias. Nonrandomized studies have shown that the reduction in insulin levels with metformin in insulin-resistant individuals may reduce miscarriage risk by restoring normal haemostasis and improving the endometrial milieu. With respect to immunological concepts there is now evidence to suggest that, in addition to a suppression of maternal cell-mediated immunity, some elements of the innate immune system are activated in successful pregnancies.

SUMMARY

With the exception of aspirin and heparin for the prevention of recurrent miscarriage in women with the antiphospholipid syndrome, no other suggested therapies for this heterogeneous group of patients have been evaluated in randomized controlled trials. These include thromboprophylaxis for inherited thrombophilias and use of insulin sensitizers in women with insulin resistance and/or polycystic ovarian syndrome. The role of the innate immune system in pregnancy was recently highlighted, and use of nonspecific therapies to suppress the maternal immune response to pregnancy should be reassessed.

Recurrent miscarriage

Recurrent miscarriage, the occurrence of three consecutive first-trimester losses of pregnancy, affects 1% of women. The purported causes of recurrent miscarriage include chromosomal abnormalities, thrombophilia, metabolic disorders, anatomical causes and immune factors. At present, the only recommended investigations are testing for lupus anticoagulant and anticardiolipin antibody levels (to diagnose antiphospholipid syndrome, an acquired thrombophilia) and the karyotyping of both parents for chromosomal abnormalities. Women with antiphospholipid syndrome should be offered treatment with aspirin and low molecular weight heparin. Couples with chromosomal abnormalities should be referred to a clinical geneticist with whom the options of prenatal diagnosis, pre-implantation genetic diagnosis, donor gametes and adoption in subsequent pregnancies should be discussed. Couples with unexplained recurrent miscarriage should be offered appropriate emotional support and reassurance that they have a good prognosis for future pregnancies.

Expression of interleukin-11 receptor α and interleukin-11 protein in the endometrium of normal fertile women and women with recurrent miscarriage

Interleukin-11 (IL-11) is a member of the IL-6 family of cytokines. Previous studies have suggested that IL-11 may play a role in human endometrial function. In this study, we have used immunocytochemistry to compare endometrial IL-11Ralpha and IL-11 expression in precisely timed peri-implantation biopsies from 9 normal fertile women and 16 recurrent miscarriage (RM) women. Immunocytochemistry was semi-quantified by obtaining an H-score value, which showed increased expression of both IL-11 and IL-11Ralpha in epithelial cells compared to stromal cells in all biopsies. There was a significant (P<0.01) reduction in epithelial cell IL-11, but not stromal cell IL-11, expression in endometrium from RM women compared to normal fertile women. There were no significant differences in expression of IL-11Ralpha protein in both stromal and epithelial cells in endometrium from the two groups of women. This work shows the presence of IL-11 and IL-11Ralpha within the endometrium of RM women during the peri-implantation period. The decreased expression of IL-11 in epithelial endometrium in RM women suggests that this cytokine may play a role in preventing miscarriage.

Should insulin-sensitizing drugs be used in the treatment of polycystic ovary syndrome?

Insulin resistance is a central feature of polycystic ovary syndrome (PCOS). Hyperinsulinaemia contributes to anovulation, hyperandrogenism, infertility and early pregnancy loss in women with PCOS. Chronic hyperinsulinaemia also predisposes women with PCOS to increased risks of diabetes and cardiovascular events. Current data indicate that metformin, either as monotherapy or in combination with clomiphene in clomiphene-resistant patients, is an effective treatment for anovulation in PCOS. Initial evidence also suggests that insulin sensitizers may have a role in preventing early pregnancy loss. Of the available insulin-sensitizing agents, metformin has been the agent most frequently studied in PCOS, and has the least undesirable pregnancy safety profile. Ameliorating the metabolic syndrome associated with insulin resistance in PCOS with metformin may also prevent long-term cardiovascular and diabetes complications, pending further evidence. Based on these data, metformin should be a first-line therapy for women with PCOS.

Endocrinological and endometrial factors in recurrent miscarriage

OBJECTIVE

To investigate the endocrinological and endometrial factors in women with unexplained recurrent miscarriage

DESIGN

Prospective, case study

SETTING

Recurrent miscarriage clinic, Jessop Hospital for Women, Sheffield

PARTICIPANTS

One hundred and forty-four women with unexplained recurrent (> or =3) miscarriages

METHODS

A blood sample was obtained in early follicular phase (day 3-5) to measure follicle stimulating hormone, luteinising hormone, prolactin, androgens and thyroid function; daily blood/urine samples were obtained from mid-follicular phase to measure luteinising hormone until the luteinising hormone surge was identified; endometrial biopsy and a further blood sample for progesterone measurement were obtained in the mid-luteal phase. A transvaginal ultrasonography was performed to evaluate ovarian morphology.

RESULTS

Hypersecretion of luteinising hormone or ultrasonographic features of polycystic ovarian disease was present in 8% and 7.8% of women, respectively. The free androgen index was elevated in 14.6% of subjects. In the mid-luteal phase, low progesterone level was found in 17.4% and delayed endometrial development was noted in 27.1% of women. Although women with recurrent miscarriage women and delayed endometrium had significantly lower progesterone levels than those with normal endometrial development, only 8/24 had mid-luteal progesterone levels below 30 nmol/L. Recurrent miscarriage was not associated with hyperprolactinaemia or abnormal thyroid function test.

CONCLUSIONS

Endocrinological and endometrial abnormalities are present in about a quarter of women with unexplained recurrent miscarriage.

Glycodelin: a reproduction-related lipocalin

Glycodelin, a human lipocalin, is a major endometrial protein with at least two differentially glycosylated isoforms. Glycodelin-A (GdA) is purified from human mid-trimester amniotic fluid, where it is secreted from the decidualized endometrium. Glycodelin-S (GdS) is synthesized in the male reproductive tract, mainly in the seminal vesicles, and secreted into seminal plasma. These two glycodelin isoforms, glycosylated in a completely different manner, serve as a good model for studying the effects of glycosylation on protein function and physicochemical properties. We have reviewed here the structure, expression and biological functions of glycodelin.

Do androgens have a direct effect on endometrial function? An in vitro study

OBJECTIVE

To test the hypothesis that androgens have a direct effect on the function of endometrial epithelial cells.

DESIGN

In vitro study.

SETTING

Academic research center.

PATIENT(S)

Endometrial epithelial cells were prepared from biopsy samples obtained from normal fertile women.

INTERVENTIONS

Cells were incubated with androstenedione, testosterone, dihydrotestosterone, and DHEA.

MAIN OUTCOME MEASURE(S)

Secretion of glycodelin A into the culture fluid was used to assess secretory activity. Uptake of (3)H-thymidine and immunostaining for Ki67 was used to assess cell growth. The specific action of the androgens was confirmed by incubation with an antiandrogen, cyproterone acetate.

RESULT(S)

Androstenedione (10(-6) M and 10(-7) M) caused a dose-dependent decrease in glycodelin A secretion, uptake of (3)H-thymidine, and percentage of positive Ki67 cells in cultured human endometrial epithelial cells. Testosterone, dihydrotestosterone, and DHEA had no effect on glycodelin A secretion or (3)H-thymidine uptake. The direct effect of androgens on endometrial function were confirmed by demonstrating the presence of androgen receptors in cultured endometrial epithelial cells and showing that the direct effects of the androgens were not observed when cyproterone acetate was added to the cultures.

CONCLUSION(S)

The results suggest that androstenedione can inhibit human endometrial cell growth and secretory activity. Infertility and miscarriage associated with high androgen levels (e.g., that caused by the polycystic ovary syndrome) may be due to an adverse effect of high androgen levels on the endometrium.

Serum androgen levels in women who have recurrent miscarriages and their correlation with markers of endometrial function

OBJECTIVE

To compare plasma androgen concentrations in women who have recurrent miscarriages and in fertile women, and to correlate the results with concentrations of the endometrial protein PP14 in uterine flushings and plasma from women who have recurrent miscarriages.

DESIGN

Retrospective study.

SETTING

Hospital research unit.

PATIENT(S)

Women attending a recurrent miscarriage clinic and normal fertile volunteers. Ten of the women with recurrent miscarriages had polycystic ovary disease (PCOD) as assessed by ultrasonography or increased follicular LH levels.

INTERVENTION(S)

Plasma samples were obtained from the women on days LH-7, LH-4, LH+0, and LH+7 or LH+10 of a cycle. An endometrial flushing sample and a biopsy specimen were taken from women with recurrent miscarriages on day LH+7 or LH+10.

MAIN OUTCOME MEASURE(S)

Androstenedione, testosterone, and sex hormone-binding globulin (SHBG) were measured in the plasma samples. The endometrial protein PP14 was measured in the uterine flushings and in the LH+7 or LH+10 plasma samples from the women with recurrent miscarriages.

RESULT(S)

Testosterone concentrations were higher in the women with recurrent miscarriages both with and without PCOD on days LH-7 and LH-4 of the cycle. Concentrations of androstenedione also were higher in the women with recurrent miscarriages, but without PCOD on day LH-7. Testosterone SHBG ratios were higher in the women with recurrent miscarriages, without PCOD compared with the controls on days LH-7, LH+0, and LH+7. Mean follicular testosterone concentrations were correlated negatively with both uterine (r = -0.47) and plasma (r = -0.49) PP14 levels on day LH+10. Mean luteal phase testosterone SHBG ratios were correlated negatively with uterine PP14 concentrations on day LH+7 of the cycle (r = -0.674).

CONCLUSION(S)

Androgen levels are higher in women who have recurrent miscarriages than in normal fertile controls. These high levels of androgens may have a detrimental effect on endometrial function.

Correlation of serum and follicular fluid concentrations of placental protein 14 and CA-125 in in vitro fertilization-embryo transfer patients

OBJECTIVE

To study serum and follicular fluid (FF) concentrations of placental protein 14 (PP14) and CA-125 in patients participating in an IVF-ET program.

DESIGN

Determination in serum and FF on the day of hCG administration, day of oocyte retrieval, and on ET day of PP14 and CA-125.

SETTING

Second Department of Obstetrics and Gynecology of the University of Athens; Euromedica IVF Unit; and Hellenic Pasteur Institute.

PATIENTS

Thirty-three patients undergoing IVF-ET divided in three groups: 8 with conception, 18 with fertilized oocytes but no conception, and 7 without fertilized oocytes.

INTERVENTIONS

All patients underwent an ovarian stimulation with a short protocol of GnRH analogue-pure-FSH-hMG. Three blood probes were collected from each patient, on the day of hCG administration, on retrieval day, and on ET day, respectively, whereas FF was collected on retrieval day.

MAIN OUTCOME MEASURES

Determination in serum and FF of CA-125 and PP14.

RESULTS

On the day of oocyte retrieval, both mean values of serum PP14 and CA-125 were significantly higher in conceptional than nonconceptional cycles. On the day of ET, the mean values of serum PP14 increased significantly in conceptional cycles whereas CA-125 showed no difference. The mean concentration of PP14 in FF was significantly higher in conceptional cycles whereas there was no significant change in the mean concentration of FF CA-125.

CONCLUSIONS

In conceptional cycles after IVF, PP14 increases in serum significantly from hCG day to ET day compared with nonconceptional cycles, whereas CA-125 increases from hCG day to oocyte retrieval day and decreases on ET day. In FF, PP14 was increased in conceptional cycles, whereas CA-125 in FF showed no change.

MUC1 as a cell surface and secretory component of endometrial epithelium: reduced levels in recurrent miscarriage

The mucin MUC1 is a large, highly glycosylated, hormonally regulated product of endometrial glandular and luminal epithelium with both cell surface-associated and secreted isoforms. The abundance of mRNA coding for MUC1 increases about sixfold from the proliferative to the early secretory phase (Hey et al., J. Clin. Endocrinol. Metab. 78:337-342, 1994). Immunohistochemical studies show intracellular deposits accumulating in the early secretory phase followed by the release of MUC1 into gland lumens. The apical surface of luminal epithelium is strongly immunopositive in the early secretory phase. We have used a two site ELISA to measure MUC1 in uterine flushings as a function of time after the luteinising hormone (LH) peak. Low levels of secretory MUC1 are observed before day LH+7, while values on days LH+7-LH+13 are much higher. Using semi-quantitative immunohistochemical methods we have shown that in women suffering recurrent spontaneous miscarriage, mid secretory phase levels of MUC1 core protein and mucin-associated glycans are reduced (Serle et al., Fertil. Steril. 62:989-996, 1994). Similarly, lower core protein levels are observed in uterine flushings after day LH+7 in these women. Reduced epithelial secretory function and a resultant change in uterine fluid composition are features of endometrium from recurrent miscarriage patients.