Aromatase inhibition reduces gonadotrophin dose required for controlled ovarian stimulation in women with unexplained infertility.

BACKGROUND: Adding clomiphene citrate (CC) to FSH for controlled ovarian stimulation (COS) decreases FSH dose required for optimum stimulation. However, because of its anti-estrogenic effects, CC may be associated with lower pregnancy rates offsetting the FSH-dose reduction benefit. Previously, we reported the success of aromatase inhibition in inducing ovulation without antiestrogenic effects. METHODS: A prospective pilot study that included women with unexplained infertility undergoing COS and intrauterine insemination. Thirty-six women received the aromatase inhibitor letrozole + FSH, 18 women received CC + FSH and 56 women received FSH only. Each woman received one treatment regimen in one treatment cycle. All patients were given recombinant or highly purified FSH (50-150 IU/day) starting on day 3 to 7 until day of hCG. RESULTS: The FSH dose needed was significantly lower in letrozole + FSH and CC + FSH groups compared with FSH-only without a difference in number of follicles >1.8 cm. Pregnancy rate was 19.1% in the letrozole + FSH group, 10.5% in the CC + FSH group and 18.7% in the FSH-only group. Both pregnancy rate and endometrial thickness were significantly lower in CC + FSH group compared with the other two groups. Estradiol (E2) levels were significantly lower in the letrozole + FSH group compared with the other two groups. CONCLUSIONS: Similar to CC, aromatase inhibition with letrozole reduces FSH dose required for COS without the undesirable antiestrogenic effects sometimes seen with CC.

Use of an aromatase inhibitor for induction of ovulation in patients with an inadequate response to clomiphene citrate.

OBJECTIVE: To use aromatase inhibition for induction of ovulation in women in whom clomiphene citrate (CC) treatment was unsuccessful. DESIGN: Prospective trial in infertility patients treated with CC. SETTING: Two tertiary-referral infertility clinics associated with the Division of Reproductive Sciences, University of Toronto. PATIENT(S): Twelve patients with anovulatory polycystic ovary syndrome (PCOS) and 10 patients with ovulatory infertility, all of whom had previously received CC with an inadequate outcome (no ovulation and/or endometrial thickness of < or =0.5 cm). INTERVENTION(S): The aromatase inhibitor letrozole was given orally in a dose of 2.5 mg on days 3-7 after menses. MAIN OUTCOME MEASURE(S): Occurrence of ovulation, endometrial thickness, and pregnancy rates. RESULT(S): With CC treatment in patients with PCOS, ovulation occurred in 8 of 18 cycles (44.4%), and all ovulatory cycles for the women included in this study had endometrial thickness of < or =0.5 cm. In 10 ovulatory patients, 15 CC cycles resulted in a mean number of 2.5 mature follicles, but all cycles had endometrial thickness of < or =0.5 cm on the day of hCG administration. With letrozole treatment in the same patients with PCOS, ovulation occurred in 9 of 12 cycles (75%) and pregnancy was achieved in 3 patients (25%). In the 10 patients with ovulatory infertility, letrozole treatment resulted in a mean number of 2.3 mature follicles and mean endometrial thickness of 0.8 cm. Pregnancy was achieved in 1 patient (10%). CONCLUSION(S): Oral administration of the aromatase inhibitor letrozole is effective for ovulation induction in anovulatory infertility and for increased follicle recruitment in ovulatory infertility. Letrozole appears to avoid the unfavorable effects on the endometrium frequently seen with antiestrogen use for ovulation induction.

Insulin-like 3/relaxin-like factor gene mutations are associated with cryptorchidism.

Cryptorchidism is a common anomaly of male sexual differentiation. Two phases of testicular descent are recognized, transabdominal and inguinoscrotal. With evidence that androgens and Müllerian inhibitory hormone were not completely responsible for testicular descent, the existence of a third testicular hormone mediating testicular descent was postulated. Insulin-like 3 (INSL3) [also known as relaxin-like factor (RLF) and Leydig insulin-like protein (LEY I-L)] is a member of the insulin/relaxin hormone superfamily that is highly expressed in Leydig cells. The phenotype of transgenic mice with targeted deletion of the Insl3 gene was bilateral cryptorchidism with morphological evidence of abnormal gubernacular development. With this implicit evidence that Insl3 mediates testicular descent in mice, we performed mutation detection analysis of the coding regions of the 2 exon INSL3 gene in genomic DNA samples obtained from 145 formerly cryptorchid patients and 36 adult male controls. Single-strand conformational polymorphism analysis was used for the mutation detection studies. Two mutations, R49X and P69L, and several polymorphisms were identified. Both mutations were located in the connecting peptide region of the protein. The frequency of INSL3/RLF gene mutations as a cause of cryptorchidism is low, because only 2 of 145 (1.4%) formerly cryptorchid patients were found to have mutations.

No association between body mass index and beta(3)-adrenergic receptor variant (W64R) in children with premature pubarche and adolescent girls with hyperandrogenism.

OBJECTIVE: To determine if the Trp(64)Arg (W64R) variant of the beta(3)-adrenergic receptor (ADRB3) could be used as a genetic marker to define risk for polycystic ovary syndrom (PCOS) and/or obesity in children and adolescents. DESIGN: Association study. SETTING: Academic research environment. PATIENT(S): Children referred for evaluation of premature pubic hair (n = 63), adolescent girls referred for evaluation of hirsutism and/or oligomenorrhea (n = 33), and healthy adult controls (n = 67). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Relationship of body mass index (BMI) to presence or absence of W64R variant and frequency of W64R variant in our patient population. RESULT(S): Body mass index (kg/m(2)) was determined for 63 children (55 girls and 8 boys) and 33 adolescent girls. Presence or absence of the W64R variant was assayed by polymerase chain reaction (PCR) amplification followed by allele-specific restriction fragment digest. Twelve subjects and 11 healthy controls were found to be heterozygous for the W64R variant. One subject was found to be homozygous for the W64R variant. Allele frequency for the W64R variant was comparable between patients and controls. Among the patients, mean BMI values were not different between carriers and noncarriers. CONCLUSION(S): Although other studies suggest that the W64R variant is associated with the development of obesity and insulin resistance, we cannot demonstrate that it has a major effect on BMI in children with premature pubarche or in adolescent girls with hyperandrogenism. Serial observations are necessary to determine if this variant predicts the development of obesity and/or PCOS in adulthood.

High ovulatory rates with use of troglitazone in clomiphene-resistant women with polycystic ovary syndrome.

This preliminary report reviews our experience with 18 infertile patients with clomiphene-resistant polycystic ovary syndrome (PCOS). In the first treatment cycle, troglitazone was administered alone. During cycles 2-5, clomiphene was added with increments of 50 mg (up to 200 mg/day) if the previous cycle was anovulatory. Basal body temperature charts and serum progesterone were obtained to confirm ovulation. In a total of 66 treatment cycles, ovulation occurred in 44 (67%) and pregnancy in seven (11%). There were no significant changes in body weight, waist:hip ratio or liver enzymes during treatment. Troglitazone, alone or with clomiphene, induced ovulation in 15 of 18 patients (83%) and seven (39%) of them achieved pregnancy. This is the first report on ovulatory rates in clomiphene-resistant women with PCOS when troglitazone was used alone or with clomiphene. Recently, metformin and clomiphene were successfully used in women with PCOS. However, our patients represent a more resistant population of women with PCOS, with each patient serving as her own historical control by previous resistance to clomiphene. Although the pregnancy rate (39%) was promising for clomiphene-resistant women with polycystic ovary syndrome, it does not seem to have a definite advantage over gonadotrophins.