1 Assisted Conception Unit, Birmingham Women's Hospital, Edgbaston, Birmingham, B15 2TG and 2 Regional Endocrine Laboratory, University Hospital, Birmingham B29 6JD, UK
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Abstract |
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Key words: GnRH stimulation test/intrauterine insemination/ovarian response
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Introduction |
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Materials and methods |
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Intrauterine insemination protocol
The ovarian stimulation protocol involved ultrasound scanning on cycle day 2 to rule out any ovarian pathology before starting intra-nasal nafarelin acetate 400 µg twice daily (Synarel; Searle, High Wycombe, Bucks, UK) from cycle day 2 until the administration of human chorionic gonadotrophin (HCG). On cycle days 35 the patients were given 150 IU of recombinant FSH (rFSH, Gonal-F; Serono UK Ltd, Garden City, Herts, UK) daily which was then reduced to 75 IU daily from day 6 onwards. The patients' response was monitored with ultrasound scanning starting on cycle day 9, and daily thereafter. When the leading follicle measured 16 mm, 10 000 IU HCG was administered.
A maximum of five follicles measuring 14 mm was the threshold above which the cycle was either cancelled or converted to IVF. A total of nine patients who failed to produce at least one follicle
14 mm after 10 days of gonadotrophin stimulation were cancelled for poor response.
Design
Blood samples were taken between 0800 and 1100 h on cycle day 2 (before starting the GnRHa) and on cycle day 3. A third blood sample was taken on HCG day. Day 2 sample was assayed for oestradiol, FSH and luteinizing hormone (LH). Day 3 sample was assayed for oestradiol and FSH, and the HCG day sample was assayed for oestradiol.
Hormonal assays
The blood samples were centrifuged at 3000 g, the serum was separated and frozen at 20°C and assayed in one batch at the end of the study. Oestradiol was measured by direct radioimmunoassay (Sorin Biomedica Diagnostica, Wokingham, Berks, UK) with interassay coefficient of variation (CV) of 9.1% at 212 pmol/l and 8.5% at 765 pmol/l. FSH was measured by an automated chemiluminometric assay (Chiron Diagnostics, Halstead, Essex, UK) calibrated against the World Health Organization (WHO) second International Reference Preparation (IRP) 78/549. CV were <10% over the range 8.651 IU/l. LH was measured by chemiluminometric assay (Chiron Diagnostics) calibrated against WHO second IRP 80/552. CV were <9% over the range 4.653 IU/l.
Data analysis
Linear and logistic regression analyses were used where appropriate to establish the relationship between age, day 2 FSH, FSH/LH, oestradiol ratio (oestradiol day 3/oestradiol day 2), and FSH ratio (FSH day 3/FSH day 2) as predictors, and the number of follicles (total and 14 mm), oestradiol on HCG day, and clinical pregnancy rate as the response. The t-value as well as the regression coefficient were provided since we believe that the t-value is more informative than the regression coefficients alone.
We also compared the age, oestradiol ratio, FSH ratio, day 2 FSH, and FSH/LH between the poor responders, over-responders and adequate responders (within the specified threshold of five follicles 14 mm). The significance of GAST was assessed at an arbitrary threshold of three mature follicles (
14 mm), which is the recommended threshold of the British Fertility Society (Balen, 1997
). The patients were divided into two groups: A (13 follicles) and B (>3 follicles) and the two groups were compared with regard to age, oestradiol ratio, FSH ratio, day 2 FSH, day 2 oestradiol, and FSH/LH, duration of stimulation, total gonadotrophin dose, clinical pregnancy rate per insemination and multiple pregnancy rate.
ANOVA (analysis of variance) test was used to carry out the comparative analyses. P < 0.05 was considered significant. Statistical analysis was carried out using Minitab for Windows (Minitab Inc., State College, PA, USA).
Ethical committee approval and patients' written consent were obtained before starting the study.
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Results |
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Correlation analysis results
Oestradiol ratio was correlated significantly with oestradiol on HCG day (regression coefficient = 1017.8, t = 4, P < 0.001), and the number of follicles 14 mm (regression coefficient = 0.5, t = 2.6, P = 0.01). Day 2 FSH/LH significantly inversely correlated with the total number of follicles (regression coefficient = 0.7, t = 2 and P = 0.02).
Age, day 2 FSH, day 2 oestradiol, and FSH ratio were not significantly correlated with oestradiol on HCG day, the total number of follicles, or the number of follicles 14 mm. Neither age, oestradiol ratio, FSH ratio, day 2 FSH, day 2 oestradiol nor FSH/LH were significantly correlated with the clinical pregnancy rate.
Poor, over- and adequate responders
The oestradiol ratio was significantly different between the over-responders and the adequate responders (P = 0.04) while no significant difference was found between the poor responders and the other two groups (Table I). Considering the oestradiol ratio, the 95% CI for the poor responders (n = 9), adequate responders (n = 60) and over-responders (n = 12) respectively were 2.13.8, 2.93.7 and 3.55.4. No significant difference was found between the three groups with regard to age, day 2 oestradiol, day 2 FSH, and FSH/LH. The mean ± SD of the compared parameters is summarized in Table I
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Discussion |
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In this study, oestradiol ratio was the only factor that was significantly correlated with the number of mature follicles (14 mm), and oestradiol on HCG day. Furthermore oestradiol ratio was distinctly different between the adequate (15 follicles
14 mm in diameter) and the over-responders (>5 follicles
14 mm) despite the similarity between the two groups with regard to age, day 2 FSH, FSH ratio, day 2 oestradiol, and FSH/LH ratio. The ability of the GAST to detect a difference in oestradiol response to GnRHa despite the small number of patients was repeated when the threshold was arbitrarily changed to three mature follicles. The sensitivity and predictive values of the test at a threshold of oestradiol ratio of 4.0 (mean oestradiol ratio in group B) was the best compromise for an acceptable sensitivity and positive and negative predictive values as shown in Table III
. However, it should be noted that the GAST is suggested only as a screening test and no major decisions should be made based on the result of the test alone. Though the predictive values are fairly low, they can be considered acceptable given the population size in the study and the incidence of the event screened for.
The use of GnRHa in conjunction with gonadotrophin prior to IUI has been a controversial issue (Dodson et al., 1991, Galgiardi et al., 1991, Sengoku et al., 1994
, Manzi et al., 1995
). Nevertheless, we believe it offers a degree of flexibility with regard to monitoring, cycle cancellation, and when conversion to IVF seems appropriate; hence it was used for ovarian stimulation in the IUI programme. Nevertheless, the use of the GAST does not require the continuation of the GnRHa provided the values of oestradiol ratio obtained in this study are validated accordingly.
The similarity of the oestradiol ratio, day 2 FSH, day 2 oestradiol, and day 2 FSH/LH ratio between the poor responders and the other groups could be due to the small number of the poor responders in the study and/or the heterogeneity of this group of patients. It should also be noted that the character of ovarian response is relative to the stimulation protocol and the gonadotrophin dose used. Therefore, in any prospective assessment of this study, validation of the test according to the stimulation protocol and the relevant population is essential. Although the number of pregnancies is too small to draw a conclusion, the data suggest that similar pregnancy and lower multiple pregnancy rates would be obtained when 3 follicles were recruited, as when a threshold of five mature follicles is used (as in this study).
We can conclude that prediction of ovarian over-response to ovarian stimulation in an IUI programme could be achieved using the modified GAST as suggested in this study and the patients could be counselled regarding the risk of cycle cancellation or conversion to IVF and multiple pregnancy. Furthermore, gonadotrophin dose adjustment could be decided prior to starting the treatment. The use of GnRH antagonist with recombinant FSH in the late follicular phase to induce a modest increase in the follicle numbers over the natural cycle has been suggested (Edwards et al., 1996). Whichever approach is used, it will have to be tested prospectively in a comparative study.
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Notes |
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References |
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Cohen, J. (1998) How to avoid multiple pregnancies in assisted reproduction. Hum. Reprod., 13 (Suppl. 3), 197214.[Medline]
Cruz, R.I., Kenman, E., Brandeis, V.T. et al. (1986) A prospective study of intrauterine insemination of processed sperm from men with oligoasthenospermia in superovulated women. Fertil. Steril., 46, 673677.[ISI][Medline]
Dodson, W.C., Whitesides, D.B., Hughes, C.L. Jr et al. (1987) Superovulation with intrauterine insemination in the treatment of infertility: a possible alternative to gamete intrafallopian transfer and in vitro fertilization. Fertil. Steril., 48, 441445.[ISI][Medline]
Dodson, W.C., Walmer, D., Hughes, C.L. et al. (1991) Adjunctive leuprolide therapy does not improve cycle fecundity in controlled ovarian hyperstimulation and intrauterine insemination of subfertile women. Obstet. Gynecol., 78, 187190.[Abstract]
Edwards, R.G., Lobo, R. and Bouchard, P. (1996) Time to revolutionize ovarian stimulation. Hum. Reprod., 11, 917919.[ISI][Medline]
Fédération CECOS, Schwartz, D. and Mayaux, B.A. (1982) Female fecundity as a function of age: results of artificial insemination in 2193 nulliparous women with azoospermic husbands. N. Engl. J. Med., 306, 404406.[ISI][Medline]
Gagliardi, C.L., Adelina, M.E., Weiss, G. et al. (1991) Gonadotrophin-releasing hormone agonist improves the efficiency of controlled ovarian hyperstimulation/intrauterine insemination. Fertil. Steril., 55, 939944.[ISI][Medline]
Manzi, D.L., Dumez, S., Scott, L.B. et al. (1995) Selective use of leuprolide acetate in women undergoing superovulation and intrauterine insemination results in significant improvement in pregnancy outcome. Fertil. Steril., 63, 866873.[ISI][Medline]
Navot, D., Rosenwaks, Z. and Margolioth, E.J. (1987) Prognostic assessment of female fecundity. Lancet, ii, 645647.
Padilla, S.L., Bayati, J. and Garcia, J.E. (1990) Prognostic value of early serum estradiol response to leuprolide acetate in in vitro fertilisation. Fertil. Steril., 53, 288294.[ISI][Medline]
Sengoku, K., Tamate, K., Takaoka, Y. et al. (1994) A randomised prospective study of gonadotrophin with or without gonadotrophin-releasing hormone agonist for treatment of unexplained infertility. Hum. Reprod., 9, 10431047.[Abstract]
Serhal, P.F., Katz, M., Little, V. and Woronowski, H. (1988) Unexplained infertility the value of Pergonal superovulation combined with intrauterine insemination. Fertil. Steril., 49, 602606.[ISI][Medline]
Toner, J.P., Philput, C.B., Jones, G.S. et al. (1991) Basal follicle stimulating hormone level is a better predictor of in vitro fertilisation performance than age. Fertil. Steril., 55, 784791.[ISI][Medline]
Winslow, K.L., Toner, J.P., Brzyski, R.G. et al. (1991) The gonadotropin-releasing hormone agonist stimulation test a sensitive predictor of performance in the flare-up in vitro fertilization cycle. Fertil. Steril., 56, 711717.[ISI][Medline]
Submitted on February 12, 1999; accepted on August 2, 1999.