Intrauterine insemination: effect of the temporal relationship between the luteinizing hormone surge, human chorionic gonadotrophin administration and insemination on pregnancy rates

Artificial intelligence in the service of intrauterine insemination and timed intercourse in spontaneous cycles

OBJECTIVE

To develop a machine learning model designed to predict the time of ovulation and optimal fertilization window for performing intrauterine insemination or timed intercourse (TI) in natural cycles.

DESIGN

A retrospective cohort study.

SETTING

A large in vitro fertilization unit.

PATIENT(S)

Patients who underwent 2,467 natural cycle-frozen embryo transfer cycles between 2018 and 2022.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Prediction accuracy of the optimal day for performing insemination or TI.

RESULT(S)

The data set was split into a training set including 1,864 cycles and 2 test sets. In the test sets, ovulation was determined according to either expert opinion, with 2 independent fertility experts determining ovulation day ("expert") (496 cycles), or according to the disappearance of the leading follicle between 2 consecutive days' ultrasound examinations ("certain ovulation") (107 cycles). Two algorithms were trained: an NGBoost machine learning model estimating the probability of ovulation occurring on each cycle day and a treatment management algorithm using the learning model to determine an optimal insemination day or whether another blood test should be performed. The estradiol progesterone and luteinizing hormone levels on the last test performed were the most influential features used by the model. The mean numbers of tests were 2.78 and 2.85 for the "certain ovulation" and "expert" test sets, respectively. In the "expert" set, the algorithm correctly predicted ovulation and suggested day 1 or 2 for performing insemination in 92.9% of the cases. In 2.9%, the algorithm predicted a "miss," meaning that the last test day was already ovulation day or beyond, suggesting avoiding performing insemination. In 4.2%, the algorithm predicted an "error," suggesting performing insemination when in fact it would have been performed on a nonoptimal day (0 or -3). The "certain ovulation" set had similar results.

CONCLUSION(S)

To our knowledge, this is the first study to implement a machine learning model, on the basis of the blood tests only, for scheduling insemination or TI with high accuracy, attributed to the capability of the algorithm to integrate multiple factors and not rely solely on the luteinizing hormone surge. Introducing the capabilities of the model may improve the accuracy and efficiency of ovulation prediction and increase the chance of conception.

CLINICAL TRIAL REGISTRATION NUMBER

HMC-0008-21.

Intrauterine Insemination After Human Chorionic Gonadotropin Trigger or Luteinizing Hormone Surge: A Meta-analysis

OBJECTIVE

To assess the odds of pregnancy after intrauterine insemination (IUI) timed by ultrasound monitoring and human chorionic gonadotropin (hCG) administration compared with monitoring luteinizing hormone (LH) levels.

DATA SOURCES

We searched PubMed (MEDLINE), EMBASE (Elsevier), Scopus (Elsevier), Web of Science (Clarivate Analytics), ClinicalTrials.gov (National Institutes of Health), and the Cochrane Library (Wiley) from the inception until October 1, 2022. No language limitations were applied.

METHODS OF STUDY SELECTION

After deduplication, 3,607 unique citations were subjected to blinded independent review by three investigators. Thirteen studies (five retrospective cohort, four cross-sectional, two randomized controlled trials, and two randomized crossover studies) that enrolled women undergoing natural cycle, oral medication (clomid or letrozole), or both for IUI were included in the final random-effects model meta-analysis. Methodologic quality of included studies was assessed with the Downs and Black checklist.

TABULATION, INTEGRATION, AND RESULTS

Data extraction was compiled by two authors, including publication information, hCG and LH monitoring guidelines, and pregnancy outcomes. No significant difference in odds of pregnancy between hCG administration and endogenous LH monitoring was observed (odds ratio [OR] 0.92, 95% CI 0.69-1.22, P=.53). Subgroup analysis of the five studies that included natural cycle IUI outcomes also showed no significant difference in odds of pregnancy between the two methods (OR 0.88, 95% CI 0.46-1.69, P=.61). Finally, a subgroup analysis of 10 studies that included women who underwent ovarian stimulation with oral medications (clomid or letrozole) did not demonstrate a difference in odds of pregnancy between ultrasonography with hCG trigger and LH-timed IUI (OR 0.88, 95% CI 0.66-1.16, P=.32). Statistically significant heterogeneity was noted between studies.

CONCLUSION

This meta-analysis showed no difference between pregnancy outcomes between at-home LH monitoring and timed IUI.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021230520.

Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review

Despite the worldwide increase in frozen embryo transfer, the search for the best protocol to prime endometrium continues. Well-designed trials comparing various frozen embryo transfer protocols in terms of live birth rates, maternal, obstetric and neonatal outcome are urgently required. Currently, low-quality evidence indicates that, natural cycle, either true natural cycle or modified natural cycle, is superior to hormone replacement treatment protocol. Regarding warmed blastocyst transfer and frozen embryo transfer timing, the evidence suggests the 6th day of progesterone start, LH surge+6 day and hCG+7 day in hormone replacement treatment, true natural cycle and modified natural cycle protocols, respectively. Time corrections, due to inter-personal differences in the window of implantation or day of vitrification (day 5 or 6), should be explored further. Recently available evidence clearly indicates that, in hormone replacement treatment and natural cycles, there might be marked inter-personal variation in serum progesterone levels with an impact on reproductive outcomes, despite the use of the same dose and route of progesterone administration. The place of progesterone rescue protocols in patients with low serum progesterone levels one day prior to warmed blastocyst transfer in hormone replacement treatment and natural cycles is likely to be intensively explored in near future.

Frozen embryo transfer: a review on the optimal endometrial preparation and timing

STUDY QUESTION

What is the optimal endometrial preparation protocol for a frozen embryo transfer (FET)?

SUMMARY ANSWER

Although the optimal endometrial preparation protocol for FET needs further research and is yet to be determined, we propose a standardized timing strategy based on the current available evidence which could assist in the harmonization and comparability of clinic practice and future trials.

WHAT IS KNOWN ALREADY

Amid a continuous increase in the number of FET cycles, determining the optimal endometrial preparation protocol has become paramount to maximize ART success. In current daily practice, different FET preparation methods and timing strategies are used.

STUDY DESIGN, SIZE, DURATION

This is a review of the current literature on FET preparation methods, with special attention to the timing of the embryo transfer.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Literature on the topic was retrieved in PubMed and references from relevant articles were investigated until June 2017.

MAIN RESULTS AND THE ROLE OF CHANCE

The number of high quality randomized controlled trials (RCTs) is scarce and, hence, the evidence for the best protocol for FET is poor. Future research should compare both the pregnancy and neonatal outcomes between HRT and true natural cycle (NC) FET. In terms of embryo transfer timing, we propose to start progesterone intake on the theoretical day of oocyte retrieval in HRT and to perform blastocyst transfer at hCG + 7 or LH + 6 in modified or true NC, respectively.

LIMITATIONS REASONS FOR CAUTION

As only a few high quality RCTs on the optimal preparation for FET are available in the existing literature, no definitive conclusion for benefit of one protocol over the other can be drawn so far.

WIDER IMPLICATIONS OF THE FINDINGS

Caution when using HRT for FET is warranted since the rate of early pregnancy loss is alarmingly high in some reports.

STUDY FUNDING/COMPETING INTEREST(S)

S.M. is funded by the Research Fund of Flanders (FWO). H.T. and C.B. report grants from Merck, Goodlife, Besins and Abbott during the conduct of the study.

TRIAL REGISTRATION NUMBER

Not applicable.

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.

Should an intrauterine insemination with donor semen be performed 1 or 2 days after the spontaneous LH rise? A prospective RCT

STUDY QUESTION

What is the impact on pregnancy rates when intrauterine insemination (IUI) is performed 1 or 2 days after the spontaneous LH rise?

SUMMARY ANSWER

IUI 1 day after the spontaneous LH rise results in significantly higher clinical pregnancy rates compared with IUI performed 2 days after the LH rise.

WHAT IS KNOWN ALREADY

IUI is scheduled within a limited time interval during which successful conception can be expected. Data about the optimal timing of IUI are based on inseminations following ovarian stimulation. There is no available evidence regarding the correct timing of IUI in a natural menstrual cycle following the occurrence of a spontaneous LH rise.

STUDY DESIGN, SIZE, DURATION

A prospective RCT, including patients undergoing IUI with donor sperm in a natural menstrual cycle. IUI cycles (n = 435) were randomized between October 2010 and April 2013, of which 23 were excluded owing to protocol deviation and 412 received the allocated intervention.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serial serum LH concentrations were analysed in samples taken between 07:00 and 09:00 h to detect an LH rise from Day 11 of the cycle onwards. The subjects were randomized to receive insemination either 1 or 2 days after the observed LH rise. In the final analysis, there were 213 cycles in the group receiving IUI 1 day after the LH rise and 199 cycles in the group receiving IUI 2 days after the LH rise.

MAIN RESULTS AND THE ROLE OF CHANCE

Significantly higher clinical pregnancy rates per IUI cycle were observed in patients undergoing IUI 1 day after the LH rise when compared with patients undergoing IUI 2 days after the LH rise [19.7 (42/213) versus 11.1% (22/199), P = 0.02]. In view of the timing of sampling for LH, the inseminations were performed at 27 h (±2 h) and 51 h (±2 h) after detection of the LH rise. The risk ratio of achieving a clinical pregnancy if IUI was scheduled 1 day after the LH rise compared with 2 days was 1.78 [95% confidence interval (CI), 1.11-2.88]. This points towards a gain of one additional clinical pregnancy for every 12 cycles performed 1 day instead of 2 days after the LH rise. When analysing the results per patient, including only women who underwent their first treatment cycle of insemination, the outcome was in line with the per cycle analysis, demonstrating an 8% difference in pregnancy rate in favour of the early group (20.5 versus 12.2%), however, this difference was not significant.

LIMITATIONS, REASONS FOR CAUTION

Optimal monitoring for the occurrence of the LH rise involves several daily LH measurements, which is not always amenable to everyday clinical practice, however, daily sampling was sufficient to detect a significant difference in pregnancy rate. The strict inclusion of a highly selected population of patients who underwent IUI in a natural cycle may have been a limitation. IUI in a natural menstrual cycle confers lower success rates compared with IUI following ovarian stimulation and is not suitable for patients with ovulatory dysfunction. Furthermore, a similar study in a larger number of women is required to confirm the result in terms of pregnancy rate per patient.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT to show that timing of IUI in a natural menstrual cycle is important and that IUI should be performed 1 day after the LH rise, rather than 2 days post-LH rise. Daily monitoring of the rise in LH, as performed in our study, can be adopted to achieve a higher pregnancy rate per IUI cycle.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. All authors declare to have no conflict of interest with regard to this trial.

TRIAL REGISTRATION NUMBER

The trial was registered at clinicaltrials.gov (NCT01622023).

The potential use of intrauterine insemination as a basic option for infertility: a review for technology-limited medical settings

Objective. There is an asymmetric allocation of technology and other resources for infertility services. Intrauterine insemination (IUI) is a process of placing washed spermatozoa transcervically into the uterine cavity for treatment of infertility. This is a review of literature for the potential use of IUI as a basic infertility treatment in technology-limited settings. Study design. Review of articles on treatment of infertility using IUI. Results. Aspects regarding the use of IUI are reviewed, including ovarian stimulation, semen parameters associated with good outcomes, methods of sperm preparation, timing of IUI, and number of inseminations. Implications of the finding in light of the needs of low-technology medical settings are summarized. Conclusion. The reviewed evidence suggests that IUI is less expensive, less invasive, and comparably effective for selected patients as a first-line treatment for couples with unexplained or male factor infertility. Those couples may be offered three to six IUI cycles in technology-limited settings.

Synchronised approach for intrauterine insemination in subfertile couples

BACKGROUND

Intrauterine insemination (IUI) should logically be performed around the moment of ovulation. Since spermatozoa and oocytes have only limited survival times correct timing is essential. As it is not known which technique of timing for IUI results in the best treatment outcome, we compared different techniques for timing IUI and different time intervals.

OBJECTIVES

To evaluate the effectiveness of different synchronisation methods in natural and stimulated cycles for IUI in subfertile couples.

SEARCH STRATEGY

We searched for all publications which described randomised controlled trials of the timing of IUI. We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), (1966 to March 2009), EMBASE (1974 to March 2009) and Science Direct (1966 to March 2009) electronic databases. Furthermore, we checked the reference lists of all obtained studies and performed a handsearch of conference abstracts.

SELECTION CRITERIA

Only truly randomised controlled trials comparing different timing methods for IUI were included. The following interventions were evaluated: detection of luteinising hormone (LH) in urine or blood, single test; human chorionic gonadotropin (hCG) administration; combination of LH detection and hCG administration; basal body temperature chart; ultrasound detection of ovulation; gonadotropin-releasing hormone (GnRH) agonist administration; or other timing methods.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the trials to be included according to the above mentioned criteria. We performed statistical analyses in accordance with the guidelines for statistical analysis developed by The Cochrane Collaboration.

MAIN RESULTS

Ten studies were included comparing urinary LH surge versus hCG injection; recombinant hCG versus urinary hCG; and hCG versus a GnRH agonist. One study compared the optimum time interval from hCG injection to IUI. The results of these studies showed no significant differences between different timing methods for IUI expressed as live birth rates: hCG versus LH surge (odds ratio (OR) 1.0, 95% CI 0.06 to 18); urinary hCG versus recombinant hCG (OR 1.2, 95% CI 0.68 to 2.0); and hCG versus GnRH agonist (OR 1.1, 95% CI 0.42 to 3.1). All the secondary outcomes analysed showed no significant differences between treatment groups.

AUTHORS' CONCLUSIONS

There is no evidence to advise one particular treatment option over another. The choice should be based on hospital facilities, convenience for the patient, medical staff, costs and drop-out levels. Since different time intervals between hCG and IUI did not result in different pregnancy rates, a more flexible approach might be allowed.

Human chorionic gonadotropin administration vs. luteinizing monitoring for intrauterine insemination timing, after administration of clomiphene citrate: a meta-analysis

OBJECTIVE

To systematically compare hCG administration as a method for intrauterine insemination (IUI) timing with conservative urinary LH surge detection in infertility treatment.

DESIGN

Meta-analysis of prospective and retrospective trials.

SETTING

Tertiary fertility and IVF center.

PATIENT(S)

One thousand four hundred sixty-one patients who received hCG after a clomiphene citrate regimen, compared with 1,162 patients who had an LH surge detection for IUI timing.

INTERVENTION(S)

Both MEDLINE and Cochrane Collaboration were searched. References of retrieved articles were included in the search. The meta-analysis included all controlled trials examining the effectiveness of hCG administration before IUI on clinical-pregnancy rates in comparison with LH detection. Two independent reviewers performed data extraction.

MAIN OUTCOME MEASURE(S)

Pregnancy rates.

RESULT(S)

Seven studies with 2,623 patients were included in the meta-analysis (1,461 patients received hCG, and 1,162 had LH surge detection). When all studies were combined, patients who received hCG before IUI demonstrated lower clinical-pregnancy rates than did women who had IUI after spontaneous ovulation (odds ratio, 0.74; 95% confidence interval, 0.57-0.961). In subgroup analysis of studies that considered ovulatory dysfunction to be the infertility reason, the results favored women who received hCG. In contrast, across studies that reported male factor as the infertility reason, as well as across studies including women with unexplained infertility, results appeared to favor the LH surge detection approach. However, none of those subgroup analyses reached statistical significance.

CONCLUSION(S)

Available data do not demonstrate a consistent, clinically important benefit of hCG-induced ovulation compared with spontaneous ovulation for IUI timing.

Clomiphene citrate induced ovulation and intrauterine insemination: effect of timing of human chorionic gonadotropin injection in relation to the spontaneous LH surge on pregnancy rates

PURPOSE

To determine the optimal time for administration of human chorionic gonadotropin in clomiphene citrate induced intrauterine insemination cycles.

METHODS

A retrospective analysis of 171 consecutive cycles was performed. An increase in luteinizing hormone level >100% over the mean of the preceding two days was defined as luteinizing hormone surge. Human chorionic gonadotropin was given in preparation for intrauterine insemination based on the follicle size and estradiol level prior to surge in 85 cycles (Group A), with the spontaneous surge in 64 cycles (Group B) and not given in 22 cycles (Group C) due to high luteinizing hormone levels.

RESULTS

The overall pregnancy rate per cycle was 18.1% (31/171), 15.2% (Group A), 20.3% (Group B) and 22.7% (Group C), (p > 0.50).

CONCLUSION

Although there may be physiological reasons to propose that timing the human chorionic gonadotropin to the luteinizing hormone surge will improve the success rate, they were not demonstrated.

Timing intrauterine insemination either 33 or 39 hours after administration of human chorionic gonadotropin yields the same pregnancy rates as after superovulation therapy

OBJECTIVE

To compare a short and long interval between hCG administration and IUI after superovulation for the treatment of infertility.

DESIGN

Prospective, randomized clinical trial.

SETTING

University hospital-based fertility clinic.

PATIENT(S)

Patients planning superovulation and IUI for the treatment of infertility.

INTERVENTION(S)

Patients with >or=2 years of infertility enrolled for superovulation and IUI treatment were randomized to IUI after a short (32-34-hour) or long (38-40-hour) interval after hCG injection. Superovulation was accomplished with hMG or recombinant FSH, with dose adjustment until the maturation of two to five follicles, at which time hCG was given. Sperm was prepared with a gradient centrifugation technique, with IUI performed high up in the uterine fundus.

MAIN OUTCOME MEASURE(S)

Pregnancy rates.

RESULT(S)

Of the 348 patient cycles randomized, 270 treatment cycles were initiated. Eighty-one initiated cycles were canceled, leaving 189 completed randomized cycles from 75 patients for analysis. Pregnancy rates were not significantly different between groups. There were pregnancies in 20 of the 96 short hCG-IUI interval cycles (21%) and in 14 of the 93 long hCG-IUI interval cycles (15%) (odds ratio = 0.673, 95% confidence interval 0.297-1.518).

CONCLUSION(S)

Pregnancy rates are the same after superovulation therapy whether IUI is done after a short or a long interval after hCG injection.

Human chorionic gonadotropin administration is associated with high pregnancy rates during ovarian stimulation and timed intercourse or intrauterine insemination

BACKGROUND

There are different factors that influence treatment outcome after ovarian stimulation and timed-intercourse or intrauterine insemination (IUI). After patient age, it has been suggested that timing of insemination in relation to ovulation is probably the most important variable affecting the success of treatment. The objective of this study is to study the value of human chorionic gonadotropin (hCG) administration and occurrence of luteinizing hormone (LH) surge in timing insemination on the treatment outcome after follicular monitoring with timed-intercourse or intrauterine insemination, with or without ovarian stimulation.

METHODS

Retrospective analysis of 2000 consecutive completed treatment cycles (637 timed-intercourse and 1363 intrauterine insemination cycles). Stimulation protocols included clomiphene alone or with FSH injection, letrozole (an aromatase inhibitor) alone or with FSH, and FSH alone. LH-surge was defined as an increase in LH level > or =200% over mean of preceding two days. When given, hCG was administered at a dose of 10,000 IU. The main outcome was clinical pregnancy rate per cycle.

RESULTS

Higher pregnancy rates occurred in cycles in which hCG was given. Occurrence of an LH-surge was associated with a higher pregnancy rate with clomiphene treatment, but a lower pregnancy rate with FSH treatment.

CONCLUSIONS

hCG administration is associated with a favorable outcome during ovarian stimulation. Awaiting occurrence of LH-surge is associated with a better outcome with CC but not with FSH treatment.

Single versus double intrauterine insemination: are outcomes affected?

PURPOSE OF REVIEW

Intrauterine insemination with or without superovulation is the initial step in assisted reproductive technologies. There have been many attempts to increase the efficiency of this route. One approach may be to increase the frequency of insemination. In the last decade, there has been a continuing debate regarding the increased efficiency of IUI with double IUI.

RECENT FINDINGS

Although the initial studies showed that superovulation with double intrauterine insemination had better pregnancy rates than with a single application, recent studies found that ovarian stimulation with double insemination has not increased the pregnancy rates.

SUMMARY

Superovulation with intrauterine insemination is a treatment modality used in unexplained infertility and mild male infertility. Increasing the efficiency of the technique has always been an interest of research. Double intrauterine insemination has been suggested to increase efficiency; recent studies, however, have not confirmed this finding.

Follicular response and pregnancy among infertile women undergoing ovulation induction and intrauterine insemination

OBJECTIVE

To determine the relationship between ovarian follicular response (number and diameter of follicles) to ovulation induction agents and pregnancy.

DESIGN

Retrospective cohort study.Hospital-based center of reproductive medicine.

PATIENT(S)

Three hundred twenty-two clinically diagnosed infertile couples undergoing 1483 cycles of ovulation induction and IUI. Oral and injectable fertility drugs were administered for 2-10 cycles; ultrasound follicular measurements were recorded around time of ovulation; hCG was administered when follicles were 18-20 mm or more in diameter; IUI was performed 36-40 hours after administration of hCG.

MAIN OUTCOME MEASURE(S)

A first positive pregnancy test as indicative for conception. Women with follicular diameters >or=20 mm were less likely to become pregnant as compared to women with diameters between 15.00 and 19.99 mm (risk ratio [RR] = 0.58, 95% confidence interval [CI] = 0.35, 0.97). Women >or=30 years of age were half as likely to become pregnant as compared to women <30 years (RR = 0.51, 95% CI = 0.30, 0.85). Likelihood of pregnancy increased by 21% for each prior pregnancy (RR = 1.21, 95% CI = 1.00, 1.47).

CONCLUSION(S)

Maternal age, gravidity, and follicular diameters around the time of insemination are prognostic factors in the likelihood of pregnancy.

Premature LH and progesterone rise in intrauterine insemination cycles: analysis of related factors

Premature LH and progesterone surges are associated with different factors and hormonal modulators. The aim of the present study was (i) to investigate the clinical and laboratory factors and (ii) to highlight the importance of different stimulation protocols in associated premature LH and progesterone surges in intrauterine insemination (IUI) cycles. The study involved a retrospective investigation of 75 patients undergoing IUI for infertility treatment (135 IUI cycles) between 1996 and 2000, with initial serum LH concentrations >10 mIU/ml during ovarian stimulation. Ultrasound characteristics, follicular sizes, serum oestradiol, progesterone and LH concentrations and ovarian stimulation protocols were measured. There was a wide range of oestradiol serum concentrations (93-2245 pg/ml) and follicular size (12-25 mm). In 49.6% of cycles, the dominant follicle was <16.5 mm. Patients with >2 follicles measuring <15 mm had higher oestradiol serum concentrations (P = 0.008). Multiple regression analyses revealed no association between these variables and premature LH/progesterone surge. In conclusion, LH/progesterone surges cannot be predicted utilizing clinical parameters normally employed, e.g. ultrasound serum oestradiol assay or ovarian stimulation protocol. Patients with follicles >14 mm or more and with high numbers of small follicles and high oestradiol are at risk of a spontaneous LH surge. These variables can be used to time the administration of GnRH antagonist administration until better predictive factors are demonstrated.

Is waiting for an endogenous luteinizing hormone surge and/or administration of human chorionic gonadotrophin of benefit in intrauterine insemination?

This retrospective study was undertaken to investigate the observation that the probability of pregnancy was higher with intrauterine insemination (IUI) when human chorionic gonadotrophin (HCG) was administered after the onset of the luteinizing hormone (LH) surge. A total of 219 patients who had 524 IUI cycles was included in this study. IUI cycles were divided into three groups: group 1, patients who had an endogenous LH surge but no HCG; group 2, patients given HCG after an endogenous LH surge was observed; and group 3, patients given HCG before an endogenous LH surge could be demonstrated. The overall clinical pregnancy rate was 16%. Forty-two (19.2%) patients had 91 cycles with their partner's semen, while 177 (80.8%) used donor semen in 433 cycles; clinical pregnancy rates were 12.1% and 16.9% respectively. There was no significant difference in pregnancy rate per cycle between patients in group 1 (12.7%) compared with those in groups 2 (15.6%) or 3 (20.5%). We could not establish any benefit in waiting for a spontaneous LH surge before administering HCG in the presence of a mature follicle(s) in this study. This strategy avoids further monitoring to detect the LH surge, allowing treatment to be planned for a time convenient to the patient.