The impact of IVF on birthweight from 1991 to 2015: a cross-sectional study

Association of duration of embryo culture with risk of large for gestational age delivery in cryopreserved embryo transfer cycles

OBJECTIVE

To examine the relationship between the day of embryo cryopreservation and large for gestational age (LGA) infants in women undergoing frozen embryo transfers (FETs) after cryopreservation on days 2-7 after fertilization and to compare the risk of the day of embryo cryopreservation to other possible risk factors of LGA after FET cycles.

DESIGN

Retrospective cohort study.

SETTING

Society of Assisted Reproduction Clinical Outcomes Reporting System.

PATIENTS

Women undergoing FET cycles.

INTERVENTION

Day of cryopreservation.

MAIN OUTCOME MEASURE

Singleton LGA infant.

RESULTS

A total of 33,030 (18.2%) FET cycles in the study group (n = 181,592) resulted in LGA infants during the study period of 2014-2019. There was an increase in LGA risk when cryopreservation was performed from day 2 (13.7%) to days 3-7 (14.4%, 15.0%, 18.2%, 18.5%, and 18.9%). In the log-binomial model, the risk increased compared with days 2-3 combined when cryopreservation was performed on days 5-7 (adjusted relative risk [aRR] 1.32, 95% confidence interval [CI] 1.22-1.44 for day 5, aRR 1.34, 95% CI 1.23-1.46 for day 6, and aRR 1.42, 95% CI 1.25-1.61 for day 7). Other factors most associated with LGA risk in the log-binomial model were preterm parity of >3 compared with 0 (aRR 1.82, 95% CI 1.24-2.69) and body mass index (BMI) of >35 kg/m2 compared with normal weight (aRR 1.94, 95% CI 1.88-2.01). Increasing gravity, parity, BMI, number of oocytes, and embryo grade were also associated with LGA in this model. Asian, Black, Hispanic, and combined Hawaiian and Pacific Islander were protective factors in the model compared with White patients. Low BMI (<18.5 kg/m2) was also considered a protective factor in the model compared with normal BMI.

CONCLUSION

Duration of embryo culture was associated with an increased risk of LGA in this study cohort when controlling for known confounders such as maternal BMI and parity. This study sheds new light on the possible link between FET and LGA infants.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

Perinatal outcomes in 13,626 singleton pregnancies after autologous IVF across three continents over 7 years

PURPOSE

Are trends in singleton autologous IVF perinatal outcomes consistent over time among five international infertility centers?

METHODS

This was a retrospective cohort study from January 1, 2012, to December 31, 2018. This study was performed through a large infertility network at five international infertility centers in which patients who had a singleton live birth resulting from fresh and frozen autologous IVF cycles were included. The primary outcome was live birth weight (BW) with secondary outcomes of preterm birth (PTB), large for gestational age (LGA), small for gestational age (SGA), and gestational age at delivery.

RESULTS

The entire cohort (n = 13,626) consisted of 6941 fresh and 6685 frozen autologous IVF cycles leading to singleton deliveries. Maternal age, parity, body mass index, neonatal sex, and GA at delivery were similar for fresh and frozen IVF cycles in the entire cohort and within each infertility center. Four centers had a trend of decreased BW and three centers had decreased rates of PTB before 32 and 28 weeks and LGA newborns annually, although significance was not reached. Three IVF centers had annual increased trends of PTB before 37 weeks and four centers had increased rates of SGA newborns, although significance was not reached.

CONCLUSION

Similar trends in perinatal outcomes were present across five international infertility centers over 7 years. Additional studies are crucial to further assess and optimize perinatal outcomes at an international level.

Growth of twins conceived using assisted reproductive treatments up to 5 years old: a national growth cohort

STUDY QUESTION

Do twins conceived through assisted reproductive treatments (ART) grow differently from naturally conceived (NC) twins in early life?

SUMMARY ANSWER

Assessments at 6-8 weeks old and at school entry show that ART twins conceived from frozen embryo transfer (FET) grow faster than both NC twins and ART twins conceived from fresh embryo transfer (ET).

WHAT IS KNOWN ALREADY

Singletons born from fresh ET grow more slowly in utero and in the first few weeks of life but then show postnatal catch-up growth by school age, compared to NC and FET babies. Evidence on early child growth of ART twins relative to NC twins is inconsistent; most studies are small and do not distinguish FET from fresh ET cycles.

STUDY DESIGN, SIZE, DURATION

This cohort study included 13 528 live-born twin babies conceived by ART (fresh ET: 2792, FET: 556) and NC (10 180) between 1991 and 2009 in Scotland. The data were obtained by linking Human Fertilisation and Embryology Authority ART register data to the Scottish Morbidity Record (SMR02) and Scottish child health programme datasets. Outcome data were collected at birth, 6-8 weeks (first assessment), and school entry (4-7 years old) assessments. The primary outcome was growth, measured by weight at the three assessment points. Secondary outcomes were length (at birth and 6-8 weeks) or height (at school entry), BMI, occipital circumference, gestational age at birth, newborn intensive care unit admission, and growth rates (between birth and 6-8 weeks and between 6-8 weeks and school entry).

PARTICIPANTS/MATERIALS, SETTING, METHODS

All twins in the linked dataset (born between 1991 and 2009) with growth data were included in the analysis. To determine outcome differences between fresh ET, FET, and NC twins, linear mixed models (or analogous logistic regression models) were used to explore the outcomes of interest. All models were adjusted for available confounders: gestational age/child age, gender, maternal age and smoking, Scottish Index of Multiple Deprivation, year of treatment, parity, ICSI, and ET stage.

MAIN RESULTS AND THE ROLE OF CHANCE

In the primary birth weight models, the average birth weight of fresh ET twins was lower [-35 g; 95% CI: (-53, -16)g] than NC controls, while FET twins were heavier [71 g; 95% CI (33, 110) g] than NC controls and heavier [106 g; 95% CI (65, 146) g] than fresh ET twins. However, the difference between FET and NC twins was not significant when considering only full-term twins (≥37 weeks gestation) [26 g; 95% CI (-30, 82) g], while it was significantly higher in preterm twins [126 g; 95% CI (73, 179) g]. Growth rates did not differ significantly for the three groups from birth to 6-8 weeks. However, FET twins grew significantly faster from 6 to 8 weeks than NC (by 2.2 g/week) and fresh ET twins (by 2.1 g/week). By school entry, FET twins were 614 g [95% CI (158, 1070) g] and 581 g [95% CI (100, 1063) g] heavier than NC and fresh ET twins, respectively. Length/height and occipital frontal circumference did not differ significantly at any time point.

LIMITATIONS, REASONS FOR CAUTION

Although the differences between ART and NC reflect the true ART effects, these effects are likely to be mediated partly through the different prevalence of mono/dizygotic twins in the two groups. We could not explore the mediating effect of zygosity due to the unavailability of data. The confounding variables included in the study were limited to those available in the datasets.

WIDER IMPLICATIONS OF THE FINDINGS

Live-born twins from FET cycles are heavier at birth, grow faster than their fresh ET and NC counterparts, and are still heavier at school entry. This differs from that observed in singletons from the same cohort, where babies in the three conception groups had similar weights by school entry age. The results are reassuring on known differences in FET versus fresh ET and NC twin outcomes. However, FET twins grow faster and are consistently larger, and more ART twins depict catch-up growth. These may lead to an increased risk profile for non-communicable diseases in later life. As such, these twin outcomes require careful evaluation using more recent and comprehensive cohorts.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the EU H2020 Marie Sklodowska-Curie Innovative Training Networks (ITN) grant Dohartnet (H2020-MSCA-ITN-2018-812660). The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Obstetric and perinatal risks after the use of donor sperm: A systematic review and meta-analysis

Donor sperm is widely used in infertility treatments. The purpose of the study was to investigate, whether use of donor sperm in intrauterine insemination (IUI) or in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments affect maternal and perinatal risks compared with spontaneously conceived pregnancies or use of partner sperm in IUI, IVF or ICSI. We provide a systematic review and meta-analyses on the most clinically relevant obstetric and perinatal outcomes after use of donor sperm compared with partner sperm: hypertensive disorders of pregnancy, preeclampsia, low birth weight, and preterm birth. Our meta-analyses showed an increased risk for preeclampsia (pooled adjusted odds ratio (aOR) 1.77, 95% CI 1.26-2.48) and hypertensive disorders of pregnancy (pooled aOR 1.55, 95%, CI 1.20-2.00) in pregnancies resulting from IUI with donor sperm compared with IUI with partner sperm. No increased risk was seen for low birth weight or preterm birth after the use of donor sperm in IUI compared with the use of partner sperm in IUI. Subgroup analysis for singletons only did not change these results. The meta-analysis on low birth weight showed a lower risk after in IVF with donor sperm compared with IVF with partner sperm (pooled aOR 0.89, 95% CI 0.83-0.94). For hypertensive disorders of pregnancy, preeclampsia and preterm birth, no difference was found between IVF with donor sperm vs. partner sperm. Patients need to be informed about the moderately increased risk of hypertensive disorders of pregnancy and preeclampsia in pregnancies after IUI with donor sperm.

Stigma predicting fertility quality of life among Chinese infertile women undergoing in vitro fertilization-embryo transfer

OBJECTIVE

To investigate stigma and fertility quality of life (FertiQoL) and identify predictors of FertiQoL in Chinese infertile women undergoing in vitro fertilization-embryo transfer (IVF-ET).

METHODS

A descriptive correlational design was adopted to investigate the association between stigma and FertiQoL in 588 infertile women undergoing IVF-ET. The personal information questionnaire, Infertility Stigma Scale (ISS) and FertiQoL tool were used to measure study variables.

RESULTS

The mean scores of ISS and FertiQoL were 62.59 (SD = 21.58) and 63.64 (SD = 13.72), respectively. There were significant differences of ISS scores among participants with different educational level, residence, occupation, religious belief, financial condition, age group, duration of infertility and infertility treatment, while significant differences of the FertiQoL scores were found in participants with different insurance status, determinism of etiology, infertile type, duration of infertility treatment and cycles of IVF-ET. Pearson's correlation analysis showed stigma was negatively correlated with FertiQoL (r = -0.081 to -0.669, p < .05). The self-devaluation (β = -0.290, p < .001), social withdrawal (β = -0.237, p < .001), family stigma (β = -0.217, p < .001) and insurance status (β = 0.066, p=.035) were identified as the significant predictor of FertiQoL accounting for 43.5% of variance.

CONCLUSIONS

The stigma was significantly associated with FertiQoL in infertile women undergoing IVF-ET with higher level of stigma predicting poorer FertiQoL. More psychological support should be provided to infertile women to reduce stigma and improve FertiQoL.

Medically Assisted Reproduction Treatment Types and Birth Outcomes

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments themselves.

OBJECTIVE:

To compare risks of adverse birth outcomes among pregnancies conceived with and without medically assisted reproduction treatments.

METHODS:

Birth certificates were used to study birth outcomes of all neonates born in Utah from 2009 through 2017. Of the 469,919 deliveries, 52.8% (N=248,013) were included in the sample, with 5.2% of the neonates conceived through medically assisted reproduction. The outcome measures included birth weight, gestational age, low birth weight (LBW, less than 2,500 g), preterm birth (less than 37 weeks of gestation), and small for gestational age (SGA, birth weight less than the 10th percentile). Linear models were estimated for the continuous outcomes (birth weight, gestational age), and linear probability models were used for the binary outcomes (LBW, preterm birth, SGA). First, we compared the birth outcomes of neonates born after medically assisted reproduction and natural conception in the overall sample (between-family analyses), before and after adjustment for parental background and neonatal characteristics. Second, we employed family fixed effect models to investigate whether the birth outcomes of neonates conceived through medically assisted reproduction differed from those of their naturally conceived siblings (within-family comparisons).

RESULTS:

Neonates conceived through medically assisted reproduction weighed less, were born earlier, and were more likely to be LBW, preterm, and SGA than neonates conceived naturally. More invasive treatments (assisted reproductive technology [ART] and artificial insemination [AI] or intrauterine insemination) were associated with worse birth outcomes; for example, the proportion of LBW and preterm birth was 6.1% and 7.9% among neonates conceived naturally and 25.5% and 29.8% among neonates conceived through ART, respectively. After adjustments for various neonatal and parental characteristics, the differences in birth outcomes between neonates conceived through medically assisted reproduction and naturally were attenuated yet remained statistically significant; for example, neonates conceived through ART were at 3.2 percentage points higher risk for LBW (95% CI 2.4–4.1) and 4.8 percentage points higher risk for preterm birth (95% CI 3.9–5.7). Among siblings, the differences in the frequency of adverse outcomes between neonates conceived through medically assisted reproduction and neonates conceived naturally were small and statistically insignificant for all types of treatments.

CONCLUSION:

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments itself.

Impact of Maternal Age on Singleton Birthweight in Frozen Embryo Transfer Cycles

BACKGROUND

Previous studies have investigated the effect of maternal age on assisted reproductive technology success rates. However, little is known about the relationship between maternal age and neonatal birthweight in frozen embryo transfer (FET) cycles. Whether maternal age influences singleton birthweight in FET cycles remains to be elucidated.

METHODS

This study was conducted at a tertiary care center, involving singleton live births born to women undergoing frozen-thawed embryo transfer during the period from January 2010 to December 2017. A total of 12,565 women who fulfilled the inclusion criteria were enrolled and grouped into four groups according to the maternal age: <30, 30-34, 35-39, and ≥40 years old. A multivariable linear regression analysis was conducted to reveal the relationship between maternal age and neonatal birthweight with controlling for a number of potential confounders.

RESULTS

The highest proportions of low birthweight (LBW, 4.1%), high birthweight (1.2%), preterm birth (PTB, 5.9%), and very PTB (0.9%) were found in the group over 40 years old, but no significant difference was observed among the four groups. Additionally, the 35-39-year-old group had the highest rate of very LBW (0.6%), whereas the 30-34-year-old group had the lowest rate of small for gestational age (SGA, 2.7%). However, multivariate analyses revealed that neonatal outcomes including PTB, LBW, and SGA were similar between the different maternal age groups.

CONCLUSION

Grouping with different maternal age was not associated with mean birthweight and Z-scores of singletons resulting from FET.

Day-3-embryo fragmentation is associated with singleton birth weight following fresh single blastocyst transfer: A retrospective study

BACKGROUND

Previous studies have arguably associated poor embryo morphology with low birth weight in singletons following single embryo transfer. However, the association between birth weight and specific morphological features in the cleavage stage remains less known. The purpose of the study was to investigate whether morphological features of embryos at the cleavage stage affect birth weight following blastocyst transfer.

METHODS

The single-center retrospective cohort study included 4,226 singletons derived from fresh single cleavage-stage embryo transfer (ET; n = 1,185), fresh single blastocyst transfer (BT; n = 787), or frozen-thawed single blastocyst transfer (FBT; n = 2,254) between 2016 and 2019. Morphological parameters including early cleavage, day-3 fragmentation, symmetry, blastomere number, and blastocyst morphology were associated with neonatal birth weight and birth weight z-score in multivariate regression models. The models were adjusted for maternal age, body mass index (BMI), parity, peak estradiol level, endometrial thickness, insemination protocol, female etiologies, order of transfer, mode of delivery, and year of treatment.

RESULTS

Adjusted for confounders, day-3 fragmentation was the only morphological feature associated with birth weight and birth weight z-score, while early cleavage, symmetry, blastomere number, and blastocyst morphology were not. Day-3 fragmentation increased the birth weight in both the ET (115.4 g, 95% CI: 26.6-204.2) and BT groups (168.8 g, 95% CI: 48.8-288.8) but not in the FBT group (7.47 g, 95% CI: -46.4 to 61.3). The associations between birth weight and these morphological parameters were confirmed through birth weight z-score analyses. The adjusted odds of large for gestational age (LGA) and high birth weight were also significantly greater in singletons following the transfer of fragmented embryos in the BT group [odds ratio (OR) 3, 95% CI: 1.2-7.51 and OR 3.65, 95% CI: 1.33-10, respectively]. The presence of fragmentation at the cleavage stage also affected the association between the blastocyst morphology and birth weight. Inner cell mass grades were negatively associated with birth weight in blastocysts with day-3 fragmentation but not in blastocysts without.

CONCLUSIONS

The birth weight following blastocyst transfer was found to be positively associated with fragmentation at the cleavage stage. The data did not support the argument that transferring a poor-looking embryo may increase the risks of low birth weight. However, concerns for LGA infants remain.

Growth analysis and blood profile in piglets born by embryo transfer

Assisted reproductive technologies (ART), besides solving several reproductive problems, it has also been used as a tool to improve the animal productivity that is required for feeding the human population. One of these techniques, the embryo transfer (ET), has presented limitations in the porcine species, which could constrain its use in the porcine industry. To clarify the potential of this technique, we aimed to compare the impact of using ET or artificial insemination (AI) on the phenotype of the offspring during its first days of age, in terms of growth and blood parameters. At birth, the body weight was higher for ET-females than AI-females, but this difference was no longer observed at day 15. On day 3, it was observed a higher concentration of red blood cells, haemoglobin, and haematocrit in females-ET and a higher concentration of white blood cells in both ET-derived piglets (males and females) when compared to AI groups. On day 3, the biochemical analysis showed a higher level of albumin for ET-derived males, and a lower level of bilirubin for ET-females than AI controls. However, all values were within the normal ranges. Our results indicate that piglets derived from ET seem to be phenotypically similar to those born by AI, which provides preliminary evidence that the ET procedure is a safe technique, but additional studies beyond 15 days of life are requested to conclude its global impact. Furthermore, the presented reference values of blood parameters in this species are interesting data for the pig industry.

Coping strategies mediate the association between stigma and fertility quality of life in infertile women undergoing in vitro fertilization-embryo transfer

BACKGROUND

The mediating role of coping strategies and its relationship with psychological well-being and quality of life has been considered in the literature. However, there is little research to explore the mechanism of coping strategies on stigma and fertility quality of life (FertiQoL) in infertile women undergoing In Vitro Fertilization Embryo Transfer (IVF-ET). The aim of this study was to examine the mediating effect of coping strategies on the relationship between stigma and fertility quality of life (FertiQoL) in Chinese infertile women undergoing In Vitro Fertilization Embryo Transfer (IVF-ET).

METHODS

In this cross-sectional study, a total of 768 infertile women undergoing IVF-ET were recruited from Assisted Reproductive Center of Shaanxi Province, China. The personal information, infertility stigma scale, coping strategy scale and FertiQoL scale were measured using a set of questionnaires. The multiple mediator model was performed using AMOS 21.0.

RESULTS

The model showed a significant negative direct effect between stigma on FertiQoL. There were significantly negative indirect effects of stigma on FertiQoL through active-avoidance, active-confronting and passive-avoidance, respectively. The meaning-based coping played a positive intermediary role. The model explained 69.4% of the variance in FertiQoL.

CONCLUSION

Active-avoidance coping strategy is the most important mediator factor between stigma and FertiQoL in infertile women undergoing IVF-ET treatment. Meaning-based coping strategy plays a positive mediating role between stigma and FertiQoL.

Advanced trophectoderm quality increases the risk of a large for gestational age baby in single frozen-thawed blastocyst transfer cycles

STUDY QUESTION

Does trophectoderm (TE) quality affect birthweight after single frozen-thawed blastocyst transfer?

SUMMARY ANSWER

Transfer of single blastocyst with advanced TE quality was associated with higher birthweight and increased risk of a large for gestational age (LGA) baby.

WHAT IS KNOWN ALREADY

Transfer of blastocysts with advanced TE quality results in higher ongoing pregnancy rates and a lower miscarriage risk. However, data on the relationship between TE quality and birthweight are still lacking.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study at a tertiary-care academic medical center included 1548 singleton babies born from single frozen-thawed blastocyst transfer from January 2011 to June 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Babies were grouped into four groups according to embryo expansion (Stages 3, 4, 5 and 6), three groups according to inner cell mass (ICM) quality (A, B and C), and three groups according to TE quality (A, B and C). Main outcomes included absolute birthweight, Z-scores adjusted for gestational age and gender, and adverse neonatal outcomes. Multivariable linear and logistic regression analyses were performed to investigate the association of neonatal outcomes with expansion stage, ICM quality and TE quality.

MAIN RESULTS AND THE ROLE OF CHANCE

As TE quality decreased, birthweight (3468.10 ± 471.52, 3357.69 ± 522.06, and 3288.79 ± 501.90 for A, B and C, respectively, P = 0.002), Z-scores (0.59 ± 1.07, 0.42 ± 1.04, and 0.27 ± 1.06 for A, B and C, respectively, P = 0.002) and incidence of LGA (28.9%, 19.7% and 17.4% for A, B and C, respectively, P = 0.027) decreased correspondingly. After adjusting for confounders, compared with the Grade A group, blastocysts with TE Grade B (standardized coefficients (β): -127.97 g, 95% CI: -234.46 to -21.47, P = 0.019) and blastocysts with TE grade C (β: -200.27 g, 95% CI: -320.69 to -79.86, P = 0.001) resulted in offspring with lower birthweight. Blastocysts with TE grade C brought babies with lower Z-scores than TE Grade A (β: -0.35, 95% CI: -0.59 to -0.10, P = 0.005). Also, embryos with TE Grade B (adjusted odds ratio (aOR):0.91, 95% CI: 0.84 to 0.99, P = 0.033) and embryos with TE Grade C (aOR : 0.89, 95% CI: 0.81 to 0.98, P = 0.016) had lower chance of leading to a LGA baby than those with TE Grade A. No association between neonatal outcomes with embryo expansion stage and ICM was observed (all P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design, lack of controlling for several unknown confounders, and inter-observer variation limited this study.

WIDER IMPLICATIONS OF THE FINDINGS

The study extends our knowledge of the down-stream effect of TE quality on newborn birthweight and the risk of LGA.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by National Key R&D Program of China (2018YFC1003000), National Natural Science Foundation of China (81771533 to Y.P.K. and 31200825 to L.S.) and Innovative Research Team of High-level Local Universities in Shanghai (SSMU-ZLCX20180401), Shanghai Sailing Program(21YF1423200) and the Fundamental research program funding of Ninth People's Hospital affiliated to Shanghai Jiao Tong university School of Medicine (JYZZ117). The authors declare no conflict of interest in this present study.

TRIAL REGISTRATION NUMBER

N/A.

Cohort profile: a national, population-based cohort of children born after assisted conception in the UK (1992-2009): methodology and birthweight analysis

PURPOSE

To generate a large cohort of children born after assisted reproductive technology (ART) in the UK between 1992 and 2009, their naturally conceived siblings (NCS) and matched naturally conceived population (NCP) controls and linking this with health outcome data to allow exploration of the effects of ART. The effects of fresh and frozen embryo transfer on birth weight (BW) were analysed to test the validity of the cohort.

PARTICIPANTS

Children recorded on the Human Fertilisation and Embryology Authority (HFEA) register as being born after ART between 1992 and 2009, their NCS and matched NCP controls linked to Office for National Statistics birth registration dataset (HFEA-ONS cohort). This cohort was further linked to the UK Hospital Episode Statistics database to allow monitoring of the child's post-natal health outcomes up to 2015 (HFEA-ONS-HES subcohort).

FINDINGS TO DATE

The HFEA-ONS cohort consisted of 75 348 children born after non-donor ART carried out in the UK between 1 April 1992 and 31 July 2009 and successfully linked to birth registration records, 14 763 NCS and 164 823 matched NCP controls. The HFEA-ONS-HES subcohort included 63 877 ART, 11 343 NCS and 127 544 matched NCP controls further linked to health outcome data. The exemplar analysis showed that children born after fresh embryo transfers were lighter (BW difference: -131 g, 95% CI: -140 to -123) and those born after frozen embryo transfers were heavier (BW difference: 35 g, 95% CI: 19 to 52) than the NCP controls. The within-sibling analyses were directionally consistent with the population control analyses, but attenuated markedly for the fresh versus natural conception (BW difference: -54 g; 95% CI: -72 to -36) and increased markedly for the frozen versus natural conception (BW difference: 152 g; 95% CI: 113 to 190) analyses.

FUTURE PLANS

To use this cohort to explore the relationship between ART conception and short-term and long-term health outcomes in offspring.

Associations of IVF singleton birthweight and gestation with clinical treatment and laboratory factors: a multicentre cohort study

STUDY QUESTION

Do IVF treatment and laboratory factors affect singleton birthweight (BW)?

SUMMARY ANSWER

BWs of IVF-conceived singleton babies are increasing with time, but we cannot identify the specific treatment factors responsible.

WHAT IS KNOWN ALREADY

IVF-conceived singleton babies from fresh transfers have slightly lower BW than those conceived naturally, whilst those from frozen embryo transfer (FET) cycles are heavier and comparable to naturally conceived offspring. Our recent studies have shown that BW varies significantly between different IVF centres, and in a single centre, is also increasing with time, without a corresponding change in BWs of naturally conceived infants. Although it is likely that factors in the IVF treatment cycle, such as hormonal stimulation or embryo laboratory culture conditions, are associated with BW differences, our previous study designs were not able to confirm this.

STUDY DESIGN, SIZE, DURATION

Data relating to BW outcomes, IVF treatment and laboratory parameters were collated from pre-existing electronic records in five participating centres for all singleton babies conceived between August 2007 and December 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Seven thousand, five hundred and eighty-eight births, 6207 from fresh and 1381 from FET. Infants with severe congenital abnormalities were excluded. The primary outcome of gestation-adjusted BW and secondary outcomes of unadjusted BW and gestation were analysed using multivariable regression models with robust standard errors to allow for the correlation between infants with the same mother. The models tested treatment factors allowing for confounding by centre, time and patient characteristics. A similar matched analysis of a subgroup of 379 sibling pairs was also performed.

MAIN RESULTS AND THE ROLE OF CHANCE

No significant associations of birth outcomes with IVF embryo culture parameters were seen independent of clinic or time, including embryo culture medium, incubator type or oxygen level, although small differences cannot be ruled out. We did not detect any significant differences associated with hormonal stimulation in fresh cycles or hormonal synchronization in FET cycles. Gestation-adjusted BW increased by 13.4 (95% CI 0.6-26.1) g per year over the period of the study, and babies born following FET were 92 (95% CI 57-128) g heavier on average than those from the fresh transfer.

LIMITATIONS, REASONS FOR CAUTION

Although no specific relationships have been identified independent of clinic and time, the confidence intervals remain large and do not exclude clinically relevant effect sizes. As this is an observational study, residual confounding may still be present.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrates the potential for large scale analysis of routine data to address critical questions concerning the long-term implications of IVF treatment, in accordance with the Developmental Origins of Health and Disease hypothesis. However, much larger studies, at a national scale with sufficiently detailed data, are required to identify the treatment parameters associated with differences in BW or other relevant outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the EU FP7 project grant, EpiHealthNet (FP7-PEOPLE-2012-ITN-317146). No competing interests were identified.

TRIAL REGISTRATION NUMBER

N/A.

Perinatal outcomes in singleton pregnancies after in vitro fertilization cycles over 24 years

OBJECTIVE

To determine how a shift in clinical practice along with laboratory changes has impacted singleton perinatal outcomes after autologous in vitro fertilization (IVF) cycles.

DESIGN

Retrospective cohort.

SETTING

Single academic fertility clinic.

PATIENT(S)

Singleton live births resulting from all IVF cycles (n = 14,424) from August 1, 1995 to October 31, 2019.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth weight, large for gestational age (GA), small for GA, and preterm birth.

RESULT(S)

The entire cohort consisted of 9,280 fresh and 5,144 frozen IVF cycles. Maternal age, parity, body mass index, neonatal sex, and GA at delivery were similar in both groups. There was a decrease in adjusted birth weight per year over the study period for the entire cohort of IVF cycles (-4.42g, 95% confidence interval [CI]: -6.63g to -2.22g). Rates of large for GA newborns decreased by 1.7% (95% CI: 2.9% to 0.6%) annually across the entire cohort of IVF cycles. Furthermore, there was a decrease in annual rates of preterm birth before 32 weeks by 3.2% (95% CI: 5.9% to 0.5%) across the entire cohort of IVF cycles. Trends were also seen in annual reduction of rates of preterm birth before 37 and 28 weeks.

CONCLUSION(S)

With the gradual evolution of clinical and IVF laboratory practices, there has been a decrease in birth weight over 24 years for the entire cohort of IVF cycles. Concurrently, noteworthy practice changes have resulted in an improvement in IVF outcomes with decreased rates of large for GA newborns and preterm birth before 32 weeks for the entire cohort of IVF cycles.

Clinical efficacy of hyaluronate-containing embryo transfer medium in IVF/ICSI treatment cycles: a cohort study

STUDY QUESTION

Does the duration of embryo exposure to hyaluronic acid (HA) enriched medium improve the rate of live birth events (LBEs)?

SUMMARY ANSWER

The use of embryo transfer (ET) medium rich in HA improves LBE (a singleton or twin live birth) regardless of the duration of exposure evaluated in this study, but does not alter gestation or birthweight (BW).

WHAT IS KNOWN ALREADY

HA-enriched medium is routinely used for ET in ART to facilitate implantation, despite inconclusive evidence on safety and efficacy.

STUDY DESIGN SIZE DURATION

A cohort study was performed evaluating clinical treatment outcomes before and after HA-enriched ET medium was introduced into routine clinical practice. In total, 3391 fresh ET procedures were performed using low HA and HA-rich medium in women undergoing publicly funded IVF/ICSI treatment cycles between May 2011 and April 2015 were included in this cohort study.

PARTICIPANTS/MATERIALS SETTING METHODS

A total of 1018 ET performed using low HA medium were compared with 1198, and 1175 ET following exposure to HA-rich medium for 2-4 h (long HA exposure) or for 10-30 min (short HA exposure), respectively. A multiple logistic regression analysis was used to compare clinical outcomes including BW, gestational age and sex ratios between groups, whilst adjusting for patient age, previous attempt, incubator type and the number of embryos transferred.

MAIN RESULTS AND THE ROLE OF CHANCE

The use of HA-rich medium for ET was positively and significantly associated with improved clinical pregnancy rate and LBE, for both exposure durations: long HA (odds ratio (OR) = 1.21, 95% CI: 0.99-1.48), short HA (OR = 1.32, 95% CI: 1.02-1.72) and pooled OR = 1.26, 95% CI: 1.03-1.54, relative to the use of low HA medium. A comparative analysis of the risks of early pregnancy loss following long HA exposure (OR = 0.76, 95% CI: 0.54-1.06), short HA exposure (OR = 0.84, 95% CI: 0.54-1.30) and late miscarriage (OR = 0.88, 95% CI: 0.51-1.53) (OR = 1.41, 95% CI 0.72-2.77), were lower and not statistically significant. Similarly, ordinary regression analysis of the differences in BW at both HA exposures; pooled OR = -0.9 (-117.1 to 115.3), and adjusted BW between both HA cohorts; pooled OR = -13.8 (-106.1 to 78.6) did not show any differences. However, a difference in gestational age (pooled OR -0.3 (-3.4 to 2.9)) and sex ratio (pooled OR 1.43 (0.95-2.15)) were observed but these were not statistically significant relative to low HA medium.

LIMITATIONS REASONS FOR CAUTION

The strength of a randomized treatment allocation was not available in this evaluation study, therefore effects of unmeasured or unknown confounding variables cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

The result of this large cohort study strengthens the case for using HA-rich medium routinely at transfer, while adding the important clinical information that duration of exposure may not be critical. The composition and effects of commercial IVF culture media on success rate and safety remains a major controversy despite increasing calls for transparency and evidence-based practice in ART. Nonetheless, the lack of differences in BW and gestational age observed in this study were reassuring. However, an appraisal of clinical outcomes and appropriate research investigations are required for the continuous evaluation of efficacy and safety of HA.

STUDY FUNDING/COMPETING INTERESTS

T.A. is funded by a Clinical Doctoral Research Fellowship (CDRF) grant (reference: ICA-CDRF-2015-01-068) from the National Institute for Health Research (NIHR). The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health. The authors declare no conflict of interest.

Growth and other health outcomes of 2-year-old singletons born after IVM versus controlled ovarian stimulation in mothers with polycystic ovary syndrome

STUDY QUESTION

Does In vitro maturation (IVM) of immature oocytes affect health, including growth at 2 years of age, in singletons born to mothers with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

This study of 92 singletons born after IVM in mothers with PCOS showed no significant differences in anthropometry and health outcome parameters in comparison with a cohort of 74 peers born after intracytoplasmic sperm injection (ICSI) and conventional controlled ovarian stimulation (COS) in mothers with PCOS.

WHAT IS KNOWN ALREADY

IVM has been used worldwide in women with PCOS. However, the paucity of available data related to children's health following IVM is an important impediment to a more widespread use of the technology. Although previous reports on the neonatal outcome after IVM are generally reassuring, these studies have flaws that hamper the interpretation of outcomes. Moreover, few studies have reported on health outcomes after IVM beyond infancy, and particularly growth data in children born after IVM of immature oocytes from mothers with PCOS are lacking.

STUDY DESIGN SIZE DURATION

This single-center cohort study compared anthropometry and health outcomes in 92 singletons born after ICSI of in vitro matured oocytes with 74 singletons born after ICSI without IVM (COS). All participants were born to mothers who were diagnosed with PCOS phenotype A, B, C or D and reached the age of 2 years between November 2012 and June 2019. Singletons born after COS were randomly selected for follow-up until young adulthood.

PARTICIPANTS/MATERIALS SETTING METHODS

Anthropometric parameters and health status data were prospectively collected at birth, 4 months and 2 years in cohorts of singletons followed since birth. Results were adjusted for neonatal (birthweight z-score, birth order), treatment (day of transfer, number of embryos transferred, mode of transfer) and parental (maternal smoking, age, body mass index (BMI), anti-Müllerian hormone level, PCOS phenotype, gestational diabetes, hypertensive disorder and paternal BMI) characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, no differences were found for bodyweight, height and head circumference z-score between IVM and COS children at birth, at 4 months or at 2 years (all P > 0.05). In addition, z-scores of waist and mid-upper arm circumference at 2 years were comparable in IVM and COS children. Adjustment for covariates did not change the conclusion. Surgical intervention rate as well as the hospital admission rate were comparable between the IVM and COS group (all P > 0.05). The proportion of children born to mothers with metabolically unfavorable PCOS phenotypes (A and C) was comparable in the two groups (52.1% in IVM and 45.9% in COS). Mothers giving birth to a child conceived using IVM were younger than mothers in the COS group but their BMI was comparable.

LIMITATIONS REASONS FOR CAUTION

Although our study describes the largest cohort to date of singletons born after IVM applied in mothers with well-defined PCOS phenotypes, the current sample size only allowed us to detect moderate differences in anthropometry. Also, follow-up of children born after IVM for indications other than PCOS, for example fertililty preservation after cancer diagnosis, is highly recommended.

WIDER IMPLICATIONS OF THE FINDINGS

We did not observe adverse effects of IVM on growth parameters in offspring ~2 years of age compared to COS, but future studies should focus on cardiovascular and metabolic outcomes in these children and adolescents given their mother's PCOS condition.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts; all issued by the Vrije Universiteit Brussel (VUB). All co-authors, except M.B., M.D.V. and H.T. declared no conflict of interest. M.B. has received consultancy fees from MSD, Serono Symposia and Merck. M.D.V. has received fees for lectures from MSD, Ferring, Gedeon Richter and Cook Medical. H.T. has received consultancy fees from Gedeon Richter, Merck, Ferring, Abbott and ObsEva. The Universitair Ziekenhuis Brussel (UZ Brussel) and the Center for Medical Genetics have received several educational grants from IBSA, Ferring, MSD and Merck for establishing the database for follow-up research and organizing the data collection.

The impact of embryo quality on singleton birthweight in vitrified-thawed single blastocyst transfer cycles

STUDY QUESTION

Does the quality of a single transferred blastocyst affect singleton birthweight in frozen-embryo transfer (FET) cycles?

SUMMARY ANSWER

The transfer of a poor-quality blastocyst was associated with lower mean birthweight and gestation-adjusted birthweight (Z-scores) when compared with the transfer of an excellent-quality blastocyst during FET cycles.

WHAT IS KNOWN ALREADY

Embryo quality is a strong predictor of IVF success rates. However, very few studies have examined the effect of embryo quality on singleton birthweight.

STUDY DESIGN, SIZE, DURATION

This retrospective study involved singleton live births born to women undergoing frozen-thawed single blastocyst transfers during the period from January 2010 to December 2017 at a tertiary care centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 1207 women who fulfilled the inclusion criteria were included and were grouped into four groups depending on the blastocyst quality: excellent, good, average and poor. The primary outcome measure was singleton birthweight. The Z-score was employed to calculate the birthweight adjusted for gestational age and newborn gender. Multiple linear regression analysis was performed to investigate the relationship between embryo quality and neonatal birthweight after adjustment for some potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

In the primary multivariable model, singletons from the poor-quality blastocyst group weighed 183.5 g less than those from the excellent-quality blastocyst group (95% CI: −295.1 to −71.9 g, P = 0.001) in terms of mean birthweight after accounting for patient characteristics, IVF treatment parameters, the year of treatment and newborn gender. Likewise, poor-quality blastocyst transfer was associated with lower gestation-adjusted Z-scores than the transfer of excellent-quality blastocysts (β = −0.35, 95% CI: −0.59 to −0.12, P = 0.003).

LIMITATIONS AND REASONS FOR CAUTION

The current study was limited by its retrospective design and the fact that our analysis was restricted to women with singleton births from single blastocyst transfers. Future prospective studies are required to confirm our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings provide new insight into the relationship between embryo quality and neonatal outcomes by showing that poor-quality blastocyst transfer was associated with a decrease in singleton birthweight.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Key Research and Development Program of China (grant no. 2018YFC1003000), the National Natural Science Foundation of China (grant nos. 81771533, 81571397 and 31770989), and the China Postdoctoral Science Foundation (Grant no. 2018M630456). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Reduced oxygen concentration during human IVF culture improves embryo utilization and cumulative pregnancy rates per cycle

STUDY QUESTION

Do different oxygen levels during human IVF embryo culture affect embryo utilization, cumulative IVF success rates per cycle and neonatal birthweight?

SUMMARY ANSWER

After 2 days of culture, a lower oxygen level (5%) leads to more good-quality embryos and more embryos that can be cryopreserved, and thereby to a higher cumulative live birth rate per cycle when compared to embryo culture in 20% oxygen, while birthweights are similar.

WHAT IS KNOWN ALREADY

Several studies have compared IVF outcome parameters after embryo culture in a more physiological level of 5% oxygen and the atmospheric level of 20%. Although there is consensus that embryo development improves in 5% oxygen, effects on pregnancy and live birth rates are mainly seen in blastocyst, but not cleavage-stage transfers. A major drawback of these studies is that only fresh embryo transfers were included, not taking additional frozen-thawed transfers from these cycles into account. This might have underestimated the effects of oxygen level, especially in cleavage-stage embryo transfers. Furthermore, little is known about the effect of oxygen level during culture on birthweight.

STUDY DESIGN, SIZE, DURATION

This is a cohort study in 871 consecutive patients who had an IVF cycle between January 2012 and December 2013, and 5–7 years follow-up to allow transfer of frozen-thawed embryos. Based on daily availability of positions in the incubators, all oocytes and embryos of one cycle were allocated to one of the three incubators with traditional ambient oxygen levels (6% CO₂ and 20% O₂ in air), or to a fourth incubator that was adjusted to have low oxygen levels of 5% (6% CO₂, 5% O₂ and 89% N₂). Embryos were cultured under 5 or 20% oxygen until Day 2 or 3, when embryos were transferred or cryopreserved, respectively. Clinical and other laboratory procedures were similar in both groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

To compare embryo characteristics and (cumulative) pregnancy outcomes between the two oxygen groups, for each patient only the first cycle in the study period was included in the analysis, resulting in 195 cycles in the 5% group (1627 oocytes) and 676 in the 20% oxygen group (5448 oocytes). Embryo characteristics were analysed per cycle and per embryo and were corrected for maternal age, cycle rank order, fertilization method (IVF or ICSI) and cause of subfertility. Perinatal data from the resulting singletons (n = 124 after fresh and 45 after frozen-thawed embryo transfer) were collected from delivery reports from the hospitals or midwife practices.

MAIN RESULTS AND THE ROLE OF CHANCE

In the 5% oxygen group, there were significantly more embryos of good quality (45.8 versus 30.9% in the 20% group, adjusted odds ratio (OR) [95% CI] = 1.9 [1.6–2.4]). This did not result in higher live birth rates per cycle, but after fresh transfers more good-quality spare embryos could be cryopreserved (46.1 versus 29.7%, adjusted OR [95% CI] = 2.0 [1.7–2.5]).

After a follow-up period of 5–7 years, in which 82.4% of the cryopreserved embryos from the 5% oxygen group and 85.4% from the 20% oxygen group were thawed, the percentage of patients with at least one live birth resulting from the study cycle was significantly higher in the low oxygen group (adjusted OR [95% CI] = 1.5 [1.01–2.2]). In 124 live born singletons from fresh embryo transfers and in 45 from transfers of cryopreserved embryos, birthweight was similar in both oxygen groups after correction for confounding factors.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study, and treatment allocation was not randomised. The study was not powered for a predefined birthweight difference. With the number of live births in our study, small differences in birthweight might not have been detected. The selection of embryos to be cryopreserved was based on embryo morphology criteria that might be different in other clinics.

WIDER IMPLICATIONS OF THE FINDINGS

Improved embryo utilization by more cryopreservation leading to higher cumulative live birth rates per cycle favours the use of 5% instead of 20% oxygen during human IVF embryo culture. This study also demonstrates that for comparison of different IVF treatment regimens, the cumulative outcome, including transfers of fresh and frozen-thawed embryos, is to be preferred instead of analysis of fresh embryo transfers only.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received for this study. None of the authors has a conflict of interest to declare.

TRIAL REGISTRATION NUMBER

NA

Effect of frozen and fresh embryo transfers on the birthweight of live-born twins

OBJECTIVE

To explore the influence of frozen embryo transfer (FET) and fresh embryo transfer (Fresh) on the birthweight of live-born twins.

STUDY DESIGN

A total of 8482 live-born twins were studied. The proportions of small for gestational age (SGA) and large for gestational age (LGA), the mean birthweight and the z score of live-born twins in the two groups were compared. Multiple linear regression analysis was used to evaluate the relationship between confounding factors and the birthweight of live-born twins.

RESULTS

The proportion of SGA infants significantly decreased as BMI increased (BMI < 20, 6.1 %; 20 ≤ BMI≤25, 4.1 %; BMI > 25, 3.6 %; P<0.05). The proportion of LGA infants significantly increased as BMI increased (BMI < 20, 20.5 %; 20 ≤ BMI≤25, 25.2 %; BMI > 25, 30.7 %; P<0.0001). The proportion of SGA infants was significantly lower in the FET group than in the Fresh group, whereas the proportion of LGA infants was significantly higher in the former than in the latter. The absolute mean birthweight of live-born twins was significantly higher in the FET group compared with the Fresh group (2579 ± 458 vs. 2534 ± 465, P < 0.0001). The mean z score of the FET group was also significantly higher than that of the Fresh group (0.420 vs. 0.240, P < 0.0001). Multiple linear regression analysis indicated that FET was a more significant factor than fresh embryo transfer in influencing the birthweight of live-born twins.

CONCLUSION

FET significantly increased the birthweight of live-born twins compared with fresh embryo transfer.

Birthweight of singletons born after blastocyst-stage or cleavage-stage transfer: analysis of a data set from three randomized controlled trials

PURPOSE

The present post hoc analysis aims to study the neonatal data of singletons born from three randomized controlled trials (RCTs) which compared the outcome of day 3 and day 5 transfers.

METHODS

Our analysis included 208 liveborn singletons from three existing RCTs (publication dates 2004, 2005, and 2006), 93 children from cleavage-stage transfers and 115 from blastocyst-stage transfers. Vanishing twins were excluded from the analysis. Singleton birthweight was the primary outcome measure. Gestational age and gender of the newborn were accounted for in the multiple regression analysis, along with other confounding factors, such as maternal age, BMI, parity, and smoking behavior.

RESULTS

There was no significant difference in gestational age (median, interquartile range) between cleavage-stage transfer (275 days; 267-281) and blastocyst-stage transfer (277 days; 270-281; p = 0.22). Singleton birthweight (median, interquartile range) was not significantly different between cleavage-stage transfer (3330 g; 3020-3610) and blastocyst-stage transfer (3236 g; 2930-3630; p = 0.40), even following multivariable regression analysis to control for potential maternal and newborn confounders.

CONCLUSION

The gestational age and birthweight were not significantly different after cleavage-stage and blastocyst-stage transfers. One limitation to be recognized is the age of the data, with original data collection dates from 2001 to 2004. Additionally, the RCTs used for the present analysis have a fairly young age restriction.

Associations of sperm telomere length with semen parameters, clinical outcomes and lifestyle factors in human normozoospermic samples

BACKGROUND

Many studies have demonstrated that lifestyle factors can affect sperm quality and fertility. Sperm telomere length (STL) has been reported as potential biomarker or sperm quality. However, no studies have investigated how lifestyle factors can affect STL and associated clinical outcomes.

OBJECTIVES

The purpose of this manuscript is to investigate any association between STL with lifestyle factors, semen parameters and clinical outcomes.

MATERIALS AND METHODS

Sperm telomere length was measured using real-time PCR in normozoospermic male partners (n = 66) of couples undergoing ART treatment. Each participant also completed a detailed questionnaire about general lifestyle. Linear regression univariate analysis and ANCOVA were performed to respectively determine correlations between STL and study parameters or identify statistically significant differences in STL while controlling for age, BMI and other factors.

RESULTS

Using a linear regression model, STL is positively correlated with in vitro fertilization success (n = 65, r = 0.37, P = .004) but not with embryo cleavage rates and post-implantation clinical outcomes including gestational age-adjusted birth weight. No associations were observed between STL and sperm count, concentration or progressive motility. We further found that STL did not associate age, BMI, health or lifestyle factors.

DISCUSSION

In somatic cells, the rate of telomere shortening is influenced by a number of lifestyle factors such as smoking, diet and occupation. However, little is known about how lifestyle factors affect STL and subsequently reproductive outcome. Out data suggest that STL might have an important role mechanistically for fertilization rate regardless of sperm parameters and lifestyle factors.

CONCLUSION

The results of this study demonstrate that STL is associated with in vitro fertilization rates, but not with semen parameters nor lifestyle factors. Further investigations are warranted to identify the potential variation of STL overtime to clarify its significance as a potential biomarker in ART.

Preimplantation Genetic Testing for Aneuploidy Improves Clinical, Gestational, and Neonatal Outcomes in Advanced Maternal Age Patients Without Compromising Cumulative Live-Birth Rate

PURPOSE

To report the effects of blastocyst stage aneuploidy testing on clinical, gestational, and neonatal outcomes for patients of advanced maternal age undergoing IVF.

METHODS

This is a single-center observational-cohort study with 2 years follow-up. The study includes a total of 2538 couples undergoing 2905 egg collections (control group), 308 (PGT-A), and 106 (drop-out group, consenting for PGT-A but withdrawing due to poor embryological outcome) RESULTS: Compared with control group, PGT-A showed improved clinical outcomes (live-birth rate per transferred embryo, LBR 40.3% vs 11.0%) and reduced multiple pregnancy rate (MPR, 0% vs 11.1%) and pregnancy loss (PL, 3.6% vs 22.6%). Drop-out group showed the worst clinical outcomes suggesting that abandoning PGT-A due to poor response to ovarian stimulation is not a favorable option. Cytogenetic analysis of product of conceptions and CVS/amniocentesis showed higher aneuploid pregnancy rates for control group regardless of embryo transfer strategy (0%, 17.9%, and 19.9%, for PGT-A, control day 5 and day 3, respectively). Multivariate analysis showed no negative impact of PGT-A-related interventions on cumulative delivery rate (26.3%, 95% CI 21.5-31.6 vs 24.0%, 95% CI 22.5-25.6 for PGT-A and control, respectively) and on neonatal outcomes.

CONCLUSION

PGT-A improves clinical outcomes, particularly by reducing pregnancy loss and chromosomally abnormal pregnancy for patients of advanced maternal age, with no major impact on cumulative live-birth rate (CLBR) per egg retrieval.