الفهرس 
Hormone contraceptives controversies and clarifications
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Abstract
Pituitary suppression with oral contraceptives (OCs) and gonadotropin releasing hormone agonist (GnRH-a) before ovarian hyperstimulation has frequently been used in vitro fertilization (IVF) treatment. Previous studies have suggested that combined use of oral contraceptives and GnRH-a may improve the IVF outcome.
Oral contraceptives can normalize the leutinizing hormone(LH)/ follicle stimulating hormone (FSH) ratio and reduce ovarian androgen concentrations.
Pituitary suppression with oral contraceptives before ovarian hyperstimulation has been reported to circumvent the initial gonadotropin flare response.
Anovulation induced by oral contraceptives, showing bilateral ovarian quiescence, has also been reported to reduce miscarriage rate in the following pregnancy.
Oral contraceptives were suggested to reduce the incidence of functional ovarian cyst formation, shorten the time required to achieve pituitary suppression and decrease gonadotropin requirements.
The use of oral contraceptives prior to controlled ovarian hyperstimulation (COH) was suggested to allow for convenient cycle scheduling as well as for ovulation suppression so that subsequent GnRH-a treatment cannot stimulate residual corpus luteum function.
On the other hand, some studies showed that pre treatment with a combined OCP resulted in fewer clinical pregnancies, more days of gonadotrophin therapy and a higher amount of gonadotrophins needed due to pituitary oversuppresion. Also it was found to increase risk of poor response in patients with low ovarian reserve. This is mainly important with regard to the financial aspect of the IVF/ICSI treatment. A limitation of this review is that most included studies were of small number and poor quality.
In the current study, we primarily aimed to investigate the effect of OCP pretreatment on clinical pregnancy rate in initial intracytoplasmic sperm injection (ICSI) cycles among normoresponders in long GnRH agonist protocol. Secondarily, we assessed the influence of OCP on Duration of induction of ovulation ,number of ampoules used for induction of ovulation ,number of oocytes retrieved.
We found that, in long GnRH agonist cycles OCP pretreatment followed by a 5-day pill-free interval is associated with a not significant difference in ongoing pregnancy rates per started cycle compared with initiation of stimulation on day 2 of the cycle after a normal luteal phase. the difference in ongoing pregnancy rate of 4.8%, which was clinically insignificant.
The two groups compared in the current study received the same fixed HMG dose, while the endogenous FSH levels were not significantly different at initiation of stimulation and during follicular development .Therefore, it appears that OCP pretreatment for 2 weeks results in a slower follicular recruitment associated with an increased consumption of gonadotrophins, which is not attributed to a difference in exogenous or endogenous FSH levels. This might be explained by the significantly lower LH levels observed in the OCP group, since LH has been shown to assist in follicular development. In addition, OCP pretreatment might exert a suppressive effect on the cohort of existing follicles.OCP pretreatment for cycle scheduling in long GnRH-agonist protocol is a valid modality with comparable IVF outcome to the non-OCP protocol. The longer stimulation and higher total dose of FSH are the only drawbacks that we found in this modification. The weight of these drawbacks has to be measured against the gain in enabling cycle scheduling.