Laparoscopic salpingotomy for tubal pregnancy: comparison of linear salpingotomy with and without suturing

BACKGROUND: The study was carried out to clarify the incidence of post-operative tubal adhesions, patency rate and pregnancy outcome after laparoscopic salpingotomy with and without suturing for tubal pregnancy. METHODS: From May 1996 to December 2002, a total of 97 cases of tubal pregnancy were treated in our centre by laparoscopic conservative surgery. The successful salpingotomy cases were randomly assigned to undergo salpingotomy without suturing (group I; n = 43) or with suturing (group II; n = 32). We compared these patients and assessed their surgical and pregnancy outcome by second look laparoscopy (SLL) 3 months after the first operation. RESULTS: Seventy-five cases (77%) were treated successfully by salpingotomy at initial laparoscopic surgery, and the remaining 22 cases were unsuccessful because of bleeding or complete tubal damage. Pelvic findings were assessed at SLL in 21 of 43 cases (49%) in group I and 17 of 32 (53%) in group II. There were no significant differences in gestational age, ectopic site, tubal diameter, tubal condition, intraperitoneal haemorrhage and pre-operative HCG levels between the two groups. Only the operation time was longer in group II than in group I (91 +/- 15 versus 69 +/- 15 min, P < 0.05). The tubal patency rate of the treated side was 90% (19/21) in group I and 94% (16/17) in group II. Also the peritubal adhesions were observed in 33% (7/21) in group I and 29% (5/17) in group II, and were mostly comprised of filmy adhesions. A tubal fistula occurred in two cases in each group. Pregnancy rate was 79% (15/19) in group I and 92% (12/13) in group II, and this did not reveal any significant difference of cumulative pregnancy rate between the groups. CONCLUSION: We recommend laparoscopic linear salpingotomy as a useful method in the management of cases with tubal pregnancy who desire future pregnancy. This preliminary study emphasizes that the procedure involving suturing has no additional benefit over the non-suturing technique during salpingotomy.     

Endometrial fluid visualized through ultrasonography during ovarian stimulation in IVF cycles impairs the outcome in tubal factor, but not PCOS, patients

BACKGROUND: The aim of the present study was to examine the impact of the presence of endometrial fluid (seen through ultrasound) on the outcome of IVF cycles and its association with the aetiology of infertility, in tubal and polycystic ovary syndrome (PCOS) cases specifically. METHODS: We retrospectively evaluated the charts of all PCOS and tubal factor infertility patients that underwent IVF between June 1, 2001 and May 31, 2002. Twenty-four PCOS and 14 tubal factor infertility patients in whom endometrial fluid was detected were compared with 94 PCOS and 160 tubal factor patients whose stimulation cycles did not show any fluid collection. The main outcome measures were implantation and pregnancy rates. RESULTS: Implantation rates were lower in the tubal factor patients in the presence of endometrial fluid (6.12% and 21.4%, respectively) in comparison with all other tubal factor infertile patients in whom no fluid accumulation inside the cavity was detected. In PCOS cycles there was no significance in patients with presence of endometrial fluid in comparison with the all other PCOS cycles without any fluid accumulation. CONCLUSIONS: When fluid collection inside the endometrial cavity is first seen during ovarian stimulation of PCOS patients undergoing IVF, embryo transfer can be performed safely if the fluid has disappeared and not returned by the day of embryo transfer. However, in tubal factor cycles one should think of either cancellation of the cycle or cryopreservation of all embryos.     

Heterotopic triplet pregnancy: report of a case with bilateral tubal pregnancy and an intrauterine pregnancy

The first report of an ectopic pregnancy following IVF was published in 1976, and since then heterotopic pregnancies (HPs) have been reported at an increasing rate. Although cases of the co-existence of a bilateral tubal and an intrauterine pregnancy following IVF-embryo transfer have been reported, a case of heterotopic triplet pregnancy caused by unilateral tubal embryo transfer has not yet been published in the literature. Here we report on a 38-year-old women (gravida 3, para 1) with a history of infertility who presented to our infertility clinic for evaluation. Hysterosalpingography revealed bilaterally patent Fallopian tubes and stricture of the cervical canal. She conceived after receiving HMG combined with pure FSH, followed by IVF-tubal embryo transfer. Four embryos were replaced into the right tube. Approximately 5 weeks after tubal embryo transfer, the patient presented with lower abdominal tenderness and shock due to internal bleeding. She underwent an emergency laparotomy under the impression of HP. Bilateral tubal pregnancy with right tubal rupture was noted during the operation. The post-operative course was uneventful. Early intervention and thorough inspection of the peritoneal cavity in patients with haemodynamic instability can prevent jeopardizing the life of the mother as well as the ongoing pregnancy.     

Evaluation of ectopic pregnancy by magnetic resonance imaging.

Patients (n = 37) suspected of ectopic pregnancy were prospectively evaluated with magnetic resonance (MR) imaging to assess the capability of MR imaging in the diagnosis of ectopic pregnancy. Five levels of confidence were defined: diagnostic, suspicious, equivocal, questionable, and negative. Tubal wall enhancement and presence of tubal haematoma or gestational sac-like structure were considered diagnostic findings. There were 21 diagnostic, two suspicious, eight equivocal, and six negative findings. MR findings were compared with the surgical findings in 18 patients. Surgical confirmation was obtained in 12 diagnostic, two suspicious, and four equivocal studies. Using the MR diagnostic criteria for tubal pregnancy, MR had 12 true positive, three true negative, three false negative, and no false positive results for the diagnosis of tubal pregnancy. Retrospective analysis of the signal intensity of haematoma and ascites was performed for these 18 surgically confirmed cases. The predominant signal intensity of tubal haematoma was an intermediate signal on T1-weighted image (WI) and a low signal on T2WI. Ascites showed signal intensity higher than that of urine on T1WI in 100% of 13 cases. In conclusion, MR imaging with use of intravenous contrast material allows a specific diagnosis of tubal pregnancy, recognizing tubal wall enhancement and fresh tubal haematoma.     

Interleukin-11 expression: its significance in eutopic and ectopic human implantation

Embryo implantation and subsequent decidualization, trophoblast invasion and formation of a functional placenta are crucial for establishment and maintenance of pregnancy. Interleukin-11 signalling has been shown to be obligatory for adequate decidualization and trophoblast invasion in mice. Defects in IL-11 signalling in mice result in trophoblast over-invasion and fetal loss. The pathological situation of human tubal pregnancy resembles that of IL-11Ralpha(-/-) mice concerning these symptoms. As our interest is focused on the human early pregnancy, we compared IL-11 expression at the implantation site of ectopic tubal pregnancy (EP) to 1st and 2nd trimester of normal intrauterine pregnancies (IP), and to the normal cycling endometrium. The mRNA expression of IL-11 and IL-11Ralpha was analysed by semiquantitative RT-PCR. Protein expression was detected by western blotting and immunohistochemistry. IL-11Ralpha is expressed constitutively in all tissue specimens analysed. IL-11 is expressed predominantly during follicular and early luteal phase of the menstrual cycle. In IP, IL-11 expression peaks during the 1st trimester and declines from the beginning of the 2nd trimester onwards. In tubal abortions, IL-11 expression is reduced in comparison to vital EP and IP. Cultured primary endometrial and decidual epithelial cells were analysed for hormonal regulation of IL-11 by enzyme-linked immunosorbent assay and RT-PCR. IL-11 is up-regulated by estrogen and down-regulated by progesterone. Overall, our results indicate that in humans, IL-11 signalling is significantly involved in regulation of trophoblast invasion. In the case of tubal abortion, inadequate IL-11 signalling may therefore result in dysregulation of trophoblast invasion.     

Pregnancy: Combined intra-uterine and extra-uterine pregnancy in the contralateral tube after gamete intra-Fallopian transfer

A case of combined intra-uterine and contralateral tubal pregnancyafter gamete intra-Fallopian transfer (GIFT) is presented. Laparotomywith partial tubal resection was performed after tubal rupture.The intra-uterine pregnancy is still ongoing without complications.Heterotopic pregnancies are dangerous conditions for the patientand should be taken into account after transfer of multipleoocytes. To our knowledge this is the first report of a heterotopicpregnancy in the contralateral tube after GIFT.     

Endometriosis in pregnant and non-pregnant women at tubal sterilization

The prevalence of endometriosis was investigated in 208 women at the time of laparoscopic tubal sterilization. In 101 women who were in the first trimester of pregnancy, 16% endometriosis was found. In 107 non-pregnant women, 22% endometriosis was detected. Endometriosis in the pregnant women showed more superficial, non-pigmented, gland-like lesions than in the non-pregnant group. In 23% of the endometriotic lesions from pregnant women, no decidualization was found. No special risk factors for developing endometriosis were found.     

Simultaneous bilateral tubal pregnancy after intracytoplasmic sperm injection

Since the advent of assisted reproductive technology, the concernabout ectopic implantation of embryos has increased dramatically.Simultaneous bilateral tubal pregnancy is the least common typeof ectopic implantation of two embryos. In this report we presentthe first case of simultaneous bilateral tubal pregnancy afterintracytoplasmic sperm injection (ICSI) and embryo transfertreatment. The present case had no risk factor for ectopic pregnancy.Therefore, for early diagnosis and management of such cases,close clinical follow-up and routine ultrasonography followingICSI are necessary.     

Prognostic capacity of transvaginal hydrolaparoscopy to predict spontaneous pregnancy

BACKGROUND: In 1998, transvaginal hydrolaparoscopy (THL) was introduced as a new outpatient procedure for exploration of tubo-ovarian structures and tubal patency in subfertile patients. At present, there are no large studies that relate the findings at THL to fertility outcome. METHODS: Consecutive patients undergoing THL for subfertility between 2000 and 2004 were included in this prospective cohort study. Follow-up ended when ongoing pregnancy or tubal surgery occurred or at the day of last contact. Kaplan-Meier curves for the occurrence of intrauterine pregnancy (IUP) (spontaneous or after intrauterine insemination) were constructed for a normal THL, a THL with a one-sided tubal pathology and a THL with a two-sided tubal pathology. Fecundity rate ratios (FRRs) were calculated to express the association between THL findings and the occurrence of IUP. Patients rated their pain experiences and acceptability on a visual analogue scale (VAS). RESULTS: We included 272 women. In 96% (261) of the patients, access to the pouch of Douglas was achieved. Complications occurred in 2% of the procedures. In 203 (78%) patients, both tubo-ovarian structures could be visualized and tubal patency was shown. One-sided tubal occlusion was found in 10%, whereas two-sided tubal occlusion was seen in 4% of the patients. Adhesions and/or endometriosis were observed in 8% of the patients. The FRRs for one-sided tubal pathology, two-sided tubal pathology and adhesions/endometriosis were 0.59, 0 and 0.80, respectively. The VAS scores showed pain to be limited and the procedure to be acceptable. CONCLUSION: THL is a feasible technique. Its capacity to predict spontaneous ongoing pregnancy is comparable to that of laparoscopy.     

Pregnancy rates after in-vitro fertilization in cases of tubal infertility with and without hydrosalpinx: a meta-analysis of published comparative studies.

This meta-analysis was intended to evaluate differences in pregnancy rates after in-vitro fertilization (IVF) in tubal fertility with and without hydrosalpinx. It examined nine published retrospective comparative series and five series published as abstracts for which additional information was obtained. In all, these studies involved 5592 patients (1004 with hydrosalpinx and 4588 with tubal infertility without hydrosalpinx). The main outcome measures were rates of pregnancy, implantation, live delivery, and early pregnancy loss. Pregnancy rates were significantly lower in the presence of hydrosalpinx: 31.2% for the tubal sterility group without hydrosalpinx and 19.7% for the group with hydrosalpinx (odds ratio: 0.64; 95% confidence interval: 0.56, 0.74). Similarly, the implantation rate and the delivery rate per transfer in the hydrosalpinx group were only slightly more than half those of the non-hydrosalpinx group (implantation: 8.5 and 13.7%, respectively; delivery: 13.4 and 23.4%). The incidence of early pregnancy loss was also higher in the hydrosalpinx group (43.7%) than in the control group (31.1%). This meta-analysis makes it clear that hydrosalpinx present during IVF-embryo transfer has negative consequences on the rates of pregnancy, implantation, live delivery, and early pregnancy loss. It would be premature, nonetheless, to conclude that routine salpingectomy should be performed on all patients with hydrosalpinx.     

Salpingectomy - the laparoscopic surgical choice for ectopic pregnancy

The aim of this study was to assess the fertility outcome afterectopic pregnancy (EP) treated by laparoscopic salpingectomy.Among the 375 patients who underwent this operation betweenJanuary 1983 and December 1993, there were 145 patients whodesired pregnancy and whose contralateral tube was not obstructed.The overall rate of intrauterine pregnancy (IUP) was 50.3%,with an EP rate of 15.2%, These results were analysed accordingto the patients‘ past history together with the conditionof the contralateral tube at the time of the laparoscopy. Wedefined two groups. Group 1 included patients who had no previoushistory of tubal surgery and whose contralateral tube was normal.Group 2 comprised those patients who had a previous historyof tubal surgery and/or those whose tube was pathological, butnot obstructed. Postoperative fertility of the patients in group1 was significantly higher than that of the patients in group2, with IUP rates of 75 and 36.6% respectively (P < 0.001),and a risk of EP recurrence of 9.6 and 183% respectively. Ingroup 1, the actuarial IUP rate at 24 months was significantlyhigher than that for the patients in group 2 (66.7 versus 36.9%;P < 0.001). The patient’s past history and the conditionof the contralateral tube were the two major factors relatedto fertility outcome after laparoscopic salpingectomy for EP.In patients with no past history of tubal surgery or infertilityand whose contralateral tube was normal, the fertility resultsafter laparoscopic salpingectomy appeared comparable to thoseobserved after conservative laparoscopic treatment     

Pregnancy: A challenge to the concept of tubal reflux to explain the rise and fall of CA125 in serum during the first trimester

Although amniotic fluid concentrations of cancer antigen (CA)125 rise during the first two trimesters of pregnancy, the serumconcentrations of CA125 peak during the first trimester anddrop to non-pregnant values in the second and third trimester.A previous hypothesis to explain this phenomenon was that inthe early first trimester decidual CA125 gains access to thematernal compartment via ‘tubal reflux’ and subsequentabsorption by peritoneal lymphatics. However, as pregnancy advances,the decidua capsularis fuses with the decidua parietalis, thusobliterating the endometrial cavity at 10–12 weeks; theFallopian tubes thus become functionally obstructed. To testthis hypothesis, we evaluated early first trimester CA125 concentrationsin women conceiving by in-vitro fertilization (IVF) and embryotransfer with patent tubes (group 1) and in those conceivingby IVF and embryo transfer with bilateral tubal occlusion (group2). We also compared those conceiving with human menopausalgonadotrophin therapy for ovulation induction without assistedreproduction (group 3) and those conceiving without fertilitydrugs in assisted reproduction (group 4). Mean CA125 concentrationswere similar in groups 1–3; the mean CA125 concentrationin group 4 was lower but this difference was not statisticallysignificant, probably due to the small sample size. These datado not support the concept that tubal reflux explains the riseand fall of serum concentrations of CA125, since these wereequal in IVF conceptions with or without tubal patency.     

Immunolocalization of integrins and fibronectin in tubal pregnancy

Integrins are a large family of cell adhesion molecules that serve as receptors involved in cell-to-cell and cell-to-matrix interactions during implantation. We studied immunohistochemical staining of integrins (alpha 3, alpha V, beta 1, and alpha 2 beta 1) and fibronectin in ectopic tubal pregnancy. Thirty fallopian tube samples with ectopic pregnancies and five normal tubal segments were obtained during ligation operations; the latter specimens served as controls in the study. Formalin-fixed paraffin-embedded tissue sections were stained with hematoxylin-eosin or primary antibodies against alpha 3, beta 1, alpha V, and alpha 2 beta 1 integrins and fibronectin, using the avidin-biotin-peroxidase method. A semi-quantitative grading system was used to compare staining intensities. In the control samples, immunostaining of all integrins was found in a single layer of tall columnar epithelial cells, the lamina propria (Lp) and the muscular layer. Fibronectin staining was detected in the Lp and the muscular layer. Staining intensities of alpha 3 and beta 1 integrins and fibronectin were increased in the normal part of fallopian tubes with ectopic pregnancies. Staining of beta 1 integrin was more intense than staining of alpha 3 and fibronectin, whereas there was no difference in alpha V and alpha 2 beta 1 integrin expression between normal tubal tissue in the ectopic pregnancy group and control tubal tissue. In the tubal pregnancy group at the site of implantation, staining intensity of alpha 3 and beta 1 integrins and fibronectin was strong in decidual cells, supporting tissue and placental villi, whereas alpha V and alpha 2 beta 1 staining was mild. We concluded that integrins, especially beta 1 and alpha 3, and fibronectin may play a role in progression of tubal implantation. Although the role of integrins has not yet been clearly defined, these molecules may function as markers of normal and abnormal states of receptivity. We like to suggest that integrins and fibronectin, which are needed in utero implantation, are expressed in tubal tissues during ectopic pregnancy and are involved in ectopic implantation.     

Salpingitis isthmica nodosa in female infertility and tubal diseases.

Salpingitis isthmica nodosa (SIN) is a condition of nodular thickening of the proximal Fallopian tube. The purpose of this study was to investigate the occurrence, distribution and frequency of SIN in Danish women salpingectomized because of tubal pregnancy or salpingitis and to correlate SIN with infertility, pregnancies, outcome of pregnancies, births, pelvic inflammatory disease and salpingitis. Sections from the isthmus were present in the specimens from 223 tubes from 193 patients and were analysed by the same pathologist. Originally, SIN was found in 12 patients but on re-examination, it was found in 24 patients. Ten women with SIN were bilaterally salpingectomized. Only one woman had SIN in both tubes. Women with SIN gave birth to as many children as women without SIN. After SIN had been diagnosed, no children were born, but this was not statistically different from the frequency of births in the non-SIN group after salpingectomy. Women with SIN had histological signs of salpingitis more often than women without SIN, but SIN complicated with salpingitis did not influence the number of children or tubal pregnancies. Women with SIN had a greater risk of two or more tubal pregnancies than women without SIN.     

Differential impact on pregnancy rate of selective salpingography, tubal catheterization and wire-guide recanalization in the treatment of proximal Fallopian tube obstruction

A total of 66 patients with proximal Fallopian tube (113 tubes)obstruction, as diagnosed by both laparoscopy and hysterosalpingogram,were each subjected to a transcervical recanalization proceduresequentially using selective salpingography followed, if necessary,by tubal catheterization with a soft Teflon 2-French catheterand finally, if needed, wire-guide cannulation. Each procedurewas terminated once patency had been achieved without recourseto the next technique. Bilateral obstruction was present in47 patients and unilateral in 19 patients. Patency was achievedin 39 (34.5%) Fallopian tubes by selective salpingography alone,in 52 (46.0%) by tubal catheterization and in 10 (8.9%) by wireguide, with 12 (10.6%) tubes remaining obstructed. Pregnancyoccurred in 24 (36.4%) patients without recourse to other treatment(mean follow-up, 17 months). Where patency was achieved (59patients), 19 out of 43 (44.1%) of those treated for bilateralobstruction and five out of 16 (31.3%) of those treated forunilateral obstruction achieved a pregnancy. Pregnancy occurredin six out of 22 patients (27.3%) where selective salpingographywas used to produce tubal patency, in 17 out of 30 patients(56.7%) where tubal catheterization was used and in one outof seven (14.3%) where a wire guide was used, which was an ectopicpregnancy. The difference between the ongoing pregnancy ratesfollowing tubal catheterization (50.0%) and wire-guide cannulation(0.0%) was significant (P = 0.033). While wire-guide cannulationis the most effective method used to achieve tubal patency,these results indicate that when it is truly necessary, as opposedto electively used by clinicians, the prognosis with regardto pregnancy is poor and alternative therapy such as microsurgeryor in-vitro fertilization should be considered early.     

Transcervical falloposcopy: preliminary experience

The new technique of endoluminal tubal exploration was evaluatedby performing transcervical falloposcopy instead of chromoperturbationunder control of concurrent laparoscopy. In this feasibilitystudy, catheterization was performed with the use of eithera transhysteroscopic or a free-hand tubal cannulation technique.A total of 66 patients were investigated for primary or secondaryinfertility with proximal and/or distal suspected tubal defectson the basis of prior hysterosalpingography; three patientswere investigated for unruptured tubal pregnancy; two patientswere investigated to localize the tip of the tubal embryo transfercatheter. Transcervical catheterization was successful in 110of the 130 tubes (84.6%). Successful and informative falloposcopywas achieved in 30% of the 110 cannulated tubes. The transcervicalfree-hand cannulation technique was as effective as the transhysteroscopicapproach. Recanalization of at least one tube was achieved in83% of women with proximal obstruction. Tubal cannulation bythe tubal embryo transfer catheter was confirmed by falloposcopyin the two cases where free-hand catheterization was used. Thisstudy confirms that it is possible to visualize the tubal lumenand demonstrates that the free-hand cannulation technique isa simple and effective alternative to the transhysteroscopicapproach. However, further progress in catheter technology hasto be achieved in order to perform regularly successful transcervicalfalloposcopy in damaged tubes.     

Fertility after ectopic pregnancy: first results of a population-based cohort study in France

The purpose of this paper was to evaluate the reproductive outcomeafter ectopic pregnancy (EP) from a population-based registerin the centre of France. Since 1992, all the women aged 15–44years, who permanently reside in the target area and who weretreated either by surgical or medical procedures for an ectopicpregnancy in one of the area centres, have been registered andprospectively followed until 45 years of age. The analysis presentedwas based on the 155 women registered between January 1992 andMarch 1994 who were followed up for at least 6 months, and whowere seeking a new pregnancy. The mean follow-up period was16 months. A total of 102 women (66%) obtained a pregnancy.The first conception was intrauterine for 92 women, and 10 hada recurrence of ectopic pregnancy. Risk factors of recurrencewere prior spontaneous abortion and prior tubal damage. Forthose women who conceived, the mean time to obtain pregnancy(’time to pregnancy‘) was 4.8 months. The 1 yearcumulative intrauterine pregnancy rate (i.e. the probabilityof obtaining an intrauterine pregnancy within 1 year of seekingpregnancy) was 70%. After multivariate analysis by a Cox regression,the factors associated with higher fertility were age < 30years, high educational level and no prior tubal damage.     

Infertility: In-vitro fertilization in completely natural cycles

Our objective was to assess the efficacy of in-vitro fertilization(IVF) in natural ovarian cycles in couples with tubal and unexplainedinfertility. A prospective study design was used. A total of39 fully investigated couples, who were patients at the ReproductiveMedicine Unit, St Michael's Hospital, Bristol, UK, took part;they were diagnosed with either tubal disease (n = 26) or unexplainedinfertility (n = 13). Procedures involved daily capillary bloodsampling, daily vaginal ultrasonography and vaginal oocyte recoveryunder sedation at mid-cycle. The main outcome measures werefertilization, implantation and pregnancy rates. Although moreof the women with tubal disease were parous, there were no othersignificant differences between the two groups. The 39 coupleswith infertility of tubal or unexplained aetiology had 79 cyclesof IVF in otherwise completely natural cycles. The overall fertilizationrate was 80% and the implantation rate was 14.0%. A trend wasobserved for higher success rates in women with tubal disease.We conclude that natural cycle IVF and embryo transfer offersan acceptable chance of pregnancy and an opportunity for thein-depth investigation of follicular and ovarian function incouples with defined causes of infertility. The possibly lowersuccess rate in women with unexplained infertility warrantsfurther study of follicular function and endocrinology.     

Pregnancy: Placental isoferritin patterns during normal first trimester and tubal gestations

Placental isoferritin (PLF) has been shown to be involved inthe down-regulation of the maternal immune system during pregnancy.In a prospective study, serum PLF concentrations were measuredin 33 pregnant women with singleton, normal, ongoing first trimestergestations and compared with those of 22 women with tubal gestations.Diagnoses were based on endocrinological, sonographic, intra-operativeand histopathological criteria. Venous blood was obtained fromboth groups for PLF determination before evacuation of the pregnancyproducts. B-Human chorionic gonadotrophin (HCG), 17B-oestradioland progesterone were determined at surgery for the tubal pregnancypatients. The mean ± SD PLF concentrations were 18 ±14, 25.4 ± 42.3 IU/ml among normal and tubal gestationsrespectively. Significant differences between normal and tubalpregnancies were found (P < 0.05). Based on PLF measurements,sensitivity (67%) and specificity (33%) values were found tobe similar for the normal and ectopic pregnancies. No correlationwas found between the other measured pregnancy hormones andPLF for the tubal pregnancy group. Low PLF concentrations amongpathological gestations may reflect abnormal trophoblastic activity.The simultaneous assessment of PLF and -HCG concentrations whichprobably originate from different trophoblastic cells, is recommendedfor better diagnosis and monitoring of first trimester placentalactivity.     

Tubal ectopic pregnancy: a patho-physiological explanation involving endometriosis

The condition of tubal ectopic pregnancy is presented from diverse points of view, bringing out physiological explanations for its occurrence in primates and striking absence in other mammals. Part of the flexibility underlying ectopic pregnancy in humans stems from the absence of a uterine luteolytic mechanism, enabling early embryonic development in the Fallopian tube without compromising function of the corpus luteum. Attention is devoted to a potential overlap between the composition of tubal and uterine fluids, and to specific mixing between the two fluid compartments, expressed in an ability of the human oocyte or zygote to tolerate transplantation to the uterus. Perturbed tubal oocyte transport is seen as a contributory factor, not least as a sequel to episodes of infection and a modified endosalpinx, but the essay then reasons strongly for an involvement of endometriosis in the aetiology of tubal ectopic pregnancy. Proliferation of refluxed endometrial tissue arrested within the Fallopian tube could provide the epithelial characteristics of a uterine environment. Accordingly, an experimental model is proposed for tubal ectopic pregnancy in animals based upon transplants of endometrial tissue and the subsequent introduction of embryos into both the Fallopian tubes and uterus; the latter would suppress the luteolytic mechanism. Finally, advances are suggested based upon molecular scanning of human ectopic tissues and those derived from animal models. If molecular probes could be developed to detect either early tubal pregnancy or a propensity to this pathology, such advances would clearly have clinical relevance-not least in view of an enhanced incidence of tubal pregnancy arising after assisted reproduction technology.