Enthalpy of collagen interfibrillar bonds in fetal membranes.

During pregnancy, the fetal membrane (FM) is subjected to mechanical stretching that may result in preterm labor. The structural integrity of the FM is maintained by its collagenous layer. The disconnection and reconnection of molecular bonds between collagen fibrils are the fundamental processes that govern the irreversible mechanical and supermolecular changes in the FM. Here, we study the activation enthalpy of interfibrillar bonds in ex-vivo human FM. We analyze the strain-rate and temperature dependence of the irreversible deformations in FM subjected to inflation tests, which apply mechanical conditions similar to those experienced by the FM prior to and during the initiation of labor contractions. The obtained activation enthalpy of interfibrillar bonds matches the typical enthalpy values of polyvalent ionic bonds, implying on another important role that ions like Ca and Mg may play in the gestation and labor.

Collagen bundling and alignment in equibiaxially stretched human amnion.

We study irreversible collagen arrangement processes in ex-vivo human amnions subjected to inflation tests, which simulate the mechanical conditions prior to and during the initiation of labor uterine contractions. The investigation is focused on the center of the membrane where the stresses are maximal and equibiaxial. Second harmonic generation reveals an unexpected collagen rearrangement in the compact layer that is responsible for the structural integrity of the fetal membrane. The observed bundling and alignment of the collagen fibers indicate a deviation from the expected equibiaxial stress state. The statistical analysis of the fiber orientations provides information on two driving forces for collagen alignment: microscale flaws and macroscale deviation from the equibiaxial strain. As the pressure increases, the macroscale effect becomes dominant, and a high density of fibers that are aligned along a specific direction is observed. A model that explains these observations and relates them to the material properties is presented. The results of this study indicate that a temporal increase in intrauterine pressure or uterine cervix dilatation causes irreversible changes in collagen molecular connections that may lead to biological changes, such as the initiation of term and preterm labor.

Ectopic pregnancy risk factors for ART patients undergoing the GnRH antagonist protocol: a retrospective study.

BACKGROUND: In-vitro fertilization is a known risk factor for ectopic pregnancies. We sought to establish the risk factors for ectopic pregnancy in GnRH antagonist cycles examining patient and stimulation parameters with an emphasis on ovulation trigger. METHODS: We conducted a retrospective, cohort study of 343 patients undergoing 380 assisted reproductive technology (ART) cycles with the GnRH antagonist protocol and achieving a clinical pregnancy from November 2010 through December 2015. RESULTS: Significant risk factors for ectopic pregnancy in the univariate analysis included prior Cesarean section (CS), endometriosis, mechanical factor infertility, longer stimulation, elevated estradiol and progesterone levels, GnRH agonist trigger, higher number of oocytes aspirated, and insemination technique. Independent risk factors for ectopic pregnancy in the multivariate analysis included GnRH agonist trigger, higher number of oocytes aspirated, insemination technique, and prior Cesarean section. CONCLUSION: Excessive ovarian response, IVF (as opposed to ICSI), prior Cesarean section and GnRH agonist trigger were found to be independent risk factors for ectopic pregnancy. Caution should be exercised before incorporating the GnRH agonist trigger for indications other than preventing OHSS. When excessive ovarian response leads to utilization of GnRH agonist trigger, strategies for preventing ectopic pregnancy, such as a freeze all policy or blastocyst transfer, should be considered. Further studies should elucidate whether adjusting the luteal support can reduce the ectopic pregnancy risk.

Empty follicle syndrome: successful treatment in a recurrent case and review of the literature.

Empty follicle syndrome is a condition in which no oocytes are retrieved after an apparently adequate ovarian response to stimulation and meticulous follicular aspiration. It is a rare condition of obscure etiology. A patient with primary infertility who underwent seven assisted reproductive technique cycles is described. In spite of a satisfactory ovarian response, aspiration yielded no oocytes in four cycles and 1-4 low quality oocytes in three cycles. In the index treatment cycle, ovulation was triggered using GnRH agonist 40 h prior to ovum pickup and hCG was added 6 h after the first trigger. Eighteen oocytes were recovered, of which 16 were mature and were inseminated by ICSI. Two embryos were transferred 48 h after aspiration and nine embryos were cryopreserved. The patient conceived and delivered a healthy boy at 38 weeks of gestation. The literature is reviewed and possible etiologies and treatment options of this enigmatic syndrome are suggested.

Effect of primary human endometrial stromal cells on epithelial cell receptivity and protein expression is dependent on menstrual cycle stage.

BACKGROUND: Successful implantation requires a receptive endometrium. We hypothesized that effects of endometrial stromal cells (ESC) on epithelial cell receptivity and trophoblast-endometrium interaction are menstrual cycle dependent. METHODS: An endometrial in vitro 3D co-culture model of primary human ESC with the endometrial epithelial cell line (RL95-2) was constructed. Co-cultures were prepared using primary ESC from biopsies taken before the window of implantation (ESCbw) and during the window of implantation (ESCw), on cycle days 10-17 and 19-23, respectively. RL95-2 served as a constant parameter upon which the influence of ESC from different phases of the cycle was investigated. proMMP-2 (MMP, matrix metalloproteinase) and proMMP-9 secretion was tested in response to progesterone. Progesterone receptor B (PR-B) and plexin B1 protein expression and mRNA levels were investigated using immunofluorescence and RT-PCR, respectively. RESULTS: Progesterone increased proMMP-2 secretion in primary ESCbw (P = 0.0046) but decreased proMMP-2 and proMMP-9 secretion in ESCw (P < 0.0005). In the presence of ESCbw, JAR spheroid attachment rate to overlying RL95-2 cells was decreased (P < 0.0001), whereas in the presence of ESCw, attachment rate was unchanged. Progesterone treatment restored epithelial cell receptivity in co-culture with ESCbw (P = 0.00004). A correlation between spheroid attachment rate and plexin B1 mRNA level was observed (P = 0.01). PR-B protein and mRNA level were influenced by the interplay between RL95-2 and stromal cells. CONCLUSION: The effects of human primary ESC on epithelial cell receptivity and trophoblast-endometrium interaction depended upon whether the ESC were taken before or during the window of implantation.

Lack of association between unexplained elevated maternal serum alpha fetoprotein and/or human chorionic gonadotropin and the occurrence of placental thrombotic lesions.

OBJECTIVE: To investigate the significance of unexplained elevated maternal serum alpha fetoprotein (MSAFP) and/or human chorionic gonadotropin (HCG) on the occurrence of placental thrombotic changes. STUDY DESIGN: Between January 2007 to April 2009, placentas of all women who delivered and had unexplained elevated MSAFP and/or HCG (above 2 MOM) were sent to histological examination. Women were divided into 2 groups. Group A included women who had uneventful pregnancies and delivered at term. Group B included women with antepartum complications attributed to thrombosis. Women in both groups (A and B) had elevated MSAFP and/or HCG. Group C was a frequency matched group of women who had normal MSAFP and HCG levels with uneventful pregnancies and delivered at term. MAIN OUTCOME MEASURE: Incidence of placental thrombotic lesions in each group. RESULTS: Of 9695 women who delivered during the study period there were 76 women with elevated MSAFP and or HCG, 48 in group A and 28 in Group B. Group C, included 30 women. The number of placentas in which any thrombotic lesion was identified was 22 (45.8%), 19 (67.9%) and 10 (33%) respectively. Changes differed significantly only between group B and C (p = 0.03). Although the rate of changes in group A was higher than in group C it did not reach statistical significance even when considering only women with two abnormal results (MSAFP and HCG) or when a cutoff of 2.5 MOM or more was set. CONCLUSION: Placental histopathological changes are associated with pregnancy complications and can only marginally be attributed to unexplained elevated MSAFP and/or HCG.

p53 Mediates epidermal growth factor (EGF) induction of MMP-2 transcription and trophoblast invasion.

Trophoblast invasion is a highly restricted process, regulated by growth factors, hormones and cytokines. Trophoblast invasion is attainable due to proteolytic degradation of the epithelial basement membrane and the extracellular matrix by proteolytic enzymes like the matrix metalloproteinases (MMPs) particularly MMP-2. Epidermal growth factor (EGF), a major mediator of implantation, has been documented to induce MMP-2 and trophoblast invasion. The aim of this study was to investigate the transcriptional regulation of MMP-2 in EGF- stimulated invasive trophoblast cells, using JAR choriocarcinoma cell line and 6-8w 1st trimester trophoblasts. MMP-2 expression was induced by EGF within 1 hour. Gelshift and supershift assay were used to explore transcription factors involved in MMP-2 regulation. EGF induced binding activity and expression of phophorylated p53, AP-2alpha and -gamma, C/EBPepsilon and -lambda to their responding sequences, found in the MMP-2 promoter. Additionally EGF induced binding activity to SP-1, but reduced the expression of SP-1 and SP-4. Inhibition of p53 by antisense reduced both basic and EGF- induced MMP-2 expression. In summary: MMP-2 transcriptional regulation by EGF in invasive trophoblasts is mediated through several binding sites and transcription factors including p53, AP-2alpha and -gamma, C/EBPepsilon and -lambda and SP-1. p53 mediates both basic and EGF-induced MMP-2 transcription.

GnRH agonist therapy as ovarian protectants in female patients undergoing chemotherapy: a review of the clinical data.

BACKGROUND: Cancer survival rates in young women are improving due to progress in treatment. This includes aggressive chemotherapy, a treatment that often poses a threat to fertility. GnRH agonists were proposed as ovarian protectors during gonadotoxic therapies. This study was undertaken in order to determine the clinical evidence concerning this issue. METHODS: The medical literature was searched for studies that reported on ovarian function after the administration of GnRH agonists concomitant with chemotherapy. Twelve studies met the predetermined selection criteria. RESULTS: Data on ovarian function were obtained for 579 women who received chemotherapy. Among 345 women who received GnRH agonist co-treatment, ovarian function was preserved in 91% and 9% had premature ovarian failure. In 234 women who did not receive GnRH agonist co-treatment, ovarian function was preserved in 41% and failed in 59%. Only two of the studies were randomized. The control and the GnRH agonist groups differed in several important characteristics: the follow-up times were not equal, different treatment protocols were utilized and end-points were poorly defined and inconsistent between the studies. CONCLUSIONS: The effectiveness of GnRH agonists as fertility-preserving agents is debatable. A thorough literature search has found insufficient evidence to show that GnRH agonist co-treatment is effective in protecting the ovary from the damage of chemotherapy. A large randomized controlled trial with adequate follow-up is needed.

Evidence for blood chimerism in dizygotic spontaneous twin pregnancy discordant for Down syndrome.

BACKGROUND: A monochorionic-diamniotic placenta (MCDAP) is rare in dizygotic (DZ) twinning. All reported cases have been documented in pregnancies achieved by the induction of ovulation alone or during the IVF cycle. METHODS AND RESULTS: We report a spontaneous pregnancy in a 39-year-old patient with evidence of MCDAP in DZ twins, discordant for trisomy 21. The first and second-trimester sonographic scans indicated male twins with MCDAP. Amniocentesis, performed because of advanced maternal age, revealed a normal karyotype in one fetus, and trisomy 21 in the other. Molecular studies, performed in order to confirm the zygosity and chorionicity, demonstrated that the fetuses were DZ. In order to identity the affected twin, a detailed sonographic examination was repeated, but no abnormal findings associated with Down syndrome were demonstrated in any of the fetuses. Therefore, umbilical cord blood samples were obtained from both fetuses. Chromosomal analysis revealed in both fetuses two cell lines: a normal cell line of 46,XY and a 47,XY,+ 21 cell line, in 65 and 80% of the cells, respectively. This result was independently confirmed by both FISH and G-banding. DNA extracted from both cord blood samples demonstrated an admixture of two distinct genotypes in each sample. CONCLUSIONS: We propose that this case represents a monochorionic-dizygotic twin pregnancy with blood chimerism. The most plausible mechanism underlying this phenomenon is placental fusion early in pregnancy, resulting in an architecturally single placenta originating from two distinct zygotes. The newly formed blood vessels created anastomoses between the DZ twins and allowed reciprocal blood chimerism between the normal and the trisomic twin.