The relationship between serum prolactin concentration and pregnancy outcome in women with unexplained recurrent miscarriage.

The role of prolactin in early pregnancy is controversial. The aim of this study was to evaluate the relationship between serum prolactin concentration and the risk of miscarriage in women with unexplained recurrent miscarriage (RM). A series of 174 women with unexplained RM, who had serum prolactin concentrations measured from January 2000 to September 2009 at the Recurrent Miscarriage Clinic in Royal Hallamshire Hospital in Sheffield, were included in this study. Among the 174 patients with unexplained RM, 40 patients did not conceive during the study period, 9 were lost to follow-up and 125 patients conceived again. Patients who did not conceive were significantly older than those who conceived (p < 0.05, OR: 1.08, 95% CI: 1.03-1.13). Among those who conceived again, the pregnancy outcome data were available for analysis in 109 patients. Those who miscarried were older (p < 0.05, OR: 1.1, 95% CI: 1.01-1.22) and had significantly lower serum prolactin concentrations (p < 0.05, adjusted OR: 0.99, 95% CI: 0.97-0.99) after adjustment has been made for age, than those who had a live birth. Lower basal serum prolactin concentrations were associated with an increased risk of miscarriage in a subsequent pregnancy in women with unexplained RM.

Expression of leukaemia inhibitory factor and interleukin 15 in endometrium of women with recurrent implantation failure after IVF; correlation with the number of endometrial natural killer cells.

BACKGROUND: Several studies have suggested that endometrial interleukin 15 (IL-15) and the leukaemia inhibitory factor (LIF) may be important in embryo implantation. IL-15 is postulated to play a role in the control of uterine natural killer (uNK) cell proliferation and function, and uNK cells are also known to play a role in implantation. The aims of this study was to (1) compare endometrial levels of IL-15 and the LIF in women with recurrent implantation failure (RIF) after IVF with those in fertile women (controls) and (2) examine the relation of IL-15 and LIF levels to the uNK cell number. METHODS: We investigated IL-15 and LIF in precisely timed endometrial biopsies (days LH + 7-LH + 9, where the day of the LH surge is LH + 0) obtained from control women (n = 15) and women with RIF (n = 45) by immunohistochemistry. A semi-quantitative analysis was performed by the H-score analysis of staining intensity in the stroma, glandular epithelium and luminal epithelium, separately. We also correlated expression of LIF and IL15 with uNK cell numbers (obtained in an earlier study of the same samples). RESULTS: The quantity of the LIF protein in endometrial glandular epithelium in women with RIF [median and range; 179 (70-365)] was lower (P = 0.01) than in control women [median and range; 247 (120-287)]. In contrast, the level of the IL-15 protein in the stroma in women with RIF [median and range; 90 (0-175)] was higher (P = 0.009) than in control women [median and range; 60 (15-150)]. There was a significant correlation between the uNK cell number and stromal expression of IL-15 (r = 0.427, P = 0.001). No correlation between the LIF expression in any compartment and the uNK cell number was seen. CONCLUSIONS: The results show an altered expression of LIF and IL-15 in the endometrium of women with RIF. Despite the limitation of not identifying uNK cells by phenotypic markers, the correlation between the uNK cell number and the stromal cell IL-15 suggests that IL-15 may play a role in the control of endometrial uNK cell function or proliferation.

Measurements of CD56+ cells in peripheral blood and endometrium by flow cytometry and immunohistochemical staining in situ.

BACKGROUND: CD56+ cells in peripheral blood or the endometrium may be increased in women with reproductive failure. However, the relationship between numbers of peripheral blood CD56+ and endometrial CD56+ cells is uncertain. The aim of this study was (i) to compare the numbers of CD56+ cells in peripheral blood and endometrium in samples taken simultaneously and (ii) to compare measurements by flow cytometry and immunohistochemistry of CD56+ cells in the same endometrial biopsy. METHOD: Endometrial biopsies and blood were obtained from women with recurrent miscarriage (n= 25) on days LH+7-LH+9 of the cycle. The total number of CD56+, CD56+ CD16- and CD56+CD16+ cells in blood was measured by flow cytometry; the number of CD56+ cells in the endometrium was determined by immunohistochemistry. Endometrial samples were also obtained from fertile women (n= 20) and used to measure CD56+ and CD45+ cells, by both flow cytometry and immunostaining. RESULTS: There was no correlation between the numbers of total CD56+, CD56+CD16- or CD56+CD16+ in peripheral blood and the number of endometrial CD56+ cells in the same women. In endometrium from fertile women, a significant correlation was found between the numbers of CD56+ cells measured by flow cytometry and immunohistochemistry (correlation= 0.497, P= 0.026, when expressed as % total cells; correlation= 0.570, P= 0.009 when expressed as % CD45+ cells). CONCLUSIONS: Measurements of CD56+ cells in peripheral blood do not correlate with endometrial CD56+ cell numbers and therefore should not be extrapolated to events in the endometrium. In contrast, measurements of endometrial CD56+ cells by flow cytometry and immunostaining correlate well.

Expression of CXCL12 and CXCR4 in human endometrium; effects of CXCL12 on MMP production by human endometrial cells.

BACKGROUND: Although several studies have suggested that CXCL12 and its receptor, CXCR4, may play a role in embryo implantation, there are limited reports of expression of CXCR4 and CXCL12 in human endometrium. The aim of this study was to investigate CXCL12 and CXCR4 expression in human endometrium and to see if CXCL12 could affect matrix metalloproteinase (MMP) production by endometrial stromal and epithelial cells. METHODS: Quantitative real-time RT-PCR (qRT-PCR) was used to detect the expression of CXCL12 and CXCR4 mRNA in endometrial biopsy samples obtained from fertile women (n = 30). Immunohistochemical analysis was carried out to determine where in the endometrium CXCL12 and CXCR4 were expressed. Primary cell culture followed by qRT-PCR and zymography was used to investigate whether CXCL12 affected MMP-2 and -9 production by endometrial stromal and epithelial cells. RESULTS: Both CXCL12 and CXCR4 were detected in the endometrium. There was no difference in CXCL12 expression at different times in the cycle, but expression of CXCR4 mRNA was significantly higher in the early proliferative (P < 0.01) compared with late proliferative and secretory phases of the cycle. CXCL12 expression was strongest in the epithelial compartment, and weaker in blood vessel walls. CXCR4 immunostaining was strong in the epithelium and blood vessel walls and weaker in the stroma. CXCL12 (10 and 100 ng/ml) had no effect on mRNA expression or activity of MMP-2 or MMP-9 in either stromal or epithelial cells. CONCLUSIONS: The results show that the expression of CXCL12 in human endometrium does not alter during the menstrual cycle, while the endometrial expression of its receptor, CXCR4, is highest in the early proliferative phase. In contrast to its effects in other cells, CXCL12 had no effect on MMP-2 or MMP-9 production by endometrial stromal or epithelial cells.

Does free androgen index predict subsequent pregnancy outcome in women with recurrent miscarriage?

BACKGROUND: Several studies have investigated plasma androgen levels in women with recurrent miscarriage (RM) with conflicting results on whether an association between hyperandrogenaemia and RM exists. However, none of these studies included sensitive androgen measurements using a large data set. We therefore investigated the free androgen index (FAI) in a large number of women with RM in order to ascertain whether hyperandrogenaemia is a predictor of subsequent pregnancy outcome. METHODS: We studied 571 women who attended the Recurrent Miscarriage Clinic in Sheffield and presented with > or =3 consecutive miscarriages. Serum levels of total testosterone and sex hormone-binding globulin were measured in the early follicular phase and FAI was then deduced. RESULTS: The prevalence of hyperandrogenaemia in RM was 11% and in a subsequent pregnancy, the miscarriage rate was significantly higher in the raised FAI group (miscarriage rates of 68% and 40% for FAI > 5 and FAI < or = 5 respectively, P = 0.002). CONCLUSIONS: An elevated FAI appears to be a prognostic factor for a subsequent miscarriage in women with RM and is a more significant predictor of subsequent miscarriage than an advanced maternal age (> or =40 years) or a high number (> or =6) of previous miscarriages in this study.

Prognostic value of the measurement of uterine natural killer cells in the endometrium of women with recurrent miscarriage.

BACKGROUND: Studies in mice suggest that CD56 + uterine natural killer (uNK) cells play an important role in implantation. Studies in humans have described an increase in the number of uNK cells in the non-pregnant mid-secretory endometrium of women with unexplained recurrent miscarriage (RM). However, the predictive value of uNK cell number in the maintenance of pregnancy is controversial. METHODS: A blind retrospective study was undertaken. The percentage of stromal cells positive for CD56 was identified by immunocytochemistry in endometrial biopsies from 10 normal control women and 87 women with unexplained RM, of whom 51 became pregnant following biopsy. Biopsies were obtained on days LH + 7 to LH + 9. RESULTS: As in previous studies, the number of uNK cells in the 87 women with RM (mean 11.2% range 1.1-41.4%) was significantly higher (P = 0.013) than in the control women (mean 6.2% range 2.2-13.9%). No significance difference in uNK numbers was observed between 19 women who miscarried (mean 9.6% range 1.7-25.0%) and 32 women who had a live birth (mean 13.3% range 1.1-41.4%) in a subsequent pregnancy. CONCLUSIONS: In this study numbers of uNK cells in the peri-implantation endometrium of women with unexplained recurrent miscarriage did not predict subsequent pregnancy outcome.

Impact of high body mass index on endometrial morphology and function in the peri-implantation period in women with recurrent miscarriage.

There is evidence that women with a high body mass index may have a higher risk of miscarriage. It is not known if this is due to an endometrial or embryo defect. The aim of this retrospective study was to examine markers of endometrial function in overweight and obese women with recurrent unexplained miscarriage. A total of 136 women were included in the study and classified according to their body mass index (BMI) into two groups, normal BMI (< 25 kg/m(2), n = 70) and high BMI (> or = 25 kg/m(2), n = 66). Endometrial morphology was examined in all patients. A subgroup of 28 patients was examined for endometrial oestrogen and progesterone receptors in different components of the endometrium, and in a further subgroup of 28 patients, endometrial glandular leukaemia inhibitory factor and leukocyte populations were examined. A modest increase in the BMI (30.4 +/- 0.71 kg/m(2)) does not have a significant impact on endometrial steroid receptors, leukocyte populations or endometrial morphology. However, there was a significant negative correlation between endometrial glandular leukaemia inhibitory factor concentrations and the BMI (r = -0.4, P = 0.02), warranting further investigation in prospective studies that include patients with higher BMI levels.

Cytokine expression in the endometrium of women with implantation failure and recurrent miscarriage.

One potential cause of reproductive failure such as infertility and recurrent miscarriage may be an endometrial defect. Numerous studies in mice have suggested the importance of various different cytokines in successful pregnancy outcome. This article reviews the literature available on the role of T helper cytokines and IL-1, IL-11, LIF, IL-12 and IL-18 in infertility and recurrent miscarriage, with particular emphasis on the role that endometrial cytokines may play. Although there are numerous studies on cytokines in recurrent miscarriage, much less has been reported on their role in infertility with or without failure after IVF. There is also considerable variation in the results obtained from various different studies, which may be due to different populations studied, the different timing of the sample collection, and whether the cytokines were measured in whole tissue or a specific cell population. The presence of complicated networks of cytokines and their overlapping biological activities means that alteration of one cytokine is likely to affect others and this also makes the study of their role in implantation failure very difficult. There is an urgent need to re-examine the role played by various cytokines in reproductive failure through carefully planned and vigorously designed studies and to compare the different types of reproductive failure.

Cytotrophoblast stem cell lines derived from human embryonic stem cells and their capacity to mimic invasive implantation events.

BACKGROUND: An effective embryonic-maternal interaction is crucial for successful human pregnancy. Failure of this process is a major cause of infertility and can lead to placental dysfunction resulting in recurrent miscarriage, fetal retardation and pre-eclampsia. Research is severely constrained by ethical and practical considerations; therefore, we aimed to generate cytotrophoblast stem (CTBS) cell lines from human embryonic stem cells (HESCs). METHOD: Beta-HCG was used as a marker of viable trophoblast cells. In defined culture, embryoid bodies were generated from HESCs and selected for trophoblast enrichment by rounds of cellular aggregation and disaggregation. Distinct CTBS cell lines were isolated and characterized. Spheroid cytotrophoblast bodies were generated and their interaction with luteal-phase endometrial stroma was analysed by real-time image analysis. RESULTS: Three CTBS cell lines were derived, which were maintained in the absence of residual HESCs, fibroblast feeder cells or extracellular matrix. CTBS cells displayed typical cytotrophoblast and syncytiotrophoblast characteristics and exhibited further differentiation to invasive endovascular cell phenotype. One cell line was generated with constitutive expression of enhanced green fluorescent protein (eGFP). Spheroid trophoblast bodies mimicked closely the early invasive stages of implantation when incubated with human endometrial stromal preparations in vitro. CONCLUSION: These human CTBS cell lines are a significant new model for investigating human placentation and may have considerable potential in cell therapy applications.

Expression of interleukin-11 receptor alpha 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.

Markers of endometrial function in women with unexplained recurrent pregnancy loss: a comparison between morphologically normal and retarded endometrium.

BACKGROUND: Endometrial defect, usually described as luteal phase defect (LPD), is associated with recurrent miscarriage. Recurrent miscarriage has also been associated with the abnormal expression of various molecules by endometrial cells. The aim of this study was to determine if any of these molecules or cells could be used to distinguish LPD from in-phase endometrium. METHODS: Immunocytochemistry was used to compare endometrial expression of CD45+, CD56+, CD3+ and CD4+ cells, leukaemia inhibitory factor, interleukin-6 and estrogen and progesterone receptors in precisely timed endometrial biopsies obtained between days LH+6 and LH+11 from recurrent miscarriage women with in-phase and retarded endometrium. RESULTS: In all samples there was a positive correlation between the number of CD45+ cells and LH day and a negative correlation between progesterone receptor and LIF expression and LH day. A significantly lower number (P<0.05) of CD56+ cells in peri-implantation endometrium and a decreased mid-cycle estrogen level (P<0.05) was seen in women with LPD compared to in-phase endometrium when single analysis was carried out. However, these differences were not significant after application of the Bonferroni correction for multiple analysis. CONCLUSIONS: The results are in line with previous associations observed between estrogen levels and LPD and suggest that the number of CD56+ cells is different in LPD and in-phase endometrium, although this could be due to delayed endometrial development in women with LPD. Interpretation must be cautious because these differences could have arisen by chance.

Expression of leptin receptor isoforms in vitro: lack of effects of leptin on endometrial cytokine and MMP production.

PROBLEM: Leptin has a key role to play in human female reproduction. Its receptor is expressed highly throughout the reproductive tract. Cytokines have an important role in preparing the endometrium for implantation and leptin is known to modulate cytokine production in other tissues. We, therefore, investigated the possible role of leptin in endometrial growth and function. METHOD OF STUDY: Reverse transcriptase polymerase chain reaction and immunocytochemistry were used to determine the pattern of expression of leptin receptor isoforms in primary human endometrial epithelial and stromal cells in culture. The effect of leptin on cell growth and on the production of cytokines [Leukaemia Inhibitory Factor (LIF), interleukin 6 and tumour necrosis factor-alpha] and matrix metalloproteinases (MMP) (MMP2 and MMP-9) was also investigated. RESULTS: Expression of the long form of the leptin was restricted to the cultured endometrial, epithelial cells. Both cultured endometrial stromal and epithelial cells expressed the short and variant isoforms of the receptor. Incubation of epithelial and stromal cell cultures with varying concentrations of leptin (0-1000 ng/mL) had no significant effect on cell growth or levels of MMP-2 or MMP-9 production. Leptin also had no significant effect on cytokine production by epithelial cells. CONCLUSIONS: This study shows for the first time, the presence of leptin receptor isoforms on endometrial, epithelial and stromal cells in culture. Leptin had no effect on cytokine and MMP production by these cells. However, it is possible that leptin affects other factors within the endometrium not investigated here.

A review of immune cells and molecules in women with recurrent miscarriage.

Immunological rejection of the fetus due to recognition of paternal antigens by the maternal immune system, resulting in abnormal immune cells and cytokine production, is postulated to be one cause of unexplained pregnancy loss. Although there is evidence for this in rodents, there is less evidence in humans. This article focuses on studies in humans, and reviews the recent literature on the differences in immune cells and molecules in normal fertile women and women with recurrent miscarriage (RM). Although much of the evidence is contradictory, these studies do suggest differences in the expression of some immune cells and molecules in women with RM. Differences in the CD56+ population of cells are seen, and there is some evidence for an alteration in the ratio of Th1 and Th2 cytokines produced by peripheral blood monocytes (PBMCs) and clones of decidual CD4+ cells. There is also some evidence for differences in endometrial cytokine production, and in particular decreased production of pro-inflammatory cytokines such as interleukin-6. Possible reasons for the variations in data are discussed, and the importance of compartment (peripheral blood, endometrium or decidua) in which the cells and molecules are measured and the timing of the sampling, both with respect to the menstrual cycle and pregnancy (at the time or just after miscarriage) is emphasized.

Expression of interleukin (IL)-11 receptor by the human endometrium in vivo and effects of IL-11, IL-6 and LIF on the production of MMP and cytokines by human endometrial cells in vitro.

Interleukin (IL)-6, leukaemia inhibitory factor (LIF) and IL-11 belong to the same family of cytokines whose receptors utilize gp130 as the signalling molecule. We have investigated the expression of the IL-11 receptor, IL-11Ralpha, protein in the human endometrium in vivo and the effects of IL-6, LIF and IL-11 on the production of metalloproteinases (MMPs) and cytokines by cultured endometrial epithelial and stromal cells. Immunostaining showed that IL-11Ralpha was expressed in both epithelial and stromal cells, with epithelial staining being more intense than stromal staining and little variation in staining in either compartment throughout the cycle. Incubation of both stromal and epithelial cells with IL-6, LIF and IL-11 had no effect on MMP-2, -7, -9, transforming growth factor (TGF)beta or IL-1beta production or cell growth. IL-6 and LIF also had no effect on tumour necrosis factor (TNF)alpha production, but IL-11 caused a dose-dependent decrease in TNFalpha production by epithelial cells. IL-6 receptor, LIF receptor and gp130 were all expressed by cultured stromal and epithelial cells, showing that the lack of effect is not due to lack of expression of the receptor components. The results show that although IL-6, LIF and IL-11 signal through the same molecule, they may have different effects in endometrial cells, suggesting the activation of different signalling pathways, which may ultimately be important in the control of endometrial function.

The correlation of adhesions and peritoneal fluid cytokine concentrations: a pilot study.

BACKGROUND: Intra-abdominal adhesion formation and reformation after surgery is a significant cause of morbidity. The greatest problem after the surgical removal of adhesions is their reformation. We examined the concentrations of interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha in the peritoneal fluid throughout the 48 h post-operative period following adhesiolysis, and correlated the results to the extent of adhesion reformation. METHODS: Peritoneal fluid, collected from eight patients following laparoscopy and again at 12, 36 and 48 h after surgery, was analysed using enzyme-linked immunosorbent assay (IL-1 and IL-6) and bioassay (TNF-alpha). At 48 h, a second look laparoscopy was performed to inspect the pelvis for adhesion formation/reformation. RESULTS: Three patients had adhesion reformation >10% at 48 h after surgery. The mean adhesion score 48 h after adhesiolysis was 5 (range 0-17). The mean reduction in adhesion score was 88% (range 83-100%). Newly formed adhesions were filmy, relatively soft and avascular in nature. Adhesion reformation of >10% was associated with (i) high concentrations of IL-6 at 12 h (P < 0.01) and (ii) high concentrations of IL-1 at 48 h (P < 0.001). CONCLUSIONS: Results from this preliminary study suggest that future treatment strategies for adhesion prevention could be aimed at the control of cellular mediators in the peritoneal fluid during the initial adhesion formation period.

Endometrial factors in recurrent miscarriage.

Recurrent pregnancy loss may be a consequence of an abnormal embryonic karyotype, or maternal factors affecting the endometrium resulting in defective implantation. In order to study the endometrial factors responsible for recurrent pregnancy loss, endometrial biopsy samples should be precisely timed according to the LH surge, and the investigation should be carried out in a non-conception cycle, prior to the next pregnancy. The various methods of studying the endometrium including morphological studies, morphometry, immunohistrochemistry, measurement of endometrial protein in plasma and uterine flushings, cytokine expression in endometrial cells, leukocyte populations in the endometrium and ultrasonographic and hysteroscopic studies, were reviewed. The clinical relevance of the observed abnormality depends on whether or not the abnormality is persistent in subsequent cycles, and if the observed abnormality is of significant prognostic value. Very little is known about the treatment of endometrial defect associated with recurrent pregnancy loss, but preliminary data suggest that the use of HMG may be of benefit.

Expression of nuclear factor kappa B components in human endometrium.

Nuclear factor kappa B (NFkappaB) is a family of transcription factors involved in signalling between IL1 and TNFalpha receptors and cytokines and adhesion molecules in a number of cell types, including those of the human endometrium. In this study, we used immunocytochemistry to investigate the in vivo expression of the p50, IkappaBalpha and IkappaBbeta NFkappaB components in endometrium obtained from normal fertile women throughout the menstrual cycle. All three components were expressed by both the stromal and epithelial cells of the endometrium and staining was predominately seen in the cytoplasm of the cells. Staining for p50 was more intense in the epithelial compartment than the stromal compartment. Staining in the stromal compartment was low to moderate throughout the cycle but, in the epithelial compartment, staining was cycle dependent and increased slightly during the mid-secretory phase. The staining patterns for IkappaBalpha and IkappaBbeta were similar. As for p50, staining for both proteins was greater in the epithelial compartment compared to the stromal compartment and stromal cell staining was low to moderate throughout the cycle. However, in contrast to p50, staining for the IkappaB proteins in epithelial cells decreased during the mid-secretory phase of the cycle. Although the immunocytochemistry technique used is only semi-quantitative, the results suggest an increased expression of the active and a decreased expression of the inhibitory NFkappaB components by the endometrium at the time of implantation. If confirmed, it would suggest that NFkappaB is involved in the control of factors important in the implantation process.

IL-1, IL-6 and TNF-alpha concentrations in the peritoneal fluid of women with pelvic adhesions.

BACKGROUND: Pelvic adhesions are a significant cause of morbidity and are associated with infertility and pain. The three pro-inflammatory cytokines interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha are involved in adhesion formation/reformation. METHODS: The concentration of these three cytokines was examined in the peritoneal fluid of women undergoing laparoscopy, in order to examine the factors affecting their concentrations, with specific reference to the presence or absence of adhesions. RESULTS: We found that the concentration of TNF-alpha in the peritoneal fluid was significantly correlated to the menstrual cycle day (P < 0.01), with increasing concentration as the menstrual cycle progressed from the follicular to the luteal phase. In contrast, IL-1 and IL-6 levels did not show any variation throughout the menstrual cycle. Increased TNF-alpha was found in patients with pelvic adhesions compared with those with normal pelvis; the concentration of TNF-alpha was highest in mild compared with severe adhesions. In contrast, IL-1 concentration was higher in the presence of severe adhesions. IL-6 levels were significantly correlated with the grade of endometriosis (P < 0.05), but there were no significant correlations of either TNF-alpha or IL-1 concentrations with the various grades of endometriosis. CONCLUSION: The exact role of TNF-alpha and IL-1 in adhesion formation is still unknown, but the results from this study suggest that their concentration in the peritoneal fluid is associated with the degree of adhesions present.

Peritoneal healing and adhesion formation/reformation.

Intra-abdominal adhesion formation and reformation after surgery is a cause of significant morbidity, resulting in infertility and pain. The understanding of the pathogenesis of adhesion formation and reformation especially at the cellular and molecular level can help to further develop more effective treatments for the prevention of adhesion formation and reformation. Following an injury to the peritoneum, fibrinolytic activity over the peritoneal surface decreases, leading to changes in the expression and synthesis of various cellular mediators and in the remodelling of the connective tissue. The cellular response to peritoneal injury and adhesion formation and reformation are reviewed. Analysis of the available literature data on the cellular mediators in the peritoneal fluid showed variation in results from different investigators. The potential sources of variability and error are examined. It is still unclear if there is significant individual variation in the peritoneal response to injury.

Leptin and leptin-binding activity in women with recurrent miscarriage: correlation with pregnancy outcome.

BACKGROUND: Previous studies in humans and mice have suggested the importance of leptin in fetal growth. Recurrent miscarriage may be a result of abnormal placental and/or fetal development and therefore abnormal leptin levels may be associated with this form of pregnancy loss. METHODS: Leptin and leptin-binding activity (LBA) were measured in blood obtained from women who had a history of recurrent miscarriage (n = 53) during weeks 5-6 and 7-8 of pregnancy, and the concentrations were correlated with subsequent pregnancy outcome. RESULTS: Concentrations of leptin ranged from 1.4-62.8 ng/ml, but there was a strong correlation (r = 0.825, P < 0.001) between leptin values at weeks 5-6 and 7-8 in the same woman. Women who subsequently miscarried had significantly lower plasma leptin concentrations on both weeks 5-6 (13.34 +/- 2.1 ng/ml) (P < 0.05) and 7-8 (13.71 +/- 2.4 ng/ml) (P < 0.01) of pregnancy, than women who subsequently had a term birth (22.04 +/- 2.43 ng/ml week 5-6, 24.76 +/- 3.66 ng/ml week 7-8). LBA values ranged from 1-8.5% but there was no significant difference in LBA in blood obtained from women who subsequently miscarried or had a live birth. CONCLUSIONS: The significantly lower concentrations of leptin in women who subsequently miscarried suggest that leptin may play a role in preventing miscarriage. However, as there was a considerable overlap between the values of leptin in women who subsequently miscarried, and those that had a live birth, these measurements are of limited use in the prediction of pregnancy outcome in these women.