Controlled natural cycle IVF: experience in a world of stimulation

Comparison of embryo quality and pregnancy outcomes for patients with low ovarian reserve in natural cycles and mildly stimulated cycles: a cohort study

BACKGROUND

As women with low ovarian reserve embark on the challenging journey of in-vitro fertilisation (IVF) treatment, the choice between natural and mildly stimulated cycles becomes a pivotal consideration. It is unclear which of these two regimens is superior for women with low ovarian reserve. Our study aims to assess the impact of natural cycles on embryo quality and pregnancy outcomes in women with low ovarian reserve undergoing IVF treatment compared to mildly stimulated cycles.

METHODS

This retrospective study enrolled consecutive patients with low ovarian reserve who underwent IVF/intracytoplasmic sperm injection (ICSI) at Guangdong Second Provincial General Hospital between January 2017 and April 2021. The primary outcome for pregnancy rate of 478 natural cycles and 448 mild stimulated cycles was compared. Secondary outcomes included embryo quality and oocyte retrieval time of natural cycles.

RESULTS

The pregnancy rate in the natural cycle group was significantly higher than that in the mildly stimulated cycle group (51.8% vs. 40.1%, p = 0.046). Moreover, natural cycles exhibited higher rates of available embryos (84.1% vs. 78.6%, p = 0.040), high-quality embryos (61.8% vs. 53.2%, p = 0.008), and utilisation of oocytes (73% vs. 65%, p = 0.001) compared to mildly stimulated cycles. Oocyte retrievals in natural cycles were predominantly performed between 7:00 and 19:00, with 94.9% occurring during this time frame. In natural cycles with high-quality embryos, 96.4% of oocyte retrievals were also conducted between 7:00 and 19:00.

CONCLUSION

Natural cycles with appropriately timed oocyte retrieval may present a valuable option for patients with low ovarian reserve.

Prediction of Fertilization Disorders in the In Vitro Fertilization/Intracytoplasmic Sperm Injection: A Retrospective Study of 106,728 Treatment Cycles

Purpose

This study aimed to develop a risk prediction of fertilization disorders during the in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

Methods

A retrospective study was performed with 106,728 fresh embryo IVF/ICSI cycles from 2009 to 2019. Basic characteristics of patients, clinical treatment data, and laboratory parameters were involved. The associations between the selected variables and risks for low fertilization rate (LFR) and total fertilization failure (TFF) were investigated. Ordinal logistic regression and the receiver operating characteristic curves (ROCs) were used to construct and evaluate the prediction models.

Results

A total of 97,181 controls, 4,343 LFR and 5,204 TFF cases were involved in this study. The model based on clinical characteristics (the ages of the couples, women's BMI, types of infertility, ART failure history, the diminished ovarian reserve, sperm quality, insemination method, and the number of oocytes retrieved) had an AUC of 0.743 for TFF. The laboratory model showed that primary infertility, ART failure history, minimal-stimulation cycle/natural cycle, numbers of oocyte retrieved < 5, IVF, and Anti-Mullerian hormone (AMH) level < 1.1ng/ml are predictors of TFF, with an AUC of 0.742.

Conclusion

We established a clinical and a laboratory prediction model for LFR/TFF. Both of the models showed relatively high AUCs.

Perinatal outcomes of human singletons conceived naturally versus assisted reproductive technologies: analysis of the effect of stimulated IVF, modified natural IVF, and frozen embryo transfer

Background

Obstetrical outcomes in assisted reproduction techniques (ART) were compared with naturally conceived pregnancies and among each other in multiple reports. However, many important changes in the practice of in vitro fertilization (IVF) over the years, including single embryo transfers (sET) and the introduction of modified natural IVF (mnIVF), and the advances in the frozen embryo transfer (FET) might have impacted the outcomes. Our study is the first to our knowledge to assess four different groups, including spontaneous pregnancies, mnIVF, stimulated IVF (sIVF), and FET altogether in a head-to-head comparison. This is a retrospective study on perinatal outcomes of singleton babies conceived naturally or using three different ART protocols between 2011 and 2014. The primary objective was the comparison of gestational age and birth weight between spontaneously conceived pregnancies (NAT, n= 15,770), mnIVF (n=235), sIVF (n=389), and FET (n=222).

Results

Our results show a significant difference in favor of naturally conceived pregnancies over ART in term of gestational age. In fact, the gestational age of babies in the NAT group was statistically higher compared to each one of the ART groups alone. Regarding the birth weight, the mean was significantly higher in the FET group compared to the other categories.

Conclusion

Differences in perinatal outcomes are still found among babies born after different modes of conception. However, there is still need for well-designed high-quality trials assessing perinatal outcomes between naturally conceived pregnancies and different ART protocols based on different maternal and treatment characteristics.

Early Short Stimulation Modified Natural Cycle IVF With GnRH Agonist Trigger and In Vitro Maturation in a Woman with Polycystic Ovary Syndrome: A Case Report

BACKGROUND

Gonadotropin-releasing hormone agonist (GnRHa) triggering of final oocyte maturation has been used successfully in GnRH antagonist IVF cycles. It has not been used to date in cycles in which immature oocytes are matured in vitro.

CASE

We report here for the first time that GnRHa triggering in a variation on the modified natural IVF cycle can be used as a strategy in the treatment of infertility secondary to polycystic ovary syndrome. In this approach, follicles were stimulated with gonadotropins for three to five days when they were small, and triggering of ovulation occurred when the largest follicles were 10 to 12 mm in diameter. This was followed by retrieval of many immature oocytes that were matured in vitro and subsequently developed to form blastocysts that resulted in a live birth.

CONCLUSION

This is the first human evidence that GnRHa triggering of ovulation can be used successfully when the aim is in vitro maturation of oocytes.

Outcomes of 1503 cycles of modified natural cycle in vitro fertilization: a single-institution experience

PURPOSE

A retrospective cohort study was conducted in a single academic center to determine if modified natural cycle in vitro fertilization (mnIVF) is an acceptable treatment for the infertile couple.

METHODS

Cycles performed between July 2005 and December 2011 were included. In our center's mnIVF protocol, a GnRH antagonist, gonadotrophin, as well as Indocid are given on a daily basis from detection of a dominant follicle until ovulation induction. The primary outcomes were clinical pregnancy rates (CPR) per cycle started and per embryo transfer (ET). Outcomes were stratified by female patient age (≤35 years and ≥36 years). They were further stratified in each age group by ovarian response status according to the 2011 Bologna criteria.

RESULTS

A total of 1503 cycles of mnIVF, performed in 782 patients, were analyzed. CPRs were 13.7 % per started cycle and 32.5 % per ET. Stratification by ovarian response status (normal or poor) in each age group showed similar CPRs in patients ≤35 years (p = 0.373), and divergent CPRs per ET in patients ≥36 years old (26.26 vs 6.25 %).

CONCLUSION

MnIVF is an acceptable treatment option for patients considering IVF, particularly for women ≤35 years old and for women ≥36 years old with normal ovarian response.

Natural cycle IVF: evaluation of 463 cycles and summary of the current literature

PURPOSE

Natural cycle (NC) IVF/ICSI has proven to be an alternative to conventional IVF/ICSI cycles.

METHODS

Within our retrospective, observational study (n = 159) infertile couples underwent (n = 463) cycles of NC-IVF/ICSI from May 2007 until December 2011. Oocyte pick-up was performed within a pure natural cycle excluding any hormonal stimulation except of hCG for ovulation induction. Oocytes were fertilized by IVF/ICSI and embryo transfer took place 2 or 3 days later. In addition, the current literature was analysed concerning pregnancy rates in NC-IVF/ICSI cycles.

RESULTS

Oocyte pick-up was performed in n = 463 NC and was successful in n = 342 cases (IVF n = 135, ICSI n = 207). 203 oocytes were fertilized (IVF n = 87, ICSI n = 116, FR 59.4 %) and lead to 192 embryo transfers. Finally, 25 pregnancies were reached (PR 13.0 % per transfer) resulting in four biochemical pregnancies, 7 (33.3 %) miscarriages, one pregnancy of unknown outcome and 13 live births. Within the current literature (n = 27 studies), PR in NC-IVF/ICSI cycles varied between 10.2 and 50 %.

CONCLUSIONS

Within our study, pregnancy rates in pure NC-IVF/ICSI remained below 15 %. Although this may be linked to unfavourable preconditions like patients' age >40 years, low ovarian reserve or long duration of infertility, further improvement is necessary to increase pregnancy rates.

Short-term, low-dose, non-steroidal anti-inflammatory drug application diminishes premature ovulation in natural-cycle IVF

A retrospective cohort study was conducted in a private infertility centre to evaluate the use of non-steroidal antiinflammatory drugs (NSAID) in natural-cycle IVF (nIVF) treatment. A total of 1865 first-rank nIVF cycles performed during 2009–2010 were evaluated. Low-dose, post-trigger NSAID was administered in a non-randomized way in cycles at higher ovulation risk where an imminent LH surge was detected on triggering day. Main outcome measures were premature ovulation rate, embryo transfer rate per scheduled cycle and clinical pregnancy and live birth rates per embryo transfer. NSAID use was associated with a significantly lower risk of premature ovulation (3.6% versus 6.8%, adjusted OR 0.24, 95% CI 0.15–0.39, P < 0.0001) and higher embryo transfer rate (46.8% versus 39.5%, adjusted OR 1.38, 95% CI 1.06–1.61, P = 0.012) per scheduled cycle. Clinical pregnancy (39.1% versus 35.9%) and live birth rates per embryo transfer (31.3% versus 31.4%) were comparable. In this retrospective series, short-term low-dose NSAID application positively influenced nIVF cycles by diminishing the rate of unwanted premature ovulations and increasing the proportion of cycles reaching embryo transfer.

Low-intensity IVF: real progress?

A recent publication in this journal strongly advocated low-intensity IVF (LI-IVF) after presenting the authors' experience with minimal ovarian stimulation (mini-IVF). The data presented failed to support their conclusions. Therefore, presented here is a critique of their manuscript and of uncontrolled clinical use of LI-IVF, in general. In the absence of properly controlled studies, all forms of LI-IVF should be considered experimental and be offered only in well-controlled research settings and with appropriate informed consent.

Successful pregnancy in an ovarian agenesis patient after modified natural cycle IVF oocyte donation

The recovery of a mature oocyte from a modified natural cycle followed by in-vitro fertilization (nIVF) is an attractive alternative to conventional IVF, involving ovarian stimulation, in the treatment of female infertility. Ovarian agenesis is a rare disorder resulting in primary amenorrhoea and infertility in affected females. A couple sought help for infertility due to ovarian agenesis of the female partner and decided to pursue treatment utilizing oocyte donation. Modified natural-cycle egg retrieval was carried out on the donor; one mature oocyte was retrieved and underwent IVF using a sperm sample from the male partner. A good-quality embryo was transferred, A viable pregnancy was confirmed by ultrasound scan and resulted in the delivery of a healthy baby boy at 36 weeks' gestation. This is the second published report of an ongoing clinical pregnancy and subsequent birth resulting from oocyte donation recovered during a modified natural cycle. The use of less invasive assisted reproduction techniques such as nIVF can be used in oocyte donation cycles successfully.

Spontaneous ovulation rate before oocyte retrieval in modified natural cycle IVF with and without indomethacin

The objective of this retrospective analysis was to evaluate the number of spontaneous ovulations occurring before oocyte retrieval in natural cycle IVF (nIVF) with and without the use of indomethacin. A total of 121 patients who underwent modified nIVF cycle between December 2003 and July 2006 were included in the study; 171 cycles without indomethacin and 84 cycles with indomethacin, started when the leading follicle reached 14 mm in size, were compared. The number of cycles with ovulation before oocyte retrieval and the number of cycles with no oocytes at retrieval were assessed with and without indomethacin. In addition, the pregnancy rates in the two groups of patients were analysed. There were 28 cycles (16%) in which ovulation occurred before oocyte retrieval in the group where no indomethacin was used and five cycles (6%) in which ovulation occurred before retrieval in the group where indomethacin was used. There was a statistically significant association between premature ovulation and indomethacin, with an odds ratio of 3.8 (95% confidence interval, 1.2-12.3). The oocyte retrieval per started cycle was 64% without indomethacin and 76% with indomethacin (P < 0.04). The clinical pregnancy rate per embryo transfer was 14% without indomethacin and 21% with indomethacin (not significant).

Natural cycle IVF: a question of semantics?

Recently there has been much discussion and presentation on IVF protocols using less stimulation or indeed none at all. Our experience with controlled natural cycle IVF over the last few years has convinced us that this is a powerful tool for many patients in the treatment of infertility. The protocol we employ has raised some questions as to whether it is natural cycle or stimulated cycle. We have reported a large series of cycles and seen no stimulatory effects of the medications used to control the cycle, thereby confirming our position that controlled natural cycle IVF is a valid option as an assisted reproduction treatment.

Age, oestradiol and blastocysts can predict success in natural cycle IVF-embryo transfer

The aim of this study was to evaluate the influence of maternal age and oestradiol concentrations on blastocyst development and live birth rates in natural cycle IVF-embryo transfer. This observational study included 397 natural cycles with IVF embryo transfer for female infertility with embryo transfer on day 5. The cycles were divided into two groups according to the woman's age (<39 and > or = 39 years of age), and into two groups according to oestradiol concentrations on the day of human chorionic gonadotrophin (HCG) administration (0.4-0.49 nmol/l and 0.5-1.2 nmol/l). Comparison between the cycles in younger versus older age groups showed significant differences in blastocyst development rate, live birth rate per embryo transfer and live birth rate per cycle (55 versus 29%, 23 versus 3% and 13 versus 2% respectively) (P < 0.001). Comparison between cycles with lower versus higher oestradiol concentrations showed no significant differences in blastocyst development rate, live birth rate per embryo transfer and live birth rate per cycle (47 versus 49%, 18 versus 18%, and 11 versus 10% respectively). Advanced maternal age negatively predicts the success of natural cycle IVF, while low oestradiol concentrations on the day of HCG administration (ultrasound criteria fulfilled) do not negatively predict blastocyst development and success of natural cycle IVF.

The problem of IVF cost in developing countries: has natural cycle IVF a place?

Infertility represents a national health problem in some African countries. Limited financial health resources in developing countries are a major obstacle facing infertility management. IVF is the definitive line of treatment for many couples. Stimulation cycles are associated with risks of ovarian hyperstimulation syndrome and multiple pregnancy. This study evaluates the client acceptability of stimulated versus natural cycle IVF among couples attending one infertility clinic, with respect to cost and pregnancy outcome. Of the patients who were indicated for IVF, 15% (16/107) cancelled, due mostly (12/16, 75%) to financial reasons. The majority of patients who completed their IVF treatment (82/91, 90.1%) felt the price of the medical service offered was high, and 68.1% (62/91) accepted the idea of having cheaper drugs with fewer side effects but with possibly lower chances of pregnancy. Natural cycle IVF has emerged as a potential option that might be suitable for patients worldwide, especially in developing countries.

Embryo transfer and luteal support in natural cycles

Embryo transfer policy and luteal supplementation was reviewed, comparing literature data and the results from the Maribor IVF Centre. A retrospective analysis of 1024 cycles in patients undergoing IVF, intracytoplasmic sperm injection (ICSI) or testicular sperm aspiration in unstimulated cycles was carried out using four different approaches for cycle monitoring. This showed that the most successful protocol for monitoring was administration of human chorionic gonadotrophin (HCG) when serum oestradiol was >0.49 nmol/l and follicle diameter was at least 15 mm. The implantation rate per transferred embryo was higher when a blastocyst was transferred (42.8%) rather than a day-2 embryo (23.5%) in the same monitoring protocol. Analysis of the influence of patient age on the success of oocyte retrieval, oocyte fertilization, embryo transfer rate and delivery rate demonstrates that patient age does not influence the rate of positive oocyte retrieval or fertilization rate as much as it influences pregnancy rate per embryo transfer. The delivery rate per cycle was dramatically influenced by age in patients over 38 years. There is no clear evidence in the literature as to whether luteal phase support is necessary in natural cycles for IVF/ICSI. Comparing the data, a higher pregnancy rate was observed if HCG was administered after embryo transfer.

Controlled natural cycle IVF: a novel approach for a dominant follicle during an in-vitro maturation cycle

The objective of this retrospective analysis is to evaluate whether patients developing a dominant follicle in an in-vitro maturation (IVM) programme can be included in a natural cycle IVF (nIVF) programme. In a university teaching hospital, a total of 38 patients with polycystic ovarian syndrome were treated by metformin before undergoing an IVM cycle. Controlled nIVF was performed on seven patients with a dominant follicle. This paper reports three ongoing pregnancies from five embryo transfers in the latter group. Hence, nIVF can be a novel approach for women developing a dominant follicle during an IVM cycle.