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Contralateral corpus luteum in ectopic pregnancy: what does it tell us about ovum pickup?

2002; Elsevier BV; Volume: 77; Issue: 4 Linguagem: Inglês

10.1016/s0015-0282(01)03271-x

1556-5653

Harry K. Ziel, Richard J. Paulson,

Reproductive Health and Contraception

Among the many causes postulated to play a role in the etiology of ectopic pregnancy (1McElin T.W Iffy L Ectopic gestation a consideration of new and controversial issues relating to pathogenesis and management.Obstet Gynecol Annu. 1976; 5: 241-291PubMed Google Scholar, 2Ankum W.M Mol B.W Van der Veen F Bossuyt P.M Risk factors for ectopic pregnancy a meta-analysis.Fertil Steril. 1996; 65: 1093-1099Abstract Full Text PDF PubMed Google Scholar, 3Cartwright P.S Incidence, epidemiology, risk factors, and etiology.in: Stovall T.J Ling F.W Extrauterine pregnancy clinical diagnosis and management. McGraw-Hill, New York1993: 27-63Google Scholar), perhaps the most controversial is the observation of the contralateral corpus luteum. Observed in 15%–60% of cases of ectopic pregnancy (4Berlind M The contralateral corpus luteum—an important factor in ectopic pregnancies.Obstet Gynecol. 1960; 16: 51-52PubMed Google Scholar, 5Kleiner G.J Roberts T.W Current factors in the causation of tubal pregnancy a prospective clinicopathologic study.Am J Obstet Gynecol. 1967; 99: 21-28PubMed Scopus (39) Google Scholar, 6Breen J.L A 21 year survey of 654 ectopic pregnancies.Am J Obstet Gynecol. 1970; 106: 1004-1019Abstract Full Text PDF PubMed Scopus (226) Google Scholar, 7Saito M Koyama T Yaoi Y Kumasaka T Yazawa K Kato K et al.Site of ovulation and ectopic pregnancy.Acta Obstet Gynecol Scand. 1975; 54: 227-230Crossref PubMed Scopus (14) Google Scholar, 8Berry S.M Coulam C.B Hill L.M Breckle R Evidence of contralateral ovulation in ectopic pregnancy.J Ultrasound Med. 1985; 4: 293-295PubMed Google Scholar, 9Walters M.D Eddy C Pauerstein C.J The contralateral corpus luteum and tubal pregnancy.Obstet Gynecol. 1987; 70: 823-826PubMed Google Scholar, 10Insunza A de Pablo F Croxatto H.D Letelier L.M Morante M Croxatto H.B On the rate of tubal pregnancy contralateral to the corpus luteum.Obstet Gynecol Scand. 1988; 67: 433-436Crossref PubMed Scopus (11) Google Scholar), the observation of the corpus luteum in the ovary that is contralateral to the ectopic pregnancy is presumptive evidence for ovum transmigration. Because the incidence of transmigration in intrauterine pregnancy is not known, it is tempting to speculate that transmigration might result in delayed transport of the fertilized zygote to the uterus (because the path by the contralateral tube appears to be longer than via the ipsilateral oviduct). Blastocyst hatching appears to be a scheduled event; therefore, it is not illogical to propose that the delay in embryo transport might result in embryo hatching while the zygote is still in the fallopian tube and thus predisposed to ectopic pregnancy. Very little data exist regarding the incidence of transmigration in association with intrauterine pregnancy (11Kamrava M.M Seibel M.M Thompson I.E Berger M.J McArdle C.R Intrauterine pregnancy following transperitoneal migration of the ovum.Obstet Gynecol. 1982; 60: 391-393PubMed Google Scholar, 12First A Transperitoneal migration of ovum or spermatozoon.Obstet Gynecol. 1954; 4: 431-434PubMed Google Scholar). In the absence of such comparative data, the role of ovum transmigration in the etiology of ectopic pregnancy remains speculative; however, the determination of the approximate frequency of ovum transmigration in pregnancy, ectopic or intrauterine, might nevertheless provide an insight into the mechanism of ovum pickup by the tubal fimbriae. The purpose of this review was to examine critically the world literature on ovum transmigration. We performed a literature search via MEDLINE, as provided by the library of Kaiser Permanente Medical Center, Los Angeles, California. This review revealed a total of seven publications (4Berlind M The contralateral corpus luteum—an important factor in ectopic pregnancies.Obstet Gynecol. 1960; 16: 51-52PubMed Google Scholar, 5Kleiner G.J Roberts T.W Current factors in the causation of tubal pregnancy a prospective clinicopathologic study.Am J Obstet Gynecol. 1967; 99: 21-28PubMed Scopus (39) Google Scholar, 6Breen J.L A 21 year survey of 654 ectopic pregnancies.Am J Obstet Gynecol. 1970; 106: 1004-1019Abstract Full Text PDF PubMed Scopus (226) Google Scholar, 7Saito M Koyama T Yaoi Y Kumasaka T Yazawa K Kato K et al.Site of ovulation and ectopic pregnancy.Acta Obstet Gynecol Scand. 1975; 54: 227-230Crossref PubMed Scopus (14) Google Scholar, 8Berry S.M Coulam C.B Hill L.M Breckle R Evidence of contralateral ovulation in ectopic pregnancy.J Ultrasound Med. 1985; 4: 293-295PubMed Google Scholar, 9Walters M.D Eddy C Pauerstein C.J The contralateral corpus luteum and tubal pregnancy.Obstet Gynecol. 1987; 70: 823-826PubMed Google Scholar, 10Insunza A de Pablo F Croxatto H.D Letelier L.M Morante M Croxatto H.B On the rate of tubal pregnancy contralateral to the corpus luteum.Obstet Gynecol Scand. 1988; 67: 433-436Crossref PubMed Scopus (11) Google Scholar) that addressed the issue of ectopic pregnancy and the location of the corpus luteum relative to the location of the ectopic pregnancy. Two other manuscripts were identified that documented the transmigration of the ovulated oocyte in the presence of an intrauterine pregnancy (11Kamrava M.M Seibel M.M Thompson I.E Berger M.J McArdle C.R Intrauterine pregnancy following transperitoneal migration of the ovum.Obstet Gynecol. 1982; 60: 391-393PubMed Google Scholar, 12First A Transperitoneal migration of ovum or spermatozoon.Obstet Gynecol. 1954; 4: 431-434PubMed Google Scholar). No comparative studies or series reports attempting to estimate the incidence of ovum transmigration in the face of an intrauterine pregnancy could be found. All relevant literature was located and the results tabulated. The results of the literature search regarding the contralateral corpus luteum in ectopic pregnancy are summarized in Table 1. The information on a total of 1,197 tubal ectopic pregnancies was found. In 629 (53%) of cases, the corpus luteum was seen and its location described. In 204 (32%) of the 629 of cases, the corpus luteum was noted on the contralateral side from the tubal pregnancy.TABLE 1Published research on tubal pregnancy and the contralateral corpus luteum.ReferenceTotal no. of ectopic pregnanciesNo. of ectopic pregnancies with corpus luteum visualizedNo. of ectopic pregnancies with contralateral corpus luteumEctopic pregnancies with contralateral corpus luteum (%)Berlind 1960 4Berlind M The contralateral corpus luteum—an important factor in ectopic pregnancies.Obstet Gynecol. 1960; 16: 51-52PubMed Google Scholar50482450Kleiner et al. 1967 5Kleiner G.J Roberts T.W Current factors in the causation of tubal pregnancy a prospective clinicopathologic study.Am J Obstet Gynecol. 1967; 99: 21-28PubMed Scopus (39) Google Scholar6460915Breen et al. 1970 6Breen J.L A 21 year survey of 654 ectopic pregnancies.Am J Obstet Gynecol. 1970; 106: 1004-1019Abstract Full Text PDF PubMed Scopus (226) Google Scholar1861036260Saito et al. 1975 7Saito M Koyama T Yaoi Y Kumasaka T Yazawa K Kato K et al.Site of ovulation and ectopic pregnancy.Acta Obstet Gynecol Scand. 1975; 54: 227-230Crossref PubMed Scopus (14) Google Scholar1301182622Berry et al. 1985 8Berry S.M Coulam C.B Hill L.M Breckle R Evidence of contralateral ovulation in ectopic pregnancy.J Ultrasound Med. 1985; 4: 293-295PubMed Google Scholar5201354634Walters et al. 1987 9Walters M.D Eddy C Pauerstein C.J The contralateral corpus luteum and tubal pregnancy.Obstet Gynecol. 1987; 70: 823-826PubMed Google Scholar114981818Insunza et al. 1988 10Insunza A de Pablo F Croxatto H.D Letelier L.M Morante M Croxatto H.B On the rate of tubal pregnancy contralateral to the corpus luteum.Obstet Gynecol Scand. 1988; 67: 433-436Crossref PubMed Scopus (11) Google Scholar133671928Totals/average1197629aThe corpus luteum was not identified or reported in 568, or 47% of tubal ectopic pregnancies.20432Ziel. Contralateral corpus luteum in ectopic pregnancy. Fertil Steril 2002.a The corpus luteum was not identified or reported in 568, or 47% of tubal ectopic pregnancies. Open table in a new tab Ziel. Contralateral corpus luteum in ectopic pregnancy. Fertil Steril 2002. It has been postulated that the ovulated oocyte is picked up by the tubal fimbriae by a gentle sweeping motion of the fimbriae over the surface of the ovary. Most recently, this process was documented by culdoscopy synchronized with the occurrence of ovulation (13Gordts S Campo R Rombauts L Brosens I Endoscopic visualization of the process of fimbrial ovum retrieval in the human.Hum Reprod. 1998; 13: 1425-1428Crossref PubMed Scopus (62) Google Scholar). Even if this is true, an alternative method of ovum pickup must exist within the pelvis, in which ovum transmigration may occur. One of the problems with the fimbrial sweeping motion theory is that the dominant follicle may not occur in the part of the ovary closest to the tubal fimbriae. This would be especially true in the case of controlled ovarian hyperstimulation prior to intrauterine insemination, in which multiple follicles are formed on both ovaries. These follicles are observed at all locations on the surface of the ovary, and when ovulation occurs, it appears most unlikely that the tubal fimbriae would be able to sweep over the entire surface of the ovary in an effort to pick up the multiple oocytes. More likely, the oocytes are simply extruded into the cul-de-sac, where they subsequently float in the fluid composed of peritoneal fluid and follicular fluid that is released during ovulation. The tubal fimbriae then sweep through this fluid and pick up the oocytes along with their investment of sticky cumulus cells, much as a sea anemone filters seawater. This latter mechanism would certainly be more consistent with the observation of ovum transmigration. Furthermore, in procedures such as peritoneal ovum-sperm transfer (POST) (14Mason B Sharma V Riddle A Campbell S Ultrasound-guided peritoneal oocyte and sperm transfer.Lancet. 1987; 1 ([Letter]): 386Abstract PubMed Scopus (16) Google Scholar) and in follicle aspirations, sperm injection, and assisted rupture (FASIAR) (15Paulson R.J Thornton M.H Follicle aspiration, sperm injection, and assisted rupture (FASIAR) a simple new assisted reproductive technique.Fertil Steril. 1997; 68: 1148-1151Abstract Full Text PDF PubMed Scopus (3) Google Scholar), ova and sperm are injected into the peritoneal cavity, from which arrival into the fallopian tubes must take place by a mechanism that is not dependent on fimbriae sweeping over the surface of the ovary. If ectopic pregnancies were more common in situations in which ovum pickup is delayed, then it would follow that high-tech fertility procedures in which the embryos were placed in the fallopian tube at a later time would logically be associated with a higher incidence of ectopic pregnancy. This is not the case, however. In the gamete intrafallopian tube (GIFT) procedure, sperm and oocytes are intermixed and placed in the ampullary portion of the fallopian tube 36 hours after hCG injection (16Craft I Brinsden P Alternatives to IVF the outcome of 1071 first GIFT procedures.Hum Reprod. 1989; 4: 29-36Crossref PubMed Scopus (21) Google Scholar). In contrast, in the tubal embryo transfer (TET) procedure, embryos are placed in the fallopian tube as late as 48 hours after follicle aspiration (17Balmaceda J.P Gastaldi C Remohi J Borrero C Ord T Asch R.H Tubal embryo transfer as a treatment for infertility due to male factor.Fertil Steril. 1988; 50: 476-479Abstract Full Text PDF PubMed Scopus (56) Google Scholar). The latter procedure, however, is not associated with a higher incidence of ectopic pregnancy than GIFT. Thus, it appears unlikely that the late arrival of the gametes in the fallopian tube predisposes to ectopic pregnancy. If this is the case, then it may very well be that ovum transmigration takes place not only in 32% of ectopic pregnancies but also, in all likelihood, in 32% of intrauterine pregnancies. To conclude this finding with any degree of certainty, however, a prospective study would have to be performed evaluating the incidence of the contralateral corpus luteum in the presence of a single open fallopian tube and an intrauterine pregnancy. The authors conclude that ovum transmigration is a frequent event. Whereas it has been reported in association with ectopic pregnancies, more recent evidence obtained from assisted reproductive technologies would suggest that the late arrival of the gametes in the fallopian tube is not associated with an increased incidence of ectopic pregnancy. This combination of observations suggests that ovum pickup by the fallopian tube does not take place by a sweeping motion of the fimbriae over the surface of the ovary, but rather by a pickup of the ovulated oocyte from the pool of peritoneal fluid in the cul-de-sac.