Higher β-HCG concentrations and higher birthweights ensue from single vitrified embryo transfers

Single day 14 serum hCG values allow prediction of viable pregnancy and are significantly higher in frozen as compared to fresh single blastocyst transfer

PURPOSE

To evaluate if single serum human chorionic gonadotropin (hCG) level measurements are sufficient for pregnancy monitoring after single embryo transfer (sET) and to compare the hCG levels between fresh (FRET) and frozen embryo transfers (FET) in medically assisted reproduction.

METHODS

This was a retrospective exploratory cohort study including all patients who met the inclusion criteria, who received a single FRET (n = 249) or FET (n = 410) of a day five blastocyst at the IVF clinic at the Johannes Kepler University Linz between 2011 and 2020. hCG levels were measured on day 14 after embryo transfer. Threshold values for the viability of pregnancies were determined using receiver operating characteristic (ROC) curves.

RESULTS

Significantly higher hCG levels were found in those who received FET than in those who received FRET (1222.8 ± 946.7 mU/ml vs. 862.7 ± 572.9 mU/ml; p < 0.001). Optimal threshold values predicting a viable pregnancy were 368.5 mU/ml and 523 mU/ml in the FRET and FET groups, respectively.

CONCLUSIONS

After FET, higher hCG values after 14 days of embryo transfer must be considered in pregnancy monitoring. Additionally, a single threshold hCG value seems to be sufficient for determining pregnancy viability. To exclude ectopic pregnancies, subsequent ultrasound examination is a mandatory requirement.

Association between the length of in vitro embryo culture, mode of ART, and the initial endogenous hCG rise in ongoing singleton pregnancies

STUDY QUESTION

Is there an association between the length of in vitro culture, mode of ART and the initial endogenous hCG rise, in cycles with a foetal heartbeat after single embryo transfer (ET) and implantation?

SUMMARY ANSWER

Both the length of in vitro culture and the mode of ART have an impact on the initial endogenous rise in hCG in singleton pregnancies.

WHAT IS KNOWN ALREADY

Different factors have been identified to alter the kinetics of hCG in pregnancies. Current studies show conflicting results regarding the kinetics of hCG after different types of ART (fresh vs frozen ET (FET)), the inclusion or not of preimplantation genetic testing (PGT), and the length of time in in vitro culture.

STUDY DESIGN, SIZE, DURATION

This was a multicentre cohort study, using prospectively collected data derived from 4938 women (5524 treatment cycles) undergoing IUI (cycles, n = 608) or ART (cycles, n = 4916) treatments, resulting a in singleton ongoing pregnancy verified by first-trimester ultrasound scan. Data were collected from the Danish Medical Data Centre, used by the three participating Danish public fertility clinics at Copenhagen University hospitals: Herlev Hospital, Hvidovre Hospital, and Rigshospitalet, from January 2014 to December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The fresh ET cycles included cleavage-stage (2 or 3 days in vitro) and blastocyst (5 days in vitro) transfers. FET cycles included cleavage-stage (3 days in vitro before cryopreservation) or blastocyst (5 or 6 days in vitro before cryopreservation) transfers. The IUI cycles represented no time in vitro. To attain a comparable interval for serum-hCG (s-hCG), the ovulation induction time was identical: 35-37 h before oocyte retrieval or IUI. The conception day was considered as: the insemination day for pregnancies conceived after IUI, the oocyte retrieval day for fresh ET, or the transfer day minus 3 or 5 as appropriate for FET of Day 3 or 5 embryos. Multiple linear regression analysis was used, including days post-conception for the hCG measurement as a covariate, and was adjusted for the women's age, the cause of infertility, and the centre. For FET, a sensitivity analysis was used to adjust for endometrial preparation.

MAIN RESULTS AND THE ROLE OF CHANCE

The study totally includes 5524 cycles: 2395 FET cycles, 2521 fresh ET cycles, and 608 IUI cycles. Regarding the length of in vitro culture, with IUI as reference (for no time in in vitro culture), we found a significantly lower s-hCG in pregnancies achieved after fresh ET (cleavage-stage ET or blastocyst transfer). S-hCG was 18% (95% CI: 13-23%, P < 0.001) lower after fresh cleavage-stage ET, and 23% (95% CI: 18-28%, P < 0.001) lower after fresh blastocyst transfer compared to IUI. In FET cycles, s-hCG was significantly higher after blastocyst transfers compared to cleavage-stage FET, respectively, 26% (95% CI: 13-40%, P < 0.001) higher when cryopreserved on in vitro Day 5, and 14% (95% CI: 2-26%, P = 0.02) higher when cryopreserved on in vitro Day 6 as compared to Day 3. Regarding the ART treatment type, s-hCG after FET blastocyst transfer (Day 5 blastocysts) cycles was significantly higher, 33% (95% CI: 27-45%, P < 0.001), compared to fresh ET (Day 5 blastocyst), while there was no difference between cleavage-stage FET (Days 2 + 3) and fresh ET (Days 2 + 3). S-hCG was 12% (95% CI: 4-19%, 0.005) lower in PGT FET (Day 5 blastocysts) cycles as compared to FET cycles without PGT (Day 5 blastocysts).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design is a limitation which introduces the risk of possible bias and confounders such as embryo score, parity, and ovarian stimulation.

WIDER IMPLICATIONS OF THE FINDINGS

This study elucidates how practices in medically assisted reproduction treatment are associated with the hCG kinetics, underlining a potential impact of in vitro culture length and mode of ART on the very early embryo development and implantation. The study provides clinicians knowledge that the type of ART used may be relevant to take into account when evaluating s-hCG for the prognosis of the pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. AP has received consulting fees, research grants, or honoraria from the following companies: Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos, Merck A/S, and Organon. AZ has received grants and honoraria from Gedeon Richter. NLF has received grants from Gedeon Richter, Merck A/S, and Cryos. MLG has received honoraria fees or research grants from Gedeon Richter, Merck A/S, and Cooper Surgical. CB has received honoraria from Merck A/S. MB has received research grants and honoraria from IBSA. MPR, KM, and PVS all report no conflicts of interest.

TRIAL REGISTRATION NUMBER

The study was registered and approved by the Danish Protection Agency, Capital Region, Denmark (Journal-nr.: 21019857). No approval was required from the regional ethics committee according to Danish law.

Perinatal outcomes of singletons following double vitrification-warming procedures: a retrospective study using propensity score analysis

BACKGROUND

Although repeated cryopreservation is an occasional occurrence, the effect on perinatal outcomes is unclear. Therefore, the aim of this study was to evaluate the perinatal outcomes of singletons after embryo re-cryopreservation.

METHODS

In this retrospective study, a total of 647 singleton live births after blastocyst freeze-thaw embryo transfer cycles were investigated. They were divided into two groups: vitrified-warmed blastocysts (once-vitrified group) and vitrified-warmed blastocysts derived from thawed cleaved embryos (re-vitrified group). Propensity score matching (PSM) was used to control for potential confounding factors.

RESULTS

A total of 592 infants were included in the once-vitrified group, and 55 infants were included in the re-vitrified group. After PSM, 108 cases were generated for comparison. The median gestational age was 38 weeks for both groups, and the birthweights were comparable (3390.6 ± 601.5 g vs. 3412.8 ± 672.6 g, P > 0.05). The incidence of preterm birth (PTB) (20.4% vs. 16.7%), low birthweight (LBW) (3.7% vs. 7.4%), macrosomia (11.1% vs. 16.7%) and large for gestational age (LGA) (29.6% vs. 22.2%) were not significantly different between the two groups. Logistic regression analysis indicated that double vitrification-warming procedures did not affect the occurrence of PTB (OR, 2.58 [95% CI, 0.77, 8.63]), LBW (OR, 0.83 [95% CI, 0.08, 8.29]), macrosomia (OR, 0.60 [95% CI, 0.13, 2.69]), or LGA (OR, 1.51 [95% CI, 0.53, 4.27]) (P > 0.05, for all).

CONCLUSION

Our findings demonstrate that double vitrification-warming procedures do not increase the risk of adverse neonatal outcomes compared with those of once-vitrified embryos.

Impact of mode of conception on early pregnancy human chorionic gonadotropin rise and birth weight

Objective

To assess whether the mode of conception and embryo biopsy impact first-trimester human chorionic gonadotropin (hCG) dynamics and subsequent risk of small for gestational age (SGA) or large for gestational age (LGA).

Design

Retrospective cohort study.

Setting

University fertility center.

Patients

Six hundred-two pregnant patients with singleton live births.

Interventions

Serial serum hCG measurements were obtained between 10 and 28 days postconception to determine the within-woman rate of change in hCG (slope) by mode of conception (unassisted pregnancy, fresh embryo transfer (ET), frozen ET, and frozen ET following preimplantation genetic testing for aneuploidy (PGT-A).

Main Outcome Measures

Primary outcomes included birth weight, SGA, and LGA.

Results

Mode of conception is not independently associated with birth weight, SGA, or LGA. Mediation analysis revealed an expected one-day increase in log-transformed hCG varied by mode of conception: unassisted (0.41), fresh ET (0.39), frozen ET (0.42), PGT-A (0.44). Human chorionic gonadotropin rise has a positive effect on birth weight (55 g per SD increase in hCG slope) and is associated with SGA (odds ratio, 0.65), but not with LGA (odds ratio, 1.18).

Conclusions

Human chorionic gonadotropin rise is an important mediator of the mode of conception/birth weight relationship. Preimplantation genetic testing for aneuploidy has the highest rate of hCG rise, followed by frozen ET, unassisted, and fresh ET. Faster rise is associated with higher birth weight and lower risk of SGA but does not impact LGA risk. Importantly, PGT-A does not increase the risk of extreme birth weight relative to other modes of conception evaluated.

The sex-specific difference in singleton birth weight after frozen embryo transfer compared with fresh embryo transfer: a secondary analysis of 3 randomized trials

OBJECTIVE

To assess whether the between-group difference in singleton birth weight following frozen vs. fresh embryo transfer varied with infant sex.

DESIGN

A post hoc exploratory secondary analysis of data from three multicenter randomized trials compared the live birth rates between freeze-only vs. fresh embryo transfer.

SETTING

Academic fertility centers.

PATIENT(S)

A total of 1,886 women who achieved singleton live birth after a frozen or fresh embryo transfer during these trials were included.

INTERVENTION(S)

Women underwent either a frozen or fresh embryo transfer.

MAIN OUTCOME MEASURE(S)

Mean birth weight, large for gestational age (LGA), and small for gestational age (SGA).

RESULT(S)

There was an interaction between the types of embryo transfer and infant sex on the birth weight and on the incidences of LGA and SGA. Among male infants, compared with singletons following fresh embryo transfer, singletons following frozen embryo transfer had higher mean birth weights (3,520.6 ± 526.1 vs. 3,345.1 ± 524.9 g), a higher risk of being LGA (25.2% vs. 15.7%), and a lower risk of being SGA (3.3% vs. 6.1%). However, among the female infants, no statistically significant difference was found in the mean birth weight (3,336.5 ± 514.8 vs. 3,299.5 ± 485.0 g) or the risks of being LGA (18.8% vs. 15.7%) or SGA (5.2% vs. 6.0%) between frozen and fresh embryo transfer.

CONCLUSION(S)

Male singletons born after frozen embryo transfer were more likely to have a higher birth weight than those born after fresh embryo transfer.

Combined analysis of human chorionic gonadotrophin concentrations at different time points after frozen-thawed blastocyst transfer can improve our ability to predict the pregnancy outcomes of single gestations

In this study, we conducted a retrospective single-centre study of 1664 singleton pregnancies derived from frozen-thawed blastocyst transfer between January 2017 and December 2018. Analysis showed that there were 596 early pregnancy losses and 1068 ongoing pregnancies. We compared serum HCG (human chorionic gonadotophin) concentrations on days 12, 14, 19, and 21, between the pregnancy loss group and the ongoing pregnancy group. The cut-off level of HCG at each time point was calculated to predict pregnancy outcome. Joint analysis of two single HCG levels taken one week apart was carried out to improve predictive accuracy. The levels of HCG at four time points were significantly lower in the early pregnancy loss group than in the ongoing pregnancy group. According to the area under ROC (receiver operating characteristic curve) curves, all levels of HCG taken at four time points showed good ability to predict the outcome of pregnancy. The joint analysis of two single HCG levels taken one week apart further improved the accuracy of prediction.Impact statementWhat is already known on this subject? Multiple studies have shown that the maternal level of serum HCG is the best parameter for predicting the course of pregnancy.What do the results of this study add? The levels of HCG on days 12, 14, 19 and 21 were significantly lower in the early pregnancy loss group than in the group of ongoing pregnancies. According to the area under ROC curves, all levels of HCG taken at four time points showed a good ability to predict the outcome of pregnancy.What are the implications of these findings for clinical practice and/or further research? The joint analysis of two single HCG levels, taken one week apart, further improved the accuracy of prediction.

Association between women's age and stage, morphology, and implantation of the competent blastocyst: a multicenter cohort study

OBJECTIVE

To study if the age of women undergoing assisted reproductive technology treatment associates with stage, morphology, and implantation of the competent blastocyst.

DESIGN

Multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial human chorionic gonadotrophin [hCG] rise) from women undergoing single blastocyst transfer resulting in singleton pregnancy/birth.

SETTING

Sixteen private and university-based facilities.

PATIENT(S)

In this study, 7,246 women who, between 2014 and 2018, underwent controlled ovarian stimulation (COS) or frozen-thawed embryo transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. Linking data to the Danish Medical Birth Registry resulted in a total of 4,842 women with a live birth being included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The competent blastocyst development stage (1-6), inner cell mass (A, B, C), trophectoderm (A, B, C), and initial serum hCG value.

RESULT(S)

Adjusted analysis of age and stage in COS treatments showed that for every 1-year increase in age there was a 5% reduced probability of the competent blastocyst assessed as being in a high stage at transfer. Comparison between hCG values in women 18-24 years and 25-29 years in both COS and FET showed significantly lower levels in the youngest women.

CONCLUSION(S)

The initial hCG rise was influenced by the age of the woman, with an identical pattern for hCG values in COS and FET treatments. In COS, the competent blastocyst had a reduced stage with increasing women's age.

Perinatal and obstetric outcomes in singleton pregnancies following fresh versus cryopreserved blastocyst transfer: a meta-analysis

The transfer of cryopreserved blastocysts is increasing in IVF centres. However, little is known about the perinatal and obstetric outcomes of this procedure. In an attempt to further elucidate these issues, a systematic review and meta-analysis was conducted to compare cryopreserved transfer with fresh blastocyst embryo transfer. The results show that the risk of both preterm (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.80-0.99, P = 0.04) and low birthweight births (OR 0.82, 95% CI 0.68-0.99, P = 0.04) was significantly lower after cryopreserved blastocyst transfer than after fresh blastocyst transfer. The rate of large for gestational age births was significantly higher (OR 1.68, 95% CI 1.55-1.82, P < 0.00001) and the rate of small for gestational age births significantly lower (OR 0.59, 95% CI 0.54-0.65, P < 0.00001) after cryopreserved blastocyst transfer. The transfer of cryopreserved blastocysts was associated with a significantly lower risk of placental abruption (OR 0.58, 95% CI 0.40-0.83, P = 0.003) but a significantly higher risk of Caesarean section (OR 1.21, 95% CI 1.01-1.43, P = 0.03). In conclusion, the perinatal and obstetric outcomes associated with the transfer of cryopreserved blastocysts differ from those associated with fresh blastocyst transfer.

Perinatal outcomes of singletons following vitrification versus slow-freezing of embryos: a multicenter cohort study using propensity score analysis

STUDY QUESTION

Is embryo vitrification associated with a higher risk of adverse perinatal outcomes than slow-freezing?

SUMMARY ANSWER

Embryo vitrification was not associated with increased risks of adverse perinatal outcomes of pre-term birth (PTB), low birthweight (LBW), small for gestational age (SGA), large for gestational age (LGA) and macrosomia, as compared to slow-freezing.

WHAT IS KNOWN ALREADY

Vitrification is becoming a widely adopted technology for embryo cryopreservation with higher embryo survival rate and live birth rate than the slow-freezing technique. However, limited data are currently available on risks of adverse perinatal outcomes following vitrification as compared to that of slow-freezing. The impact of vitrification on perinatal outcomes remains further to be elucidated.

STUDY DESIGN, SIZE, DURATION

Six large reproductive medical centers in Guangdong province, Southeast of China, took part in this multicenter retrospective cohort study. Cohorts of 3199 live born singletons after Day 3 frozen-thawed embryo transfer (FET) cycles with either vitrification or slow-freezing between January 2011 and December 2015 were included in the study. Each patient only contributed one cycle per cohort and vanishing twins were excluded. Propensity score (PS) matching was used to control for potential confounding factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All live-born singletons following either a vitrified or a slow-frozen cleavage FET cycle during the period from 2011 to 2015 were analyzed. Perinatal outcomes of PTB, LBW, macrosomia, SGA and LGA were compared. The vitrified and slow-frozen cohorts were matched by propensity scores with a 1:1 ratio accounting for potential confounding factors associated with perinatal outcomes. These variables included baseline demographics (maternal age, BMI, education level, parity, type of infertility and cause of infertility), as well as IVF characteristics (insemination method, endometrial preparation protocol and embryo cryopreservation duration).

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 2858 cases from vitrified embryo transfer (ET) and 341 babies from the slow-freezing group were included. After PS matching, 297 pairs of newborns were generated for comparison. The median gestational age was 39 weeks for both cohorts and the birthweights were comparable (3187.7 ± 502.1 g in the vitrified group vs. 3224.6 ± 483.6 in the slow-freezing group, P>0.05). There were no significant differences between the two groups on the incidence of PTB (5.4% vs. 7.7%), LBW (6.7% vs. 5.7%), macrosomia (5.7% vs. 6.1%), SGA (12.5% vs. 8.4%) and LGA (6.4% vs. 8.1%). Parallel logistic regression analysis indicated that vitrification was non-inferior to slow-freezing method in terms of the occurrence of PTB (OR, 0.68 [95% CI, 0.35, 1.31]), LBW (OR, 1.19[0.61-2.32]), macrosomia (OR, 0.94 [0.48-1.86]), SGA (1.55[0.91-2.64]) and LGA (0.78[0.42-1.45]), P>0.05. Sex-stratified PS matching models with multivariable regression analysis further confirmed that vitrification did not increase the risks of above-mentioned adverse perinatal outcomes in either the male or female infant cohort.

LIMITATIONS, REASONS FOR CAUTION

Although the analysis was adjusted for a number of important confounders, the hospital dataset did not contain other potential confounders such as the medical history and obstetrics outcomes of women during pregnancy to allow adjustment. In addition, the current findings are only applicable to cleavage stage FET, but not pronuclei stage or blastocyst stage ET.

WIDER IMPLICATIONS OF THE FINDINGS

Vitrified ET, in comparison with slow-frozen ET, was not associated with increased risks of adverse neonatal outcomes. With its superiority on live birth rates and non-inferiority on safety perinatal outcomes, transition from slow-freezing to the use of vitrification for embryo cryopreservation is reassuring. Nonetheless, future research is needed for the long-term effects of vitrification method on offspring's health outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Key Research and Development Program (2016YFC100205), Guangzhou Science and Technology Project (201804020087), Guangdong Province Science and Technology Project (2016A020218008) and Guangdong Provincial Key Laboratory of Reproductive Medicine (2012A061400003). The authors have no conflicts of interest to declare.

LIF in embryo culture medium is a predictive marker for clinical pregnancy following IVF-ET of patients with fallopian tube obstruction

Leukemia inhibitory factor (LIF) has played a vital role in a series of reproductive events, including follicle growth, embryo growth and differentiation. However, it is unclear whether the level of LIF in embryo culture medium can be used as a marker for clinical pregnancy. In this study, we aimed to investigate whether LIF level in embryo culture medium can act as a predictive marker for pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) in infertile women due to tubal problems. A total of 208 infertile women due to tubal problems underwent IVF-ET treatment. The women were divided into two groups according to whether they were clinically pregnant. The level of LIF in the embryo culture medium was measured, and the correlation between LIF level and embryo quality and clinical pregnancy outcome was analyzed. The embryo culture medium was collected on the day of blastocyst transplantation. Compared to non-pregnant group, LIF level in the embryo culture medium on the day of blastocyst transplantation was significantly higher in the pregnant group. LIF level in the embryo culture medium may be used as a non-invasive auxiliary biomarker for predictive clinical pregnancy in infertile women with tubal problems that using single blastocyst transfer method.

MPA given orally during the first trimester for threatened miscarriage carries no specific risk for foetal abnormalities albeit the rate is higher than non-threatened pregnancies

This observational study examines the outcomes of pregnancies arising in women referred for infertility, where those who experienced threatened miscarriage were treated with medroxyprogesterone acetate (MPA) tablets. The 14-year study period covers comprehensive real-time data entries into the validated electronic database including details of the infertility management, pregnancy outcomes and any foetal anomalies among the infants, each being tracked and recorded. Of 4057 clinical pregnancies, 1343 received MPA for threatened miscarriage; 934 (69.6 %) of which continued to livebirths. These were compared with the remaining 2714 clinical pregnancies without threatened miscarriage or MPA and which resulted in 2075 (76.5 %) livebirths. There were 134 developmental abnormalities recorded among the 3009 livebirths of which 78 (2.6 %) were categorised appropriate for the Western Australian Developmental Abnormalities Register; WARDA. These comprised 55 in the MPA group, 36 of which were categorised as serious (being 2.7 % of clinical pregnancies and 3.9 % of births). In the group without MPA, there were 79 abnormalities, of which 42 were categorised as serious (being 1.7 % of clinical pregnancies and 2.2 % of births). Specifically, there were no cases of androgenisation noted among the female infants. The abnormality rates were low overall and well within the annual WARDA ranges. We cautiously suggest that oral MPA can be considered for studies throughout pregnancy including the early first trimester to assess a potential role in reducing miscarriage, as well as advanced pregnancies to evaluate a potential role in reducing stillbirths and preterm delivery.

Association between infertility treatment and intrauterine growth: a multilevel analysis in a retrospective cohort study

OBJECTIVES

This study aimed to identify intrauterine growth differences according to infertility treatment compared with spontaneous conception and to describe intrauterine growth trajectories.

DESIGN

Retrospective cohort study.

SETTING

A single primary and tertiary medical centre in Japan.

PARTICIPANTS

This study included singleton pregnant women with prenatal check-ups and delivery at the University of Yamanashi Hospital between 1 July 2012 and 30 September 2017. Patients were divided into four groups: spontaneous conception, infertility treatment without assisted reproductive technology (ART), fresh-embryo transfer and frozen embryo transfer (FET).

INTERVENTIONS

Differences in intrauterine growth according to the infertility treatment, including ART, and birth weight were evaluated. Multilevel analysis was employed to evaluate intrauterine growth trajectories stratified by the sex of the offspring.

PRIMARY OUTCOME MEASURE

Estimated fetal weight (EFW) assessed by ultrasound examination.

RESULTS

We assessed data from 37 239 prenatal examination results from 2377 pregnant women (spontaneous conception, n=1764; infertility treatment without ART, n=171; fresh-embryo transfer, n=112; and FET, n=330) in the final analysis. Multilevel analysis was adjusted for gestation duration, gestation period, parity, hypertensive disorders of pregnancy, type of infertility treatment, maternal age, smoking status, placenta previa, thyroid disease, gestational diabetes mellitus and the interaction between each potential confounding factor and gestation duration. In male fetuses, the interaction between FET and gestational duration (estimate: 0.36; 95% CI: 0.06 to 0.67) significantly affected the EFW. Similarly, in female fetuses, FET (estimate: -69.85; 95% CI: -112.09 to -27.61) and the interaction between FET and gestation duration (estimate: 0.57; 95% CI: 0.28 to 0.87) significantly affected the EFW.

CONCLUSIONS

This study shows that FET affects intrauterine growth trajectory from the second trimester to term, particularly in female fetuses. Our findings require further prospective research to examine the effect of infertility treatment on fetal growth.

Live birth outcomes of vitrified embryos generated under growth hormone stimulation are improved for women categorized as poor-prognosis

OBJECTIVE

To determine the clinical pregnancy (CP) and live birth (LB) rates arising from frozen embryo transfers (FETs) that had been generated under the influence of in vitro fertilization (IVF) adjuvants given to women categorized as poor-prognosis.

METHODS

A registered, single-center, retrospective study. A total of 1,119 patients with first FETs cycle include 310 patients with poor prognosis (109 treated with growth hormone [GH], (+)GH group vs. 201 treated with dehydroepiandrosterone, (-)GH group) and 809 patients with good prognosis (as control, (-)Adj (Good) group).

RESULTS

The poor-prognosis women were significantly older, with a lower ovarian reserve than the (-)Adj (Good) group, and demonstrated lower chances of CP (p<0.005) and LB (p<0.005). After adjusting for confounders, the chances of both CP and LB in the (+)GH group were not significantly different from those in the (-)Adj (Good) group, indicating that the poor-prognosis patients given GH had similar outcomes to those with a good prognosis. Furthermore, the likelihood of LB was significantly higher for poor-prognosis women given GH than for those who did not receive GH (p<0.028). This was further confirmed in age-matched analyses.

CONCLUSION

The embryos cryopreserved from fresh IVF cycles in which adjuvant GH had been administered to women classified as poor-prognosis showed a significant 2.7-fold higher LB rate in subsequent FET cycles than a matched poor-prognosis group. The women with a poor prognosis who were treated with GH had LB outcomes equivalent to those with a good prognosis. We therefore postulate that GH improves some aspect of oocyte quality that confers improved competency for implantation.

Fresh versus frozen embryo transfer has no effect on childhood weight

OBJECTIVE

To evaluate the effect of frozen, compared with fresh, embryo transfer on neonatal and pediatric weight and weight gain trajectory.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Women who underwent fresh or frozen embryo transfer at the Mayo Clinic from 2010 to 2014. All included embryo transfers resulted in a singleton live birth. Children were followed from birth to at least 18 months. When possible, growth was evaluated to 5 years of age.

INTERVENTIONS(S)

Fresh versus frozen embryo transfer.

MAIN OUTCOME MEASURE(S)

Propensity score methodology was used to balance the two groups by maternal characteristics and gestational age before evaluating outcomes. Each infant and childhood growth measurement was compared between the two groups.

RESULT(S)

Of the 136 women, 87 underwent a fresh embryo transfer and 49 underwent a frozen embryo transfer. Birth length and head circumference were significantly different in infants delivered after fresh versus frozen embryo transfer. There was a statistically significant difference in birth weight between infants born after fresh versus frozen embryo transfer. However, this difference did not persist when adjusted for gestational age, sex, and maternal factors. Childhood growth measurements including age- and sex-specific weight, and body mass index percentiles were not significantly different between groups.

CONCLUSION(S)

This study confirmed an association of frozen embryo transfer and increased birth weight, but the association did not persist when controlling for confounding maternal factors. We found no effect of fresh versus frozen embryo transfer on neonatal weight and childhood weight gain trajectory.

Maternal serum levels of angiogenic markers and markers of placentation in pregnancies conceived with fresh and vitrified-warmed blastocyst transfer

PURPOSE

The aim of the study was to compare the levels of angiogenic markers and markers of placentation between pregnancies conceived with fresh (ET) and vitrified-warmed blastocyst transfer (FET).

METHODS

Women with singleton pregnancies resulting from fresh ET or FET during the period between 2013 and 2017 were included in this prospective observational study. Fresh ET was performed in a stimulated and FET in natural cycle. At 6-7 weeks of gestation, after ultrasound confirmation of a single gestational sac with a viable embryo, serum levels of free β-hCG, pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PIGF) and fms-like tyrosine kinase (sFlt-1) were measured. Data on the patients' characteristics, pregnancy complications and outcomes were collected from a questionnaire and National Perinatal Information System of Slovenia.

RESULTS

Among 211 pregnancies, 126 were achieved with fresh ET and 85 with FET. There were no significant differences in perinatal outcome, pregnancy complication and PIGF level between the fresh ET and FET group. Women achieving pregnancy with FET had significant higher levels of free β-hCG (40.20 ± 30.62 IU/L vs. 28.74 ± 23.52, p = 0.002), PAPP-A (0.09 ± 0.06 vs. 0.06 ± 0.05 IU/L, p = 0.004) and sFlt-1 (596.19 ± 283.06 vs. 436.53 ± 248.23 pg/L, p < 0.0001) compared to women having conceived with fresh ET. There were no significant differences in the levels of evaluated biomarkers between patients with different pregnancy outcomes and complications.

CONCLUSION

Levels of angiogenic markers and markers of placentation differ between pregnancies achieved with fresh ET and FET which may reflect altered implantation and early placentation with some forms of assisted reproductive technologies.

[Comparison of birth weights of children born after slow frozen embryo replacement versus fresh embryo transfer]

OBJECTIVE

It is already known that children born after slow frozen embryo replacement have a significantly higher birth weight compared to children born after fresh embryo transfer. Similar data have been reported related to frozen embryo transfer using an open vitrification system. However, few data relative to birth weight using a complete embryo closed vitrification system has been reported. The purpose of this study was to know if frozen embryo in closed vitrification system is associated with a higher birth weight compared to fresh embryo replacement.

DESIGN

This was a monocentric retrospective cohort study, 371 children were issued from fresh embryo replacement and 127 from vitrified embryo transfer.

MATERIALS AND METHODS

All singletons born after fresh or vitrified embryo transfer between January 2011 and April 2015 were included. Births from the vitrified or fresh transfers of egg or sperm donation, and preimplantation genetic diagnosis were excluded. In addition, pregnancies with more than one gestational sac at the first ultrasound were excluded. An analysis of covariance (ANCOVA) was used for multivariate analysis.

RESULTS

Mean birth weight was 205g higher in the frozen embryo compared with fresh embryos transfer groups (3368g vs. 3163g respectively, P<0.001). This difference remained after multivariate analysis adjusted on confounding factors such as gestational age, maternal age, maternal body mass index (BMI), tobacco exposure, number of embryo transferred and birth order (P<0.001)..

CONCLUSIONS

Embryo frozen in closed vitrification system is associated with a higher birth weight compared to fresh embryo replacement. Our findings are consistent with the previous studies related to slow freezing and open vitrification systems data. The effects of controlled ovarian stimulation (COS), ex vivo culture conditions and cryopreservation systems on birth weight of children born should be further explored.

Serum Human Chorionic Gonadotropin Among Women With and Without Obesity After Single Embryo Transfers

CONTEXT

Serum human chorionic gonadotropin (hCG) levels are essential for diagnosing and monitoring early pregnancy. Obesity is a health care epidemic; however, the performance of this vital serum hormone in women with an elevated body mass index (BMI) is unknown.

OBJECTIVE

To investigate the association of BMI with serum hCG values and rate of hCG increase.

DESIGN

Retrospective cohort study.

SETTING

University-based infertility clinic.

PATIENTS

Women undergoing fresh vs frozen in vitro fertilization cycles with single-day three or five embryo transfers resulting in singleton live births (≥24 weeks' gestational age) from 2008 to 2015.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The initial hCG (mIU/mL, 16 days after oocyte retrieval) and 2-day percentage of hCG increases among BMI categories were compared using multivariable linear and logistic regression, adjusted a priori for the day of embryo transfer.

RESULTS

The initial serum hCG values correlated inversely with the BMI (P < 0.0001, test for trend). Low initial hCG values (<100 mIU/mL) were significantly more common across increasing BMI classes, from 1.4% of normal weight patients to 15.6% of those with a BMI ≥40 kg/m2 (P = 0.001, test for trend). The mean 2-day hCG increases were similar and normal (≥53%) across the BMI groups.

CONCLUSIONS

Patients with obesity achieving live births had statistically significantly lower initial serum hCG values compared with patients who were nonobese. However, the mean 2-day percentage of increases in hCG were similar across BMI categories. The initial hCG values might lack sensitivity for live births in patients with obesity. The rate of hCG increase remains the mainstay of monitoring very early pregnancies after in vitro fertilization. Future studies should investigate whether serum analyte ranges should be adjusted according to the BMI.

Effect of frozen/thawed embryo transfer on birthweight, macrosomia, and low birthweight rates in US singleton infants

BACKGROUND

Singleton infants conceived using assisted reproductive technology have lower average birthweights than naturally conceived infants and are more likely to be born low birthweight (<2500 gr). Lower birthweights are associated with increased infant and child mortality and poor adult health outcomes, including cardiovascular disease, hypertension, and diabetes. Data from registry and single-center studies suggest that frozen/thawed embryo transfer may be associated with larger birthweights. To date, however, a nationwide, full-population study on United States infants born using frozen/thawed embryo transfer has not been reported.

OBJECTIVES

The objective of this study was to compare the effect of frozen/thawed vs fresh embryo transfer on birthweight outcomes for singleton, term infants conceived using in vitro fertilization in the United States between 2007 and 2014, including average birthweight and the risks of both macrosomia (>4000 g) and low birthweight (<2500 g).

STUDY DESIGN

We used data from the Centers for Disease Control and Prevention's National Assisted Reproductive Technology Surveillance System to compare birthweight outcomes of live-born singleton, autologous oocyte, term (37-43 weeks) infants. Generalized linear models for all infants and stratified by infant sex were used to assess the relationship between frozen/thawed embryo transfer and birthweight, in grams. Infertility diagnosis, year of treatment, maternal age, maternal obstetric history, maternal and paternal race, and infant gestational age and sex were included in the models. Missing race data were imputed. The adjusted relative risks for macrosomia and low birthweight were evaluated using multivariable predicted marginal proportions from logistic regression models.

RESULTS

In total, 180,184 singleton, term infants were included, with 55,898 (31.02%) having been conceived from frozen/thawed embryos. Frozen/thawed embryo transfer was associated with, on average, a 142 g increase in birthweight compared with infants born after fresh embryo transfer (P < .001). An interaction between infant sex and embryo transfer type was significant (P < .0001), with frozen/thawed embryo transfer having a larger effect on male infants by 16 g. The adjusted risk of a macrosomic infant was 1.70 times higher (95% confidence interval, 1.64-1.76) following frozen/thawed embryo transfer than fresh embryo transfer. However, adjusted risk of low birthweight following frozen/thawed embryo transfer was 0.52 (95% confidence interval, 0.48-0.56) compared with fresh embryo transfer.

CONCLUSION

Frozen/thawed embryo transfer, in comparison with fresh embryo transfer, was associated with increased average birthweight in singleton, autologous oocytes, term infants born in the United States, with a significant interaction between frozen/thawed embryo transfer and infant sex. The risk of macrosomia following frozen/thawed embryo transfer was greater than that following fresh embryo transfer, but the risk of low birthweight among frozen/thawed embryo transfer infants was significantly decreased in comparison with fresh embryo transfer infants.

The interval transfer of a frozen-thawed embryo is more successful than a fresh embryo transfer for women undergoing IVF with recurrent implantation failure after cleavage stage embryo biopsy

BACKGROUND

Recurrent implantation failure (RIF) is repeated unsuccessful embryo transfers (ETs).

AIMS

To identify predictive embryonic markers of implantation in RIF, following pre-implantation genetic screening (PGS) of cleavage stage embryos, after accounting for male and female factors.

MATERIALS AND METHODS

Retrospective analysis of RIF patients undergoing PGS after correction of modifiable causes.

RESULTS

Eighty-four patients underwent 140 in vitro ferilisation cycles. Forty-one cycles were excluded: 12 (no embryo for transfer), four (double ETs) and 25 (no biopsy). Sixty-three patients underwent 99 single euploid ETs (48 fresh, 51 frozen) resulting in 11 biochemical pregnancies, 36 clinical pregnancies (CP), and six miscarriages and 30 live births (LB). Frozen ET was more successful than fresh; respective live birth rate (LBR) and clinical pregnancy rate (CPR), 39.2% versus 20.8%, (P = 0.02), 45.1% versus 27.1% (P = 0.04). LBR and CPR were lower when 5-6 blastomeres were present at embryo biopsy, compared to embryos with ≥7 blastomeres: 15.4% versus 32.6% (P = 0.185) and 15.4% versus 39.5% (P = 0.074) respectively. Serum β human chorionic gonadotropin (βhCG) concentration was greater when a more developed embryo was biopsied (r = 0.448, P = 0.017 and r = 0.476, P = 0.118, fresh and frozen transfers, respectively). Embryo morphokinetic analysis demonstrated faster development to blastocyst stage when more cells were present at biopsy: mean 103.3, 102.2 and 96.0 h for biopsy at the 5-6, 7-8 or ≥9 cell stage respectively (P = 0.040 for difference between 7-8 cells vs ≥9).

CONCLUSIONS

After cleavage stage biopsy, frozen ET was more successful than fresh ET. Chance of conception and serum βhCG concentration correlated with number of cells present at time of biopsy.

Mosaic embryo transfer after oocyte in vitro maturation in combination with non-invasive prenatal testing (NIPT)-first report of a euploid live birth

PURPOSES

The purpose of this study is to describe a healthy life birth after a mosaic embryo transfer in oocyte in vitro maturation (IVM).

METHODS

Patient received minimal stimulation, starting on day 3 after menstrual period. No hCG trigger was administered. Oocyte retrieval was performed and oocytes were matured for 30 h. After denuding, mature oocytes were inseminated by ICSI. Embryos were cultured until blastocyst stage and biopsied.

RESULTS

One euploid embryo after array comprehensive genome hybridization (aCGH) was diagnostic. However, the next-generation sequencing (NGS) re-analysis showed that embryo was a mosaic for chromosome 13 and 21. Nevertheless, pregnancy ultrasound scans and non-invasive prenatal test (NIPT-Verifi-Illumina) indicated a normal fetus development. Finally, a healthy baby was born after 38 weeks. Its weight was 4480 g, head circumference 36 cm, and total length of 51 cm. To confirm that the baby was chromosomically normal, an NGS test was performed in buccal cells, a normal profile was obtained.

CONCLUSIONS

Our finding confirmed that mosaic embryo transfer would bring a healthy offspring.

Predictive value of initial serum human chorionic gonadotropin levels for pregnancies after single fresh and frozen blastocyst transfer

As one of the earliest markers for predicting pregnancy outcomes, human chorionic gonadotropin (hCG) values have been inconclusive on reliability of the prediction after frozen and fresh embryo transfer (ET). In this retrospective study, patients with positive hCG (day 12 after transfer) were included to examine the hCG levels and their predictive value for pregnancy outcomes following 214 fresh and 1513 vitrified-warmed single-blastocyst transfer cycles. For patients who got clinical pregnancy, the mean initial hCG value was significantly higher after frozen cycles than fresh cycles, and the similar result was demonstrated for patients with live births (LB). The difference in hCG value existed even after adjusting for the potential covariates. The area under curves (AUC) and threshold values calculated by receiver operator characteristic curves were 0.944 and 213.05 mIU/mL for clinical pregnancy after fresh ET, 0.894 and 399.50 mIU/mL for clinical pregnancy after frozen ET, 0.812 and 222.86 mIU/mL for LB after fresh ET, and 0.808 and 410.80 mIU/mL for LB after frozen ET with acceptable sensitivity and specificity, respectively. In conclusion, single frozen blastocyst transfer leads to higher initial hCG values than single fresh blastocyst transfer, and the initial hCG level is a reliable predictive factor for predicting IVF outcomes.

High oestradiol concentration after ovarian stimulation is associated with lower maternal serum beta-HCG concentration and neonatal birth weight

In this retrospective study, the relationship between maternal serum oestradiol and progesterone levels after fresh embryo transfer or frozen embryo transfer (FET), and serum beta-HCG levels in early pregnancy and neonatal birth weight was examined. Included for analysis were 5643 conceived singletons: 2610 after FET and 3033 after fresh embryo transfer. Outcome measures included maternal serum oestradiol, progesterone, beta-HCG levels during the peri-implantation period, birth weight and small-for-gestational-age (SGA). Results at 4, 5 and 6 weeks' gestation were as follows: serum oestradiol and progesterone levels were significantly higher in women who underwent fresh embryo transfer compared with FET (all P < 0.0001 except progesterone at 6 weeks; P = 0.009); for fresh embryo transfers, serum beta-HCG levels were significantly lower than in women who underwent FET (P < 0.0001); beta-HCG levels were negatively correlated with serum oestradiol; and birth weight was negatively correlated with serum oestradiol. Incidence of SGA in fresh embryo transfer was increased significantly compared with FET (P < 0.001). Higher maternal oestradiol levels after fresh embryo transfer was correlated with lower beta-HCG in early pregnancy, lower birth weight and higher incidence of SGA.

Vitrified-warmed single-embryo transfers may be associated with increased maternal complications compared with fresh single-embryo transfers

Cryopreservation of embryos allows single-embryo transfer and storage of supernumerary embryos, maximizing cumulative pregnancy rates. The purpose of this retrospective cohort study was to compare pregnancy outcome in singletons born after fresh or vitrified-warmed single blastocyst transfer (SBT). Singleton live births resulting from SBT of fresh or vitrified-warmed embryos were compared. Primary outcomes were perinatal outcomes including small for gestational age (SGA), low birthweight, preterm deliveries (PTD), large for gestational age (LGA) and congenital malformations. Maternal complications included pre-eclampsia, placenta previa, placental abruption, gestational diabetes mellitus (GDM) and chorioamnionitis. Adjustment for confounding factors was performed. Of 1886 fresh SBTs and 1200 vitrified-warmed SBTs during the study period, vitrified-warmed SBTs compared with fresh SBTs resulted in significantly lower clinical pregnancy rate (P < 0.0001). Live birth and miscarriage rates calculated only for pregnancy with known outcome revealed lower live birth rates and higher miscarriage rates for the vitrified-warmed group. Perinatal complications were calculated for clinical pregnancies with known outcomes (12.9% catchment failure was excluded from analysis). The vitrified-warmed group showed a trend toward higher rates of pre-eclampsia, GDM, Caesarean delivery and LGA neonates. Rates of PTD and SGA were comparable. In conclusion, vitrified-warmed SBT might be associated with increased feto-maternal complications.

Live birth rates are satisfactory following multiple IVF treatment cycles in poor prognosis patients

This seven-year retrospective study analysed the live birth rate (LBR) for women undergoing IVF treatment with various antral follicle counts (AFC). The LBR decreased with lower AFC ratings, and in 290 treatment cycles for women in the poorest AFC category, ≤4 follicles (group E), the LBR was the lowest at 10.7%. The pregnancy loss rate (PLR) significantly increased with poorer AFC categories, from 21.8% in AFC group A (≥20 follicles), to 54.4% in AFC group E (p<0.0001). This trend was repeated with advancing age, from 21.6% for younger women (<35years), to 32.9, 48.5 and 100% for ages 35-39, 40-44 and ≥45 years, respectively (p<0.0001). However, LBR within the specific AFC group E cohort was also age-dependent and decreased significantly from 30.0% for <35 years old, to 13.3, 3.9 and 0% for patients aged 35-39, 40-44 and ≥45 years, respectively. Most, importantly, LBR rates within these age groups were not dependent on the number of IVF attempts (1st, 2nd, 3rd or ≥4 cycles), which indicated that cycle number should not be the primary deciding factor for cessation of IVF treatment in responding women <45years old.