***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Twenty-four healthy adult female volunteers participated in a r and omized , three-phase double-blind crossover trial comparing the single-dose ( 50 mg ) pharmacokinetics of three formulations of clomiphene citrate ( CC ) .  Plasma levels of both the Z(cis ) and E(trans ) isomers of  CC  , as well as principal metabolites , were determined at periodic intervals ; and no differences between formulations were observed . The active Z isomer attained peak blood levels later than the inactive E isomer and was eliminated much more slowly , significant plasma concentrations still being detected up to 1 month after treatment . The results of this study demonstrate that three commercially available formulations of CC are bioequivalent This study evaluates the efficacy of a stimulation protocol with clomiphene citrate (CC)/human menopausal gonadotropin (hMG)/cetrorelix and its effects on oocyte quality and endometrium .  One hundred and twenty couples with male-factor infertility who were about to undergo their first intracytoplasmic sperm injection cycles were r and omized into two groups . Sixty women were stimulated with the CC/hMG/cetrorelix protocol ( cetrorelix group ) and 60 received the buserelin long protocol ( buserelin group ) . Fewer oocytes were recovered in the cetrorelix group than in the buserelin group ( mean ± st and ard deviation ( SD ) : 11.1 ± 4.0 vs. 17.3 ± 5.8 , p < 0.001 ) ; however , the percentages of metaphase II , metaphase I and germinal vesicle oocytes were similar between the two groups . Serum estradiol level was significantly lower in the cetrorelix than in the buserelin group ( mean ± SD : 2600.58 ± 1189.11 vs. 3293.46 ± 1221.49 pg/ml , p = 0.006 ) , but the endometrial thickness was similar . The implantation rates ( 19.2 % vs. 17.7 % ) and the pregnancy rates ( 41.7 % vs. 40.0 % ) were similar between groups . The ampoules ( mean ± SD : 18.9 ± 3.0 vs. 38.9 ± 12.2 , p < 0.001 ) and injections ( mean ± SD : 6.8 ± 1.1 vs. 15.7 ± 3.1 , p < 0.001 ) of gonadotropin used were significantly lower in the cetrorelix group than in the buserelin group . No patients in either group developed a premature luteinizing hormone surge . The present study found no statistically significant difference between the two treatment modalities with regard to pregnancy rates In an attempt to improve the pregnancy rate following in vitro fertilization and embryo transfer by increasing the numbers of embryos available for transfer to each patient , a prospect i ve , r and omized comparison of clomiphene citrate alone ( 50 mg/day , cycle days 5 to 9 ) with the combination of clomiphene as above plus human menopausal gonadotropin ( 2 ampules/day , cycle days 6 , 8 , and 10 ) was undertaken from January through April 1983 , with 17 patients in each group . The combination produced increased follicular development , compared with clomiphene alone , result ing in the retrieval of more fertilizable oocytes . Two clinical pregnancies result ed in each group . These results show that a fixed combination of clomiphene and human menopausal gonadotropin produces a greater degree of enhanced follicular recruitment , result ing in the recovery of an increased number of fertilizable oocytes . The lack of a statistically significant increase in the number of embryos transferred per patient in the combination group as well as the identical number of clinical pregnancies in both groups suggests that this particular combination of clomiphene and human menopausal gonadotropin offers no advantage over the use of clomiphene alone for enhanced follicular recruitment The efficiency of IVF in unstimulated cycles was compared with that following ovarian stimulation with clomiphene citrate in a simple protocol with ultrasound monitoring only . A total of 132 couples with no previous IVF attempts , selected by female age < 35 years , indication for intracytoplasmic sperm injection or infertility caused by tubal factor or unexplained infertility were r and omized to the two protocol s. R and omization yielded two comparable groups . The clomiphene group ( 68 couples ) performed significantly better than the unstimulated group ( 64 couples ) in terms of number of cycles with oocyte harvest ( 90/111 or 81 % versus 65/114 or 57 % ; chi(2 ) = 9.21 , P < 0.002 ) , embryo transfers per started cycle ( 59/111 or 53 % versus 29/114 or 25 % ; chi(2 ) = 18.14 , P < 0.0001 ) , live intrauterine pregnancy rate per started cycle ( 20/111 or 18 % versus 4/114 or 4 % ; chi(2 ) = 12.42 , P < 0.0001 ) , live intrauterine pregnancy rate per embryo transfer ( 20/59 or 34 % versus 4/29 or 14 % ; chi(2 ) = 3.96 , P = 0.047 ) , but not in terms of implantation rate ( 22/85 or 26 % versus 4/29 or 14 % ; chi(2 ) = 1.65 ) . Only two twin pregnancies occurred . Modest side-effects were recorded following clomiphene . Accordingly , a simple clomiphene citrate protocol , but not IVF in unstimulated cycles , seems compatible with the concept of ' friendly IVF ' , yielding a fair pregnancy rate both per cycle started and per embryo transfer in selected patients . The results do not substantiate any important negative anti-oestrogenic effects of clomiphene OBJECTIVE To determine the follicular and luteal phase impact of low-dose GnRH agonist ( GnRH-a ) treatment during follicular stimulation for IVF . DESIGN A r and omized prospect i ve study compared patients receiving low-dose GnRH-a and hMG therapy to clomiphene citrate ( CC ) and hMG cycles .  SETTING Patients were treated through a university-based IVF-ET program . PATIENTS Thirty-six patients underwent follicular stimulation with low-dose GnRH-a and hMG  and were compared with 34 patients undergoing ovulation induction with CC and hMG .  RESULTS Significantly shorter luteal phase length occurred with GnRH-a and hMG therapy ; however , there was no statistically significant difference in luteal P levels . Follicular parameters were the same ( peak E2 , number of follicles , and number of oocytes ) , suggesting that folliculogenesis was not altered . There were no statistical differences in pregnancy rates . CONCLUSIONS Sustained low-dose GnRH-a therapy during follicular stimulation does not have a clinical effect on luteal function OBJECTIVE To compare 3 stimulation protocol s in poor ovulation responders undergoing in-vitro fertilization ( IVF ) . METHODS The study was a r and omized , prospect i ve clinical trial from June 2003 to July 2004 , in Royan Institute , Tehran , Iran . One hundred and fifty-four patients , who had poor responses to ovulation induction in at least one previous IVF attempt , were r and omly divided into 3 groups . In the first group , human menopausal gonadotropin ( HMG ) was administered from day 3 of the cycle at a dose rate of 150 IU/day . In the second group , gonadotropin-releasing hormone ( GnRH ) agonist was started at a dose rate of 800 microg/day by nasal spray or 500 microg/day subcutaneously in the mid-luteal phase , followed by a st and ard HMG dose after pituitary down regulation was confirmed . In the third group , clomiphene at a dose rate of 100 mg/day was given from day 3 and HMG from day 6 . Our main outcomes were number of mature oocytes , cancellation rate , number of HMG ampoules used and incidence premature luteinizing hormone ( LH ) surge . RESULTS There was a high incidence of premature LH surge in all groups except in the GnRH group ( p=0.0001 ) and there were significant differences between groups in HMG requirements ( p=0.004 ) . There were no significant differences between groups in number of mature oocytes recovered and cancellation rate . CONCLUSION Results showed no advantage in the use of GnRH agonist compared to the older regimens of clomiphene plus HMG and HMG alone . The cancellation rate was similar for 3 protocol s and HMG requirement was higher with the use of GnRH agonist . The treatment of poor responders in assisted reproductive technologies remains a challenge The quality of ovarian stimulation for in vitro fertilization with or without an LH-RH analogue was investigated in a r and omized trial involving 30 women divided into 3 groups . Group I women were treated with the conventional clomiphene citrate-human menopausal gonadotropin combination without LH-RH analogue . Group II women ( long regimen ) received a slow-release preparation of triptorelin ( DTRp6-LH-RH ) , an LH-RH analogue , and human menopausal gonadotropin . Group II women ( short regimen ) were given triptorelin with human menopausal gonadotropin . Inhibition of the endogenous luteinizing hormone using triptorelin improved the results of in vitro fertilization in group II and group III women , but the short regimen was distinctly less compelling and less expensive than the long regimen Purpose To compare the IVF outcome of clomiphene citrate/gonadotropin/antagonist ( mild protocol ) and microdose GnRH agonist flare protocol s for poor responders undergoing in vitro fertilization . Methods 159 poor responder patients were r and omized and ovarian stimulation was performed with clomiphene citrate , gonadotropin and antagonist ( group I ) or microdose GnRH agonist flare ( group II ) protocol s. Main outcome was clinical pregnancy rate and secondary outcomes were doses of gonadotropin administration and duration of stimulation . Results There were no significant differences in age , causes of infertility , basal FSH , BMI , duration of infertility , E2 level on the day of hCG injection in both groups . Although the cancellation , fertilization , and clinical pregnancy rates were similar in both groups , the endometrial thickness , number of retrieved oocytes , mature oocytes and implantation rate were significantly higher in mild protocol . The doses of gonadotropin administration and duration of stimulation were significantly lower in mild protocol . Conclusion We recommend mild protocol in assisted reproductive technology cycles for poor responders based on our results regarding less doses of used gonadotropin and a shorter duration of stimulation A prospect i ve , r and omized , double-blind , multicentre ( n = 6 ) study was conducted to compare the influence of either a 150 or 250 IU daily fixed-dose regimen of recombinant follicle stimulating hormone ( FSH , Puregon ) on the number of oocytes retrieved and the total dose used in down-regulated women between 30 and 39 years of age undergoing ovarian stimulation . In all , 138 women were treated with  recombinant FSH , 67 with 150 IU and 71 with 250 IU . The number of oocytes retrieved in the low-dose group was 9.1 compared to 10.6 in the high-dose group ( not significant ) . In the 30 - 33 years of age class receiving the 250 IU dose , a surplus of 4.2 oocytes ( 14.8 versus 10.6 ) was found , whereas in the 37 - 39 age class nearly one oocyte more was retrieved in the 150 IU group ( 8.1 versus 7.4 ) . The total dose used to reach the criterion for human chorionic gonadotrophin ( HCG ) administration was 1727 IU for the women treated with 150 IU daily and 2701 IU for the 250 IU treated women ( P < 0 . 001 ) . No significant relationships were found between serum FSH concentrations as obtained in the early follicular phase and the number of oocytes collected , or the total dose . It is concluded that in women between 30 and 39 years of age , the decline in number of oocytes retrieved with increasing age can not be overcome by augmenting the daily dose of recombinant FSH from 150 to 250 IU OBJECTIVE To compare luteal phase leuprolide acetate ( LA ) initiated pituitary down regulation followed by human menopausal gonadotropins ( hMG ) versus clomiphene citrate ( CC ) and hMG for follicular recruitment and oocyte maturation before in vitro fertilization ( IVF ) . DESIGN R and omized , prospect i ve comparison in first cycles of IVF . SETTING University Hospital , a tertiary referral center offering assisted reproductive technologies . PARTICIPANTS Participants were couples undergoing their first ever cycle of IVF and consenting to participation in the trial . RESULTS Luteal phase initiated LA/hMG was associated with a lower 
    Output:
    
There was no evidence to indicate that clomiphene with gonadotropins ( with or without GnRH antagonist ) differed significantly from gonadotropins in GnRH agonist protocol s for women undergoing IVF treatment , in terms of live births or pregnancy rates .
Meanwhile , use of clomiphene led to a reduction in the incidence of OHSS .
Hence there was insufficient evidence to recommend use of clomiphene citrate in routine IVF practice .