Ectopic pregnancy: histopathology and assessment of cell proliferation with and without methotrexate treatment**Supported by Wyeth/Lederle, Copenhagen, Denmark.††Presented in part at the Fifth Conference of Endocrinology and Metabolism in Human Reproduction, Academic Unit of Obstetrics and Gynaecology, London, United Kingdom, March 27 to 29, 1995

Triaging and Evaluation of Products of Conception in Abortions and Post-Partum Hemorrhage

The proper evaluation of abortion specimens and placentas from stillbirth and post-partum cases is important for adequate clinical care of post-abortion and post-partum patients. The following topics will be reviewed: (1) the importance of evaluation of both fetal and placental tissue in first trimester abortions to confirm an intrauterine pregnancy versus an ectopic pregnancy; (2) the clinical history associated with an abortion specimen or retained products of conception (POC) influences how the pathologist should triage the specimen; (3) the criteria for diagnosis of a molar pregnancy, which is critical for clinicians to know which patients need follow-up; (4) the utility of genetic studies for both diagnosis and appropriate follow-up of the patient; and (5) the pathologic evaluation of specimens from patients with post-partum hemorrhage for placenta accreta spectrum and subinvolution of maternal vessels.

Folic Acid Levels During Pregnancy Regulate Trophoblast Invasive Behavior and the Possible Development of Preeclampsia

Background

One of the unique features of placentation is its similarity to tumorigenesis yet being very well regulated. It allows rapid proliferation, migration, and invasion of mononuclear trophoblast cells into the maternal uterus and remodeling the maternal vasculature. This pseudomalignant nature of trophoblastic cells is strictly regulated and its importance becomes evident in abnormal pregnancies that are characterized by aberrant trophoblast proliferation/invasion like preeclampsia. In addition to this, the importance of folic acid supplementation during pregnancy is well documented. We aimed to analyze the molecular and epigenetic regulation of the pseudomalignant nature of placentation via folic acid levels.

Methods

Placental tissue samples were collected from different pregnancies in three different gestational stages. We estimated the impact of folic acid levels on global methylation, LINE1 methylation, and expression of DNMTs in all three gestational stages in pregnant women and preeclampsia pregnancies. We also analyzed the effect of folic acid supplementation on trophoblastic invasion using placental derived cells viz, JEG-3 and HTR-8/SVneo cell line and verified the molecular and epigenetic mechanisms involved in this regulation.

Results

Development of preeclampsia was observed to be associated with lower folate levels in placental tissue, higher global methylation level, and higher expression of DNMT1and DNMT3A. Folic acid supplementation was found to increase the invasive potential of placental trophoblasts by almost two folds which were associated with the decreased expression of tumor suppressor genes and tissue inhibitors of matrix metalloproteinases; and increased expression of oncogenes, telomerase gene, and matrix metalloproteinases. These folic acid-mediated changes were observed to be regulated by CpG methylation in the case of many genes. Folic acid supplementation was also observed to significantly decrease global methylation in placental trophoblasts related to decreasing expression of DNMT1 and DNMT3A.

Conclusion

Lower folic acid levels are associated with preeclampsia development and folic acid supplementation regulates the invasive potential of placental trophoblasts as mediated by various epigenetic changes in the placenta suggesting the protective effect of folic acid against preeclampsia.

Effect of Methotrexate on Salpingostomy Completion Rate for Tubal Ectopic Pregnancy: A Retrospective Cohort Study

STUDY OBJECTIVE

To determine whether completion rates of salpingostomy for tubal ectopic pregnancy are compromised by initial medical management with methotrexate (MTX).

DESIGN

Retrospective cohort study.

SETTING

Single academic hospital system.

PATIENTS

Patients requiring surgery for ectopic pregnancy between 2006 and 2017.

INTERVENTIONS

A subset of patients who went directly to surgery, and all patients who failed MTX before requiring surgery underwent detailed chart review. Salpingostomy plan and success rate and salpingostomy failure reasons were compared between patients pretreated with MTX and those who were MTX-untreated.

MEASUREMENTS AND MAIN RESULTS

Among 94 ectopic pregnancies requiring surgery after failed MTX treatment, 55 (59%) underwent planned salpingostomy. From 693 ectopic pregnancies managed without MTX, 166 were analyzed in detail, of which 80 (48%) underwent planned salpingostomy. The patients who underwent planned salpingostomy were thinner (body mass index 27.3 ± 7.2 kg/m² vs 29.3 ± 8.3 kg/m²; p = .048), less frequently African American (33% vs 47%; p = .017), and more likely to have a visualized adnexal lesion (70% vs 52%; p = .004) than those undergoing planned salpingectomy. Preoperative ultrasound identified fetal cardiac activity and hemoperitoneum at comparable rates. MTX exposure was not associated with age, body mass index, race, ectopic risk factors, human chorionic gonadotropin levels, or gestational age at diagnosis, but the patients treated with MTX underwent surgery later than those who were untreated (gestational age 53.4 ± 11.2 days vs 43.5 ± 11 days; p <.001). The differences between the adnexal lesion size and rates of fetal cardiac activity and hemoperitoneum on ultrasound related to MTX exposure did not meet significance. Planned salpingostomy was completed in 22 (40%) of the patients treated with MTX vs 34 (42%) of those who were untreated. The reasons for failure, surgery time, and rates of hemoperitoneum or ectopic rupture were not associated with MTX exposure. Body mass index, race, tubal anastomosis history, visualization of the adnexal lesion, and MTX exposure were not significantly associated with the salpingostomy rate in a multivariate logistic regression model, but having a subspecialist surgeon (odds ratio 2.70; 95% confidence interval, 1.08-6.76; p = .033) and tubal rupture at surgery (odds ratio 0.23; 95% confidence interval, 0.09-0.54; p = .001) were.

CONCLUSION

The initial medical management of an ectopic pregnancy with MTX is not associated with a decreased salpingostomy success rate.

Failed Methotrexate-Treated Ectopic Pregnancies: Clinicopathologic Correlations

Methotrexate (MTX) administration as an alternative to surgical therapy for unrupured ectopic pregnancies (EPs) has a 5-11% failure rate. The histologic findings in surgical specimens from patients for whom MTX therapy failed have not been exensively described. Review of pathology records from January 1991 through June 1996 revealed 12 MTX-treated tubal EPs that subsequently required surgical interention. Clinical data and histologic findings were compared with those from tubal EPs from maternalagend gestational-age-matched controls. Semiquantitative obervations of chorionic villous morphology were assessed by a senior pathologist unware of the treatment regimens. The average maternal age was 27 years and the mean gestational age was 9 weeks. Patients received one to two intramuscular injecions of MTX (50 mg/M2) and were followed up with serial serum betahuman chorinic gonadotropin (f-hCG) determinations. P-hCG levels fell from presentation to surgical intervention in 36.4% of MTX-treated patients, increased in 9.1%, and rose then fell in 54.5%. Peak r-hCG titers were significantly higher in MTX-exposed paients as compared with controls. There was no correlation between,3-hCG profile and villous morphology. Sixty-seven percent of MTX-treated EPs showed significant trophoblastic atypia as compared with 25% of control cases. Atypical villous trohoblasts had enlarged nuclei with irregular contours, smudged chromatin, and prominent nucleoli. There were no significant differences between failed MTX-exosed EPs and controls in terms of the presence or degree of villous necrosis, trohoblastic vacuolization, or embryonic development. Chorionic villous morphology in failed MTX-treated EPs showed no significant differences from that of nontreated EPs except for a trend toward increased trophoblastic atypia, features that may be confused with early gestational trophoblastic disease. Failed MTX-treated EPs may represent a subset of gestations that are resistant to MTX. As the uses of MTX are exanded to encompass the termination of early intrauterine pregnancies, the recogniion of possible treatmentrelated alterations in the histologic appearance of chorinic villi, trophoblasts, and implantation sites will be pertinent to avoid misdiagnosis.

The role of leukemia inhibitory factor in tubal ectopic pregnancy

INTRODUCTION

Ectopic pregnancy is unique to humans and a leading cause of maternal morbidity and mortality. The etiology remains unknown however factors regulating embryo implantation likely contribute. Leukemia inhibitory factor (LIF) has roles in extravillous trophoblast adhesion and invasion and is present in ectopic implantation sites. We hypothesised that LIF facilitates blastocyst adhesion/invasion in the Fallopian tube, contributing to ectopic pregnancy.

METHODS

We immunolocalised LIF receptor (R) in tubal ectopic pregnancy (N = 5). We used an oviduct cell line (OE-E6/E7) to model Fallopian tube epithelial cells and a trophoblast spheroid co-culture model (HTR-8/SVneo cell line formed spheroids) to model blastocyst attachment to the Fallopian tube. We examined LIF signaling pathways in OE-E6/E7 cells by Western blot. The effect of LIF and LIF inhibition (using a novel LIF inhibitor, PEGLA) on first-trimester placental outgrowth was determined.

RESULTS

LIFR localised to villous and extravillous trophoblast and Fallopian tube epithelium in ectopic pregnancy. LIF activated STAT3 but not the ERK pathway in OE-E6/E7 cells. LIF stimulated HTR-8/SVneo spheroid adhesion to OE-E6/E7 cells which was significantly reduced after PEGLA treatment. LIF promoted placental explants outgrowth, while co-treatment with PEGLA blocked outgrowth.

DISCUSSION

Our data suggests LIF facilitates the development of ectopic pregnancy by stimulating blastocyst adhesion and trophoblast outgrowth from placental explants. Ectopic pregnancy is usually diagnosed after 6 weeks of pregnancy, therefore PEGLA may be useful in targeting trophoblast growth/invasion.

CONCLUSION

LIF may contribute to the development of ectopic pregnancies and that pharmacologically targeting LIF-mediated trophoblast outgrowth may be useful as a treatment for ectopic pregnancy.

Human chorionic gonadotropin level as a predictor of trophoblastic infiltration into the tubal wall in ectopic pregnancy: a blinded study

OBJECTIVE

To determine the relationship between gestational age, tubal ultrasonographic diameter, and serum hCG levels and different stages of trophoblastic infiltration of the tubal wall in ectopic pregnancy.

DESIGN

Blinded prospective study.

SETTING

University-based clinic in Italy.

PATIENT(S)

Thirty-seven consecutive patients with an ampullary ectopic pregnancy.

INTERVENTION(S)

Laparoscopic salpingectomy.

MAIN OUTCOME MEASURE(S)

Gestational age, diameter of the tubal mass as determined by transvaginal ultrasonography. and hCG level on the day of surgery. Ectopic pregnancy was classified according to the depth of trophoblastic infiltration: trophoblast limited to the tubal mucosa (stage I), extension to the tubal muscularis (stage II), or complete tubal wall infiltration up to the serosa discontinued by trophoblastic cells (stage III).

RESULT(S)

Fifteen patients (40.5%) had stage I tubal infiltration, 14 (37.8%) had stage II infiltration, and 8 (21.6%) had stage III infiltration. Gestational age and diameter of the tube did not differ among the three groups. The median hCG level was 1,710.5 mIU/mL (range, 113-5,635 mIU/mL) for patients with stage I infiltration. 4,690.0 mIU/mL (range, 150-21,531 mIU/mL) for patients with stage II infiltration, and 15,700.0 mIU/mL (range, 13,809-21,650 mIU/mL) for patients with stage III infiltration. All the patients with hCG levels > 6,000 mIU/mL had stage II or III invasion.

CONCLUSION(S)

These findings may explain why the conservative treatment of ectopic pregnancy is less successful in patients with high hCG levels than in patients with low levels. Use of radical procedures may be justified in the former group.

Does plasminogen activator inhibitor-1 (PAI-1) control trophoblast invasion? A study of fetal and maternal tissue in intrauterine, tubal and molar pregnancies

Urokinase plasminogen activator, its receptor and the inhibitor PAI-1 are believed to control proteolysis and remodelling of maternal tissue during trophoblast invasion. This system appears to be strictly regulated in normal intrauterine pregnancies whereas tubal and molar pregnancies seem to be characterized by an uncontrolled excessive placental invasion. This study evaluates subcellular PAI-1 by immunohistochemistry in the villous placenta, in the basal plate and placental bed, and in the decidual compartments of normal, tubal and molar pregnancies. PAI-1 was present in villous syncytiotrophoblasts and co-localized focally with fibrin-type fibrinoid on the surface of the chorionic villi. Basal plate and placental bed extravillous interstitial trophoblasts, as well as vascular trophoblasts, were also PAI-1 positive. In the decidua parietalis, PAI-1 was observed in the cytoplasm of the non-invaded decidual cells. In the decidua basalis comprising the basal plate, PAI-1 was seen to be membrane-associated or confined to the extracellular matrix (ECM) facing the invasive front of anchoring villi. The ECM of decidua capsularis and chorion laeve displayed the most pronounced PAI-1 expression towards the maternal interface. In contrast, the majority of placental bed decidual cells adjacent to the interstitial and vascular trophoblasts were PAI-1 negative. Only a few stromal cells distant from the implantation site were PAI-1 positive in the tubal pregnancies and decidualization was not present. Likewise, excessive decidual necrosis and fibrinoid deposition devoid of PAI-1 was a common finding in complete molar pregnancies. These results suggest that PAI-1 defines specific extravillous invasive trophoblasts within the maternal decidua. Moreover, maternal cellular lack of PAI-1 in tubal pregnancies and excessive decidual necrosis in molar pregnancies indicate an uncontrolled placental invasion. The present data indicate that trophoblast invasion is primarily regulated by signals from decidual cells.

Localization and significance of urokinase plasminogen activator and its receptor in placental tissue from intrauterine, ectopic and molar pregnancies

Urokinase plasminogen activator receptor (uPAR) is a membrane-anchored protein with urokinase plasminogen activator (uPA) as the ligand. This complex induces proteolysis and remodelling of maternal decidua during placental implantation. The presence of uPAR on trophoblasts is supposed to promote adhesion, migration and invasion. In cancer tissue, high levels of uPAR are correlated with a poor prognosis. This immunohistochemical study shows the localization of uPA and uPAR in a prospective design with stereological sampling of fetal and maternal tissue from normal, ectopic and hydatidiform molar (HM) pregnancies. Cytokeratin and Ki67 were used as markers for trophoblasts and proliferating cells. Membrane-bound uPAR was observed on villous non-proliferating intermediate trophoblasts (IT) within cell columns in intrauterine and ectopic pregnancies. The corresponding proliferating IT with cytological atypia sprouting from the chorionic villi in HM was uPAR-negative. uPA but not uPAR was observed in anchoring distal IT at the attachment-point to the basal plate. In the placental bed, extravillous interstitial trophoblasts were uPA-positive but uPAR-negative. The trophoblast giant cells were both uPA- and uPAR-negative. In relation to the maternal vessels, a focal distribution for uPA and uPAR was present in the endovascular and perivascular trophoblasts. The intraluminal trophoblasts overlying endothelial cells were uPAR-positive only. In maternal tissue from intrauterine and molar pregnancies, uPAR was seen in the decidual cells in a zone facing the anchoring villi and the fibrinoid lesions with embedded trophoblasts. In contrast, the stromal cells of the fallopian tube without a decidual reaction facing the implanted gestation were uPAR-negative. Non-invaded decidual, myometrial and muscular tissue of the pregnant uterus and fallopian tube was extensively positive for uPA whereas 'pseudodecidual' cells from the intrauterine evacuate in patients with an ectopic pregnancy only showed a focal and scanty reaction for uPA. When trophoblast invasion of the decidua was present, the decidual cells were uPA-negative. A semi-quantitative assessment of the receptor was estimated in villous IT within cell columns in normal and molar pregnancies but, in conclusion, quantitative evaluation of uPAR cannot be used to predict development of post-molar persistent trophoblastic disease (PTD).

Methotrexate effects on trophoblast and the corpus luteum in early pregnancy

OBJECTIVE

Our purpose was to determine whether methotrexate affects the trophoblast or corpus luteum when administered for abortion.

STUDY DESIGN

A randomized controlled trial was performed in women requesting an abortion up to 49 days' gestation. Twenty patients were treated with intramuscular methotrexate 50 mg/m2 (10 women) or 60 mg/m2 (10 women). Serum beta-human chorionic gonadotropin, progesterone, and 17-hydroxyprogesterone levels were determined at baseline and then serially after methotrexate administration for the first 24 hours, then every 24 hours for 7 days. On the seventh day misoprostol 800 microg was administered vaginally.

RESULTS

Serum beta-human chorionic gonadotropin increased at a lower rate than occurs in normal pregnancy. Progesterone levels averaged 56.9 +/- 19.8 nmol/L at baseline and 45.5 +/- 20.5 nmol/L (P = .01) 1 week after methotrexate. Progesterone decreased in 16 women over the 7 days and increased in the other 4; these latter women all aborted after a single dose of misoprostol. Levels of 17-hydroxyprogesterone plateaued during the first day after methotrexate administration; both progesterone and 17-hydroxyprogesterone declined simultaneously between the third and fourth day after methotrexate.

CONCLUSIONS

Methotrexate most likely primarily affects trophoblast production of human chorionic gonadotropin, as evidenced by a blunting of the expected increase in serum beta-human chorionic gonadotropin resulting in less support for the production of progesterone by the corpus luteum. However, changes in progesterone levels after methotrexate administration were inconsistent and are unlikely to represent the ultimate effect of methotrexate in abortion. The less-than-normal increase in serum beta-human chorionic gonadotropin levels after methotrexate administration is most likely a result of disruption of cytotrophoblast syncytialization. This disruption may be the true effect of methotrexate in destabilizing the implantation site of an early pregnancy.

Are serum human chorionic gonadotropin clearance curves of use in monitoring methotrexate treatment in cervical pregnancy?

OBJECTIVE

To describe the monitoring of an unsuccessful case of methotrexate treatment of cervical pregnancy.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

A 27-year-old woman, gravida 3, para 1, with a vital cervical pregnancy.

INTERVENTION(S)

Feticide and methotrexate administered both locally and systemically.

MAIN OUTCOME MEASURE(S)

Treatment success, defined as elimination of the cervical pregnancy with preservation of the uterus.

RESULT(S)

Despite reassuringly declining serum hCG concentrations, several episodes of severe vaginal bleeding demanded transfusions of 19 U of packed cells, two angiographic embolizations that were complicated by septicemia, and a balloon catheter tamponade followed by a third angiographic embolization. Ultimately, a hysterectomy was necessary because of uncontrollable vaginal bleeding.

CONCLUSION(S)

This case report shows that serum hCG monitoring was not helpful in the detection of impending treatment failure. Currently, no guidelines are available to clinicians for predicting treatment failure of methotrexate in patients with cervical pregnancy. Serum hCG clearance curves do enable the timely detection of inadequately declining serum hCG concentrations, for which additional methotrexate can be administered.