Contralateral tubal-ovarian apposition and fertility in hemiovariectomized primates*

Transcription

1 FERTILITY AND STERILITY Copyright 1984 The American Fertility Society Vol. 42, No.4, October 1984 Printed in U.8A. Contralateral tubal-ovarian apposition and fertility in hemiovariectomized primates* Victoria M. Sopelak, Ph.D.t Gary D. Hodgen, Ph.D.:j: Pregnancy Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland Here, we examined longitudinally (1) the incidence of pregnancy in hemiovariectomized macaques possessing only one ovary contralateral to a single fallopian tube, i.e., pregnancy after transabdominal ovum migration; (2) the pregnancy rate after surgically achieving contralateral apposition of the ovary and fallopian tube; and (3) the frequency of ovulatory menstrual cycles, patterns of menstruation, and steroid profiles in serum of intact versus hemiovariectomized monkeys to determine whether the ovarian cycle is altered by constraining recurrent follicular maturation and corpus luteum function to one ovary. Despite matings during 28 ovulatory menstrual cycles, none of the five primates possessing only one ovary contralateral to a single fallopian tube became pregnant. In contrast, following contralateral tubal-ovarian apposition, three of these five monkeys conceived after only nine ovulatory menstrual cycles. Hemiovariectomy of monkeys did not compromise the regularity of menstrual cycles or frequency of ovulation, compared with intact control females over the 13-month interval of study (P > 0.01). Thus, tubal-ovarian apposition is required in these primates for efficient ovum pickup and fertilization and deserves further clinical scrutiny for women having one functional ovary and one healthy fallopian tube, albeit contralateral. Fertil Steril42:633, 1984 Received April 23, 1984; revised and accepted June 15, *Supported in part by Ford Foundation grant tpresent address: Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, Mississippi. :j:present.address and reprint requests: Gary D. Hodgen, Ph.D., Department of Obstetrics and Gynecology, Lewis Hall, Room 2049, Eastern Virginia Medical School, Norfolk, Virginia Normal pregnancy after transabdominal migration of an ovum from a single ovulating ovary to a single contralateral fallopian tube has been reported in women, although the frequency of this course is unknown. 1 In addition, chronic constraintof follicle growth to one ovary in unilaterally ovariectomized women and monkeys has not been rigorously investigated. The present study was designed to examine two separate issues, both using hemiovariectomized macaques. First, we examined (1) the incidence of pregnancy in hemiovariectomized primates where the ovary was contralateral to the remaining fallopian tube, i.e., pregnancy after transabdominal migration of the ovum; and (2) the pregnancy rate after surgically achieving contralateral tubal-ovarian apposition. Second, we characterized menstrual cycle lengths and the attendant patterns of circulating ovarian steroids in consecutive menstrual cycles longitudinally (over a 13- month interval), compared with those of intact monkeys. Thus, we tested the importance of pro x imity of the fallopian tube to the single contralateral ovary. The observations reported suggest po- Vol. 42, No.4, October 1984 Sopelak and Hodgen Contralateral tubal-ovarian apposition 633

2 tential clinical implications for women having only one healthy fallopian tube that is contralateral to a single functional ovary. MATERIALS AND METHODS Fifteen adult female cynomolgus monkeys (Macaca fascicularis) of presumably normal fertility were randomly selected and assigned to one of two longitudinal studies. STUDY 1: OVUM MIGRATION AND TUBAL-OVARIAN APPOSITION One ovary and the contralateral fallopian tube (fimbria and distal tube) were removed from five monkeys. For 15 months, blood samples were drawn by femoral venipuncture under light ketamine anesthesia (40 mg intramuscularly, Parke-Davis, Inc., Morris Plains, NJ) from days 8 to 14 and on days 18 and 21 of each menstrual cycle for measurement of estradiol (E2) and progesterone (P), respectively. During six ovulatory menstrual cycles per monkey, females cohabitated with males of proven fertility on days 11 to 13 of the menstrual cycle. Ovulation and pregnancy diagnosis were performed by serum P patterns and urinary or serum macaque chorionic gonadotropin (mcg) levels and by uterine palpation.2 Thereafter, one fallopian tube was surgically placed in apposition to the single contralateral ovary. The fimbria ovarica was attached to the infundibulopelvic ligament of the ovary with nonabsorbable 2-0 polyester suture (Mersilene, Ethicon, Inc., Somerville, NJ). After surgical apposition, the fallopian tube traversed the pelvis on the posterior uterine surface, just above the uterosacralligaments. The fimbria was positioned in direct contact with the ovarian tunica. High molecular weight dextran (10 ml, Hyskon, Pharmacia, Piscataway, NJ) was injected into the peritoneal cavity to minimize postsurgical adhesions. 3 Following contralateral tubal-ovarian apposition, the blood sampling and breeding protocols described above were resumed until pregnancy occurred or for up to four menstrual cycles, Pregnancy rates in this study were compared with that of our normal intact breeding colony during the same 15-month interval, where 23% became pregnant per cycle of coital exposure. Chi-square analysis was used to test the significance of differences between pregnancy rates before and after tubal-ovarian apposition. STUDY 2: NORMALITY OF THE OVARIAN/MENSTRUAL CYCLE Ten monkeys were randomly assigned to either group I or group II and kept on experiment for 13 months. Group I intact monkeys retained both ovaries (n = 4); group II monkeys underwent either right or left ovariectomy (n = 6). One rest cycle was allowed following surgery. Thereafter, menstrual cyclicity (designating the first cycle as cycle A) was monitored by daily menstrual records; follicle growth and ovulation were documented by laparoscopy on days 11 and 21 of each cycle and by serum steroid profiles. In order to monitor each cycle, but without causing anemia, during cycles A, B, F, G, K, and L, blood (3.5 ml) was collected by venipuncture every other day from days 2 to 8, daily from days 8 to 14, and every other day from day 14 until menses. In all other cycles, femoral blood (3.5 ml) was collected daily from days 8 to 14; additional samples were collected on days 18 and 21. Blood samples were allowed to clot and then were centrifuged, with sera collected and stored frozen ( - 20 C) until assayed for E2 and P as previously described. 4, 5 Data on the ovarian and menstrual cycles were compared between intact and hemiovariectomized monkeys using Student's t-test. RESULTS OVUM MIGRATION AND TUBAL-OVARIAN APPOSITION Despite coital exposure to fertile males during 28 ovulatory menstrual cycles, none of the five monkeys having one ovary contralateral to the remaining fallopian tube became pregnant. None of these females showed elevated urinary or serum mcg levels or enhanced P secretion at 20 days after mating or indications of pregnancy by rectal palpation; there was no evidence of pelvic adhesive disease. During this same interval, 23% of intact females in the breeding colony became pregnant when mated with the same males. In contrast, following tubal-ovarian apposition, three of the five monkeys were pregnant after a total of only nine ovulatory cycles. The difference in pregnancy rate, after versus before apposition, was statistically significant (P < 0.01). In fact, monkey 955N became pregnant the first cycle following contralateral tubal-ovarian apposition; 78N conceived during the second ovulatory cycle following surgery; 932N conceived during the 634 Sopelak and Hodgen Contralateral tubal-ovarian apposition Fertility and Sterility

3 Figure 1 The 150-day gravid uterus (tenn, 167 days) of a monkey showing(a) the round ligament, (B) absence of the entire fallopian tube on the side retaining the ovary, (C) the ovary with corpus luteum of pregnancy, (D) fimbria of the contralateral fallopian tube (no ovary on this side), and (E) stretching of the fallopian tube and the ligaments (fimbria ovarica sutured to the infundibulopelvic ligament of the ovary) securing the contralateral tube to the only remaining ovary. fourth cycle following tubal-ovarian proximity. In these monkeys, serum mcg levels were > 1000 mg/ml, and P levels were > 20 ng/ml within 20 days after mating; rectal palpations were positive at 40 days after mating. All these monkeys accomplished unassisted vaginal deliveries of live offspring at term. During gestation, the ligatures between the fimbria ovarica bound to the contralateral infundibulopelvic ligament did not tear. As evidenced during laparotomy prior to and following parturition, the tissues joining the ovary and fallopian tube stretched as much as 10 cm to accommodate the gravid uterus (Figs. 1 and 2). tomized monkeys, P was > 9 ng/ml, whereas P reached these levels in only 26% of ovulatory cycles in intact monkeys. The lengths of the ovulatory menstrual cycles were similar in both intact and hemiovariectomized monkeys (Table 1). Although both groups of animals experienced intervals of amenorrhea and occasional anovulatory cycles, neither the number of anovulatory cycles per monkey nor the length of these anovulatory cycles was different when group I and II animals were compared (Table 1). Two of six hemiovariectomized animals went for 167 and 113 days without an ovulatory cycle or overt signs of menses; similarly, two of four intact primates had 200 and 142 days of amenorrhea. We are not aware of any causal factors for the "spontaneous" events. DISCUSSION Transabdominal ovum migration has been documented in women, although estimates of frequency in the literature are scanty.1 Some cases of extrauterine pregnancy have been attributed to abdominal migration of sperm or ovum,6 without consideration for intrauterine migration or tubal fistulas. Here, we observed the infrequency of transabdominal ovum migration in cynomolgus monkeys possessing one ovary and a single contralateral fallopian tube. Further, we demonstrated the relative importance of the spatial association of the fimbria and the ovarian surface in these primates. Recently, Cohen7, 8 indicated the OVARIANIMENSTRUAL CYCLICITY Hemiovariectomy of monkeys did not compromise menstrual cyclicity or increase the incidence of anovulation or amenorrhea, in spite of restricting all ovarian function to one ovary. In fact, over the 13-month interval studied, the hemiovariectomized (group II) monkeys had more ovulatory cycles per animal than the intact (group I) primates (Table 1). The hormonal profiles of E2 and P were similar (P > 0.05) between ovulatory hemiovariectomized and intact monkeys. Consecutive ovulatory cycles were characterized by normal surges of E2 > 150 pg/ml, followed by luteal phase elevations of P > 4 ng/ml. In 49% of the ovulatory menstrual cycles of hemiovariecvol. 42, No.4, October 1984 Figure 2 Apposition of the ovary and contralateral fallopian tube is nearly restored by 5 days postpartum. (A), Round ligament. (B), Ligature from previous salpingectomy (notice the nonfunctional proximal remnant of the tube). (C), Ovary with the corpus luteum of the preceding pregnancy. (D), Functional contralateral fallopian tube. (E), Surgical plication of the contralateral tube and remaining ovary. Sopelak and Hodgen Contralateral tubal-ovarian apposition 635

4 Table 1. Ovarian/Menstrual Cycle Characteristics of Intact Versus Hemwvariectomized Primates over a 13-Month Interval a Group I (intact) No. of animals 4 No. of ovulatory cycles 5.8 ± 1.0 per monkey Length of ovulatory 32.9 ± 1.3 cycles (days) No. of anovulatory cycles 2.0 ± 0.8 per monkey Length of anovulatory 56.5 ± 7.4 cycles (days) amean ± standard error of the mean. bgroup I versus group II (P < 0.05). Group II (hemiovariectomized) ± LOb 30.6 ± ± ± 6.5 importance of fimbrial-gonadal relationships to achievement of pregnancy in women. Twenty patients with ipsilateral fimbria ovarica > 4 cm were termed "infertile" due to failure to become pregnant over a 2-year interval. Following plication of the fimbria ovarica to achieve close apposition of the fimbria to the ovarian surface, 70% of the patients conceived within 24 months. In the intact rhesus monkey, pregnancy has been reported even when the mesotubarium superius of the oviduct and the fimbria ovarica were severed from the ovary on both sides. 9 Although the transection destroyed the normal anatomic connection of the fimbria to the ovary and resulted in full mobilization of the fimbria away from the ovary, it did not prevent contact between the ipsilateral fimbria and ovary. The investigators suggested that successful ovum pickup was the result of healthy functional fimbria located in proximity to the ovary, but not necessarily directly attached to it or in contact with it via a given arrangement of mesenteries. A correlation between tube-ovary distance and the nidation-ovulation index has been reported for hemicastrate rabbits as wel1.10 However, the importance of physical association of the ovary and tube for achievement of pregnancy seems to be species-dependent. In the litter-bearing rabbit, pregnancies were attained even after fimbriectomy,1l-13 although the nidation-ovulation index was generally lower in the defimbriated hom of the uterus. Here, the pregnancy rate among cynomolgus monkeys was nil in the absence of tubal-ovarian apposition. If the response of these laboratory primates is indicative of human response to surgical apposition of one ovary and single contralateral fimbria, then such a surgical procedure may have clinical implications in patients with one patent tube and one functional ovary, albeit on contralateral sides of the pelvis. The hormonal patterns during consecutive menstrual cycles in hemiovariectomized cynomolgus monkeys were similar to those of intact monkeys. These findings are in agreement with the previously reported hormonal profiles in intact1 4,15 and hemiovariectomized16 cynomolgus monkeys studied only briefly. As in young rats,17 hemiovariectomy was not detrimental to cyclicity in these young adult primates. However, the hemiovariectomized monkeys in the present study tended to exhibit higher P levels during the luteal phase, compared with intact monkeys. This apparent difference in P levels is not explained on the basis of. our observations and may be only intrinsic variation among small group numbers. In summary, we suggest that pregnancy by transabdominal ovum migration in these primates is an infrequent occurrence even in regularly cycling, otherwise fertile hemiovariectomized adults. Further, apposition of the remaining fallopian tube and ovary to approximate a near normal fimbrial-gonadal spatial relationship is important for achievement of pregnancy in cynomolgus monkeys possessing one ovary contralateral to a single patent tube. These findings encourage clinical studies to extend and refine our understanding of the importance of tubalovarian apposition for fertility in women. REFERENCES 1. First A: Transperitoneal migration of ovum or spermatozoon. Obstet Gynecol 4:431, Hodgen GD, Tullner WW, Vaitukaitis JL, Ward DN, Ross GT: Specific radioimmunoassay of chorionic gonadotropin during implantation in rhesus monkeys. J Clin Endocrinol Metab 39:457, dizerega GS, Hodgen GD: Prevention of postoperative tubal adhesions. Am J Obstet Gynecol 136:173, Hodgen GD, Wilks JW, Vaitukaitis JL, Chen HC, Papkoff H, Ross GT: A new radioimmunoassay for follicle-stimulating hormone in macaques: ovulatory menstrual cycles. Endocrinology 99:137, Goodman AL, Hodgen GD: Post partum patterns of circulating FSH, LH, prolactin, estradiol and progesterone in nonsuckling cynomolgus monkeys. Steroids 31:731, Baldwin WF: Abdominal pregnancy: discussion, classification, and case presentation. Obstet Gynecol 4:435, Cohen BM: Surgical repair of abnormal fimbria gonadal relationships in the human female. J Reprod Med 25:33, Cohen BM: The elongated fimbria ovarica in the infertile female. Int J Fertil 28:19, Sopelak and Hodgen Contralateral tubal-ovarian apposition Fertility and Sterility

5 9. Eddy CA, Laufe LE: Fertility following microsurgical dissociation of the ovary and fimbria in the rhesus monkey. Fertil Steril 39:566, Watrelot A, Rengnier C, Taouk C, Cognat M, Delecour M: Relationship between tube and ovary in animals. Int J Fertil 28:6, Beyth Y, Winston RML: Ovum capture and fertility following microsurgical fimbriectomy in the rabbit. Fertil Steril 35:464, Halbert SA, McComb PF, Patton DL: Function and structure of the rabbit oviduct following fimbriectomy. I. Distal ampullary salpingostomy. Fertil Steril 35:349, Perez LE, Flores JJ, Bajpai VK, Asch RH, Eddy CA: Fertility following fimbriectomy and tubo-ovarian microsurgery in the rabbit. Fertil Steril 35:573, Wilks JW, Hodgen GD, Ross GT: Luteal phase defects in the rhesus monkey: the significance of serum FSH:LH ratios. J Clin Endocrinol Metab 43:1261, Goodman AL, Descalzi CD, Johnson DK, Hodgen GD: Composite pattern of circulating LH, FSH, estradiol, and progesterone during the menstrual cycle in cynomolgus monkeys (39834). Proc Soc Exp BioI Med 155:479, Goodman AL, Hodgen GD: Menstrual cycle characteristics in chronically hemiovariectomized cynomolgus monkeys (Macaca fascicularis). J Clin Endocrinol Metab 48:345, Sopelak VM, Butcher RL: Contribution of the ovary versus hypothalamus-pituitary to termination of estrous cycles in aging rats using ovarian transplants. BioI Reprod 27:29, Vol. 42, No.4, October 1984 Sopelak and Hodgen Contralateral tubal-ovarian apposition 637