The association between follicular size on human chorionic gonadotropin day and pregnancy rate in clomiphene citrate treated polycystic ovary syndrome patients

Effect of follicle size on pregnancy outcomes in patients undergoing first letrozole-intrauterine insemination

BACKGROUND

Letrozole has been proven to be an effective method for inducing ovulation. However, little attention has been paid to whether the lead follicle size will affect the success rate of intrauterine insemination (IUI) with ovulation induction with alone letrozole. Therefore, we hope to investigate the effect of dominant follicle size on pregnancy outcomes on human chorionic gonadotropin (hCG) day of the first letrozole-IUI.

METHODS

A retrospective cohort study design was employed. We included patients with anovulation or unexplained infertility undergoing first IUI treatment with letrozole for ovarian stimulation. According to the dominant follicle size measured on the day of hCG trigger, patients were divided into six groups (≤ 18 mm, 18.1-19.0 mm, 19.1-20.0 mm, 20.1-21.0 mm, 21.1-22.0 mm, > 22 mm). Logistic models were used for estimating the odds ratios (ORs) with their 95% confidence interval (CIs) for achieving a clinical pregnancy or a live birth. A restricted cubic spline was drawn to explore the nonlinear relationship between follicle size and IUI outcomes.

RESULTS

A total of 763 patients underwent first letrozole-IUI cycles in our study. Fisher exact test showed significant differences among the six follicle-size groups in the rates of pregnancy, clinical pregnancy and live birth (P < 0.05 in each group). After adjusting the potential confounding factors, compared with the follicles ≤ 18 mm in diameter group, 19.1-20.0 mm, 20.1-21.0 mm groups were 2.3 or 2.56 times more likely to get live birth [adjusted OR = 2.34, 95%CI (1.25-4.39); adjusted OR = 2.56, 95% CI (1.30-5.06)]. A restricted cubic spline showed an inverted U-shaped relationship between the size of dominant follicles and pregnancy rate, clinical pregnancy rate, and live birth rate, and the optimal follicle size range on the day of hCG trigger was 19.1-21.0 mm. When the E2 level on the day of hCG trigger was low than 200 pg/mL, the clinical pregnancy rates of 19.1-20.0 mm, 20.1-21.0 mm groups were still the highest.

CONCLUSIONS

The optimal dominant follicle size was between 19.1 and 21.0 mm in hCG-triggered letrozole-IUI cycles. Either too large or too small follicles may lead to a decrease in pregnancy rate. Using follicle size as a predicator of pregnancy outcomes is more meaningful when estrogen on the day of hCG trigger is less than 200 pg/ml.

Estimation of follicular growth-widely used, seldom studied

We assessed whether estimation of follicular growth, rather than actual measurement of follicular size on the day of hCG trigger, affected pregnancy rates in intrauterine insemination (IUI) cycles. Patient and cycle characteristics were extracted from an existing database. Comparisons were made between the pregnant (defined as a positive beta hCG) and non-pregnant groups for the following variables: patient's age, number of previous IUI cycles, type of ovarian stimulation, endometrial thickness, number of follicles measuring 14 mm and above, pre and post wash sperm parameters, cycle day when IUI was done and number of days between last ultrasound scan and ovulation trigger. A total of 7302 cycles were included in the final analysis. In 4055 cycles (55.5%) the hCG trigger was on the day of the last ultrasound, in 2285 cycles (31.3%) the hCG trigger was 1 day after the last ultrasound, in 850 (11.6%) it was 2 days after the last ultrasound and in 112 (1.5%) it was 3 or more days after the last ultrasound. Sperm parameters, younger maternal age, and the number of follicles above 14 mm were all associated with pregnancy. No association was found between positive pregnancy test rates and the time from last ultrasound to hCG trigger. Planning IUI based on the estimation of follicular growth 1-4 days before trigger, does not affect pregnancy rates.

Optimal lead follicle size in letrozole human menopausal gonadotrophin intrauterine insemination cycles with and without spontaneous LH surge

RESEARCH QUESTION

What is the optimal lead follicle size in letrozole, human menopausal gonadotrophin and intrauterine insemination (IUI) cycles with and without spontaneous LH surges?

DESIGN

This retrospective cohort study included 3797 letrozole HMG IUI cycles between January 2010 and May 2021. All cycles were divided into two groups: the HCG trigger group (trigger day LH ≤15 mIU/ml) and the spontaneous LH surge group (trigger day LH >15 mIU/ml). These two groups were subdivided into smaller groups based on the diameter of the follicles. The primary outcome measure was clinical pregnancy rate. Logistic regression analysis was conducted to explore other risk factors.

RESULTS

In the HCG trigger group, the clinical pregnancy rate varied significantly, with rates of 20.8%, 14.9% and 11.8% for the 16.1-18.0, 18.1-20.0 and 20.1-22.0 mm groups, respectively (P = 0.005). In the spontaneous LH surge group, the pregnancy rate of follicles within 14.1-16.0 mm was significantly higher than that of follicles within 20.1-22.0 mm (adjusted OR 0.533, 95% CI 0.308 to 0.923, P = 0.025). Also, patients with two lead follicles were 2.569 times more likely to achieve a clinical pregnancy than those with only one lead follicle (adjusted OR 2.569, 95% CI 1.258 to 5.246, P = 0.010). The duration of infertility was also found to be a common influencing factor in both groups.

CONCLUSIONS

The optimal lead follicle size was between 16.1 and 18.0 mm in HCG-triggered letrozole HMG IUI cycles. If the lead follicle size is relatively small (14.1-18.0 mm) when a spontaneous LH surge occurs, there is no need to cancel the IUI cycle.

Impact of follicular size categories on oocyte quality at trigger day in young and advanced-age patients undergoing GnRH-ant therapy

Aim

To study the effect of follicle sizes of different proportions on oocyte and embryo quality in young and advanced-age patients, and provide evidence for personalized protocol adjustment.

Methods

This was a retrospective real-world data study including a total of 11,462 patients who had started their first in vitro fertilization cycle with a gonadotropin-releasing hormone antagonist (GnRH-ant) protocol during 2018-2021. We classified patients into groups according to the size of the dominant proportion of follicles on the human chorionic gonadotropin (hCG) trigger day: Large, Medium, Small, and Equal (containing equivalent proportions of all three size categories). The Cochran-Mantel-Haenszel test by different Anti-Mullerian Hormone (AMH) and antral follicle count (AFC) was used to compare factors such as the metaphase II (MII) oocyte rate, normal fertilization rate, and two pronuclei (2PN) cleavage rate between groups. General linear model (GLM) analysis was performed for inter-group comparison of the oocyte and embryo quality.

Results

In patients aged < 35 years and with AMH ≥ 1.2μg/L, the MII oocyte percentages in the Large and Medium groups were significantly higher than in the Small group (P < 0.001). The germinal vesicle (GV) oocyte and unavailable oocyte percentages in the Large and Medium groups were lower than in the Small group (P < 0.001). Among patients aged ≥ 35 years with AFC < 5 and AMH ≥ 1.2μg/L, the GV oocyte percentage in the Large group was significantly lower than in the Medium group (2.54% vs. 4.46%, P < 0.001). In patients < 35 years, the GLM demonstrated that the Large and Medium groups had positively impacted on the development of MII oocyte and live birth rate(LBR) of first embryo transfer(ET)(β>0, all P value < 0.05);and had less likely to develop into unavailable oocyte, degenerated oocyte, GV oocyte and MI oocyte rates relative to the Small group(β<0, all P value < 0.05). And among patients ≥ 35 years, the Medium group had positively impacted on the development of MII oocyte and 2PN rates relative to the Small group(β>0, all P value < 0.05); and had less likely to develop into MI oocytes relative to the Small group(β<0, all P value < 0.05). The GLM indicated that AMH, along with Gn total dose, start dose, and Gn days, had significant impact on oocyte and embryo quality. For young patients, age was not a significant influencing factor, but for advanced-age patients, age influenced the outcomes.

Conclusion

Our analysis suggests that for young patients (< 35 years), triggering when there is a high proportion of large or medium follicles results in better quality oocytes, while for older patients (≥ 35 years), it is better to trigger when the proportion of medium follicles is no less than that of small follicles. Further research is required to confirm these findings.

Determining the optimal follicle size at trigger in patients undergoing ovarian stimulation with a clomiphene citrate plus gonadotropin and GnRH antagonist protocol for in vitro fertilization

OBJECTIVE

Determine the optimal follicle size at trigger in clomiphene citrate-based IVF protocols.

STUDY DESIGN

This is a retrospective cohort study performed in at a single academic institution that included first IVF cycles with clomiphene citrate-based protocols at our center between 01/01/2013-03/31/2019. Patients were dichotomized by whether they had ≥2 follicles >20 mm on trigger day. Group A consisted of patients with <2 follicles >20 mm on trigger day and Group B consisted of patients with ≥2 follicles >20 mm on trigger day. The primary outcome was the number of mature oocytes retrieved. Secondary outcomes included pregnancy and live birth rates.

RESULTS

A total of 635 patients were included: (Group A = 399 patients and Group B = 236 patients). The median (IQR) diameter of the largest follicle was 20.0 mm (19.0-21.0) in Group A and 22.7 mm (21.8-24.0) in Group B (p < 0.001). Among the entire cohort, mean number of oocytes retrieved was significantly higher in Group B (9.9 ± 6.5; RR 1.08 (95% CI 1.03-1.14)) compared to Group A (9.2 ± 6.3). In a subgroup analysis of patients in the upper quartile for age (≥41.7 years), Group B had significantly more oocytes retrieved (8.1 ± 5.9 vs. 6.7 ± 4.5; RR 1.23 (95% CI 1.10-1.38)), more mature oocytes retrieved (6.0 ± 4.0 vs. 5.2 ± 3.4; RR 1.16 (95% CI 1.02-1.33)), and more zygotes (4.7 ± 3.5 vs. 3.6 ± 2.8; RR 1.32 (95% CI 1.13-1.55)). In the secondary analysis, pregnancy and live birth rates after fresh transfer were similar between groups.

CONCLUSIONS

In clomiphene citrate-based IVF protocols, administering the ovulatory trigger at larger follicle sizes yielded more total oocytes retrieved without a significant difference in mature oocyte number. In older patients, larger follicle sizes at trigger yielded more mature oocytes and zygotes per retrieval. Based on these results, in older patients it may be advantageous to administer the ovulatory trigger in clomiphene-based IVF cycles when two or more follicles measures >20 mm. However, this benefit was not observed when assessed among all ages combined.

Optimal lead follicle size for human chorionic gonadotropin trigger in clomiphene citrate and intrauterine insemination cycles: an analysis of 1,676 treatment cycles

OBJECTIVE

To identify the optimal lead follicle size for hCG trigger in clomiphene citrate (CC)-intrauterine insemination (IUI) cycles.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated center.

PATIENT(S)

Patients <40 years of age with ovulatory dysfunction or unexplained infertility undergoing their first CC-IUI cycle.

INTERVENTION(S)

Ovulation induction, hCG trigger, and IUI.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (CPR) was the primary outcome and was plotted against lead follicle size in increments of 1 mm. Odds ratios with 95% confidence intervals for associations between lead follicle size and CPR were calculated from a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated for CPR as a function of lead follicle size.

RESULT(S)

1,676 cycles were included. The overall CPR was 13.8% (232/1,676). There was no difference in baseline demographics or ovulation induction parameters of patients who did or did not conceive. The odds of clinical pregnancy were 2.3 and 2.2 times higher with lead follicle sizes of 21.1-22.0 mm and >22.0 mm, respectively, compared with the referent category of 19.1-20.0 mm. Lead follicle size was an independent predictor of CPR, even after accounting for confounders. A lead follicle size of 22.1 mm corresponded to a sensitivity and specificity of 80.1% and 90.4% for clinical pregnancy, respectively, with an area under the ROC curve of 0.89.

CONCLUSION(S)

hCG administration at a lead follicle size of 21.1-22.0 mm is associated with higher odds of clinical pregnancy in patients undergoing their first CC-IUI cycles for ovulatory dysfunction or unexplained infertility.

Is there a correlation between follicle size and gene expression in cumulus cells and is gene expression an indicator of embryo development?

BACKGROUND

In an article published in 2017, we discussed the results of the first part of our study into the morphokinetic development of embryos in relation to follicle diameter and homogeneity of follicular development. Our findings showed that embryos coming from small follicles in heterogeneous cycles had significantly higher rates of arrest or failure to reach blastocyst than embryos coming from large follicles in homogenous cycles. The aim of this further study was to investigate the relationship between follicular size and gene expression of cumulus cells (CCs) and evaluate whether gene expression could be an indicator of embryo development.

METHODS

This study was based on 2495 COCs from 184 patients. CC expressions of five genes (TNFAIP6, PTGS2, HAS2, PTX3 and GDF9) were studied by generalized linear mixed models (GLMMs) regarding follicular size. CC expressions were then separately analysed regarding patient-specific variables (age, BMI, AMH and follicular size) in relation to embryos reaching blastocyst (eRB) or top or good quality blastocysts (TQ + GQ) using GLMMs with logit link.

RESULTS

Follicular size significantly correlated with the potential of an oocyte to develop into a blastocyst: oocytes developing from large follicles were more than twice as likely to develop into an eRB than oocytes from small follicles (p < 0.001). Gene expression of HAS2 and GDF9 correlated with blastocyst quality when separately evaluated with follicular size and the patient specific variables of age, BMI and AMH. However, no such correlation was found in other gene expressions studied.

CONCLUSIONS

Our findings suggest that differences in the expression of genes studied could be related to follicular size rather than to embryo quality. Although gene expression of HAS2 and GDF9 correlated with blastocyst quality, the only variable correlating with eRB and TQ and GQ blastocysts for each of these five models was follicular size.

TRIAL REGISTRATION

This prospective cohort study was registered at clinicaltrials.gov (NCT02230449).

Efficacy of GnRH agonist trigger in women having history of follicular-endometrial asynchrony with clomiphene/IUI cycles in unexplained infertility

PURPOSE

An alternative option to human chorionic gonadotropin (hCG) is GnRH agonist (GnRH-a) for ovulation trigger in intrauterine insemination (IUI) cycles. This study aims to compare the efficacy of GnRH-a with hCG in women with history of follicular-endometrial asynchrony after clomiphene in IUI cycles.

METHODS

This prospective observational study recruited 631 women with unexplained infertility and follicular-endometrial asynchrony (follicle ≥ 18 mm, endometrial thickness (ET) < 7 mm) in previous two failed clomiphene/IUI cycles. Overall 27 patients with synchronized follicular-endometrial relationship and 49 women with persistent ET < 7 mm and/or follicle > 26 mm were excluded. Remaining women (n = 555) were divided into two groups: Group A (n = 285) received GnRH-a and Group B (n = 270) received hCG ovulation trigger. Finally, 513 patients, who underwent IUI, were analysed.

RESULTS

Cancellation due to luteinized unruptured follicle was more in hCG group (P = 0.01). Higher clinical pregnancies (10.33 vs. 4.96%, P = 0.03) and live birth rates (8.86 vs. 4.13%, P = 0.03) were noted with GnRH-a trigger. Miscarriage rate was comparable in both the groups (10.71 and 16.67% in Group A and Group B, respectively).

CONCLUSION

In unexplained infertility, GnRH agonist is an useful alternative for triggering ovulation in women with follicular-endometrial asynchrony following clomiphene induction.

Effect of follicular diameter at the time of ovulation triggering on pregnancy outcomes during intrauterine insemination

OBJECTIVE

To compare pregnancy outcomes when triggering ovulation at different follicle sizes during intrauterine insemination (IUI) cycles.

METHODS

A prospective observational study was undertaken at two collaborative fertility centers in Saudi Arabia between January 2014 and May 2016. Women of any age were enrolled if they met inclusion criteria: primary, secondary, or unexplained infertility (≥1 year); day-2 follicle-stimulating hormone less than 12 IU/mL; normal prolactin, thyroid function, and uterine cavity; at least one patent tube; and a male partner with normal semen count and motility. IUI cycles were subdivided by size of dominant follicle (17 to <18 mm, 18 to <19 mm, 19 to <20 mm, and ≥20 mm), and pregnancy outcomes compared.

RESULTS

Data from 516 IUI cycles were analyzed. Frequencies of clinical pregnancy, ongoing pregnancy, and live birth for a follicle size of 19-20 mm were 30.2% (39/129), 24.0% (31/129), and 24.0% (31/129), respectively; these rates were significantly higher than those in other groups (all P<0.05). Only endometrial thickness was found to also contribute to outcome: probability of pregnancy increased as thickness rose (odds ratio 1.148, 95% confidence interval 1.065-1.237; P<0.001).

CONCLUSION

The optimal follicular diameter associated with increased pregnancy rates in gonadotropin-stimulated IUI cycles was between 19 and 20 mm.

The effect of follicle size and homogeneity of follicular development on the morphokinetics of human embryos

Purpose

Our aim was to investigate follicular size (large, ≥17 mm and small, <17 mm) at the time of OPU and homogeneity of follicular development (homogenous development: follicles being present in a homogenous spread of all sizes; heterogeneous: a predominance of small and large follicles) by analysing the morphokinetics of embryo development.

Methods

In this prospective cohort study, 2526 COCs belonging to 187 patients were cultured to day 5. Embryos were evaluated morphokinetically. Four subgroups were defined: large follicles from heterogeneous cycles (LHet) and homogenous cycles (LHom) and small follicles from heterogeneous cycles (SHet) and homogenous cycles (SHom).

Results

Rates of fertilization, blastocyst formation and top and good quality blastocysts were found to be significantly higher in embryos from the LHom group (p < 0.001; p < 0.001; p < 0.001). Small follicles from both homogenous and heterogeneous cycles had significantly lower blastocyst formation and top and good quality blastocyst rates (p < 0.001; p < 0.001). Embryos from SHet had significantly more direct cleavages (p = 0.011). Time to reach blastocyst was shorter in SHom than LHet and LHom (p = 0.002; p = 0.027, respectively). However, once the blastocyst stage was achieved, implantation rates were not significantly different between subgroups, the highest rate being observed in the LHom group. Multivariable analysis revealed that homogeneity of follicular development and follicular size had a significant effect on blastocyst development and quality (p = 0.049; p < 0.001, respectively).

Conclusion

Follicular dynamics, illustrated by follicular size and homogeneity of follicular development, influence early human embryo development. Patterns of follicular growth have an impact on embryo quality and viability which is reflected in morphokinetic variables.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-017-0935-1) contains supplementary material, which is available to authorized users.

A retrospective analysis of ovarian stimulation with letrozole in women undergoing artificial insemination by donor

The aim of this retrospective study was to determine the clinical pregnancy rate in women undergoing letrozole ovarian stimulation and artificial insemination by donor (AID). Between 2012 and 2015, 130 natural cycles, 939 letrozole cycles and 130 letrozole plus gonadotrophin cycles were conducted. Letrozole cycles were divided into three groups according to LH concentration on the day of HCG administration (LH <10 mIU/ml and follicle size ≥18 cm; LH ≤10 to <20 mIU/ml; and LH ≥20 mIU/ml). Pregnancy rates were 17.3%, 22.4% and 26.8%, respectively (P = 0.012). In women given 10 mIU/ml LH or more, logistic regression identified oestradiol (OR 1.002, 95% CI, 1.000 to 1.004, P = 0.029) and leading follicle size (OR 0.861, 95% CI, 0.772 to 0.960, P = 0.007) as significant predictive factors of pregnancy rate; the higher the oestradiol and the smaller the follicles, the better the pregnancy rate. The pregnancy rate was significantly higher in the letrozole plus gonadotrophin group than the letrozole group (P = 0.04). Better pregnancy rates can be achieved if LH surge occurs before HCG administration, especially with higher oestradiol and lower follicle size; treatment with letrozole plus gonadotrophin was significantly more effective than letrozole alone in AID.

Transcriptional characteristics of different sized follicles in relation to embryo transferability: potential role of hepatocyte growth factor signalling

STUDY HYPOTHESIS

We hypothesized that a better discrimination between follicles containing oocytes with high developmental competence and those containing oocytes with low competence, based on a combination of a follicle's size and transcriptomic signature, will provide a reliable method to predict embryonic outcome of IVF.

STUDY FINDING

This study provides new insights on the impact of follicular size on oocyte quality as measured by embryonic development and demonstrates that medium follicles yield a better percentage of transferable embryos.

WHAT IS KNOWN ALREADY

Although it is generally accepted that large ovarian follicles contain better eggs, other studies report that a better follicular size subdivision and a better characterization are needed.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Individual follicles (n = 136), from a total of 33 women undergoing IVF, were aspirated and categorized on the basis of their follicular liquid volume (small, medium or large) and the embryonic outcome of the enclosed oocyte: poor or good development. Comprehensive gene expression analysis between cells from the different sized follicles was performed using microarrays and quantitative RT-PCR to find molecular markers associated with follicular maturity and oocyte developmental competence.

MAIN RESULTS AND THE ROLE OF CHANCE

The analysis of embryonic outcome in relation to follicular size indicates that the medium-sized follicles category yielded more transferable embryos (35%) compared with the largest follicles (30%) (NS). Gene expression analysis revealed expression markers with significant (P < 0.05) discrimination between the poor development groups for all three follicle sizes, and good development medium-size follicles, including up-regulation of thrombomodulin, transforming growth factor, beta receptor II and chondrolecti, and those associated with hyaluronan synthesis, coagulation and hepatocyte growth factor signalling.

LIMITATIONS, REASONS FOR CAUTION

These analyses were performed in a single cohort of patients coming from a single clinic and the biomarkers generated will require validation in different geographical and biological contexts to ensure their global applicability.

WIDER IMPLICATIONS OF THE FINDINGS

Medium-size follicles seem to be the optimal size for a positive embryonic outcome and are associated with competence markers that may help in understanding the ideal differentiation status during late folliculogenesis.

LARGE SCALE DATA

The data discussed in this publication have been deposited in The National Center for Biotechnology Information Gene Expression Omnibus database and are accessible through GEO Series accession number GSE52851.

STUDY FUNDING AND COMPETING INTERESTS

This study was supported by Canadian Institutes of Health Research (CIHR) and Natural Sciences and Engineering Research Council of Canada (NSERC) to M.A.S. There are no competing interests to declare.

Comparison of pregnancy rates in PCOS patients undergoing clomiphene citrate and IUI treatment with different leading follicular sizes

PURPOSE

The objective of the study was to compare the pregnancy rates in PCOS patients undergoing clomiphene citrate (CC) and intrauterine insemination (IUI) treatment with different leading follicular sizes.

METHODS

A total of 358 infertile women with PCOS who underwent 563 clomiphene citrate and IUI treatment cycles were included in this prospective study. Treatment cycles were divided into three groups according to leading follicular size on the day of hCG administration: Group I: follicular size 17-18 mm (n = 177), Group II: 19-22 mm (n = 321), and Group III : >22 mm (n = 65). Pregnancy rates were evaluated. Treatment outcomes of the groups were further analyzed related to endometrial thickness measurement on the day of hCG. For this purpose, cycles were placed into three subgroups as follows: endometrial thickness <7, 8-9, and >9 mm.

RESULTS

There was no statistically significant difference in clinical pregnancy rate per cycle between the groups (8.5, 10, and 9.2 % for Group I, II, and III, respectively, p = 0.86). In further analyses related to endometrial thickness, no significant difference was also found in pregnancy rate among the groups.

CONCLUSION

This results suggest that pregnancy rate is not related to leading follicle size on the day of hCG administration in PCOS patients treated with CC and IUI. In addition, pregnancy rate in women with different follicular sizes is not influenced by the endometrial thickness.

The association between follicular size at the time of spontaneous rupture and pregnancy rates in clomiphene citrate treated PCOS patients in coit cycles

OBJECTIVE

To investigate the follicular size at spontaneous rupture on pregnancy rate in patients with polycystic ovary syndrome (PCOS) undergoing clomiphene citrate (CC) ovulation.

DESIGN

Cross-sectional study.

PATIENTS AND METHODS

One hundred and four women with ovulatory cycles after use of CC followed by ultrasound to determine the follicle size at the time of rupture, which was subsequently correlated with the occurrence of pregnancy or not in coit cycles.

RESULTS

In the group of follicular rupture at a mean diameter ≤25 mm (n = 54), pregnancy rate was 35.1% and when follicular rupture occurred at a mean diameter >25 mm (n = 50), it was 34% (p > 0.05). When different diameters at follicular rupture were randomly correlated with the pregnancy rate, there was no significant difference.

CONCLUSION

Our data suggest that the occurrence of pregnancy after ovulation induction with CC in women with PCOS is not associated with follicle size at the time of rupture.

Does optimal follicular size in IUI cycles vary between clomiphene citrate and gonadotrophins treatments?

OBJECTIVE

To evaluate pregnancy-related leading follicles during ovulation induction and superovulation with clomiphene citrate (CC) or gonadotropin.

DESIGN

Retrospective cohort.

PATIENTS

Five hundred and forty-two women who underwent a total of 615 treatment cycles with CC or gonadotropin.

INTERVENTION

We evaluated the effects of CC and gonadotropin on the leading follicles, clinical pregnancy rates and miscarriage rate.

RESULTS

The number of follicles larger than 15 mm in the different protocols was comparable. In those treated with CC, the diameter of the dominant follicles before human chorionic gonadotropins (hCG) trigger in the conception cycles (20.4 ± 1.2 mm) was significantly larger than in the non-conception cycles (18.8 ± 1.9 mm). In women treated with gonadotropin, the diameter of the leading follicle in the conception cycles (18.5 ± 1.7 mm) was comparable to that in the non-conception cycles (18.2 ± 1.7 mm). The pregnancy-related diameter of the leading follicle in CC cycles (20.4 ± 1.2 mm) was significantly larger than that in gonadotropin cycles (18.8 ± 1.9 mm; p = 0.001; 95% CI, -2.2 to -0.9).

CONCLUSION

Pregnancy-related diameter of the leading follicle in CC cycles is significantly larger than that in gonadotropin cycles and the best time for hCG trigger in the CC cycle is when the leading follicle reaches 20 mm.

Clomifene citrate or low-dose FSH for the first-line treatment of infertile women with anovulation associated with polycystic ovary syndrome: a prospective randomized multinational study

BACKGROUND

Clomifene citrate (CC) is accepted as the first-line method for ovulation induction (OI) in patients with polycystic ovary syndrome (PCOS) associated with infertility owing to anovulation. Low-dose FSH has been reserved for women failing to conceive with CC. In this RCT, we tested the hypothesis that pregnancy rate (PR) and live birth rates (LBR) are higher after OI with low-dose FSH than with CC as first-line treatment.

METHODS

Infertile women (<40 years old) with PCOS-related anovulation, without prior OI treatment, attending 10 centres in Europe/South America were randomized to OI with either CC (50-150 mg/day for 5 days) or FSH (starting dose 50 IU) for up to three treatment cycles. The primary outcome was clinical PR.

RESULTS

Patients (n = 302) were randomized to OI with FSH (n = 132 women; 288 cycles) or CC (n = 123; 310 cycles). Per protocol analysis revealed that reproductive outcome was superior after OI with FSH than with CC with respect to PR per first cycle [30 versus 14.6%, respectively, 95% confidence interval (CI) 5.3-25.8, P = 0.003], PR per woman, (58 versus 44% of women, 95% CI 1.5-25.8, P = 0.03), LBR per woman (52 versus 39%, 95% CI 0.4-24.6, P = 0.04), cumulative PR (52.1 versus 41.2%, P = 0.021) and cumulative LBR (47.4 versus 36.9%, P = 0.031), within three cycles of OI.

CONCLUSIONS

Pregnancies and live births are achieved more effectively and faster after OI with low-dose FSH than with CC. This result has to be balanced by convenience and cost in favour of CC. FSH may be an appropriate first-line treatment for some women with PCOS and anovulatory infertility, particularly older patients.