A simple, inexpensive and effective artificial cycle with exogenous transdermal oestradiol and vaginal progesterone for the transfer of cryopreserved pronucleated human oocytes in women with normal cycles

A comparison of frozen-thawed embryo transfer protocols in 2920 single-blastocyst transfers

OBJECTIVE

To assess the effect of frozen-thawed embryo transfer (FET) protocol on live-birth rate (LBR) and clinical pregnancy rate (CPR), in single-vitrified-blastocyst transfer MATERIALS AND METHODS: Retrospective cohort study with FET of a single-blastocyst embryos (n = 2920 cycles) thawed 2013-2018. FET protocols were natural cycles (NC-FET) (n = 147), artificial hormone replacement treatment cycles (HRT-FET) (n = 2645), and modified NC (mNC) with hCG triggering (n = 128). Primary outcome was LBR. Adjustment for age, embryo grade, year of freezing\thawing, infertility cause, and endometrial thickness was performed.

RESULTS

There were no significant differences between the groups with regard to female age, embryo grade, and endometrial thickness. LBR was higher in the mNC compared to HRT-FET cycles (38.3% vs. 20.9% P < 0.0001), and in the NC compared to HRT-FET cycles (34.7% vs. 20.9%, P = 0.0002). CPR was higher in the mNC compared to HRT-FET cycles (46.1% vs. 33.3% P = 0.0003), and in the NC compared to HRT-FET cycles (45.9% vs. 33.3%, P = 0.002). There was no significant difference in LBR or CPR between NC-FET and mNC-FET. Higher LBR with NC-FET and mNC-FET remained significant after adjusting for confounders (aOR 2.42, 95%CI 1.53-3.66, P < 0.0001).

CONCLUSION

The use of the convenient artificial HRT-FET cycles must be cautiously reconsidered in light of the potential negative effect on LBR when compared with natural cycle FET.

The effect of LH rise during artificial frozen-thawed embryo transfer (FET) cycles

Purpose

To evaluate the association between a rise in serum luteinizing hormone (LH) levels during artificial frozen–thawed embryo transfer (FET) cycles and clinical pregnancy rate.

Methods

A retrospective cohort study of women undergoing artificial FET cycles. We compared cycles in which LH double itself from the early follicular phase and further (group A) to cycles without a rise in LH (group B). Endometrium preparation was achieved by administration of 2 mg three times per day estradiol valerate tablets. Embryo transfer (ET) was conducted after achieving endometrial thickness > 7 mm and vaginal progesterone was added according to the embryo’s age. A beta-hCG was measured 13–14 days after ET. Clinical pregnancy was diagnosed on transvaginal ultrasound.

Results

Data from 984-FET cycles were retrieved. LH, exogenous estradiol (E2), progesterone values, endometrial thickness, and pregnancy outcomes were available in all patients. From 984-FET cycles, 629 (63.9%) had a doubling, and 355 (36.07%) had no rise in LH. Patients mean age was 30 years, similar in both groups. A multivariable logistic regression analysis was calculated to assess the effect of LH rise and pregnancy outcomes, after adjusting for confounders including a rise in E2 level and endometrial thickness. In this model, there was no association between doubling LH values and pregnancy rates (adjusted odds ratio: 1.06, 95% CI: 0.75–1.5, P = 0.74).

Conclusion

LH rise during artificial FET cycles does not alter pregnancy rates. Apparently, hormonal monitoring of LH levels may not yield useful information in the artificial FET cycle and may be omitted.

Lay summary

Supplementation of estradiol, a hormone produced by the ovaries, starting at the beginning of the menstrual cycle of an artificially frozen embryo transfer (FET) can lead to a rise in luteinizing hormone (LH), the hormone that induces ovulation. Such a rise in LH may interfere with embryo implantation, the process where the embryo attaches to the inner lining of the uterus and, therefore, could affect the chances of pregnancy. The current study is the first to assess the effect of a dynamic rise in LH levels during FET cycles on pregnancy rates. This study found no difference in pregnancy rates between FET cycles where the LH doubled compared to cycles without such a rise in LH. Larger, prospective studies should be conducted to assess the impact of LH elevation on pregnancy outcomes.

Elective frozen-thawed embryo transfer (FET) in women at risk for ovarian hyperstimulation syndrome

Elective cryopreservation of cultured embryos has become a treatment option for women at risk for ovarian hyperstimulation syndrome (OHSS). The aim of our study was to investigate the outcome of elective cryopreservation and consecutive frozen-thawed embryo transfer (FET) in a large IVF clinic in Austria. A total of 6104 controlled ovarian hyperstimulation cycles (COH) were performed on 2998 patients including 200 patients (6.7%) who were undergoing elective cryopreservation and FET due to high risk of OHSS. We estimated the cumulative live birth rate using the Kaplan-Meier method and evaluated independent predictors for successful live births with a Cox model. A total of 270 frozen-thawed embryo transfers were performed on 200 patients with up to 4 transfers per patient. The first embryo transfer showed a live birth rate of 42.0%, the second transfer showed a cumulative rate of 58.5%. After a total of 4 FETs from the same COH cycle, a cumulative live birth rate of 61.0% per COH cycle could be achieved. Four cases of OHSS occurred amongst these patients (2.0%), all of them of moderate severity. Multivariate analysis identified maternal age, the use of assisted hatching and the number of embryos transferred at the blastocyst stage as independent predictors for cumulative live birth. Our study clearly suggests that elective FET is safe and shows excellent cumulative live birth rates. This concept can, therefore, be used to avoid the severe adverse events caused by COH and the inefficient use of cultured embryos.

Cycle regimens for frozen-thawed embryo transfer

BACKGROUND

Among subfertile couples undergoing assisted reproductive technology (ART), pregnancy rates following frozen-thawed embryo transfer (FET) treatment cycles have historically been found to be lower than following embryo transfer undertaken two to five days following oocyte retrieval. Nevertheless, FET increases the cumulative pregnancy rate, reduces cost, is relatively simple to undertake and can be accomplished in a shorter time period than repeated in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles with fresh embryo transfer. FET is performed using different cycle regimens: spontaneous ovulatory (natural) cycles; cycles in which the endometrium is artificially prepared by oestrogen and progesterone hormones, commonly known as hormone therapy (HT) FET cycles; and cycles in which ovulation is induced by drugs (ovulation induction FET cycles). HT can be used with or without a gonadotrophin releasing hormone agonist (GnRHa). This is an update of a Cochrane review; the first version was published in 2008.

OBJECTIVES

To compare the effectiveness and safety of natural cycle FET, HT cycle FET and ovulation induction cycle FET, and compare subtypes of these regimens.

SEARCH METHODS

On 13 December 2016 we searched databases including Cochrane Gynaecology and Fertility's Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. Other search sources were trials registers and reference lists of included studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing the various cycle regimens and different methods used to prepare the endometrium during FET.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Our primary outcomes were live birth rates and miscarriage.

MAIN RESULTS

We included 18 RCTs comparing different cycle regimens for FET in 3815 women. The quality of the evidence was low or very low. The main limitations were failure to report important clinical outcomes, poor reporting of study methods and imprecision due to low event rates. We found no data specific to non-ovulatory women. 1. Natural cycle FET comparisons Natural cycle FET versus HT FETNo study reported live birth rates, miscarriage or ongoing pregnancy.There was no evidence of a difference in multiple pregnancy rates between women in natural cycles and those in HT FET cycle (odds ratio (OR) 2.48, 95% confidence interval (CI) 0.09 to 68.14, 1 RCT, n = 21, very low-quality evidence). Natural cycle FET versus HT plus GnRHa suppressionThere was no evidence of a difference in rates of live birth (OR 0.77, 95% CI 0.39 to 1.53, 1 RCT, n = 159, low-quality evidence) or multiple pregnancy (OR 0.58, 95% CI 0.13 to 2.50, 1 RCT, n = 159, low-quality evidence) between women who had natural cycle FET and those who had HT FET cycles with GnRHa suppression. No study reported miscarriage or ongoing pregnancy. Natural cycle FET versus modified natural cycle FET (human chorionic gonadotrophin (HCG) trigger)There was no evidence of a difference in rates of live birth (OR 0.55, 95% CI 0.16 to 1.93, 1 RCT, n = 60, very low-quality evidence) or miscarriage (OR 0.20, 95% CI 0.01 to 4.13, 1 RCT, n = 168, very low-quality evidence) between women in natural cycles and women in natural cycles with HCG trigger. However, very low-quality evidence suggested that women in natural cycles (without HCG trigger) may have higher ongoing pregnancy rates (OR 2.44, 95% CI 1.03 to 5.76, 1 RCT, n = 168). There were no data on multiple pregnancy. 2. Modified natural cycle FET comparisons Modified natural cycle FET (HCG trigger) versus HT FETThere was no evidence of a difference in rates of live birth (OR 1.34, 95% CI 0.88 to 2.05, 1 RCT, n = 959, low-quality evidence) or ongoing pregnancy (OR 1.21, 95% CI 0.80 to 1.83, 1 RCT, n = 959, low-quality evidence) between women in modified natural cycles and those who received HT. There were no data on miscarriage or multiple pregnancy. Modified natural cycle FET (HCG trigger) versus HT plus GnRHa suppressionThere was no evidence of a difference between the two groups in rates of live birth (OR 1.11, 95% CI 0.66 to 1.87, 1 RCT, n = 236, low-quality evidence) or miscarriage (OR 0.74, 95% CI 0.25 to 2.19, 1 RCT, n = 236, low-quality evidence) rates. There were no data on ongoing pregnancy or multiple pregnancy. 3. HT FET comparisons HT FET versus HT plus GnRHa suppressionHT alone was associated with a lower live birth rate than HT with GnRHa suppression (OR 0.10, 95% CI 0.04 to 0.30, 1 RCT, n = 75, low-quality evidence). There was no evidence of a difference between the groups in either miscarriage (OR 0.64, 95% CI 0.37 to 1.12, 6 RCTs, n = 991, I² = 0%, low-quality evidence) or ongoing pregnancy (OR 1.72, 95% CI 0.61 to 4.85, 1 RCT, n = 106, very low-quality evidence).There were no data on multiple pregnancy. 4. Comparison of subtypes of ovulation induction FET Human menopausal gonadotrophin(HMG) versus clomiphene plus HMG HMG alone was associated with a higher live birth rate than clomiphene combined with HMG (OR 2.49, 95% CI 1.07 to 5.80, 1 RCT, n = 209, very low-quality evidence). There was no evidence of a difference between the groups in either miscarriage (OR 1.33, 95% CI 0.35 to 5.09,1 RCT, n = 209, very low-quality evidence) or multiple pregnancy (OR 1.41, 95% CI 0.31 to 6.48, 1 RCT, n = 209, very low-quality evidence).There were no data on ongoing pregnancy.

AUTHORS' CONCLUSIONS

This review did not find sufficient evidence to support the use of one cycle regimen in preference to another in preparation for FET in subfertile women with regular ovulatory cycles. The most common modalities for FET are natural cycle with or without HCG trigger or endometrial preparation with HT, with or without GnRHa suppression. We identified only four direct comparisons of these two modalities and there was insufficient evidence to support the use of either one in preference to the other.

Initiation of ovarian stimulation independent of the menstrual cycle: a case-control study

PURPOSE

In the GnRH-antagonist protocol, ovarian stimulation with gonadotropins typically commences on cycle day 2 or 3. Initiation of ovarian stimulation with a spontaneously occurring menstruation, however, poses significant organizational challenges for treatment centres and patients alike. It has previously been demonstrated in the context of fertility preservation that initiation of stimulation in the luteal phase is feasible in terms of retrieval of mature oocytes for cryopreservation. Herein, we report the extension of this concept to a routine IVF setting with the aim of establishing an ovarian stimulation protocol, which can be utilized independent of menstruation. Because of asynchrony of endometrium and embryo in such a setting, all fertilized oocytes have to be cryopreserved for a later transfer.

METHODS

This was a prospective, case-control study (trial registration: NCT00795041) on the feasibility of starting ovarian stimulation in a GnRH-antagonist protocol in the luteal phase. Inclusion criteria were: IVF or ICSI; 18-36 years; ≤3 previous IVF/ICSI attempts; BMI 20-30 kg/m(2); regular cycle (28-35 days); luteal phase progesterone >7 ng/ml at initiation of stimulation. Exclusion criteria were: PCOS, endometriosis ≥AFS III°, unilateral ovary, expected poor response. Stimulation was performed with highly purified uFSH (Bravelle®) 300 IU/day and 0.25 mg/day GnRH-antagonist starting on cycle day 19-21 of a spontaneous menstrual cycle and commencing until hCG administration when three follicles ≥17 mm were present. All 2PN stage oocytes were vitrified for later transfers in programmed cycles. Feasibility was defined as the achievement of ongoing pregnancies progressing beyond the 12th gestational week in at least 2/10 study subjects (primary outcome). Secondary outcomes were gonadotropin consumption per oocyte obtained, stimulation duration, and fertilization rates. Study subjects were matched in a 1:3 ratio with concomitantly treated control cases of similar age, BMI, and duration of infertility who were treated in a conventional GnRH-antagonist protocol with 150-225 rFSH or HP-HMG/day.

RESULTS

The study group consisted of ten subjects, mean age 31.4 years, BMI 25.4 kg/m(2), of which one had fertilization failure. Mean stimulation duration was 11.7 (SD 1.6) vs. 9.1 (SD 1.3) days, mean cumulative FSH dose was 3,495.0 (SD 447.5) vs. 2,040.5 (SD 576.2) IU, and mean number of oocytes was 8.8 (SD 5.0) vs. 10.0 (SD 5.4) in study vs. control group, respectively. Per follicle ≥10 mm, the cumulative FSH dose was 274.5 (SD 130.8) IU vs. 245.2 (SD 232.3) IU in study and control groups, respectively. Cumulative ongoing pregnancy rates were 1/10 (10 %) and 6/30 (20.0 %) in study and control group, respectively (difference: 10 %, 95 % confidence interval of the difference: -29.2-22.2 %, p = 0.47). Fertilization rate was similar between groups, with 63.5 % (SD 32.9) in the study and 61.3 % (SD 26.7) in the control group, respectively. Serum estradiol levels were significantly lower on the day of triggering final oocyte maturation with 1,005.3 (SD 336.2) vs. 1,977.4 pg/ml (SD 1,106.5) in study and control group, respectively. Similarly, peak estradiol biosynthesis per growing follicle ≥10 mm was lower in the study group (134 pg/ml, SD 158.4 vs. 186.7 pg/ml, SD 84.7).

CONCLUSIONS

Per retrieved oocyte, a nearly threefold higher dose of FSH had to be administered when ovarian stimulation had been initiated in the luteal phase. Furthermore, the present study casts doubt on the efficacy of initiating ovarian stimulation in the luteal phase in terms of pregnancy achievement. Thus, this concept is currently not feasible for routine use, and it should also be explored further before using it at larger scale in the context of emergency stimulation for fertility preservation.

Patients undergoing frozen-thawed embryo transfer have similar live birth rates in spontaneous and artificial cycles

PURPOSE

To evaluate the outcome of frozen-thawed embryo transfer (FET) when freezing takes place at the pronuclear stage, a retrospective analysis was performed comparing spontaneous and artificial cycles.

METHODS

148 women received FET in a spontaneous cycle (Group A) and 55 women received FET in an artificial cycle (Group B) induced by administering estrogen (E2) and progesterone (P). Pregnancy rates, endometrial thickness and serum levels of E2, P and luteinizing hormone (LH) were measured. Statistical analysis included the mean, the standard deviation, the Chi-squared test and the T-test.

RESULTS

The clinical pregnancy rate was 34.5% for Group A and 21.8% for Group B (p = 0.084), with a live birth rate of 20.9% and 12.7% respectively (p = 0.15). There was no difference in endometrial thickness or the P levels, while LH and E2 levels were significantly higher in group B (p < 0.0001).

CONCLUSION

Our retrospective study shows a trend towards higher pregnancy rates and live birth rates with the administration of FET during a spontaneous cycle compared to FET during an artificial cycle. Large randomized controlled trials are needed to confirm this trend.

Intensified ovarian stimulation in a GnRH antagonist protocol with agonist triggering: a prospective, clinical feasibility study

The threat of severe ovarian hyperstimulation syndrome (OHSS) and the increase in discomfort for the patient has limited the feasibility of maximizing the oocyte yield per treatment cycle. A gonadotrophin-releasing hormone (GnRH) antagonist protocol with agonist triggering and vitrification of all 2PN oocytes can eliminate the risk of OHSS. This prospective, single-centre, cohort study in 30 good-responder IVF patients ≤ 36 years reports the feasibility of arbitrarily intensifying stimulation in a GnRH antagonist protocol in terms of tolerability, safety and efficacy. Ovarian stimulation was performed with 225-375IU FSH, induction of final oocyte maturation with 0.2mg GnRH agonist followed by vitrification of all 2 pronuclear (2PN) oocytes and repetitive vitrified-warmed embryo transfer cycles. Main outcomes were severe OHSS incidence, tolerability, assessed by a questionnaire, and cumulative live birth rate. On average, 17 oocytes were retrieved (range 4-42) and 8.4 oocytes at the 2PN stage were cryopreserved (range 3-22). No case of severe OHSS was observed (0%, 95 CI 0-11.4%). Tolerability was good. The cumulative live birth rate per patient undergoing at least one vitrified-warmed embryo transfer was 26.9% (7/26, 95% CI 13.7-46.1%). This approach can be explored in future larger-sized controlled studies.

Cycle regimens for frozen-thawed embryo transfer

BACKGROUND

Pregnancy rates following frozen-thawed embryo transfer (FET) treatment have always been found to be lower than following embryo transfer using fresh embryos. Nevertheless, FET increases the (cumulative) pregnancy rate, reduces cost, is relatively simple to undertake and can be accomplished in a shorter time period compared to repeated 'fresh' cycles. FET is performed using different cycle regimens: spontaneous ovulatory cycles, cycles in which ovulation is induced by drugs and cycles in which the endometrium is artificially prepared by oestrogen (O) and progesterone (P) hormones, with or without a gonadotrophin releasing hormone agonist (GnRHa).

OBJECTIVES

To determine whether there is a difference in outcome between natural cycle FET, artificial cycle FET and ovulation induction cycle FET.

SEARCH STRATEGY

Our search included CENTRAL,DARE, MEDLINE (1950 to 2007), EMBASE (1980 to 2007) and CINAHL (1982 to 2007).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the various cycle regimens and different methods used to prepare the endometrium during FET in assisted reproductive technology (ART).

DATA COLLECTION AND ANALYSIS

The two authors independently extracted data. Dichotomous outcomes results (e.g. clinical pregnancy rate) were expressed as an odds ratio (OR) with 95% confidence intervals (CI) for each study. Continuous outcome results (endometrial thickness) were expressed as weighted mean difference (WMD). Where suitable, results were combined for meta-analysis with RevMan software using the Peto-modified Mantel-Haenszel method.

MAIN RESULTS

Seven randomised controlled studies assessing six comparisons and including 1120 women in total were included in this review.1) O + P FET versus natural cycle FET: this comparison demonstrated no significant differences in outcomes but confidence intervals remain wide, and therefore moderate differences in either direction remain possible (OR 1.06, 95% CI 0.40 to 2.80, P 0.91).2) GnRHa + O + P FET versus O + P FET: this comparison showed that the live birth rate per woman was significantly higher in the former group (OR 0.38, 95% CI 0.17 to 0.84, P 0.02). The clinical pregnancy rate was also higher but not significantly so (OR 0.76, 95% CI 0.52 to 1.10, P 0.14).3) O + P FET versus follicle stimulating hormone (FSH) FET, 4) O + P FET versus clomiphene FET and 5) GnRHa + O + P FET versus clomiphene FET: there were no differences in the outcomes in the comparison of these cycle regimens.6) Clomiphene + human menopausal gonadotrophin (HMG) FET versus HMG FET: in a comparison of two ovulation induction regimes the pregnancy rate was found to be significantly higher in the HMG group (OR 0.46, 95% CI 0.23 to 0.92). There were also fewer cycle cancellations and a lower multiple pregnancy rate when HMG was used without clomiphene but these did not reach statistical significance.

AUTHORS' CONCLUSIONS

At the present time there is insufficient evidence to support the use of one intervention in preference to another.

The usefulness of a thyrotropin-releasing hormone stimulation test in subfertile female patients

BACKGROUND

The thyrotropin-releasing hormone (TRH) stimulation test is widely used as a screening procedure in subfertile patients to identify subclinical hypothyroidism. However, its usefulness in daily clinical practice has not been proven, despite more than 30 years of use.

MATERIAL AND METHODS

We analyzed data from a cohort of 371 consecutive female subfertility patients, who were screened with an intravenous TRH test when they came for the first evaluation. All patients with positive thyroid peroxidase antibodies, basal TSH <1.5 mU/l, known thyroid disease or actual thyroid medication were not screened and excluded from the analysis.

RESULTS

We found a good correlation between basal and stimulated levels of thyroid-stimulating hormone (TSH). Basal TSH and the difference between stimulated and basal TSH did not correlate with prolactin levels. Definition of a positive TRH test (difference of 15 or 20 mU/l) did not have sufficient sensitivity and specificity, as confirmed by analysis of receiver operating characteristic curves, to identify subclinical hypothyroidism.

CONCLUSION

TRH stimulation testing is not helpful to identify patients with subclinical hypothyroidism and should not be part of initial screening in this group.

Elective cryopreservation of all pronuclear oocytes after GnRH agonist triggering of final oocyte maturation in patients at risk of developing OHSS: a prospective, observational proof-of-concept study

BACKGROUND

A bolus dose of GnRH agonist can substitute for hCG as a trigger for the resumption of meiosis in ovarian stimulation with GnRH antagonists, which has been suggested to reduce the risk of ovarian hyperstimulation syndrome (OHSS). As the efficacy of this measure in fresh embryo transfer (ET) cycles is unclear, we evaluated a new clinical concept of GnRH-agonist triggering.

METHODS

In this prospective, observational proof-of-concept study, 20 patients considered at increased risk of developing OHSS (> or = 20 follicles > or = 10 mm or estradiol > or = 4000 pg/ml, or a history of cycle cancellation due to OHSS risk or the development of severe OHSS in a previous cycle) after ovarian stimulation and concomitant GnRH-antagonist administration had final oocyte maturation triggered with 0.2 mg triptorelin s.c. All two pronucleate (2 PN) oocytes were cryopreserved by vitrification, and frozen-thawed ETs (FT-ETs) were performed in an artificial cycle. Main outcome measures were the cumulative ongoing pregnancy rate per patient and the ongoing pregnancy rate per first ET. Secondary outcomes included the incidence of moderate-to-severe OHSS.

RESULTS

Of the 20 patients triggered with GnRH agonist, 19 patients underwent 24 FT-ETs in the observational period. The cumulative ongoing pregnancy rate was 36.8% (95% confidence interval: 19.1-59.0%). The ongoing pregnancy rate per first FT-ET was 31.6% (15.4-54.0%). No cases of moderate or severe OHSS were observed.

CONCLUSIONS

The present study is the proof of the concept that GnRH-agonist triggering of final oocyte maturation in combination with elective cryopreservation of 2 PN oocytes offers OHSS risk patients a good chance of pregnancy achievement, while reducing the risk of moderate and severe OHSS.

Artificial versus stimulated cycles for endometrial preparation prior to frozen-thawed embryo transfer

The objective of this study was to compare the implantation rate, pregnancy rate and endometrial thickness of frozen-thawed embryo transfers using endometrial preparation with either an artificial cycle or stimulated cycle. This was a prospective randomized trial at a single academic IVF centre. Seventy-seven patients undergoing artificial cycles received oral oestradiol; patients with endometrium < 7 mm on day 9-10 were switched to vaginal oestradiol. Eighty-six patients undergoing stimulated cycles received recombinant FSH followed by human gonadotrophin hormone injection. Vaginal progesterone was begun 2 or 3 days prior to embryo transfer. There was no difference in implantation rate (8.5% versus 7.3%), pregnancy rate (16% versus 13%), cancellation rate (both 23%) or endometrium thickness (8.7 +/- 1.1 mm versus 8.7 +/- 1.0 mm) between artificial and stimulated cycles. Stimulated cycles had a higher incidence of thin endometrium (27% versus 5%, P < 0.01). In artificial cycles, patients switched to vaginal oestradiol had improved pregnancy rate (31%) versus patients who received oral oestradiol alone (13%) (P = 0.05). It is concluded that artificial and stimulated cycles produce comparable pregnancy rates, implantation rates, cancellation rates and endometrial thickness, although stimulated cycles have a higher incidence of thin endometrium. Vaginal oestradiol supplementation improved implantation rates.

Vaginal administration of oral micronized estradiol results in successful twin pregnancy in a functionally agonadal woman

CASE REPORT

A 31-year-old nulligravid woman seeking fertility treatment with in vitro fertilization and intracytoplasmic sperm injection failed to achieve pregnancy. Supernumerary embryos were cryopreserved for future use. In preparation for the transfer of the frozen embryos, the patient was prescribed hormones, which included pituitary down-regulation with leuprolide acetate, followed by oral micronized estradiol (E2) and vaginal progesterone (P4) suppositories. At the time of embryo transfer (ET) it was noted that the patient had misunderstood her instructions and was administering both her estrogen and progesterone vaginally. Ultrasound examination revealed a well-developed endometrium adequate for ET so the procedure was performed, and at that point she was instructed to use E2 orally as originally prescribed. Two weeks later, her beta-hCG was elevated, and subsequent ultrasound examinations revealed a twin gestation. The pregnancy progressed normally.

CONCLUSION

This patient's hormones were adequately replaced despite vaginal placement of oral medication. Although not commonly prescribed, oral E2 tablets may be administered vaginally in functionally agonadal women preparing for ET, and may serve as an alternative route for women who experience difficulties with oral formulations.

Counselling on cryopreservation of pronucleated oocytes

The German Embryo Protection Law permits only the cryopreservation of supernumerary pronuclear stage eggs. Data are needed to counsel patients about their individual benefits from this procedure. All fresh embryo transfer cycles performed from January 1994 until December 1998 in which supernumerary pronucleate eggs were cryopreserved (n = 557) were analysed retrospectively, together with data from all subsequent cycles involving transfers of frozen-thawed pronucleate eggs (n = 420) from January 1994 until June 2001. The additional cumulative pregnancy rate per fresh cycle was 11.5%. This rate depended on the number of embryos per transfer, i.e. 1.9, 8.2 and 13.0% respectively when one, two or three embryos were transferred (P < 0.05). A strong correlation was found between the numbers of cryopreserved pronucleate eggs and pregnancy rates, of 9.3, 10.5 and 17.1% when 1-3, 4-6, or at least 7 pronucleate eggs were available respectively. Additional benefit in terms of this rate from cryopreservation for a patient with and without a pregnancy in the fresh embryo transfer cycles was 5.3 and 12.7% respectively. It is concluded that higher pregnancy rates in cycles involving cryopreserved eggs for patients who did not become pregnant in fresh transfer cycles reveals the disadvantage of the German Embryo Protection Law, which does not allow embryo selection. Therefore, cryopreservation of pronucleate eggs with a higher developmental potential is possible. The total pregnancy rate could be raised from 28.0 to 35.5% per fresh transfer cycle.

Preparation of cycles for cryopreservation transfers using estradiol patches and Crinone 8% vaginal gel is effective and does not need any monitoring

Supernumary pronucleated stage oocytes (PN) can be cryopreserved and later transferred in spontaneous, stimulated or artificial cycles. In this study, we re-evaluated 342 artificial cycles with a transdermal estradiol release system (Estraderm TTS 100) in combination with a vaginal progesterone delivery system (Crinone 8%). Endometrial thickness and serum estradiol on day 14 were correlated with clinical and ongoing pregnancy rates. Endometrial thickness between 7 and 15 mm did not relate to significantly different pregnancy rates. The estradiol serum level did not predict success. In conclusion, this method of endometrial preparation is comfortable for patients and monitoring is unnecessary.

Pregnancy/implantation rates as related to age following transfer of frozen embryos produced by ICSI

A study has suggested that one drawback of ICSI is that if these embryos are cryopreserved they have lower implantation rates after thawing and transfer as compared to other frozen embryos derived from conventional oocyte insemination. Other studies have not shown such adverse effects on pregnancy rates following frozen embryo transfer (ET) of embryos formed by ICSI. The study presented here evaluated the largest number of frozen ET cycles of embryos following ICSI, which were compared to couples having frozen ET with embryos formed by conventional insemination. In women age 39 and younger, the clinical, viable, pregnancy rates and implantation rates were very similar. Similar rates were reached for the older group. These data convincingly demonstrate that fertilization by ICSI does not adversely effect the implanting capacity of frozen-thawed embryos.