Association of number of retrieved oocytes with live birth rate and birth weight: an analysis of 231,815 cycles of in vitro fertilization

OBJECTIVE

To determine if number of retrieved oocytes correlates with live birth rate and incidence of low birth weight (LBW).

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

Women undergoing fresh embryo transfer with the use of either autologous (n = 194,627) or donor (n = 37,188) oocytes whose cycles were reported to the Society for Assisted Reproductive Technology in the years 2004-2010.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth rate, birth weight, birth weight z-score, LBW.

RESULT(S)

For both autologous and donor oocyte cycles, increasing number of retrieved oocytes paralleled live birth rate and embryos available for cryopreservation in most analyses, with all models adjusted for age and previous births. For cycles achieving singleton pregnancy with the use of autologous oocytes via transfer of two embryos, a higher number of retrieved oocytes was associated with lower mean birth weight, lower birth weight z-score, and greater incidence of LBW. In contrast, for cycles using donor oocytes, there was no association of number of retrieved oocytes with measures of birth weight.

CONCLUSION(S)

A higher number of retrieved oocytes was associated with an increased incidence of LBW in autologous singleton pregnancies resulting from transfer of two embryos, but not in donor oocyte cycles. Although the effect of high oocyte number on the incidence of LBW in autologous cycles was of modest magnitude, further study is warranted to determine if a subgroup of women may be particularly vulnerable.

The impact of thyroid autoimmunity on IVF/ICSI outcome: a systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity (TAI) is the most frequent autoimmune condition and the first cause of thyroid dysfunction among women of reproductive age. Notably, it has been associated with adverse obstetric outcomes during all trimesters of pregnancy. Furthermore, since most studies show an increased prevalence of TAI among women attending infertility clinics, a detrimental impact of this condition on natural fertility and on the rate of success of assisted reproductive techniques has been suggested. However, to date, the results have been inconsistent.

OBJECTIVE AND RATIONALE

The objective of this study was to define the relation between TAI per se and the outcome of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

SEARCH METHODS

A systematic literature review and meta-analysis were conducted. A Medline search was performed to identify all the comparative studies published from January 1990 to November 2015 in the English language literature on IVF/ICSI outcome in women with and without TAI, using combinations of the medical subject heading terms 'thyroid autoimmunity', 'thyroid autoantibodies', 'IVF', 'ICSI', 'pregnancy', 'miscarriage' and 'delivery'. The primary outcome was live birth rate (LBR). Our secondary outcomes were number of oocytes retrieved (NOR), fertilisation rate (FR), implantation rate (IR), clinical pregnancy rate (CPR) and miscarriage rate (MR). We also extracted data on mean age and basal serum concentrations of thyroid stimulating hormone (TSH) and performed a meta-regression analysis to assess the effect of these two covariates on CPR and MR.

OUTCOMES

We selected 12 studies for the meta-analysis. Six of the included studies were prospective cohort studies, and six were retrospective cohort studies. Compared with women with negative TAI, women with positive TAI had a lower LBR (odds ratio (OR) 0.73; 95% confidence interval (CI) [0.54-0.99]; P = 0.04; 9 studies; 4396 women; I2 = 41%), a higher MR (OR 1.44; 95% CI [1.06-1.95]; P = 0.02; 12 studies; 4876 women; I² = 35%), a similar CPR (OR 0.90; 95% CI [0.77-1.06]; P = 0.22; 12 studies; 4876 women; I² = 7%), a similar number of oocytes (standardized mean difference [SMD] 0.10; 95% CI [-0.09 to 0.29]; P = 0.28; 5 studies; 1506 women; I² = 47%), a similar FR (OR 1.11; 95% CI [0.97-1.27]; P = 0.13; 3 studies; 1082 women; I² = 0%) and a similar IR (OR 0.98; 95% CI [0.73-1.32]; P = 0.91; 2 studies; 918 women; I² = 0%). Both mean age (SMD 0.96; 95% CI [0.66-1.27]; P < 0.00001; 9 studies; 3256 women; I² = 85%) and serum TSH (SMD 0.24; 95% CI [0.15-0.34]; P < 0.00001; 6 studies; 2098 women; I² = 59%) were higher in women with TAI. However, neither of these two covariates were significantly associated with CPR or MR.

WIDER IMPLICATIONS

TAI does not impact on IVF/ICSI outcome in terms of NOR and likelihood of fertilisation, implantation and clinical pregnancy. On the contrary, the presence of thyroid autoantibodies may have a detrimental effect on the course of a pregnancy, determining an increased risk of miscarriage and a decreased chance of live birth. However, given the possible modifying effects of age and serum TSH, further evidence is warranted prior to drawing inferences on causality.

Individualized ovarian stimulation in IVF/ICSI treatment: it is time to stop using high FSH doses in predicted low responders

In IVF/ICSI treatment, the FSH starting dose is often increased in predicted low responders from the belief that it improves the chance of having a baby by maximizing the number of retrieved oocytes. This intervention has been evaluated in several randomized controlled trials, and despite a slight increase in the number of oocytes—on average one to two more oocytes in the high versus standard dose group—no beneficial impact on the probability of a live birth has been demonstrated (risk difference, −0.02; 95% CI, −0.11 to 0.06). Still, many clinicians and researchers maintain a highly ingrained belief in ‘the more oocytes, the better’. This is mainly based on cross-sectional studies, where the positive correlation between the number of retrieved oocytes and the probability of a live birth is interpreted as a direct causal relation. If the latter would be present, indeed, maximizing the oocyte number would benefit our patients. The current paper argues that the use of high FSH doses may not actually improve the probability of a live birth for predicted low responders undergoing IVF/ICSI treatment and exemplifies the flaws of directly using cross-sectional data to guide FSH dosing in clinical practice. Also, difficulties in the de-implementation of the increased FSH dosing strategy are discussed, which include the prioritization of intermediate outcomes (such as cycle cancellations) and the potential biases in the interpretation of study findings (such as confirmation or rescue bias).

Acylcarnitine esters profiling of serum and follicular fluid in patients undergoing in vitro fertilization

BACKGROUND

L-carnitine-mediated beta-oxidation of fatty acids has a well established role in energy supply of oocytes and embryos. Disturbed carnitine metabolism may impair the reproductive potential in IVF and can serve as a biomarker of pregnancy outcome.

METHODS

Our study was performed between March 24, 2011 and May 9, 2011. We performed 44 unselected IVF cycles, (aged 23-40 years (mean: 32.3+/-5.1 years) and had BMI of 17.3-34.7 (mean: 23.80+/-4.9). Samples were also obtained from 18 healthy women of similar age admitted for minor elective surgery to serve as control for plasma carnitine profile. Serum and follicular fluid (FF) free carnitine (FC) and 20 major acylcarnitines (ACs) were measured by ESI/MS/MS method.

RESULTS

Serum FC and AC levels in IVF patients were comparable to those in healthy control women. In FF FC and short-chain AC concentrations were similar to those in maternal serum, however, the levels of medium-chain, and long-chain AC esters were markedly reduced (p<0.05). The serum to FF ratio of individual carnitine compounds increased progressively with increasing carbon chain length of AC esters (p<0.05). There was a marked reduction in total carnitine, FC and AC levels of serum and FF in patients with oocyte number of >9 and/or with embryo number of >6 as compared to the respective values of <9 and/or <6 (p<0.05).

CONCLUSIONS

In IVF patients with better reproductive potential the carnitine/AC pathway appears to be upregulated that may result in excess carintine consumption and relative depletion of carnitine pool. Consequently, IVF patients may benefit from carnitine supplementation.

The ovarian sensitivity index is predictive of live birth chances after IVF in infertile patients

STUDY QUESTION

Does the ovarian sensitivity index (OSI) predict embryo quality, pregnancy and live birth in patients undergoing FSH/hMG stimulation for IVF?

SUMMARY ANSWER

The OSI is predictive of pregnancy and live birth in older women with a more unfavorable prognosis undergoing FSH/hMG stimulation for IVF.

WHAT IS KNOWN ALREADY

The OSI was previously reported to reflect gonadotrophin requirements among high, normal and poor responders and to predict pregnancy potential in younger patients undergoing ovarian stimulation with FSH.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study that included 1282 women undergoing IVF with FSH/hMG stimulation was carried out between January 2010 and December 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We evaluated 1282 women who underwent fertility treatment with FSH/hMG stimulation and oocyte retrieval at an academically affiliated private fertility center. OSI was calculated as (oocytes ×1000)/total gonadotrophin dose and grouped into two classes based on a receiver operating characteristic (ROC) curve analysis of a randomly selected development sample comprising one-third of the cycles. The remaining cycles comprised the validation group. ROC curves were also used to compare the predictive value of OSI to that of baseline FSH and anti-Müllerian hormone (AMH). Logistic regression models evaluated the effect of high (OSI >0.83) and low (OSI ≤0.83) on clinical pregnancy and live birth in the validation group. Models were adjusted for female age, baseline FSH, AMH and oocyte yield and gonadotrophin dose.

MAIN RESULTS AND THE ROLE OF CHANCE

Women presented with a mean ±SD age of 38.6 ± 5.4 years and showed median AMH levels of 0.65 (95% CI 0.61–0.74) ng/ml. They received 5145 ± 2477 IU of gonadotrophins and produced a median 5.2 (95% CI 5.0–5.5) oocytes. Pregnancy and live birth rates per oocyte retrieval for all women were 20.6% and 15.8%, respectively. Patients with higher OSI (less gonadotrophin required per oocyte retrieved) produced significantly more high-quality embryos than patients with low OSI (3.5 (95% CI 3.2–3.8) versus 0.6 (95% CI 0.5–0.7) (P = 0.0001)) and demonstrated higher pregnancy (23.2% versus 9.7%) and live birth rates (8.8% versus 5.3%) than their counterparts (P = 0.0001 and P = 0.0001, respectively). After adjustments for age, baseline AMH and FSH, total gonadotrophin dosage and oocyte yield, an OSI >0.83 was associated with greater odds of pregnancy (odds ratio 2.12, 95% CI 1.30–3.45, P < 0.003) and live birth (odds ratio 1.91, 95% CI 1.07–3.41, P < 0.028).

LIMITATIONS, REASONS FOR CAUTION

The results may not be applicable to women with excellent pregnancy potential or FSH-only stimulation.

WIDER IMPLICATIONS OF THE FINDINGS

The predictive capacity of OSI for embryo quality, pregnancy and live birth, which is independent of AMH or FSH, may help in counseling patients about their pregnancy potential and live birth chances.

STUDY FUNDING/COMPETING INTEREST(S)

Intramural funding from the Center for Human Reproduction and the Foundation for Reproductive Medicine. A.W., V.A.K., D.F.A., D.H.B. and N.G. have received research grant support, travel funds and speaker honoraria from various pharmaceutical and medical device companies: none, however, related to the topic presented here. D.H.B. and N.G. are listed as inventors on already awarded and still pending US patents, claiming beneficial effects on diminished ovarian reserve and embryo ploidy from dehydroepiandrosterone supplementation.

TRIAL REGISTRATION NUMBER

N/A.

What number of oocytes is appropriate for defining poor ovarian response?

PURPOSE

This study attempted to derive an objective and sophisticated definition of poor ovarian response (POR).

MATERIALS AND METHODS

A total of 176 consecutive in vitro fertilization (IVF) cycles (137 patients) with conventional ovarian stimulation during 2009 to 2012 were studied by retrospective analysis. Optimal oocyte number (total or mature) was determined by statistics-based (distribution of oocyte number) and prognosis-based approaches (prediction for IVF outcome). Receiver operating characteristics curve analysis was used to show what number of oocytes could predict IVF pregnancy and whether clinical and laboratory variables could predict newly defined POR.

RESULTS

The 25th percentile of the distribution corresponded to total oocytes ≤2 and mature oocyte ≤1. The cut-off values for the prediction of IVF outcomes were total oocytes >5 and mature oocyte >1. Considering the incidence of POR (34.1%), a reasonable definition of POR was decided as total oocytes ≤2 or mature oocyte ≤1. For the prediction of this new definition, the extreme cut-off value (by setting a false positive rate of 5%) of serum anti-Mullerian hormone (AMH) was ≤0.76 ng/mL, which was better than serum follicle stimulating hormone or age. A new simple definition of POR was derived as total oocytes ≤2 or mature oocyte ≤1 in a previous cycle or a serum AMH level of ≤0.76 ng/mL. When this simple criterion was re-applied to our data, the predictive performance was similar to the Bologna criteria.

CONCLUSION

We here propose a new definition of POR, which is simple and supported by statistical and prognostic analyses.

Impact of pituitary suppression on antral follicle count and oocyte recovery after ovarian stimulation

OBJECTIVE

To investigate the potential influence of short-term pituitary suppression on antral follicle count (AFC) and correlate the AFC with the number of oocytes retrieved after ovarian stimulation.

DESIGN

Retrospective study.

SETTING

University fertility center.

PATIENT(S)

A total of 1,479 infertile patients.

INTERVENTION(S)

Patients had baseline AFC, when they were not on any medications known to cause pituitary suppression, and follow-up AFC (suppressed AFC) while on E2, GnRH agonist (GnRH-a), oral contraceptive (OC) pills, or OC pills/GnRH-a in preparation for ovarian stimulation, performed within 6 months of initial baseline AFC.

MAIN OUTCOME MEASURE(S)

The AFC at baseline, AFC during pituitary suppression, and the number of oocytes retrieved.

RESULT(S)

Although there was an average unadjusted decline of 0.4, 0.9, 2.2, and 3.0 in AFC while patients were on E2, GnRH-a, OC pills, and OC pills/GnRH-a, respectively, this decline was driven by age, baseline AFC, and the hormones used. Although baseline and suppressed AFC were found to be good predictors of the number of oocytes retrieved after ovarian stimulation, statistically, suppressed AFC was found to be a marginally better predictor.

CONCLUSION(S)

Short-term pituitary suppression has a negative impact on AFC. This decline in AFC may influence the number of oocytes retrieved, suggesting the suppressive impact of exogenous hormones on the biological capacity of the ovary during stimulation.

Comparison of the morphokinetic parameters of embryos according to ovarian reserve in IVF cycles

The aim of this study is to evaluate the impact of ovarian reserve and age of women on early morphokinetic parameters of embryos with a time-lapse monitoring system. In total, 197 infertile couples with poor ovarian reserve (Group 1, n = 41), normal ovarian reserve (Group 2, n = 59), or polycystic ovaries (Group 3, n = 97) were included. The time from insemination to the following events were analyzed: pronuclear fading (Pnf) and cleavage to 2, 3, 4 and 5 cells. The optimal ranges for morphokinetic parameters of t5, s2 and cc2 in each group were also evaluated. In total, 1144 embryos were evaluated. Morphokinetic parameters did not differ statistically between the groups. Data were analyzed according to different age groups (20-30, 30-40, >40). The morphokinetic parameters did not differ statistically in Group 1 and 3. In Group 2, the times from insemination to tPnf, t2, t3, t4 were significantly shorter in the younger age group than the older age group (p < 0.05). The percentages of optimal embryos, according to t5, s2 and cc2, did not differ statistically between the groups. In conclusion, ovarian reserve did not seem to affect the morphokinetic parameters of embryos.

Fertility After Ovarian Cystectomy: How Does Surgery Affect IVF/ICSI Outcomes?

Introduction For patients considering undergoing assisted reproductive techniques (ART), many concerns arise when persistent ovarian cysts are found. This large study aimed to determine how ovarian cyst removal affects success rates of IVF/ICSI therapies.

Methods 550 patients who underwent an IVF/ICSI treatment between 2002 and 2011 with a persistent ovarian cyst ≤ 5 cm before treatment were analyzed retrospectively. 328 patientsʼ preference was to undergo a laparoscopic cystectomy and 222 patients opted for a conservative management. Control subjects included 13 552 patients undergoing IVF/ICSI at the same period of time without an ovarian cyst.

Results After adjusting for age, patients with ovarian cysts without surgery needed a significant higher stimulation dose than the control group (2576.4 vs. 2207.5 IU, p < 0.001). However, on average, they had 1.13 (− 0.25 – 2.01) higher oocyte number retrieved compared to the operated patients (9.0 ± 5.5 vs. 8.2 ± 5.0) (p = 0.012). Patients after surgical cyst removal had a significant lower number of oocytes retrieved (MNOR) in comparison to the control group (8.2 ± 5.0 vs. 9.5 ± 5.4) (p = 0.00). Compared to controls, operated patients had similar clinical pregnancy rate (CPR) (34.2 vs. 33.5%) OR 1.031 (95% CI 0.817 – 1.302) (p = 0.815). Compared to controls, patients without surgery showed significant lower pregnancy rate (34.2 vs. 25,7%) OR 1.428 (95% CI 1.054 – 1.936) (p = 0.002) and lower live birth rate (LBR) (21.9 vs. 13.5%) OR 1.685 (95% CI 1.143 – 2.485) (p = 0.008).

Conclusions Ovarian cystectomy did not negatively impact the pregnancy rate or the live birth rate compared to controls.

Are all antral follicles the same? Size of antral follicles as a key predictor for response to controlled ovarian stimulation

The aim of this study was to evaluate whether antral follicle size has any value with respect to antral follicle count (AFC) in predicting ovarian response to controlled ovarian stimulation. Patients who were considered to be normal responders based on their ovarian reserve markers were consecutively recruited. Total AFC was the number of 2-10 mm follicles in both ovaries. Antral follicles were separated into two subgroups according to the size: 2-5 mm and 6-10 mm follicles. Patients were divided into two main groups according to ovarian response to COS. Group 1 (suboptimal response, 4-9 oocytes retrieved, n = 61) and Group 2 (normal responders, ≥10 oocytes retrieved, n = 65). Demographic parameters were comparable between the groups. The number of 2-5 mm follicles was significantly lower in the suboptimal response group (5 [4:7] and 8 [6:10], respectively, p < .001). The ratio of 2-5 mm follicles to total antral follicles was also significantly lower in Group 1 (44.4% and 75%, respectively, p < .001). The ratio of small antral follicles was positively correlated with ovarian response (r = 0.587, p < .001). In conclusion, the ratio of small (2-5 mm) antral follicles could be a more specific predictive marker than AFC for ovarian response.IMPACT STATEMENTWhat is already known on this subject? Prediction of the ovarian response during ovarian stimulation is commonly based on antral follicle count and anti-mullerian hormone. The ovarian response may be inadequate even in patients with normal antral follicle count and anti-mullerian hormone.What do the results of this study add? A high ratio of small-size (2-5 mm) basal antral follicles is a predictive factor for higher ovarian response to ovarian hyperstimulation.What are the implications of these findings for clinical practice and/or further research? To obtain optimal ovarian response, the antral follicles should be evaluated initially in a more detailed and systematic way by taking their sizes into consideration in addition to their counts. Small antral follicle count rather than whole antral follicle count may be beneficial for optimising the ovarian response. Future studies may determine the cut off values of small antral follicle count for high/poor ovarian response.

Detection of zeb1 Gene in Granulosa Cells in Women Undergoing IVF Treatment

BACKGROUND

ZEB1 plays a role in epithelial-to-mesenchymal transition and acts as a repressor of E-cadherin, TGF-β, and Wnt/β-catenin. Since ZEB1 protein is expressed in estrogen-responsive tissues, and expression of the gene in the normal ovary and endometrium is positively correlated with high estrogen levels, we performed a direct analysis of granulosa cell samples to determine whether there are any significant changes in zeb1 expression during folliculogenesis.

METHODS

ZEB1 expression levels were measured in the granulosa cells of 56 infertile women undergoing IVF treatment. RNA extraction from granulosa cells was performed along with reverse transcription quantitative polymerase chain reaction (RT-qPCR) with SYBR Green I to determine zeb1 gene expression levels. Statistical analysis was performed by using t-test, while possible correlations of the expression of ZEB1 protein with body mass index (BMI), age, number of oocytes, and oocyte maturation were investigated.

RESULTS

Zeb1 gene expression levels correlate significantly with body mass index (BMI) and age, but not with oocyte number and oocyte maturation stage. Obese women demonstrate a higher expression level of zeb1 gene compared to normal and overweight women. Moreover, zeb1 gene is overexpressed in women aged 35-40 years old and is under-expressed in women >40 years old.

CONCLUSIONS

ZEB1 expression should be further investigated as it may unveil new potential findings of the zeb1 gene's role in female fertility and its use as a biomarker in fertility workups.

The Effectiveness of the GnRH Agonist/Antagonist Protocols for Different Poseidon Subgroups of Poor Ovarian Responders

Background/Objectives: Poor responder patients represent the greatest challenge in ART. An inadequate response to COS strongly correlates with a reduced chance of conception. A novel classification of poor responders overcame a deficiency in the Bologna criteria and distinguished an expected and unexpected low ovarian response, allowing for an individual treatment approach to be created. In this study, we compared the clinical outcomes in poor responders, according to two different ovarian stimulation protocols, GnRH agonists and antagonists, classified according to the Poseidon criteria, to determine the most effective protocol for each group. Methods: This retrospective study involved 1323 low-prognosis women ranked according to the Poseidon classification and a control group of normal responders. Results: The GnRH-antagonist protocol showed some advantage in the Poseidon 1b group whereas the GnRH-agonist protocol was more effective in the Poseidon 4 group. There were no differences in live births or miscarriage rates in poor responders among these two protocols. Conclusions: Using both the agonist/antagonist approaches, live birth rates are two or even three times less in Poseidon patients in comparison to normal responders. The number of obtained oocytes, their maturity and quality, and women's ages were found to be the most influential determinants for a successful outcome. Further investigations into ovarian stimulation strategies are required to enhance oocyte number and live birth occurrence.