Effect of elevated estradiol levels on the hCG administration day on IVF pregnancy and birth outcomes in the long GnRH-agonist protocol: analysis of 3393 cycles

The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

Impact of Endometrial Thickness and Volume Compaction on the Live Birth Rate Following Fresh Embryo Transfer of In Vitro Fertilization

OBJECTIVES

The aim of our study was to compare the live birth rate following fresh embryo transfer (ET) during in vitro fertilization (IVF) in women with or without endometrial compaction in thickness and volume between the day of human chorionic gonadotrophin (hCG) and the ET day.

METHODS

This is a retrospective analysis of infertile women undergoing the first IVF cycle with fresh ET. A single operator performed all the ultrasound measurements for endometrial thickness and endometrial volume using three-dimensional ultrasound. Endometrial compaction was calculated as the difference of the measurement between the hCG day and ET day. The predictive values of age of women, number of embryos transferred, and endometrial compaction in thickness and volume on live birth were studied.

RESULTS

A total of 268 women who underwent the first IVF cycle with fresh ET between June 2005 and August 2006 were included in this retrospective analysis. Endometrial thickness was significantly higher on the ET day than the hCG day while endometrial volume was significantly smaller on the ET day than the hCG day. Women with a live birth were younger, had a higher serum estradiol level on the hCG day, and similar absolute or percentage change of endometrial thickness and volume when compared to those without a live birth.

CONCLUSION

Endometrial thickness and volume compaction was not a significant predictor of live birth in the multivariate logistic regression model. Endometrial thickness and volume compaction did not affect the live birth rate in the fresh IVF cycle.

Positive correlation of oestradiol level on trigger day with the secretion level of endometrial kisspeptin and leukaemia Inhibitory Factor in the Mid-Luteal Stimulated Cycle

Background:

Kisspeptin plays a role in the oestradiol negative-feedback regulation of GnRH as well as gonadotropin. In addition, kisspeptin has been postulated to induce the production of an important cytokine called leukaemia inhibitory factor (LIF).

Aims:

This study aims to investigate the correlation between varying oestradiol levels measured on trigger day of the ovarian stimulation and the mRNA expression level of endometrial kisspeptin and LIF.

Study Setting and Design:

Prospective cross-sectional study took place in Morula IVF Jakarta clinic.

Materials and Methods:

A total of 43 infertile couples underwent an in-vitro fertilization (IVF) program. Subjects were grouped based on oestradiol levels as follows: group A ([≧ 3000 pg/mL, n = 15], group B [2000–2999 pg/mL, n = 14], group C [<2000 pg/mL, n = 14]).

Statistical Analysis Used:

ANOVA test was utilised to compare the expression of kisspeptin and LIF among study groups while Pearson correlation was used to identify the correlation between variables.

Results:

A significantly higher mRNA expression of both Kisspeptin and LIF was found in group A than in groups B and C (P < 0.001). The mRNA expression of kisspeptin and LIF correlated positively with the oestradiol level (r = 0.638, P < 0.001 and r = 0.634, P < 0.001, respectively). Moreover, a strong association between Kisspeptin and LIF expression was also detected (r = 0.700, P < 0.001).

Conclusions:

mRNA expression of kisspeptin and LIF was significantly different according to the oestradiol levels in the study groups. Increased oestradiol level was shown to elevate the expression of endometrial kisspeptin and LIF in women undergoing the IVF programme.

Evaluation of the relationship between serum estradiol levels on human chorionic gonadotropin administration day and intracytoplasmic sperm injection outcomes: A retrospective population-based study

Background

The correlation between high estradiol (E2) levels induced by controlled ovarian hyperstimulation (COH) and pregnancy is controversial.

Objective

To assess the effect of serum E2 levels on the day of human chorionic gonadotropin administration on the intracytoplasmic sperm injection (ICSI) outcome.

Materials and Methods

The current study included 551 participants who had undergone ICSI between May 2014 and May 2016. Based on E2 levels, the individuals aged < 37 yr (n = 502) and 37-42 yr (n = 49) were categorized into six and three groups, respectively. ICSI outcomes including the number of retrieved oocytes (NRO), number of embryos (NE), pregnancy rate, and abortion rate were analyzed in both groups.

Results

Among participants aged < 37 yr, the NRO and NE were 8.69 ± 3.82 and 5.24 ± 2.32, respectively and they had a significant correlation with the E2 level on human chorionic gonadotropin administration day (p < 0.001 for both). Among participants aged > 37 yr, NRO and NE were 5.18 ± 3.17 and 3.40 ± 2.23, respectively, and the NRO (p < 0.001), NE (p < 0.001), pregnancy rate (p < 0.001), abortion rate (p = 0.007), and the number of grade A and B embryos (p = 0.003) had a significant association with the E2 level.

Conclusion

COH is a costly procedure that may have negative effects on endometrial receptivity. Thus, in order to prevent these effects and also to reduce the costs of COH, we recommend gaining optimum number of oocytes rather than maximum number during the procedure.

Progesterone/Oestradiol ratio can Better Predict Intracytoplasmic Sperm Injection Outcomes than Absolute Progesterone Level

Background:

Several parameters were proposed to predict the impact of premature luteinization on intracytoplasmic sperm injection (ICSI) outcomes such as isolated progesterone (P) level, progesterone to oocyte ratio, and progesterone/estradiol ratio (P/E2).

Aim:

The aim of this study is to compare the predictive value of P/E2 ratio and isolated P level on the ovulation triggering day for pregnancy outcomes in fresh GnRH antagonist ICSI cycles.

Settings and Design:

A retrospective cohort study conducted in a university-affiliated in vitro fertilization center between January 2017 and April 2019.

Methods:

The study included women who underwent their first- or second-ranked GnRH antagonist ICSI cycles with day-3 embryo transfer. P/E2 ratio was calculated as (P [ng/mL] × 1000)/E2 (pg/mL). Cutoff values of ≥1.5 ng/ml for high P (HP) and ≥0.55 for HP/E2 ratio were chosen based on the literature.

Statistical Analysis:

A receiver operating curve was performed to detect the predictability of serum P/E2 and P for the ongoing pregnancy rate. First, patients were divided according to either P level (low P < 1.5 ng/mL and HP ≥1.5 ng/mL) or P/E2 ratio (low P/E2 <0.55 and HP/E2 ≥ 0.55). Patients were further divided into four subgroups: (Group A: HP and HP/E2 ratio, Group B: low P and low P/E2 ratio, Group C: HP only, and Group D: HP/E2 only). A multivariate regression analysis models were used to account for the effect of the cycle confounders on the likelihood of pregnancy.

Results:

A total of 402 ICSI cycles were analyzed. The area under the curve was 0.67 and 0.59 for P/E2 and P, respectively. P/E2 showed a significant association with ongoing pregnancy (adjusted odds ratios [aOR]: 0.409, 95% confidence interval [CI] 0.222–0.753, P = 0.004) while HP revealed no significant predictive value (aOR: 0.542, 95% CI 0.284–1.036, P = 0.064) after the multivariate analysis.

Conclusions:

P elevation may not present as an independent predictor for cycle outcomes. P/E2 ratio has a better prognostic value than P alone in predicting pregnancy of GnRH antagonist cycles.

Supraphysiological estradiol levels on the hCG trigger day are associated with SGA for singletons born from fresh embryo transfer

The effects of supraphysiological estradiol (E2) on neonatal outcomes and the significance of specific E2 concentrations remain unclear. The purpose of this study was to investigate whether supraphysiological E2 levels on the human chorionic gonadotropin (hCG) trigger day are associated with small size for gestational age (SGA) in singletons born from fresh embryo transfer (ET) cycles. Patients with singleton pregnancies who delivered after the transfer of fresh embryos, during the period from July 2012 to December 2017, at our center were included. We excluded cycles involving a vanishing twin, maternal age >35 years, basal follicle-stimulating hormone ≥10 mIU/ml, or anti-Müllerian hormone ≤1 ng/ml. We then divided all cycles into five groups by E2 level on trigger day: group A, <2000 pg/ml (reference group); group B, 2000 pg/ml≤E2<2999 pg/ml; group C, 3000 pg/ml≤E2<3999 pg/ml; group D, 4000 pg/ml≤E2<4999 pg/ml; and group E, ≥5000 pg/ml. The prevalence of SGA among singletons from fresh ET was the primary outcome. The SGA rate significantly increased when the E2 level was ≥4000 pg/ml, as observed by comparing groups D (odds ratio [OR]: 1·79, 95% confidence interval [CI]: 1·16-2·76, P = 0·01) and E (OR: 1·68, 95% CI: 1·10-2·56, P = 0·02) with the reference group. Multivariate logistic regression indicated that a serum E2 level of at least 4000 pg/ml on the hCG trigger day was associated with increased SGA and with significant differences for groups D (adjusted OR [AOR]: 1·65, 95% CI: 1·05-2·59, P = 0·03) and E (AOR: 1·60, 95% CI: 1·03-2·53, P = 0·04) relative to the reference group. In conclusion, in fresh ET cycles, the supraphysiological E2 ≥4000 pg/ml on the hCG trigger day increases the risk of SGA.

Association between serum oestradiol level on the hCG administration day and neonatal birthweight after IVF-ET among 3659 singleton live births

Oestradiol, an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization-embryo transfer (IVF-ET) cycles. A supraphysiologic E2 level is inevitable during controlled ovarian hyper-stimulation (COH), and its effect on the outcome of IVF-ET is controversial. The aim of this retrospective study is to evaluate the association between elevated serum oestradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and neonatal birthweight after IVF-ET cycles. The data of 3659 infertile patients with fresh IVF-ET cycles were analysed retrospectively between August 2009 and February 2017 in First Hospital of Zhengzhou University. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E₂ levels ≤ 1000 pg/mL, n = 230), group 2 (serum E2 levels between 1001 and 2000 pg/mL, n = 524), group 3 (serum E₂ levels between 2001 and 3000 pg/mL, n = 783), group 4 (serum E₂ levels between 3001 and 4000 pg/mL, n = 721), group 5 (serum E2 levels between 4001 and 5000 pg/mL, n = 548 ), and group 6 (serum E2 levels > 5000 pg/mL, n = 852). Univariate linear regression was used to evaluate the independent correlation between each factor and outcome index. Multiple logistic regression was used to adjust for confounding factors. The LBW rates were as follows: 3.0% (group 1), 2.9% (group 2), 1.9% (group 3), 2.9% (group 4), 2.9% (group 5), and 2.0% (group 6) (P = 0.629), respectively. There were no statistically significant differences in the incidences of neonatal LBW among the six groups. We did not detect an association between peak serum E2 level during ovarian stimulation and neonatal birthweight after IVF-ET. The results of this retrospective cohort study showed that serum E2 peak levels during ovarian stimulation were not associated with birth weight during IVF cycles. In addition, no association was found between higher E2 levels and increased LBW risk. Our observations suggest that the hyper-oestrogenic milieu during COS does not seem to have adverse effects on the birthweight of offspring after IVF. Although this study provides some reference, the obstetric-related factors were not included due to historical reasons. The impact of the high estrogen environment during COS on the birth weight of IVF offspring still needs future research.

Does the elevated estradiol level on the day of human chorionic gonadotropin administration affect embryo quality among women undergoing in vitro fertilization?

OBJECTIVE

To evaluate the association between estradiol (E₂ ) levels on the day of human chorionic gonadotropin (hCG) administration and embryo quality during in vitro fertilization (IVF) cycles.

METHODS

A retrospective study of 6676 IVF cycles among women treated at the Reproductive Center of The First Affiliated Hospital of USTC, Hefei, China, from June 2014 to May 2017. E₂ levels on hCG day were divided into four groups by 25th percentile: 0-1763 pg/mL (group I), 1763-3692 pg/mL (group II), 3692-4800 pg/mL (group III), and higher than 4800 pg/mL (group IV). Analysis of variance and multiple linear regression were used to test associations.

RESULTS

There were significant differences in the frequency of high-quality embryos between group I (51.6 ± 1.1%) and groups II (65.6 ± 0.8%), III (62.1 ± 0.7%), and IV (62.3 ± 0.7%). Using E₂ as a dummy variable and group II as a control, multiple linear regression showed that E₂ levels were associated with the frequency of high-quality embryos obtained (P < 0.05).

CONCLUSION

Serum E₂ on hCG day had an impact on embryo quality. Higher E₂ levels did not produce the most high-quality embryos; the highest frequencies were achieved for E₂ levels within 1763-3692 pg/mL.

Clinical and genetic analysis of cytochrome P450 oxidoreductase (POR) deficiency in a female and the analysis of a novel POR intron mutation causing alternative mRNA splicing : Overall analysis of a female with POR deficiency

OBJECTIVE

To characterize the clinical features of a female with P450 oxidoreductase (POR) deficiency and to investigate the underlying mechanisms of POR inactivation.

METHODS

The proband was a 35-year-old woman with primary infertility and menstrual irregularity. The reproductive endocrine profile was evaluated. DNA sequencing was conducted for the identification of POR gene mutation. RT-PCR was performed to confirm the impact of the mutation on POR mRNA. A molecular model was built for the structural analysis of mutant POR protein.

RESULTS

The evaluation of reproductive endocrine profile revealed elevation of serum follicle-stimulating hormone (11.48 mIU/ml), progesterone (11.00 ng/ml), 17α-hydroxyprogesterone (24.24 nmol/l), dehydroepiandrosterone (6300 nmol/l), and androstenedione (3.89 nmol/l) and decreased estradiol (36.02 pg/ml). Sequencing of the POR gene showed the female was a compound heterozygote of the paternal P399_E401 deletion and a novel maternal IVS14-1G>C mutation. Functional analysis revealed IVS14-1G>C mutation caused alternative splicing of POR mRNA, with the loss of 12 nucleotides in exon 15 (c.1898_1909delGTCTACGTCCAG). Also, the resulting mutant POR protein had a V603_Q606 deletion, which inactivated the nucleotide-binding domain of NADPH in POR protein (K602_Q606).

CONCLUSION

The mutation IVS14-1G>C of the POR gene could cause alternative splicing of POR mRNA and dysfunction of the resulting POR protein. Under proper IVF strategy with glucocorticoid therapy and endometrial preparation, females with mild POR deficiency still have the opportunity to have a live birth.

Association between serum estradiol level on the human chorionic gonadotrophin administration day and clinical outcome

BACKGROUND

Estradiol, as an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization embryo transfer (IVF-ET) cycles. The aim of this retrospective study was to evaluate the association between elevated serum estradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and IVF-ET pregnancy and birth outcomes.

METHODS

A total of 1771 infertile patients with their first fresh IVF-ET cycles were analyzed retrospectively between January 2011 and January 2016 in Peking University First Hospital. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels ≤ 1000 pg/mL, n = 205), group 2 (serum E2 levels 1001-2000 pg/mL, n = 457), group 3 (serum E2 levels 2001-3000 pg/mL, n = 425), group 4 (serum E2 levels 3001-4000 pg/mL, n = 310), group 5 (serum E2 levels 4001-5000 pg/mL, n = 237), and group 6 (serum E2 levels > 5000 pg/mL, n = 137). The retrieved oocyte and MII oocyte numbers and implantation and clinical pregnancy rates of the groups were compared as the first objective of the study. For the 360 women with singleton births among all patients, the area under the corresponding receiver operating characteristic curve (ROC curve) was calculated to assess the predictive value of the E2 change for the probability of low birth weight (LBW) infants as the second objective.

RESULTS

The retrieved oocyte and MII oocyte numbers and implantation and clinical pregnancy rates gradually increased from groups 1 to 5 but decreased in group 6. The parameters of group 1 were statistically worse than those of the other groups, from group 2 to group 6 (the number of retrieved oocytes, t = 13.096, t = 23.307, t = 23.086, t = 26.376, t = 19.636, P < 0.003; the number of retrieved MII oocytes, t = 10.856, t = 20.868, t = 21.874, t = 23.374, t = 19.092, P < 0.003; the implantation rate, χ = 12.179, χ = 22.239, χ = 23.993, χ = 23.344, χ = 16.758, P < 0.003; the clinical pregnancy rate, χ = 16.415, χ = 28.074, χ = 35.387, χ = 37.025, χ = 24.590, P < 0.003). ROC analysis revealed that when a serum peak E2 of 3148 pg/mL was used to predict LBW.

CONCLUSIONS

The results indicate that serum E2 levels have a concentration-dependent effect on clinical outcomes. The optimal range of the E2 level during a fresh IVF-ET cycle is 1000 to 3148 pg/mL.

Relationship between a low ratio of serum estradiol to follicle number and fertility treatment outcomes: A retrospective cohort study of 516 cases

The aim of this retrospective study was to examine how a low estradiol/follicle (E2/fol) may be related to in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)-embryo transfer outcomes in polycystic ovary syndrome (PCOS) and non-PCOS patients, respectively. Between 2013 and 2017, 516 IVF/ICSI cycles (146 cycles in PCOS patients and 370 cycles in non-PCOS patients) with a long gonadotrophin releasing hormone receptor agonist protocol-including 338 involved fresh transfer cycles (89 cycles in PCOS patients and 249 cycles in non-PCOS patients)-were conducted. Outcomes were compared between 5 groups of PCOS patients defined by E2/fol (pg/mL) as follows: A, <140; B, 140 to 210; C, 210 to 280; D, 280 to 350; and E, >350. Non-PCOS patients' outcomes are grouped as well. Whether in PCOS or non-PCOS patients, those in the lowest E2/fol group (<140 pg/mL) tended to be younger, and with a greater body mass index (BMI) and antral follicle count (AFC), than the patients in the other groups. Relative to the other groups, Group A showed a lower number and rate of oocytes, higher single pronucleus (1PN) and triple pronucleus (3PN) formation rate, early and advanced abortion rates, but these did not differ significantly from those of the other groups, it perhaps due to the limited sample size. Group A have a higher incidence of moderate or severe ovarian hyperstimulation syndrome than the other groups in non-PCOS patients (P > .05). Whether in PCOS or non-PCOS patients, greater BMI, greater AFC, and younger age may favor the phenomenon of low E2/fol. In turn, low E2/fol may reduce the oocyte retrieval rate and increase the risk of 1PN and 3PN formation and abortion.

[Pregnancy and obstetric outcomes of elective single versus double cleavage-stage embryo transfer]

OBJECTIVE

To compare the pregnancy and obstetric outcomes in elective single versus two cleavage-stage embryo transfer.

METHODS

Fresh cleavage-stage embryo transfer cycles between January, 2014 and October, 2015 were reviewed, including 39 single embryo transfer (eSET) cycles and 200 double embryo transfer (DET) cycles. The clinical pregnancy rates, implantation rates, multiple pregnancy rates, live birth rate, and obstetric outcomes (gestational age, preterm delivery rate and mean birth weight) were compared between the two groups.

RESULTS

The baseline characteristics were comparable between the two groups. The estradiol level on the day of trigger and the oocyte number were significantly higher in eSET group than in DET group (10654.4 pmol/L vs 8284.2 pmol/L and 8.4 vs 7.0, respectively). No significant difference was found in the pregnancy rate (56.4% vs 66.0%) or live birth rate (48.7% vs 51.5%) between the two groups, and their implantation rates differed significantly (56.4% vs 37.8%). No multiple pregnancies occurred in eSET group while the rate of multiple pregnancies was 22.7% in DET group. The gestational age and mean birth weight were significantly higher in eSET group (P<0.05), and the preterm delivery rate after DET was nearly three times of that after eSET, although this difference was not statistically significant.

CONCLUSIONS

Elective single embryo transfer can be performed without compromising the live birth rates. Multiple pregnancy rates can be significantly reduced with eSET, which also results in a higher chance of delivering a term singleton live birth compared with DET.