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Comparative prolactin profiles in IUD users and non-IUD users
CONTRACEPTION
COMPARATIVE
PROLACTIN
PROFILES
IN IUD USERS
AND NON-IUD USERS
Christopher
A. Adejuwon
1
Sheldon J. Segal 2 Anibal
Faundes *3
Francisco
Alvarez-Sanchez
1.
Reproductive Biomedicine Research Chemical Pathology Department College of Medicine University of Ibadan, Nigeria
2.
Fopulation Sciences Division Rockefeller Foundation 1133 Avenue.of the Americas New York, N.Y. 10036
3.
Department of Obstetrics E Gynecology Faculty of Medical Sciences UNICAMP, Campinas, S.P. Brazil
4.
Department of Obstetrics Hospital Moscoso Pnello, Dominican Republic
E Training
4
Unit
6 Gynecology Santo Domingo
ABSTRACT Starting from the 10th day of the menstrual cycle through onset of the subsequent menstrual bleeding, daily blood samples were- collected from 14 women using Copper T The serum samples were IUDs and 10 normal control women. analysed by radioimmunoassay (RIA) for human prolactin (hPRL) and human luteinizing hormone (hLH). hPRL values Episodic patterns of were subjected to statistics. IUD users show hPRL were observed for all subjects. generally lower daily levels of hPRL than non-IUD users, but the apparent differences were statistically insignificant. *Reprint requests Submitted Accepted
JUNE
for for
publication publication
November
18,
1981
May 17, 1982
1982 VOL. 25 NO. 6
613
CONTRACEPTION
The overall means of the daily prolactin values did not show any statisticalJy significant difference. Ovulation peaks of prolactin were not observed. It is concluded that as a result of the marked fluctuations observed in the day-to-day levels of prolactin, single sample determinations cannot be used while comparing prolactin levels in two groups of subjects. It is also concluded that the prolactin profiles of IUD users do not differ statistically from those of non-IUD users. INTRODUCTION Various published reports indicate that intrauterine contraceptive devices (IUDs) can markedly affect the concentrations of peripheral prolactin in human subjects (l-5). Many of these reports did not consider the factor of the daily variations in serum prolactin. A more recent study by Spellacy -et al. (61, claiming that IUD users and non-IUD users have the same level of hPRL in their blood, utilized the same RIA kit as the previous investigators. Despite this, the results remain conflicting. However, Ehara -et al. (7) had clearly demonstrated the episodic patterns exhibited by serum prolactin levels in normally cycling women. In order to nullify the factor of the day-to-day variation in the comparison of hPRL levels in IUD users and non-IUD users, daily blood samples collected, starting from day 10 of the cycle through onset of subsequent menstruation, was analysed by a highly specific RIA for hPRL. MATERIALS AND METHODS The study groups consist of 14 women using Copper T IUDs for l-10 months - 5.725.2 (z & SD) and 10 other women not on any form of contraception for about 3 years. All subjects were aged 18-38 years with apparently normal regular menstrual cycles, not known to be on any drugs and with no history of any chronic disease,
614
JUNE
1982 VOL. 25 NO. 6
CONTRACEF’TION
Starting from the 10th day of menstrual cycle, daily blood was collected at 10 a.m. until onset of the subsequent menstrual bleeding. Sera separated from cells were stored at -2OOC until assay. hPRL was measured by a sensitive RIA method using the complete ready-to-use kit from Serono Laboratories Incorp., Masachussetts 02184. The method is based on the double antibody technique. l.Ong of the Serono hPRL standard is equivalent to 30.2i2.8 u.IU. of WHO 75/504 standard of hPRL and is equivalent to l.Ong of NIH Fl hPRL standard. The second antibody used is rapid sheep anti-rabbit gamma globulin. The first incubation lasted 24 hr at room temperature (approximately 22OC) while the second lasted 4 hr at room temperature. The precipitate formed was invisible and was separated by adding 2ml of cold water, centrifuging at 3,000 r.p.m. for 30 min at 4'C and discarding the supernatant by inversion. Tubes were wiped and the radioactivity counted. The sensitivity of the method was The intral.O6ng/ml serum and only 50 ul serum was used. assay coefficient of variation is 7.4% (n = 44). All PRL results were synchronized with the ovulation surge of LH. The means of all values for each day were calculated for each subject and the mean of the daily means These means were then calculated for each study group. compared using the students' 't' test and the 2-tailed table. The specificity of the prolactin pre-determined by Serono Company.
assay had been
In our hands, no cross-reaction was observed with up to 8,000 ng/ml hCG CR 119 (NIH) and with up to 4,000 rig/m highly purified hLH LER 960 (NIH). The impure hLH preparation LER 907 (NIH), however, shows some displacement The method is entirely satisfactory only after 2,000 ng/ml. as it is also capable of measuring low prolactin levels (without any under-estimation) in early human gestation, a characteristic that is not shared by commonly used methods (8 1. (report of this published separately elsewhere) RESULTS Both IUD users and non-IUD users show episodic patterns The of prolactin values throughout the menstrual cycles. mean daily prolactin values tend to be lower in IUD users than non-IUD users, but the apparent differences were Ovulation peaks of statistically non-significant. prolactin were not observed in all subjects (Figure).
JUNE 1982 VOL. 25 NO. 6
615
CONTRACEPTION
a
P
5
O-O
Normal
4 3
&.A
IUD lJsers(n=llJ
Note:
2
‘I
-7-6-5-4-3~4 CYCLE
0 LIAY
12
SYNCHRONIZED
3
4
5
Bars
6
WITH
7 MID
Cmtrds
mpns*nl
8
II-EWI
man?S.E.
9101ff213IL~5 CYCLE
LHPEAKS
COMPARATIVE SEW PR(XACTIN.PROFlLES OF IUD USERS AND NON-IUD USERS (VALUES SYNCHRONIZED WITH LH FfAK OF OVULATION)
616
JUNE
1982 VOL. 25 NO. 6
CONTRACEPTION
DISCUSSION The results of this study confirm the episodic patterns in prolactin levels in regularly menstruating women as earlier reported (7). Although IUD users, in this study, tend to show a lower level of serum prolactin than the control group, when synchronized day-to-day values relative to ovulation surges of LH were compared, the differences were not statistically significant. Also the mean pre-ovulatory and mean postovulatory values for each group did not show any statistically significant differences. The mean ovulatory values of PRL in each group was not statistically different from either the pre-ovulatory or post-ovulatory values. Although the results presented here basically show the same conclusion as those of Spellacy (61, the sampling method used here is more satisfactory. It is also suggester that when using non-specific methods for hPRL assay, cross-reaction with hLH may cause elevated hPRL (especially at ovulation) thereby rendering the use of random sampling invalid for the purposes of comparison of data. It is concluded from the results of this study that the use of Copper T IUDs does not affect the peripheral levels of prolactin in women. ACKNOWLEDGEMENT This study was supported in part by grant CB 77.29X C.A.A. was suppor ted from the Population Council, New York. by a Rockefeller Foundation Fellowship in Reproductive The technical expertise of Mr. Andrew Gonsales Biology. (Pop. Council) and of Patricia Leon and Vivian Brache of Santo Domingo are thankfully acknowledged. We thank Dr. S.S. Koide (Pop. Council) for his useful suggestions. The Serono Company of Massachusetts is acknowledged for the satisfactory hPRL RIA Kit. Messrs. Ewetuga, G and Jaiyeoba, E.O. are gratefully acknowledged for their expert medical illustration technique.
JUNE
1982 VOL. 25 NO. 6
617
CONTRACEPTION
REFERENCES
1.
Horn, H., Finkelstein, M., Ben-David, M., Salzberger, M. Chowers L Ben-Assuly, S. and Bell, J. Possrble effe& A; intrauterine device Contraception 12, on galactorrhoea in women. 419, 1975.
2.
Spellacy, W.N., Buhi, W.C. and Birk, S.A. Stimulated plasma prolactin levels in women using MPA or an IUD for contraception. Fertil. Steril. 26, 970, 1975.
3.
Lactation and lactational Hingorani, V. and Bai, U. amenorrhoea with postpartum IUCD insertion. J. Reprod. Fertil. 23., 513, 1970
4.
Abu-Fadil, S., Devane, G., Siler, T.M. and Yen, S.S.C. Effects of oral contraceptive steroids on pituitary prolactin secretion. Contraception 13, 79, 1976
5.
Mehta, S., Pawar, V., Joshi, J., Kora, S., Rajani, U., Virkar, K.D., Raikar, R.S. and Sheth, A.R. Serum prolactin levels in women using copper IUDs. Contraception 15, 327-334, 1971.
6,
Spellacy, W.N., Mahan, C-S., Buhi, W.C. and Dumbaugh, V.S. Plasma prolactin levels and contraception: oral contraceptive and intrauterine devices. Contraception 17, 71-77, 1978
7.
Ehara, Y., Siler, T., Vandenberg, G., Sinha? Y.N. and Circulating prolactin levels during the Yen, S.S. Episodic release and diurnal variation. menstrual cycle: Am. J. Obstet. Gynecol. 117, 962-970, 1973.
8.
Adejuwon, C-A., Faundes, A., Segal, S.J., Leon P., Brache, V. and Alvarez-Sanchez, F. Serum prolactin profiles of normal human conceptual Am. J. Obstet. Gynecol. (In press). cycles,
618
JUNE
1982 VOL. 25 NO. 6
COMPARATIVE
PROLACTIN
PROFILES
IN IUD USERS
AND NON-IUD USERS
Christopher
A. Adejuwon
1
Sheldon J. Segal 2 Anibal
Faundes *3
Francisco
Alvarez-Sanchez
1.
Reproductive Biomedicine Research Chemical Pathology Department College of Medicine University of Ibadan, Nigeria
2.
Fopulation Sciences Division Rockefeller Foundation 1133 Avenue.of the Americas New York, N.Y. 10036
3.
Department of Obstetrics E Gynecology Faculty of Medical Sciences UNICAMP, Campinas, S.P. Brazil
4.
Department of Obstetrics Hospital Moscoso Pnello, Dominican Republic
E Training
4
Unit
6 Gynecology Santo Domingo
ABSTRACT Starting from the 10th day of the menstrual cycle through onset of the subsequent menstrual bleeding, daily blood samples were- collected from 14 women using Copper T The serum samples were IUDs and 10 normal control women. analysed by radioimmunoassay (RIA) for human prolactin (hPRL) and human luteinizing hormone (hLH). hPRL values Episodic patterns of were subjected to statistics. IUD users show hPRL were observed for all subjects. generally lower daily levels of hPRL than non-IUD users, but the apparent differences were statistically insignificant. *Reprint requests Submitted Accepted
JUNE
for for
publication publication
November
18,
1981
May 17, 1982
1982 VOL. 25 NO. 6
613
CONTRACEPTION
The overall means of the daily prolactin values did not show any statisticalJy significant difference. Ovulation peaks of prolactin were not observed. It is concluded that as a result of the marked fluctuations observed in the day-to-day levels of prolactin, single sample determinations cannot be used while comparing prolactin levels in two groups of subjects. It is also concluded that the prolactin profiles of IUD users do not differ statistically from those of non-IUD users. INTRODUCTION Various published reports indicate that intrauterine contraceptive devices (IUDs) can markedly affect the concentrations of peripheral prolactin in human subjects (l-5). Many of these reports did not consider the factor of the daily variations in serum prolactin. A more recent study by Spellacy -et al. (61, claiming that IUD users and non-IUD users have the same level of hPRL in their blood, utilized the same RIA kit as the previous investigators. Despite this, the results remain conflicting. However, Ehara -et al. (7) had clearly demonstrated the episodic patterns exhibited by serum prolactin levels in normally cycling women. In order to nullify the factor of the day-to-day variation in the comparison of hPRL levels in IUD users and non-IUD users, daily blood samples collected, starting from day 10 of the cycle through onset of subsequent menstruation, was analysed by a highly specific RIA for hPRL. MATERIALS AND METHODS The study groups consist of 14 women using Copper T IUDs for l-10 months - 5.725.2 (z & SD) and 10 other women not on any form of contraception for about 3 years. All subjects were aged 18-38 years with apparently normal regular menstrual cycles, not known to be on any drugs and with no history of any chronic disease,
614
JUNE
1982 VOL. 25 NO. 6
CONTRACEF’TION
Starting from the 10th day of menstrual cycle, daily blood was collected at 10 a.m. until onset of the subsequent menstrual bleeding. Sera separated from cells were stored at -2OOC until assay. hPRL was measured by a sensitive RIA method using the complete ready-to-use kit from Serono Laboratories Incorp., Masachussetts 02184. The method is based on the double antibody technique. l.Ong of the Serono hPRL standard is equivalent to 30.2i2.8 u.IU. of WHO 75/504 standard of hPRL and is equivalent to l.Ong of NIH Fl hPRL standard. The second antibody used is rapid sheep anti-rabbit gamma globulin. The first incubation lasted 24 hr at room temperature (approximately 22OC) while the second lasted 4 hr at room temperature. The precipitate formed was invisible and was separated by adding 2ml of cold water, centrifuging at 3,000 r.p.m. for 30 min at 4'C and discarding the supernatant by inversion. Tubes were wiped and the radioactivity counted. The sensitivity of the method was The intral.O6ng/ml serum and only 50 ul serum was used. assay coefficient of variation is 7.4% (n = 44). All PRL results were synchronized with the ovulation surge of LH. The means of all values for each day were calculated for each subject and the mean of the daily means These means were then calculated for each study group. compared using the students' 't' test and the 2-tailed table. The specificity of the prolactin pre-determined by Serono Company.
assay had been
In our hands, no cross-reaction was observed with up to 8,000 ng/ml hCG CR 119 (NIH) and with up to 4,000 rig/m highly purified hLH LER 960 (NIH). The impure hLH preparation LER 907 (NIH), however, shows some displacement The method is entirely satisfactory only after 2,000 ng/ml. as it is also capable of measuring low prolactin levels (without any under-estimation) in early human gestation, a characteristic that is not shared by commonly used methods (8 1. (report of this published separately elsewhere) RESULTS Both IUD users and non-IUD users show episodic patterns The of prolactin values throughout the menstrual cycles. mean daily prolactin values tend to be lower in IUD users than non-IUD users, but the apparent differences were Ovulation peaks of statistically non-significant. prolactin were not observed in all subjects (Figure).
JUNE 1982 VOL. 25 NO. 6
615
CONTRACEPTION
a
P
5
O-O
Normal
4 3
&.A
IUD lJsers(n=llJ
Note:
2
‘I
-7-6-5-4-3~4 CYCLE
0 LIAY
12
SYNCHRONIZED
3
4
5
Bars
6
WITH
7 MID
Cmtrds
mpns*nl
8
II-EWI
man?S.E.
9101ff213IL~5 CYCLE
LHPEAKS
COMPARATIVE SEW PR(XACTIN.PROFlLES OF IUD USERS AND NON-IUD USERS (VALUES SYNCHRONIZED WITH LH FfAK OF OVULATION)
616
JUNE
1982 VOL. 25 NO. 6
CONTRACEPTION
DISCUSSION The results of this study confirm the episodic patterns in prolactin levels in regularly menstruating women as earlier reported (7). Although IUD users, in this study, tend to show a lower level of serum prolactin than the control group, when synchronized day-to-day values relative to ovulation surges of LH were compared, the differences were not statistically significant. Also the mean pre-ovulatory and mean postovulatory values for each group did not show any statistically significant differences. The mean ovulatory values of PRL in each group was not statistically different from either the pre-ovulatory or post-ovulatory values. Although the results presented here basically show the same conclusion as those of Spellacy (61, the sampling method used here is more satisfactory. It is also suggester that when using non-specific methods for hPRL assay, cross-reaction with hLH may cause elevated hPRL (especially at ovulation) thereby rendering the use of random sampling invalid for the purposes of comparison of data. It is concluded from the results of this study that the use of Copper T IUDs does not affect the peripheral levels of prolactin in women. ACKNOWLEDGEMENT This study was supported in part by grant CB 77.29X C.A.A. was suppor ted from the Population Council, New York. by a Rockefeller Foundation Fellowship in Reproductive The technical expertise of Mr. Andrew Gonsales Biology. (Pop. Council) and of Patricia Leon and Vivian Brache of Santo Domingo are thankfully acknowledged. We thank Dr. S.S. Koide (Pop. Council) for his useful suggestions. The Serono Company of Massachusetts is acknowledged for the satisfactory hPRL RIA Kit. Messrs. Ewetuga, G and Jaiyeoba, E.O. are gratefully acknowledged for their expert medical illustration technique.
JUNE
1982 VOL. 25 NO. 6
617
CONTRACEPTION
REFERENCES
1.
Horn, H., Finkelstein, M., Ben-David, M., Salzberger, M. Chowers L Ben-Assuly, S. and Bell, J. Possrble effe& A; intrauterine device Contraception 12, on galactorrhoea in women. 419, 1975.
2.
Spellacy, W.N., Buhi, W.C. and Birk, S.A. Stimulated plasma prolactin levels in women using MPA or an IUD for contraception. Fertil. Steril. 26, 970, 1975.
3.
Lactation and lactational Hingorani, V. and Bai, U. amenorrhoea with postpartum IUCD insertion. J. Reprod. Fertil. 23., 513, 1970
4.
Abu-Fadil, S., Devane, G., Siler, T.M. and Yen, S.S.C. Effects of oral contraceptive steroids on pituitary prolactin secretion. Contraception 13, 79, 1976
5.
Mehta, S., Pawar, V., Joshi, J., Kora, S., Rajani, U., Virkar, K.D., Raikar, R.S. and Sheth, A.R. Serum prolactin levels in women using copper IUDs. Contraception 15, 327-334, 1971.
6,
Spellacy, W.N., Mahan, C-S., Buhi, W.C. and Dumbaugh, V.S. Plasma prolactin levels and contraception: oral contraceptive and intrauterine devices. Contraception 17, 71-77, 1978
7.
Ehara, Y., Siler, T., Vandenberg, G., Sinha? Y.N. and Circulating prolactin levels during the Yen, S.S. Episodic release and diurnal variation. menstrual cycle: Am. J. Obstet. Gynecol. 117, 962-970, 1973.
8.
Adejuwon, C-A., Faundes, A., Segal, S.J., Leon P., Brache, V. and Alvarez-Sanchez, F. Serum prolactin profiles of normal human conceptual Am. J. Obstet. Gynecol. (In press). cycles,
618
JUNE
1982 VOL. 25 NO. 6