CONTRACEPTION
ASSESSMENT OF HUMAN CHORIONIC GONADOTROPIN (hCG) LEVELS DURING LUTEAL PHASE IN WOMEN USING INTRAUTERINE CONTRACEPTION Jose M. Aubert, M.D., Maria C. Boria, M.D., M.P.H., Martin L. Stone. M.D., J. Victor Reyniak, M.D.
From the Department of Obstetrics and Gynecology New York Medical College 1249 Fifth Avenue Room A-406 New York, N.Y. 10029
ABSTRACT
103 Blood specimens, obtained during the luteal phase from women using various types of intrauterine contraceptive devices (IUD) were examined for the presence of hCG. A sensitive radioreceptor assay for hCG was used. In contrast with recent reports, all specimens examined were negative for hCG. Hence, we question the validity of the hypothesis that the presence of an IUD may allow for fertilization, but cause degeneration of the blastocyst.
Accepted
for publication
September
DECEMBER 1977 VOL. 16 NO. 6
26, 1977
CONTRACEPTION
INTRODUCTION The precise mechanism of intrauterine devices remains unknown. Recent reports (1.2) suggest, however, that a significant percentage of women wearing an IUD conceive and spontaneously abort during menses. The development in the field of radioimmuno- and radioreceptor assays for human chorionic gonadotropin (hCG) enables detection of this hormone at very low levels, with minimal interference from luteinizing hormone (LH). Radioreceptor assay (RRA) offers high specificity (3). and higher sensitivity (1) than radioimmunoassay (RIA). It has been reported that significant levels of hCG can thus be detected as early as 4-6 days after conception (3). This diagnostic technique can be readily applied to the detection of early pregnancy (3,4), the diagnosis of ectopic gestation (5) and in follow-up of patients with trophoblastic disease (6,7). It has also been applied in studies of contraceptive mechanism and effectiveness of IUDs. It has been postulated that the presence of an IUD does not interfere with fertilization, but will prevent implantation, causing degeneration of the blastocyst (1.2). The present study was undertaken to assess the validity of this postulation. MATERIAL AND METHOD 103 random samples of blood were obtained in the luteal phase from patients with regular menstrual patterns of 26- to 35-day intervals, who were using IUDs. Of these patients aged 16 to 43, with an average of 27 years, 90 were multiparous, 8 had voluntary abortions and 5 were nulliparous. The devices used for 64 of the patients were cf the inert type (61 Lippes Loops, 1 M, 1 Dalkon Shield and 1 Ring) and in the rest (39 patients), of the medicated type: in this case all of them copper devices (CuJ). The duration of intrauterine contraception varied from 2 to 130 cycles, with an average of 29.9 cycles.
558
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
The samples were collected in the luteal phase, from cycle days 16 to 35. For the purpose of dating, the first day of the LMP was considered 1st cycle day. The blood was centrifuged and the serum was rapidly stored at -20'~ until the procedure for radioreceptor assay was to be carried out. The number of samples were grouped as follows: Cycle Day
Samples
No. of
16 17 18
8
19
7
20
17
21
9
22
9
23
8
24
3
25
6
26
6
27
5
28
4
29
3
30 31 34
2 6 2
35
A sensitive, accurate and simple to perform method was used for the determination of hCG in this study. The material was supplied in kit-form by Wampole Laboratories (3iocept Gtm). The procedure is based on the principle of competitive binding for receptor sites on a lyophylized preparation of bovine corpus luteum membrane, between hCG present in the test serum and a trace amount of 1125 hCG. A Reference Control containing 0.2 I.U./ml of hCG is run with each set of unknowns. The tubes containing the reagents are incubated and centrifuged. The unbound hCG is then removed. The radioactivity bound to the receptor site was counted on a gamma counter (Reckman Biogamma II) programmed to display positive results greater than 0.2 I.U./ml of serum. Counts greater than the reference control run are considered negative. Counts less than the reference control run are considered positive.
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
RESULTS All 103 specimens examined were negative for presence of ~CG and no borderline results were obtained. Thus it can be stated that in the study group of 103 women, none displayed a luteal phase level of hCG which could be suggestive of an early pregnancy. DISCUSSION AND CCMMENTS With the use of RRA, levels of 0.2 I.U./ml of hCG can be The finding of no measurable presence of hCG in detected. 103 samples of blood obtained during the luteal cycle phase This finding from women wearing an IUD appears significant. is also in contrast with the previous reports (1.2) which suqgested a high conception rate in users of IUD. Xe obtained blood samples throughout the luteal phase, aiming at using the early post-ovulatory samples as controls. There is debate as to whether the dividing ovum produces hCG before implantation (8,9). Although it has been reported that hCG can be detected in the pre-implantation stage (3), a more recent investigation (9) carried out during the ovulationinduction cycles in women sho:+s that a significant rise in plasma hCG occurs 9 to 13 days after ovulation. In'the latter study it was noted that radioliqand-receptor assay was subject to nonspeci.fic interference by plasma proteins, causing an apparent elevation of gonadotropin levels during the first few days after fertilization (9). The finding of positive hCG levels during the luteal phase Theoretically, the in women wearing an IUD could be erroneous. possibility of either non-specific interference, or a crossreaction between the anti-serum used for the beta-hCG-RIA and LH (10) could be the source of the error. Our findings do not support the hypothesis of fertilization and then shedding of the blastocyst during the use of an IUD. The true mechanism of action of an IUD still remains unknown, and other factors, such as the lysis or alteration of sperm miqration (11) may play an important role.
560
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
ACKNOWLEDGEMENT We are grateful to Mr. A. Heisler of Madison Laboratories, New York, N.Y., for his technical assistance and advice. REFERENCES of Gona1. Beling, G., Cederquist, L., and Fuchs, F.: Demonstration dotropin During the Second Half of the Cycle in Women Using Intrauterine Contraception. Am. J. Obstet. Gynecol. 125:855, 1976 2. Landesman, R., Coutinho, M., and Saxena, B.: Detection of Human Chorionic Gonadotropin in Blood of Regularly Bleeding Women Using Copper Intrauterine Contraceptive Devices. Fert. Ster. 27:1062, 1976 M.: 3. Saxena, B., Hasan, S.H.. Haour, F., and Schmidt-Gollwitzer, Radioreceptor Assay of Human Chorionic Gonadotropin: Detection Science l-4:793, 1974 of Early Pregnancy. 4. Braunstein, G.D., ME.: Serum Human Normal Pregnancy.
Rasor, 3.. Adler, D., Dnnzer, H., and Wade, Chorionic Gonadotropin Levels Thrcuqhout Am. J. Ohstet. Cynecol. 126:678, 1976
5. KosaSa, T-S., Taymor, M.. Goldstein, D.P., -et al: use of Radioimmunoassay Specific for Human Chorionic Gonadotropin in the Diagnosis of Early Ectopic Pregnancy. Ohstet. Gynecol. 42:868, 1973 6. Goldstein, D.P.. Pastorfide, B., Osthanondh, R., and KoSasa, T.S.: A Rapid-Solid-Phase Radioimmunoassay Specific for Human Chorionic Gonadotropin in Gestational Disease. Obstet. Gynecol. 45:527, 1975 7. Pastorfide, G.B., Goldstein, D.P., and Kosasa, T.S.: The Use of Radioimmunoassay Specific for hCG in Patients with Molar Preqnancy and Gestational Trophoblastic Disease. Am. J. Obstet. Gynecol. 120:1025, 1974 8. Belinq, C.G., Fuchs, A.R., Haour, F.. Park, K., and Saxena, B.: Progesterone and 20-Alpha-Hydroxy-Progesterone in Peripheral Plasma of Pregnant Rabbits and Possible Luteotrophic Actions of Pre-implantation Blastocyst. J. Steroid Biochem. 5:363, 1974
DECEMBER 1977 VOL. 16 NO. 6
561
CONTRACEPTION
9. Catt, K.J., Dufau, M.L., and Vaitukaitis, J.L.: Appearance of hCG in Pregnancy Plasma Following the Initiation of Implantation of the Blastocyst. J. Clin. Endocrinol. Metab. 40:537. 1975 10. Klein, T.A.. Kletzy, D.A.& Mishell, D.R.: Presentation at the Annual Meeting of Pacific Coast Fertility Society (Unpublished Data),1977 11. Tredway, D.R., Settlage, D.S., and Mishell, D.R.: Effect of Intrauterine Devices on Sperm Transport in Human. Am. J. Obstet. Gynecol. (in press)
562
DECEMBER 1977 VOL. 16 NO. 6
ASSESSMENT OF HUMAN CHORIONIC GONADOTROPIN (hCG) LEVELS DURING LUTEAL PHASE IN WOMEN USING INTRAUTERINE CONTRACEPTION Jose M. Aubert, M.D., Maria C. Boria, M.D., M.P.H., Martin L. Stone. M.D., J. Victor Reyniak, M.D.
From the Department of Obstetrics and Gynecology New York Medical College 1249 Fifth Avenue Room A-406 New York, N.Y. 10029
ABSTRACT
103 Blood specimens, obtained during the luteal phase from women using various types of intrauterine contraceptive devices (IUD) were examined for the presence of hCG. A sensitive radioreceptor assay for hCG was used. In contrast with recent reports, all specimens examined were negative for hCG. Hence, we question the validity of the hypothesis that the presence of an IUD may allow for fertilization, but cause degeneration of the blastocyst.
Accepted
for publication
September
DECEMBER 1977 VOL. 16 NO. 6
26, 1977
CONTRACEPTION
INTRODUCTION The precise mechanism of intrauterine devices remains unknown. Recent reports (1.2) suggest, however, that a significant percentage of women wearing an IUD conceive and spontaneously abort during menses. The development in the field of radioimmuno- and radioreceptor assays for human chorionic gonadotropin (hCG) enables detection of this hormone at very low levels, with minimal interference from luteinizing hormone (LH). Radioreceptor assay (RRA) offers high specificity (3). and higher sensitivity (1) than radioimmunoassay (RIA). It has been reported that significant levels of hCG can thus be detected as early as 4-6 days after conception (3). This diagnostic technique can be readily applied to the detection of early pregnancy (3,4), the diagnosis of ectopic gestation (5) and in follow-up of patients with trophoblastic disease (6,7). It has also been applied in studies of contraceptive mechanism and effectiveness of IUDs. It has been postulated that the presence of an IUD does not interfere with fertilization, but will prevent implantation, causing degeneration of the blastocyst (1.2). The present study was undertaken to assess the validity of this postulation. MATERIAL AND METHOD 103 random samples of blood were obtained in the luteal phase from patients with regular menstrual patterns of 26- to 35-day intervals, who were using IUDs. Of these patients aged 16 to 43, with an average of 27 years, 90 were multiparous, 8 had voluntary abortions and 5 were nulliparous. The devices used for 64 of the patients were cf the inert type (61 Lippes Loops, 1 M, 1 Dalkon Shield and 1 Ring) and in the rest (39 patients), of the medicated type: in this case all of them copper devices (CuJ). The duration of intrauterine contraception varied from 2 to 130 cycles, with an average of 29.9 cycles.
558
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
The samples were collected in the luteal phase, from cycle days 16 to 35. For the purpose of dating, the first day of the LMP was considered 1st cycle day. The blood was centrifuged and the serum was rapidly stored at -20'~ until the procedure for radioreceptor assay was to be carried out. The number of samples were grouped as follows: Cycle Day
Samples
No. of
16 17 18
8
19
7
20
17
21
9
22
9
23
8
24
3
25
6
26
6
27
5
28
4
29
3
30 31 34
2 6 2
35
A sensitive, accurate and simple to perform method was used for the determination of hCG in this study. The material was supplied in kit-form by Wampole Laboratories (3iocept Gtm). The procedure is based on the principle of competitive binding for receptor sites on a lyophylized preparation of bovine corpus luteum membrane, between hCG present in the test serum and a trace amount of 1125 hCG. A Reference Control containing 0.2 I.U./ml of hCG is run with each set of unknowns. The tubes containing the reagents are incubated and centrifuged. The unbound hCG is then removed. The radioactivity bound to the receptor site was counted on a gamma counter (Reckman Biogamma II) programmed to display positive results greater than 0.2 I.U./ml of serum. Counts greater than the reference control run are considered negative. Counts less than the reference control run are considered positive.
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
RESULTS All 103 specimens examined were negative for presence of ~CG and no borderline results were obtained. Thus it can be stated that in the study group of 103 women, none displayed a luteal phase level of hCG which could be suggestive of an early pregnancy. DISCUSSION AND CCMMENTS With the use of RRA, levels of 0.2 I.U./ml of hCG can be The finding of no measurable presence of hCG in detected. 103 samples of blood obtained during the luteal cycle phase This finding from women wearing an IUD appears significant. is also in contrast with the previous reports (1.2) which suqgested a high conception rate in users of IUD. Xe obtained blood samples throughout the luteal phase, aiming at using the early post-ovulatory samples as controls. There is debate as to whether the dividing ovum produces hCG before implantation (8,9). Although it has been reported that hCG can be detected in the pre-implantation stage (3), a more recent investigation (9) carried out during the ovulationinduction cycles in women sho:+s that a significant rise in plasma hCG occurs 9 to 13 days after ovulation. In'the latter study it was noted that radioliqand-receptor assay was subject to nonspeci.fic interference by plasma proteins, causing an apparent elevation of gonadotropin levels during the first few days after fertilization (9). The finding of positive hCG levels during the luteal phase Theoretically, the in women wearing an IUD could be erroneous. possibility of either non-specific interference, or a crossreaction between the anti-serum used for the beta-hCG-RIA and LH (10) could be the source of the error. Our findings do not support the hypothesis of fertilization and then shedding of the blastocyst during the use of an IUD. The true mechanism of action of an IUD still remains unknown, and other factors, such as the lysis or alteration of sperm miqration (11) may play an important role.
560
DECEMBER 1977 VOL. 16 NO. 6
CONTRACEPTION
ACKNOWLEDGEMENT We are grateful to Mr. A. Heisler of Madison Laboratories, New York, N.Y., for his technical assistance and advice. REFERENCES of Gona1. Beling, G., Cederquist, L., and Fuchs, F.: Demonstration dotropin During the Second Half of the Cycle in Women Using Intrauterine Contraception. Am. J. Obstet. Gynecol. 125:855, 1976 2. Landesman, R., Coutinho, M., and Saxena, B.: Detection of Human Chorionic Gonadotropin in Blood of Regularly Bleeding Women Using Copper Intrauterine Contraceptive Devices. Fert. Ster. 27:1062, 1976 M.: 3. Saxena, B., Hasan, S.H.. Haour, F., and Schmidt-Gollwitzer, Radioreceptor Assay of Human Chorionic Gonadotropin: Detection Science l-4:793, 1974 of Early Pregnancy. 4. Braunstein, G.D., ME.: Serum Human Normal Pregnancy.
Rasor, 3.. Adler, D., Dnnzer, H., and Wade, Chorionic Gonadotropin Levels Thrcuqhout Am. J. Ohstet. Cynecol. 126:678, 1976
5. KosaSa, T-S., Taymor, M.. Goldstein, D.P., -et al: use of Radioimmunoassay Specific for Human Chorionic Gonadotropin in the Diagnosis of Early Ectopic Pregnancy. Ohstet. Gynecol. 42:868, 1973 6. Goldstein, D.P.. Pastorfide, B., Osthanondh, R., and KoSasa, T.S.: A Rapid-Solid-Phase Radioimmunoassay Specific for Human Chorionic Gonadotropin in Gestational Disease. Obstet. Gynecol. 45:527, 1975 7. Pastorfide, G.B., Goldstein, D.P., and Kosasa, T.S.: The Use of Radioimmunoassay Specific for hCG in Patients with Molar Preqnancy and Gestational Trophoblastic Disease. Am. J. Obstet. Gynecol. 120:1025, 1974 8. Belinq, C.G., Fuchs, A.R., Haour, F.. Park, K., and Saxena, B.: Progesterone and 20-Alpha-Hydroxy-Progesterone in Peripheral Plasma of Pregnant Rabbits and Possible Luteotrophic Actions of Pre-implantation Blastocyst. J. Steroid Biochem. 5:363, 1974
DECEMBER 1977 VOL. 16 NO. 6
561
CONTRACEPTION
9. Catt, K.J., Dufau, M.L., and Vaitukaitis, J.L.: Appearance of hCG in Pregnancy Plasma Following the Initiation of Implantation of the Blastocyst. J. Clin. Endocrinol. Metab. 40:537. 1975 10. Klein, T.A.. Kletzy, D.A.& Mishell, D.R.: Presentation at the Annual Meeting of Pacific Coast Fertility Society (Unpublished Data),1977 11. Tredway, D.R., Settlage, D.S., and Mishell, D.R.: Effect of Intrauterine Devices on Sperm Transport in Human. Am. J. Obstet. Gynecol. (in press)
562
DECEMBER 1977 VOL. 16 NO. 6
