O-075 The association between high birth weight and long-term outcomes-implications for Assisted Reproductive Technologies: a systematic review and meta-analysis

Study question

Do high birth weight or large for gestational age (LGS) increase the risk of serious disease later in life?

Summary answer

High birth weight and/or LGA were associated with elevated risks for certain child malignancies, breast cancer, psychiatric disorders, childhood hypertension and diabetes type 1.

What is known already

Previous studies have shown that children born after frozen embryo transfer (FET) have an increased risk of being born LGA or having a high birth weight. In recent years the practice of FET in Assisted Reproductive Technology (ART) has increased rapidly. The perinatal risks of being born LGA or with a high birth weight are well studied, however less is known about the impact on long-term health and morbidity.

Study design, size, duration

Pubmed, Scopus and Web of Science were searched until December 2020. 11 748 abstracts were screened, 172 publications were selected for systematic review and 63 for meta-analyses. The methodological quality in terms of risk of bias was assessed by pairs of reviewers. Robin-I (www.methods.cochrane.org) was used for assessing risk of bias in original articles. For systematic reviews AMSTAR was used. For certainty of evidence the GRADE system was used.

Participants/materials, setting, methods

Exposures were LGA and high birth weight. Long-term morbidity outcomes were cancer, metabolic disease, cardiovascular disease and psychiatric disorders. Cancer was focused on breast cancer, child malignancies in the central nervous system (CNS), hematological malignancies and Wilm´s tumor. Metabolic diseases included diabetes type 1 and type 2. Cardiovascular diseases were focused on hypertension and other cardiovascular disorders and psychiatric disorders on schizophrenia/psychosis and cognitive disorders.

Main results and the role of chance

Pooled Adjusted Odds Ratios (AOR) for outcome variables were compared for birth weights >4000 or > 4500 g versus < 4000 g. For cancer, meta-analyses showed AOR of 1.24 (95% 1.11-1.39) for development of breast cancer, AOR of 1.15 (95% CI 1.05-1.27) for development of CNS tumors, AOR of 1.29 (95% CI 1.20-1.39) for childhood leukemia and AOR 1.68 (95% CI 1.38-2.06 ) for Wilm´s tumor.

For metabolic disease a meta-analysis showed AOR of 1.15 (95%CI 1.05-1.26) for the association between high birth weight and type 1 diabetes.

For psychiatric diseases an association was found between high birth weight and/or LGA and schizophrenia and depression.

For cardiovascular disease, an association was found between high birth weight and hypertension in childhood with an inverse association in adulthood. No difference in the risk of coronary heart disease in adults born with high birth weight compared to normal birth

Limitations, reasons for caution

The main limitation is that all data are based on observational studies with their inborn risk of selection bias. Our conclusions are however, mainly based on meta-analyses and/or studies with low risk of bias.

Wider implications of the findings

Even though high birth weight and LGA are associated with an increased risk of serious diseases, both in childhood and in adulthood, the size of these effects seems modest. However, the identified risk associations should be taken into account in stimulation strategies and when considering fresh or frozen embryo transfer.

Trial registration number

Not applicable

P–767 Cumulative live birth rate after IVF - trend over time and the impact of blastocyst culture and vitrification

Study question

Has cumulative live birth rate (CLBR) improved over time and which factors are associated with such an improvement?

Summary answer

During 2007–2017, CLBR per oocyte aspiration increased significantly (27.0% to 36.3%), in parallel with an increase in blastocyst transfer and cryopreservation by vitrification.

What is known already

While it has been shown that live birth rate (LBR) per embryo transfer (ET) is higher for fresh blastocyst than for fresh cleavage stage embryo transfer, CLBR per oocyte aspiration, including one fresh ET and all subsequent frozen embryo transfers (FET), does not seem to differ between the two culture strategies.

Study design, size, duration

STUDY DESIGN, SIZE, DURATION: National register study including all oocyte aspirations performed in Sweden 2007–2017, n = 124 700. Donation cycles excluded.

Participants/materials, setting, methods

Data were retrieved from the Swedish National Registry of Assisted Reproduction (Q-IVF). CLBR was defined as the number of deliveries with at least one live birth resulting from one oocyte aspiration, including all fresh and/or frozen embryo transfers within one year. The delivery of a singleton, twin, or other multiples was registered as one delivery. Cryopreservation of cleavage stage embryos was performed by slow freezing and of blastocyst by vitrification.

Main results and the role of chance

Overall, the CLBR per oocyte aspiration increased significantly during the study period, from 27.0% to 36.3% (OR 1.039, 95% CI 1.035–1.043) and from 30.0% to 43.3% if at least one ET was performed (AOR 1.055, 95% CI 1.050–1.059). The increase in CLBR was independent of maternal age, number of oocytes retrieved and number of previous IVF live births. The CLBR for women <35 years and ≥ 35 years both increased significantly, following the same pattern. During the study period a substantially increasing number of blastocyst transfers were performed, both in fresh and in FET cycles. An important contributor included in the blastocyst strategy, may be the extended culture of the total cohort of embryos, also embryos earlier discarded at early cleavage stages, in order to reach the blastocyst stage. These embryos may contribute to the total number of available blastocysts and thereby increase the chance of a live birth within that oocyte aspiration cycle. Other important predicting factors for live birth, such as number of embryos transferred, could not explain the improvement, on the contrary the single embryo transfer (SET) rate increased with time.

Limitations, reasons for caution

The retrospective design implicates that other confounders of importance for CLBR can not be ruled out. In addition, some FET cycles might be performed later than one year post oocyte aspiration for the last year (2017) and are thus not included in this study.

Wider implications of the findings: The results suggest that blastocyst transfer, particularly when used in FET cycles and in combination with vitrification, is an important contributor to the improved live birth rates over time. This gives a possibility for fewer oocyte aspirations needed to achieve a live birth and a shortened time to live birth.

Trial registration number

-

P-767 Cumulative live birth rate after IVF - trend over time and the impact of blastocyst culture and vitrification

Study question

Has cumulative live birth rate (CLBR) improved over time and which factors are associated with such an improvement?

Summary answer

During 2007-2017, CLBR per oocyte aspiration increased significantly (27.0 % to 36.3 %), in parallel with an increase in blastocyst transfer and cryopreservation by vitrification.

What is known already

While it has been shown that live birth rate (LBR) per embryo transfer (ET) is higher for fresh blastocyst than for fresh cleavage stage embryo transfer, CLBR per oocyte aspiration, including one fresh ET and all subsequent frozen embryo transfers (FET), does not seem to differ between the two culture strategies.

Study design, size, duration

STUDY DESIGN, SIZE, DURATION: National register study including all oocyte aspirations performed in Sweden 2007-2017, n = 124 700. Donation cycles excluded.

Participants/materials, setting, methods

Data were retrieved from the Swedish National Registry of Assisted Reproduction (Q-IVF). CLBR was defined as the number of deliveries with at least one live birth resulting from one oocyte aspiration, including all fresh and/or frozen embryo transfers within one year. The delivery of a singleton, twin, or other multiples was registered as one delivery. Cryopreservation of cleavage stage embryos was performed by slow freezing and of blastocyst by vitrification.

Main results and the role of chance

Overall, the CLBR per oocyte aspiration increased significantly during the study period, from 27.0 % to 36.3 % (OR 1.039, 95% CI 1.035-1.043) and from 30.0 % to 43.3 % if at least one ET was performed (AOR 1.055, 95% CI 1.050-1.059). The increase in CLBR was independent of maternal age, number of oocytes retrieved and number of previous IVF live births. The CLBR for women < 35 years and ≥ 35 years both increased significantly, following the same pattern. During the study period a substantially increasing number of blastocyst transfers were performed, both in fresh and in FET cycles. An important contributor included in the blastocyst strategy, may be the extended culture of the total cohort of embryos, also embryos earlier discarded at early cleavage stages, in order to reach the blastocyst stage. These embryos may contribute to the total number of available blastocysts and thereby increase the chance of a live birth within that oocyte aspiration cycle. Other important predicting factors for live birth, such as number of embryos transferred, could not explain the improvement, on the contrary the single embryo transfer (SET) rate increased with time.

Limitations, reasons for caution

The retrospective design implicates that other confounders of importance for CLBR can not be ruled out. In addition, some FET cycles might be performed later than one year post oocyte aspiration for the last year (2017) and are thus not included in this study.

Wider implications of the findings

The results suggest that blastocyst transfer, particularly when used in FET cycles and in combination with vitrification, is an important contributor to the improved live birth rates over time. This gives a possibility for fewer oocyte aspirations needed to achieve a live birth and a shortened time to live birth.

Trial registration number

-

The correlation between AMH assays differs depending on actual AMH levels

STUDY QUESTION

What is the correlation of serum anti-Müllerian hormone (AMH) levels between two frequently used laboratory assays?

SUMMARY ANSWER

A considerable difference was found in serum AMH levels measured with the two different assays, particularly for low AMH values.

WHAT IS KNOWN ALREADY

AMH is regarded as being a robust, highly sensitive and specific biomarker for ovarian response and has become widely used as the basis for fertility treatment decisions. However, several available assays with different reference values, in addition to inter-laboratory variations and issues of sample stability, make interpretation of the AMH values and their clinical implications complicated.

STUDY DESIGN SIZE DURATION

An observational study was performed including 269 serum samples from infertile women, originating from a RCT conducted in 2013-2016 (www.clinicaltrials.gov NCT02013973).

PARTICIPANTS/MATERIALS SETTING METHOD

Serum AMH levels analysed with the Modified Beckman Coulter Gen II ELISA assay (Premix method) were compared to AMH levels analysed with the Beckman Coulter Gen II ELISA original assay (Gen II original). All samples were handled identically and analysed with the two assays in a parallel setting.

MAIN RESULTS AND THE ROLE OF CHANCE

The slope of the regression line showed a mean of 18% higher values with the Premix method compared to the Gen II original assay, and more than 40% higher values for AMH levels in the lower range.

LIMITATIONS REASONS FOR CAUTION

The Gen II original assay is no longer in clinical use as it has been replaced by the Premix method, which, in turn, recently has been further developed into an automated method.

WIDER IMPLICATIONS OF THE FINDINGS

The finding of differences in AMH levels between assays is clinically important and may imply an incorrect classification in the assessment of ovarian reserve. The robustness of serum AMH as a marker for ovarian reserve and as a tool for fertility counselling has to be investigated further. There is an urgent need for international standards on interpretation of AMH values for different assays.

STUDY FUNDING/COMPETING INTERESTS

Financial support was received through Sahlgrenska University Hospital (ALFGBG-70940) and the Hjalmar Svensson Research Foundation. None of the authors declares any conflict of interest.

The addition of anti-Müllerian hormone in an algorithm for individualized hormone dosage did not improve the prediction of ovarian response-a randomized, controlled trial

Study question

Does the addition of anti-Müllerian hormone (AMH) to a conventional dosage regimen, including age, antral follicle count (AFC) and BMI, improve the rate of targeted ovarian response, defined as 5-12 oocytes after IVF?

Summary answer

The addition of AMH did not alter the rate of targeted ovarian response, 5-12 oocytes, or decreased the rate of ovarian hyperstimulation syndrome (OHSS) or cancelled cycles due to poor ovarian response.

What is known already

Controlled ovarian hyperstimulation (COH) in connection with IVF is sometimes associated with poor ovarian response resulting in low pregnancy and live birth rates or leading to cycle cancellations, but also associated with excessive ovarian response, causing an increased risk of OHSS. Even though it is well-established that both AMH and AFC are strong predictors of ovarian response in IVF, few randomized trials have investigated their impact on achieving an optimal number of oocytes.

Study design, size and duration

Between January 2013 and May 2016, 308 patients starting their first IVF treatment were randomly assigned, using a computerized randomization program with concealed allocation of patients and in the proportions of 1:1, to one of two dosage algorithms for decisions on hormone starting dose, an algorithm, including AMH, AFC, age and BMI (intervention group), or an algorithm, including only AFC, age and BMI (control group). The study was blinded to patients and treating physicians.

Participants/materials, setting, methods

Women aged >18 and <40 years, with a BMI above 18.0 and below 35.0 kg/m2 starting their first IVF cycle where standard IVF was planned, were eligible. All patients were treated with a GnRH agonist protocol and recombinant FSH was used for stimulation. The study was performed as a single-centre study at a large IVF unit at a university hospital.

Main results and the role of chance

The rate of patients having the targeted number of oocytes retrieved was 81/152 (53.3%) in the intervention group versus 96/155 (61.9%) in the control group (P = 0.16, difference: -8.6, 95% CI: -20.3; 3.0). Cycles with poor response (<5 oocytes) were more frequent in the AMH group, 39/152 (25.7%) versus the non-AMH group, 17/155 (11.0%) (P < 0.01), while the number of cancelled cycles due to poor ovarian response did not differ 7/152 (4.6%) and 4/155 (2.6%) (P = 0.52). An excessive response (>12 oocytes) was seen in 32/152 (21.1%) and 42/155 (27.1%) patients, respectively (P = 0.27). Moderate or severe OHSS was observed among 5/152 (3.3%) and 6/155 (3.9%) patients, respectively (P = 1.0). Live birth rates were 48/152 (31.6%) and 42/155 (27.1%) per started cycle.

Limitations, reasons for caution

The categorization of AMH values in predicted low, normal and high responders was originally established using the Diagnostic Systems Laboratories assay and was translated to more recently released assays, lacking international standards and well-established reference intervals. The interpretation of AMH values between different assays should therefore be made with some caution.

Wider implications of the findings

An individualised dosage regimen including AMH compared with a non-AMH dosage regimen in an unselected patient population did not alter the number of women achieving the targeted number of oocytes, or the cancellation rate due to poor response or the occurrence of moderate/severe OHSS. However, this study cannot answer the question if using an algorithm for dose decision of FSH is superior to a standard dose and neither which ovarian reserve test is the most effective.

Study funding/competing interest

Financial support was received through Sahlgrenska University Hospital (ALFGBG-70 940) and unrestricted grants from Ferring Pharmaceuticals and the Hjalmar Svensson Research Foundation. None of the authors declares any conflict of interest.

Trial registration

The study was registered at www.clinicaltrials.gov NCT02013973.

Trial registration date

6 December 2013.

DATE OF FIRST PATIENT RANDOMIZED

14 January 2013.

Familial influence and childhood trauma in female alcoholism

BACKGROUND

To assess the role of genetic and environmental factors in female alcoholism using a large population-based twin sample, taking into account possible differences between early and late onset disease subtype.

METHOD

Twins aged 20-47 years from the Swedish Twin Registry (n=24 119) answered questions to establish lifetime alcohol use disorders. Subjects with alcoholism were classified for subtype. Structural equation modeling was used to quantify the proportion of phenotypic variance due to genetic and environmental factors and test whether heritability in women differed from that in men. The association between childhood trauma and alcoholism was then examined in females, controlling for background familial factors.

RESULTS

Lifetime prevalence of alcohol dependence was 4.9% in women and 8.6% in men. Overall, heritability for alcohol dependence was 55%, and did not differ significantly between men and women, although women had a significantly greater heritability for late onset (type I). Childhood physical trauma and sexual abuse had a stronger association with early onset compared to late onset alcoholism [odds ratio (OR) 2.54, 95% confidence interval (CI) 1.53-3.88 and OR 2.29, 95% CI 1.38-3.79 respectively]. Co-twin analysis indicated that familial factors largely accounted for the influence of physical trauma whereas the association with childhood sexual abuse reflected both familial and specific effects.

CONCLUSIONS

Heritability of alcoholism in women is similar to that in men. Early onset alcoholism is strongly association with childhood trauma, which seems to be both a marker of familial background factors and a specific individual risk factor per se.