Letrozole versus combined clomiphene citrate plus metformin as a first line treatment in women with polycystic ovarian syndrome: a prospective randomized trial

To compare the effect of letrozole to combined clomiphene citrate plus metformin as a first-line treatment to induce ovulation in women with polycystic ovarian syndrome [PCO]. In the present prospective randomised trial, 200 infertile women with PCOS were equally randomised to receive letrozole 2.5 mg for ,five days [days 3-7 of the cycle] or clomiphene citrate [CC]100 mg for five days [days 3-7 of the cycle] plus metformin 1500 mg daily for three treatment cycles. Human chroinic gonadotropine injection [HCG] was given when at least one follicle 18 mm present. The 3-month rate of ovulation, pregnancy and abortion were evaluated. The groups were similar with regard the baseline clinical characteristics and hormonal profiles. The ovulation rate was higher in the letrozole group [76.5% versus 71.6%] but without significant difference and the endometrial thickness at day of HCG was significantly higher in the letrozole group [8.6 mm versus 7.4 mm]. Letrozole shows higher pregnancy rate [45.7% versus 39.2%] and lower rate of abortion [10.8% versus 18.2%] but with no significance. The rate of multiple pregnancy was significantly higher in the CC metformin group 12.1% versus no case in the letrozole group letrozole is a suitable alternative first-line ovulation inducing drug in PCO

Blood levels of nitric oxide and endothelin-1 during normal menstrual cycle

Nitric oxide [NO] is a free radical gas synthesized from L-arginine by a class of specific enzymes known as NO synthases, and inducible NO synthase isoforms. Nitric oxide synthase activity has been identified in the human uterus and has been thoroughly studied in pregnant women. All three NO synthase isoforms are thought to play an important role in the maintenance of uterine quiescence during gestation, and inducible NO synthase is involved in the induction of cervical ripening before labour. However, few studies have examined the role of NO in the normal menstrual cycle. Endonthelin-1 [ET-1] might play a role in endometrial bleeding and /or repair, as previously reported. In the present study, the serum levels of NO, estradiol [E2] and plasma levels of ET-1 were measured in menstrual follicular and luteal phases of the menstrual cycle to evaluate their role in menstrual cycle. This study included twenty unmarried females with regular menstrual cycles ranging from 27 to 30 days. The levels of serum E[2] and plasma ET-1 were measured by ELISA, and the serum NO were estimated by chemical method. Our results showed that serum levels of E[2] were significantly increased during luteal phase compared with menstrual and follicular phases, whereas plasma levels of ET-1 were significantly higher during menstrual phase compared with follicular and luteal phases of the menstrual cycle. Serum levels of NO did not show significant change during the three phases of the cycle. ET-1 levels were negatively correlated with E[2] while no significant correlation between ET-1 and NO and between NO and E[2]. It can be concluded that ET-1 may play an important role in menstruation and E2 inhibits secretion of ET-1. While NO shows no relation to ET-1 and E[2]