Maternal serum pregnancy-associated plasma protein-A and free β-human chorionic gonadotrophin in pregnancies conceived with fresh and frozen-thawed embryos fromin vitro fertilization and intracytoplasmic sperm injection

The impact of fresh versus frozen-thawed embryos on maternal serum analyte levels in IVF singleton and twin pregnancies

PURPOSE

To determine whether embryo cryopreservation is associated with a difference in maternal serum analyte levels in singleton and twin pregnancies conceived via in vitro fertilization (IVF).

METHODS

This was a retrospective cohort study of singleton and twin pregnancies conceived via IVF from a university health system from 01/2014 to 09/2019. Patients with available first and second trimester serum analyte data were included and analyzed separately. Multiple of the median (MoM) values for free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A, alpha-fetoprotein (AFP), Inhibin A, and unconjugated estriol (uE3) were compared between two groups: pregnancies conceived after the transfer of fresh embryos versus pregnancies conceived after the transfer of frozen-thawed embryos. Multiple linear regression of log MoM values with F test was performed to adjust for potential confounders.

RESULTS

For singletons, fresh embryos were associated with a lower median first trimester free β-hCG (1.00 MoM vs. 1.14 MoM; parameter estimate [PE] 0.90, 95% CI 0.82-0.99, p = .03) compared to frozen-thawed embryos. Fresh embryos were also associated with a lower median second trimester uE3 (0.93 MoM vs. 1.05 MoM; PE 0.88, CI 0.83-0.95, p = .0004) and AFP (1.02 MoM vs. 1.19 MoM; PE 0.91, CI 0.84-0.99, p = .02) compared to frozen-thawed embryos in singletons. There were no significant differences between median first and second trimester serum analytes in twin pregnancies compared between the two groups.

CONCLUSION

Singleton pregnancies derived from fresh embryos had lower first (free β-hCG) and second (uE3 and AFP) trimester analytes compared to frozen-thawed embryos. Twin pregnancies demonstrated no difference between the groups.

Supraphysiological hCG day estradiol levels can predict pregnancy-associated plasma protein A levels in maternal serum in the first trimester

OBJECTIVE

To investigate the effect of hCG day estradiol (hCG-E2) used in Down Syndrome screening on maternal serum levels of PAPP-A in fresh in vitro fertilization (IVF) cycles.

METHODS

This study was a retrospective analysis of a cohort that resulted in a single pregnancy after a total of 92 fresh IVF cycles. The primary outcome of this study was to determine the effect of fresh IVF cycle parameters on the PAPP-A level and the cutoff value for hCG-E2 predicting a low PAPP-A level, while the secondary outcome was to determine whether the effect of IVF parameters on the PAPP-A level was significant.

RESULTS

There was a negative correlation between PAPP-A levels and the number of hCG-E2 and grade 1 embryos (respectively, p = .049; .047), while a positive correlation was observed between baby weight at birth and the PAPP-A (p < .05). At a PAPP-A value of 0.82, the difference between the two groups, in terms of hCG-E2, the number of grade 1 embryos, and pregnancy-related complications was significant (p = .050; .029; .033, respectively). The threshold value of hCG-E2 affecting PAPP-A levels was statistically significant (AUC = 0.618; p = .050; hCG-E2 = 4869.5 pg/ml). In the model, an increase in the number of grade 1 embryos resulted in higher PAPP-A levels (OR = 2.26; p = .044).

CONCLUSION

The fact that the hCG-E2 cutoff value, which lowers PAPP-A, reflects excessive ovarian stimulation argues for the correction of the dual screening test in a subset of patients with high response to the first-trimester screening test.

The expression of pregnancy-associated plasma protein-A (PAPP-A) in human blastocoel fluid-conditioned media: a proof of concept study

Purpose

The aim of this study was to determine if pregnancy-associated plasma protein-A (PAPP-A), typically measured in maternal serum and a potential predictor of adverse maternal and fetal outcomes such as spontaneous miscarriage, pre-eclampsia, and stillbirth, is expressed in blastocoel fluid–conditioned media (BFCM) at the embryonic blastocyst stage.

Design

This is an in vitro study.

Methods

BFCM samples from trophectoderm-tested euploid blastocysts (n = 80) from in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) patients were analyzed for PAPP-A mRNA. BFCM was obtained from blastocyst stage embryos in 20 uL drops. Blastocysts underwent trophectoderm biopsy for preimplantation genetic testing for aneuploidy prior to blastocyst vitrification and BFCM collection for snap freezing. cfDNA was synthesized using BFCM collected from 80 individual euploid blastocysts. Next, real-time qPCR was performed to detect expression of PAPP-A with GAPDH for normalization of expression in each sample.

Results

PAPP-A mRNA was detected in 45 of 80 BFCM samples (56.3%), with varying levels of expression across samples.

Conclusion

Our study demonstrates the expression of PAPP-A in BFCM. To our knowledge, this is the first study to report detection of PAPP-A mRNA in BFCM. Further studies are required and underway to investigate a greater number of BFCM samples as well as the possible correlation of PAPP-A expression with pregnancy outcomes of transferred euploid blastocysts. If found to predict IVF and obstetric outcomes, PAPP-A may provide additional information along with embryonic euploidy for the selection of the optimal blastocyst for embryo transfer.

Fetal fraction of cell-free DNA in pregnancies after fresh or frozen embryo transfer following assisted reproductive technologies

STUDY QUESTION

Is the fetal fraction (FF) of circulating cell-free DNA (cfDNA) affected in pregnancies following ART treatment with either fresh or frozen embryo transfer (ET) compared with natural conception?

SUMMARY ANSWER

This study shows a significant reduction in the FF in ART patients compared with naturally conceived pregnancies, which seems to be more pronounced after fresh ET compared with frozen ET.

WHAT IS KNOWN ALREADY

Non-invasive prenatal testing (NIPT) is based on cfDNA in maternal blood, of which about 10% is of placental origin and thus represents the fetal karyotype. Validation studies have demonstrated a high sensitivity, specificity and positive predictive value of NIPT for the detection of fetal trisomy 21, 18 and 13. Nevertheless, the FF of cfDNA is an important factor for NIPT test accuracy. Several studies have found a reduction in FF for pregnancies following ART in comparison with natural conception. However, knowledge on how the FF is affected in ART pregnancies after fresh ET compared with frozen ET is very limited.

STUDY DESIGN, SIZE, DURATION

The study was designed as a case-control study. A total of 54 women with an ongoing pregnancy following ART treatment were included. After exclusion for different reasons, statistical analyses were based on 23 NIPT samples from pregnant women treated with fresh ET and 26 NIPT samples from pregnant women treated with frozen-thawed ET in a modified natural cycle. Women were included between February 2018 and November 2018. The results were compared with a control group of 238 naturally conceived pregnancies with a high-risk result from the combined first trimester screening (cFTS).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included women from the Fertility Clinics at Copenhagen University Hospital Hvidovre and Copenhagen University Hospital Rigshospitalet. Blood samples for NIPT analysis were drawn between 11 + 0 and 14 + 2 weeks of gestation and were all analyzed at the NIPT Center at Copenhagen University Hospital Hvidovre. The NIPT-test was performed by massive-parallel whole-genome sequencing. The FF was determined using the SeqFF algorithm.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a reduction in FF in ART patients compared with naturally conceived pregnancies, and the reduction was more pronounced for ART pregnancies after fresh ET (mean FF = 0.049) compared with frozen ET (mean FF = 0.063) (multivariate analysis adjusted for maternal BMI, P = 0.02). Another multivariate analysis, adjusted for BMI and multiples of median (MoM) values for pregnancy-associated plasma protein-A (PAPP-A), demonstrated a significantly reduced FF for ART pregnancies (mean FF = 0.056) compared with naturally conceived pregnancies (mean FF = 0.072) (P < 0.0001). We found that FF was significantly reduced with increasing maternal BMI (P < 0.0001) and with decreasing MoM values of PAPP-A (P = 0.003).

LIMITATIONS, REASONS FOR CAUTION

A limitation of our study design was the relatively small sample size. Another limitation was that the control group was not matched with the ART-treated women. The majority of the women from the control group had a high risk from cFTS, thereby their biochemical markers were diverging. However, the biochemical markers for the ART-treated women with fresh or frozen ET were not divergent within the subgroups.

WIDER IMPLICATIONS OF THE FINDINGS

Concurrent with other studies demonstrating a reduced FF for singleton pregnancies after ART treatment compared with naturally conceived pregnancies, we found a reduction in FF between the two groups. This is one of the first studies to examine FF in ART pregnancies after fresh ET compared with frozen ET, hence the existing knowledge is limited. We find that FF is even more reduced in pregnancies following fresh ET compared with frozen ET, which might possibly reflect the predisposition of being small for gestational age after fresh ET compared with natural cycle frozen ET.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the A.P. Møller og Hustru Chastine Mc-Kinney Møllers Fond til almene Formaal (the A.P. Møller Foundation for General Purposes). All authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

NA.

Impact of preimplantation genetic testing for aneuploidies (PGT-A) on first trimester biochemical markers - PAPP-A (placenta-associated plasma protein) and free β-hCG (human chorionic gonadotropin)

OBJECTIVE

The objective of the study was to study the effect of preimplantation genetic testing for aneuploidies (PGT-A) performed at blastocyst stage on the levels of first trimester biomarkers.

METHODS

This is an observational, collaborative, retrospective study. Seven hundred and twenty-eight patients were included in the study. Patients were with singleton pregnancies resulting from either natural conception (NC), or assisted reproductive techniques (ARTs) with PGT-A and frozen embryo transfer (FET) (ART/PGT-A/FET) or after ART without PGT-A and fresh ET (ART/no PGT-A/fresh ET) or FET (ART/no PGT-A/FET), who had first trimester combined screening test between 11 and 14 gestational weeks. They were stratified into four groups: group A (ART/PGT-A/FET) - 143 patients; group B (ART/no PGT-A/FET) - 100 patients; group C (ART/no PGT-A/fresh ET) - 346 patients, and group D (NC) - 139 patients.

RESULTS

Statistically significant differences among the examined groups were observed for maternal age, BMI, ethnicity, and parity. The median placenta-associated plasma protein (PAPP-A) was lowest in the group with ART/PGT-A/FET and the highest result was obtained in the group with ART/no PGT-A/FET. Statistically significant difference in the median PAPP-A levels was identified among the examined groups (p = .0186). When a subgroup analysis was performed, a statistically significant difference was observed in the median PAPP-A between ART/PGT-A/FET group versus ART/no PGT-A/FET group (p = .01) and NC versus ART/no PGT-A/FET (p = .01). A similar trend toward statistical significance was noted when comparing NC versus ART/no PGT-A/fresh ET (p = .06). Multivariate analysis elucidated that when age is present in the model, the effect of any method of conception or testing for aneuploidy disappears. The other factors (BMI, ethnicity, and parity) do not influence the levels of PAPP-A. The lowest median free human chorionic gonadotropin (β-HCG) was recorded in the NC group and the highest result was identified in the group with IVF/PGT-A/FET. No statistically significant difference was observed in the median concentration levels of free β-hCG among the compared groups (p = .5789) and when subgroup analysis was performed (p>.05). The normality of the distribution of variables was analyzed by the Kolmogorov-Smirnov test and the median PAPP-A and free βhCG concentration difference by the Wilcoxon rank-sum test with nonparametric ANOVA.

CONCLUSIONS

Testing for aneuploidy (PGT-A) and the decision to transfer either fresh or cryopreserved embryos (ET) appear not to affect the levels of first trimester biochemical markers. The findings of the present study should be a baseline for future studies and could be used to improve the antenatal screening counseling for women with ART pregnancies and PGT-A.

Association between blastocyst morphology and maternal first trimester serum markers in ongoing pregnancies obtained after single fresh blastocyst transfer

OBJECTIVE

Is there an association between blastocyst morphology and maternal first trimester serum markers in In Vitro Fertilization (IVF) pregnancies obtained after fresh single blastocyst transfer?

STUDY DESIGN

This bi-centric retrospective study was conducted between January 2012 and August 2018. We included 122 women aged from 18 to 43 years-old, whose pregnancy progressed at least beyond 13 weeks after a single blastocyst transfer and who participated in the first trimester combined screening test. Day 5 and day 6 blastocysts were evaluated according to Gardner and Schoolcraft classification. Patients were classified into three groups according to blastocysts morphological quality: excellent (≥ 3AA), good (3-6AB, 3-6BA, B2), and medium to poor (3-6BB, 3-6AC, 3-6CA, B1, 3-6CB, 3-6BC). First trimester serum markers were measured in maternal blood between 9 and 11 + 6 gestational weeks. Univariate and multivariate analyses were performed.

RESULTS

Female body mass index, smoking status, type of infertility, geographical origin, anti-mullerian hormone level, ovarian stimulation characteristics, pregnancy outcomes and obstetrical complications were comparable between the three groups. Patient's age was not distributed evenly across groups, with women in group "Medium to Poor" appearing to be slightly younger than in other groups. There were no significant differences in mean first trimester serum markers between the three groups (PAPP-A: excellent: 1.23 ± 0.59 MoM; good: 1.45 ± 0.71 MoM; medium to poor: 1.22 ± 0.52 MoM; p = 0,20; free beta-HCG: excellent: 1.66 ± 1.38 MoM; good: 1.19 ± 0.76 MoM; medium to poor: 1.81 ± 1.34 MoM; p = 0,12). No significant difference was found either between mean first trimester serum markers and inner cell mass morphology (PAPP-A: grade A: 1.23 ± 0.58 MoM; grade B: 1.26 ± 0.60 MoM; medium to poor: 1.64 ± 0.87 MoM; p = 0,67 ; free beta-HCG: grade A: 1.66 ± 1.36 MoM; grade B: 1.52 ± 1.10 MoM; medium to poor: 1.57 ± 0.39 MoM p = 0,60), trophectoderm cells morphology (PAPP-A: grade A: 1.25 ± 0.63 MoM; grade B: 1.26 ± 0.51 MoM; medium to poor: not comparable; p = 0,66; free beta-HCG: grade A: 1.60 ± 1.34 MoM; grade B: 1.69 ± 1.14 MoM; medium to poor: not comparable; p = 0,25), or blastocoel expansion (PAPP-A: B1: 1.08 ± 0.51MoM; B2: 1.57 ± 0.70 MoM; B3: 1.26 ± 0.61 MoM; B4: 1.28 ± 0.62 MoM; B5: 1.04 ± 0.38 MoM; p = 0,22; free beta-HCG: B1: 2.01 ± 1.88 MoM; B2: 1.07 ± 0.49 MoM; B3: 1.43 ± 0.87 MoM; B4: 1.68 ± 1.28 MoM ; B5: 1.82 ± 2.03 MoM; p = 0,48). After adjustment on potential confounding factors (female age, type of gonadotropin, parity, number of oocytes retrieved and occurrence of ovarian hyperstimulation syndrome), we did not observe any association between PAPP-A or free beta-HCG levels and blastocyst morphology.

CONCLUSION

Our study concluded that first trimester serum markers were not associated with blastocyst morphological characteristics. Although this needs further confirmation, this suggests that blastocyst morphology would not have an impact on placentation. Therefore, these findings are reassuring for couples undergoing IVF and blastocyst transfer.

Spontaneous and in vitro fertilization pregnancies have comparable first trimester screening profiles for Down syndrome

Objective

We aimed to compare the first trimester screening profiles of spontaneous (n=972) and in in vitro fertilization (IVF) pregnancies (n=339) in a population of patients who had uncomplicated singleton pregnancies comparable for maternal age, gestation, body mass index, and ethnicity.

Material and Methods

A non-interventional analysis of retrospective cohort data and review of the literature.

Results

All IVF pregnancies were achieved via intracytoplasmic sperm injection using the same ovarian stimulation protocol with recombinant follicle-stimulating hormone and a gonadotropin-releasing hormone antagonist, cetrorelix acetate. The means of the multiple of median (MoM) of pregnancy-associated plasma protein-A (PAPP-A) were slightly lower in the fresh (1.19±0.6 vs 1.33±0.7, respectively; p=0.056) and frozen embryo transfer (1.03±0.5 vs 1.33±0.7, respectively; p=0.036) IVF pregnancies compared with natural conceptions. However, when the medians of the MoMs of PAPP-A and beta-human chorionic gonadotrophin (β-hCG), and their distributions were compared across the mode of conception, there were no differences between IVF pregnancies spontaneous pregnancies. Furthermore, the scatterplot diagram and curve fitting regression analyses revealed no difference in the temporal relations of β-hCG and PAPP-A with each other and gestational age between spontaneous and IVF pregnancies.

Conclusion

These results support the notion that uncomplicated singleton IVF pregnancies have similar first trimester screening profiles to spontaneous conceptions.

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.

Trends in primeval β-hCG level increment after fresh and frozen-thawed IVF embryo transfer cycles

Mid-trimester beta-human chorionic gonadotropin (BHCG) levels are considerably higher in pregnancies resulting from frozen embryo transfer (FET) compared with fresh (FRET), leading to a higher false positive rate in aneuploidy screening tests. We aimed to investigate the dynamics of BHCG increment and its predictive value for cycle outcome. A retrospective analysis of FRET and FET cycles. BHCG values on days 14 and 16 post embryo transfer were compared and stratified according to the number of sacs demonstrated on US scan at six weeks gestation, and pregnancy outcome (biochemical pregnancy, ectopic pregnancy, spontaneous abortion, and a singleton or twin birth). A prediction model for live birth was built. A total of 430 treatment cycles were analyzed. The average BHCG levels were significantly higher in FET compared with FRET group in nonviable pregnancies on day 14, 450 vs. 183 IU/L, p < .05 and day 16, 348 vs. 735 IU/L, p < .05, respectively. The increment of BHCG was significantly steeper in the FET compared with FRET group in biochemical pregnancies (F = 6.485, p = .012*). Optimal cutoff level for live birth prediction in the FRET group was 211 IU/L (sensitivity 84%, specificity 76.2%) for day 14 and 440 IU/L (sensitivity 86.0% and specificity 72.5%) for day 16. The increment in BHCG differed significantly between the FRET and FET cycles in nonviable pregnancies. Nevertheless, the difference in BHCG levels observed in the second trimester in pregnancies conceived after FRET and FET cycle may begin as early as the fourth week of pregnancy.

Placental volume and other first-trimester outcomes: are there differences between fresh embryo transfer, frozen-thawed embryo transfer and natural conception?

RESEARCH QUESTION

Does mode of conception influence placental volume and other first-trimester outcomes?

DESIGN

This retrospective single-centre case-control study led in Dijon University Hospital included 252 singleton pregnancies (84 IVF with either fresh embryo transfer or frozen-thawed embryo transfer [FET] and 168 natural conceptions). First-trimester placental volume, uterine artery pulsatility index and maternal serum PAPP-A and beta-HCG were measured. Statistical analyses were adjusted for gestational age, the newborn's gender, maternal age, parity, body mass index and smoking status.

RESULTS

Placental volume was significantly greater in the FET group than in the control group (P = 0.043) and fresh embryo transfer (P = 0.023) groups. At birth, fresh embryo transfer newborns were significantly smaller than controls (P = 0.01) and FET newborns (P = 0.008). Postpartum haemorrhage was far more frequent in FET than in controls and fresh embryo transfer group (38.1%, 2.6% and 1.9%, respectively; P < 0.0001). Placental volume positively correlated with PAPP-A, beta-HCG and the newborn's birth weight, and negatively correlated with uterine artery pulsatility index.

CONCLUSIONS

Placental volume and other first-trimester parameters are modified by IVF with fresh embryo transfer and FET compared with natural conception, but with opposite trends. Given the different protocols used for these techniques, hormonal treatment per se may have a major effect on pregnancy outcomes through the modification of placental invasiveness.

The first trimester aneuploidy biochemical markers in IVF/ICSI patients have no additional benefit compared to spontaneous conceptions in the prediction of pregnancy complications

OBJECTIVES

The aim of this study was to determine if the levels of biochemical aneuploidy markers in in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) pregnancies differ from those in spontaneous pregnancies and to verify if biochemical markers could predict pregnancy outcome in IVF/ICSI gestations.

METHODS

This was a prospective observational study performed in a group of 551 patients who underwent a combined first trimester prenatal screening (ultrasound scan and serum markers). All patients were divided into two groups according to the mode of conception: IVF/ICSI pregnancies (study group) and spontaneous conceptions (control group). The concentrations of first trimester biochemical markers were presented as multiples of median (MoM) and were compared between the study and control groups. Analysed pregnancy complications included: preterm delivery (PTD), small for gestational age (SGA), gestational hypertension (GH), preeclampsia (PE) and gestational diabetes (GDM).

RESULTS

The analysis was performed on 183 IVF/ICSI and 368 spontaneously conceived gestations, with complete data regarding obstetric outcome. There were no significant differences in the concentrations of biochemical markers between the analysed groups. Pregnancy-associated plasma protein-A (PAPP-A) levels were lower in hypertensive than in normotensive patients, although the difference was not significant. Twenty-three patients had GDM (12.5%), 16 had GH or PE (8.7%), SGA was diagnosed in 18 (9.8%) and 25 delivered preterm (13.6%).

CONCLUSIONS

The trend for lower PAPP-A MoM was visible in all affected patients, although the results did not reach statistical significance. The first trimester biochemical markers in assisted reproduction technique (ART) pregnancies do not seem to have additional effect on predicting the risk of pregnancy complications.

Comparing Maternal Serum Screening Markers Among IVF and Spontaneous Conceptions in Ontario Through Registry Data

OBJECTIVE

The objectives of this study were as follows: (1) to investigate the accuracy of IVF identification on the prenatal screening record from prenatal screening laboratories; (2) to compare the screening markers in IVF and non-IVF pregnancies in the population of Ontario; and (3) to propose more appropriate IVF adjustment factors for the Ontario population.

METHODS

Two years of IVF treatment, data from all fertility clinics in Ontario were merged with the corresponding prenatal screening data from all five prenatal screening labs. New adjustment factors for IVF were developed for each maternal serum screening marker and nuchal translucency measurement. Means and SDs and linear regression models were reported for all prenatal screening records, as well as for records that had IVF identified through the prenatal screening requisition and records that were identified through the Canadian Assisted Reproductive Technologies Register (CARTR) Plus database.

RESULTS

Significant differences between IVF and non-IVF groups on the basis of the prenatal screening requisition information and CARTR Plus information were found among the ethnicity-adjusted mean multiple of the medians for alpha fetoprotein, first trimester pregnancy-associated plasma protein A, second trimester unconjugated estradiol, first trimester human chorionic gonadotropin, total human chorionic gonadotropin, and dimeric inhibin A.

CONCLUSION

This study proposed alternate IVF adjustment factors that will produce more accurate screening results within the population of Ontario.

Non-Invasive Prenatal Testing (NIPT) in pregnancies with trisomy 21, 18 and 13 performed in a public setting - factors of importance for correct interpretation of results

OBJECTIVES

We have established an open source platform for non-invasive prenatal testing (NIPT) based on massively parallel whole-genome sequencing in a public setting. The objective of this study was to investigate factors of importance for correct interpretation of NIPT results to ensure a high sensitivity and specificity.

STUDY DESIGN

This investigation is a retrospective case-control study performed in a public NIPT center. The study included 108 aneuploid cases and 165 euploid controls. MPS was performed on circulating cell-free DNA in maternal blood. The pipeline included automated library preparation and sequencing on a HiSeq1500 (Illumina). The software programmes WISECONDOR and SeqFF were used for data analysis of aneuploidy status and fetal fraction of cell-free DNA, respectively. Lower limit of fetal fraction for aneuploidy testing was 0.02.

RESULTS

We identified four false negative aneuploidy cases of which two were explained by a vanishing twin. The number of no-call cases due to low fetal fraction was 8 out of 273 (2.9%). The sensitivity and specificity, when no-calls and vanished twins were excluded, were 100% and 99.5% for T21, 91% and 99.2% for T18, and 100% and 99.6% for T13. By multiple regression analysis we found a significant association between fetal fraction and gestational age, maternal BMI and ART treatment.

CONCLUSION

With a non-commercial open source NIPT set-up having the same high test-performance as reported by large private laboratories, we show that fetal fraction, a vanishing twin, BMI, gestational age and ART treatment are important factors in the interpretation of NIPT results.

Low first-trimester PAPP-A in IVF (fresh and frozen-thawed) pregnancies, likely due to a biological cause

PURPOSE

The purpose of this study is to confirm a difference in the first-trimester screen maternal biochemistry and false-positive rates (FPR) between pregnancies conceived spontaneously and those conceived via assisted reproductive technologies (ART).

METHODS

Retrospective analysis of the complete population of women (17,889 pregnancies) who had undergone first-trimester screening between January 2004 and September 2009 at three private ultrasound clinics in Queensland, Australia was used in the study. The age, gestation, method of conception, ultrasound markers, biochemistry markers (PAPP-A, fβ-hCG), and type of biochemical analyzer platform (Brahms Kryptor, Immulite 2000) data was collated. Univariate analysis of variance (ANOVA), Spearman's rank nonparametric correlation analysis, and Binary Logistic Regression analysis were used to analyze data. Spontaneous pregnancies were used as controls. Results were considered significant when the p value was less than 0.05.

RESULTS

After exclusions, 16,363 singleton pregnancies, including 1543 conceived via ART, were analyzed. Results from the two biochemistry platforms, Brahms Kryptor and Immulite 2000 were significantly different (p < 0.001); thus, the data was divided for analysis purposes. PAPP-A was universally significantly lower in IVF pregnancies compared to spontaneously conceived pregnancies (p < 0.001). Using the Brahms Kryptor platform, ICSI was associated with significantly decreased PAPP-A (p < 0.046), and a significantly increased FPR (p = 0.012).

CONCLUSIONS

Consistent with previous studies IVF pregnancies had significantly lower PAPP-A levels supporting the need to appropriately adjust the combined first-trimester screening (cFTS) risk algorithm for IVF conceptions. The Brahms Kryptor and Immulite 2000 platforms are significantly different; however, the universally lower PAPP-A findings support the hypothesis that the lower PAPP-A is due to a biological cause.

Nuchal translucency measurement, free β-hCG and PAPP-A concentrations in IVF/ICSI pregnancies: systematic review and meta-analysis

So far, data on the effect of assisted reproductive technologies (ART) on the components of first trimester combined screening for Down syndrome are still controversial. A systematic search of the literature was performed in order to identify the effect of ART, particularly in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with fresh embryo transfer, on the nuchal translucency, free beta-human chorionic gonadotrophin and pregnancy-associated plasma protein-A measurements. Moreover, a meta-analysis and a descriptive graphical representation of the ratios between ART and spontaneous pregnancies (controls) values of median of the multiple of median (m₀ MoM) were performed. Free beta-human chorionic gonadotrophin test showed slightly higher values in the ICSI group than controls (RR = 1.09, 95%CI: 1.03-1.16) but not in the IVF group (RR = 1.03, 95%CI: 0.94-1.12). Pregnancy-associated plasma protein-A values for IVF/ICSI, IVF and ICSI showed lower values in comparison with controls (RR, 95%CI 0.85, 0.80-0.90; 0.82, 0.74-0.89 and 0.83, 0.79-0.86, respectively). The nuchal translucency measurement did not show any statistical differences between study groups (IVF and ICSI) and controls (RR = 1.00, 95%CI: 0.94-1.08 and RR = 1.01, 95%CI: 0.97-1.05, respectively). These results may be due to alterations in the placentation of ART pregnancies. Differentiating further subgroups of ART pregnancies may explain the differences in biomarker concentrations, in prenatal behavior and in obstetric outcomes between ART and spontaneous pregnancies. © 2017 John Wiley & Sons, Ltd.

Perinatal outcomes in children born after fresh or frozen embryo transfer: a Catalan cohort study based on 14,262 newborns

OBJECTIVE

To ascertain whether perinatal outcomes are affected by vitrification and/or controlled ovarian hyperstimulation (COH).

DESIGN

Register-based cohort study.

SETTING

Not applicable.

PATIENT(S)

Women undergoing in vitro fertilization (IVF) between 2008 and 2012 using autologous or donated eggs who had a singleton pregnancy delivered from the 24th week onward.

INTERVENTION(S)

Fresh embryo transfer (ET) or frozen-thawed ET in women undergoing IVF.

MAIN OUTCOME MEASURE(S)

Primary outcome birthweight, and secondary outcomes gestational age at delivery, small for gestational age, mode of delivery, and perinatal mortality.

RESULT(S)

In the autologous egg population, newborns from the fresh ET group had lower birthweight than the frozen-thawed ET group (3,152.9 ± 545.5g and 3,343.2 ± 532.3g, respectively), and this difference persisted even after adjusting for confounding factors, and the newborns had a higher risk of being small for gestational age (SGA). In contrast, among egg-donor recipients undergoing ET, the mean birthweight did not differ between the groups (3,165 ± 604.15 g and 3,143.60 ± 604.21g in the fresh and frozen-thawed ET groups, respectively); however, in the adjusted regression model birthweight was statistically significantly higher in the fresh ET group than the frozen-thawed ET group. The risk of SGA remained comparable between the fresh versus frozen-thawed ET groups. We observed no statistically significant differences in perinatal mortality between groups either in the autologous egg population or in the donor recipient group.

CONCLUSION(S)

Perinatal outcomes are negatively affected by COH and not affected by the vitrification process.

Association of the very early rise of human chorionic gonadotropin with adverse outcomes in singleton pregnancies after in vitro fertilization

OBJECTIVE

To determine if very early serum hCG, a marker of trophoblast differentiation, is associated with adverse perinatal outcomes in singleton pregnancies.

DESIGN

Retrospective cohort study.

SETTING

University fertility program.

PATIENT(S)

A total of 360 singleton IVF live births.

INTERVENTION(S)

Serial hCG measurements were used to determine the within-woman slope for hCG (hCG rise).

MAIN OUTCOMES MEASURE(S)

Primary outcomes included birth weight and gestational age at delivery. Statistical comparisons used t test, chi-square test, and linear and logistic regressions as appropriate.

RESULT(S)

hCG rise was positively associated with birth weight but not gestational age at delivery. Infant sex, gestational age, and type of embryo transfer (fresh vs. frozen/thawed) were significantly associated with birth weight and confounded the associations of interest. hCG rise was slower among subjects delivering an infant with low birth weight (slope 0.386 ± 0.05 vs. 0.407 ± 0.06) or small for gestational age (slope 0.371 ± 0.07 vs. 0.406 ± 0.06). Analysis of hCG rise by quartile showed that, compared with the first quartile (slowest), subjects with a rate of hCG rise in the fourth quartile (fastest) had a significantly decreased risk of delivering an infant of low birth weight. No relationship was noted between hCG rise and hypertensive disorders of pregnancy.

CONCLUSION(S)

Slower very early first-trimester hCG rise is associated with low birth weight but not gestational age at delivery among singleton IVF conceptions. The rate of increase in serum hCG may reflect early trophoblast differentiation and placentation and, possibly, may predict subsequent development.

Are first-trimester screening markers altered in assisted reproductive technologies pregnancies?

PURPOSE OF REVIEW

To review the current literature on first-trimester screening with respect to specific issues for assisted reproductive technologies (ARTs) singleton and twin pregnancies.

RECENT FINDINGS

A number of different first-trimester sonographic and biochemical markers have been validated in first-trimester screening for trisomy 21. Among sonographic markers, measurement of fetal nuchal translucency is the most investigated and least affected screening method in ART pregnancies, achieving comparable results in singletons and twins compared with spontaneous conceptions. The small deviation of nuchal translucency thickness observed in ART singletons did not influence overall screening performance, including the number of false-positive results. First-trimester maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels are more obviously altered in assisted conceptions and carry the risk of higher false-positive rates if not adjusted accordingly. The reason behind the alterations is currently not quite explored, but might be attributed to infertility and a higher incidence of placental disorders rather than to the use of ART. In twin pregnancies, chorionicity is an important confounding variable with evident impact on nuchal translucency measurements and maternal biochemistry, but both issues have not been sufficiently investigated in ART twins so far.

SUMMARY

First-trimester measurement of fetal nuchal translucency in singleton and twin gestations is associated with similar screening results when compared with spontaneous conception. Adjustments for the mode of conception are required if maternal serum biochemistry is included in the screening algorithm. Further studies on assisted conception twins are essential to permit more conclusive results on this issue.

Relationships between cell-free DNA and serum analytes in the first and second trimesters of pregnancy

OBJECTIVE

To assess the relationship between first- and second-trimester cell-free DNA levels and maternal serum screening markers.

METHODS

First- and second-trimester residual maternal serum samples from 50 women were obtained. First-trimester (pregnancy-associated plasma protein A and beta-hCG) and second-trimester serum analytes (beta-hCG, alpha-fetoprotein, unconjugated estriol, and inhibin A) had been measured at the time of sample receipt. All fetuses were male as confirmed by birth records. Cell-free DNA was extracted and measured by real-time quantitative polymerase chain reaction amplification using glyceraldehyde phosphate dehydrogenase and DYS1 as markers of total DNA and fetal DNA, respectively. Determination of linear associations between first- and second-trimester serum markers and cell-free DNA levels using Pearson correlations was performed.

RESULTS

Statistically significant correlations between first-trimester pregnancy-associated plasma protein A multiples of the median and both total (r=0.36, P=.016) and fetal (r=0.41, P=.006) DNA in the first trimester were observed. There were no significant correlations between first-trimester serum human chorionic gonadotropin or any second-trimester serum marker with DNA levels.

CONCLUSION

Correlation between serum pregnancy-associated plasma protein A and first-trimester circulating cell-free fetal and total DNA levels is a novel finding. Pregnancy-associated plasma protein A is a glycoprotein of placental origin, and its correlation to cell-free fetal DNA in maternal serum suggests a common tissue origin through apoptosis of placental cells. However, because pregnancy-associated plasma protein A and cell-free DNA were only marginally correlated and cell-free DNA can be reliably detected in the first trimester, the addition of cell-free DNA to serum screening strategies may be helpful in predicting adverse pregnancy outcome.

LEVEL OF EVIDENCE

II.

First-trimester screening markers are altered in pregnancies conceived after IVF/ICSI

OBJECTIVES

To determine the levels of first-trimester screening markers and to assess the false-positive rate for first-trimester combined screening for Down syndrome in a large national population of women pregnant after assisted reproductive technology (ART), in order to decide whether or not to correct risk calculation for mode of conception.

METHODS

A national prospective cohort study of 1000 pregnancies achieved after ART was compared with a control group of 2543 pregnancies conceived spontaneously. All women completed a first-trimester combined screening program. Risk calculation was performed retrospectively based on the screening parameters to avoid bias due to the use of different algorithms of risk calculation.

RESULTS

In chromosomally normal pregnancies conceived after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), the pregnancy-associated plasma protein-A multiples of the median value was significantly decreased when compared with that of pregnancies conceived spontaneously (0.78 and 0.79 vs. 0.98), while there was no difference in the group treated by frozen embryo replacement. There was no difference in the level of free beta-human chorionic gonadotropin between groups. The median nuchal translucency thickness was smaller in the overall ART group compared with controls. The false-positive rate of first-trimester combined screening in the overall ART group, adjusted for maternal age, was significantly higher when compared with controls (9.0% vs. 6.0%).

CONCLUSIONS

It seems advisable to use a population of IVF/ICSI pregnancies to establish median curves for the first-trimester serum screening parameters and perhaps also for nuchal translucency thickness. However, care must be taken, as different ART treatment methods and aspects of medical history seem to alter the screening parameters in different ways.

First-trimester screening in pregnancies conceived by assisted reproductive technology: significance of gestational dating by oocyte retrieval or sonographic measurement of crown-rump length

OBJECTIVES

To evaluate, in pregnancies conceived by assisted reproductive technology, whether determination of gestational age (GA) by date of oocyte aspiration (DOA) or crown-rump length (CRL) at first-trimester screening influences the distribution of serum and sonographic markers or the performance of first-trimester screening for chromosomal abnormalities.

METHODS

GA was calculated using either DOA or CRL at blood sampling and nuchal translucency thickness (NT) measurement in 729 singleton pregnancies conceived by in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Weight-corrected log multiples of the median (MoM) marker distributions specific for IVF pregnancy were established using multiple log regression and compared for DOA- and CRL-based GA calculation.

RESULTS

GA determined by CRL was significantly larger, albeit slightly, than was GA determined by DOA, with a mean difference of 1.50 (SD, 2.4) days (P < 0.001). Log MoM distributions of free beta-human chorionic gonadotropin and NT showed that GA dating by CRL resulted in significantly higher, albeit slightly, mean log MoM values compared with DOA dating. The reverse was the case for mean log MoM pregnancy-associated plasma protein-A. The SDs were similar for CRL and DOA dating. According to Monte Carlo simulation, the use of DOA or CRL for GA dating did not appreciably influence the performance of first-trimester screening.

CONCLUSIONS

DOA and CRL are practically equivalent when calculating GA for first-trimester screening. The correct method of GA dating for other purposes (e.g. estimated time of delivery) in IVF/ICSI pregnancies is still unresolved.

Nuchal translucency in pregnancies conceived after assisted reproduction technology

PURPOSE OF REVIEW

Nuchal translucency is one of the important markers in the first trimester during antenatal screening for fetal Down's syndrome. With the observation of alterations in biochemical markers in pregnancies conceived after assisted reproduction, this review presents current information related to the thickness of nuchal translucency in these pregnancies.

RECENT FINDINGS

Early small studies did not demonstrate any discrepancy in the thickness of nuchal translucency in fetuses from assisted reproduction and from spontaneous pregnancies, but there has been recent evidence to suggest an increased level of nuchal translucency in singletons from various modes of assisted-reproduction technology. Nuchal translucency in twins following assisted reproduction did not, however, show a similar increase. Although the effect of chorionicity was not specifically addressed, nuchal translucency thickness in twins born after assisted reproduction was reported to be comparable to that in spontaneous singletons. It is possible that singletons and twins after assisted reproduction exhibit different antenatal behavior and pregnancy courses.

SUMMARY

Similar to other biochemical markers of fetal Down's syndrome, nuchal translucency is increased in singletons after assisted-reproduction technology. Further studies on twin pregnancies, in particular dichorionic twins, are necessary before conclusive evidence can be drawn for multiple pregnancies.

Serum PAPP-A levels at 10–14 weeks of gestation are altered in women after assisted conception

OBJECTIVES

Increased screen-positive rate was observed in the first-trimester screening for trisomy 21 (T21) among women after assisted conception. The aim of this study was to identify the trends of changes in serum marker levels after different modes of assisted conception.

METHODS

Retrospectively, we analyzed the levels of free beta human chorionic gonadotrophin (f beta HCG), pregnancy-associated plasma protein-A (PAPP-A) and inhibin A in maternal serum, and fetal nuchal translucency (NT) thickness at 10-14 gestational weeks in 1098 women with singleton pregnancies: 130 after IVF-ET, 54 after ICSI and 914 after spontaneous conception.

RESULTS

In women after IVF-ET and ICSI, PAPP-A was decreased (0.94 MoM and 0.82 MoM, respectively) and inhibin A increased (1.11 MoM and 1.48 MoM, respectively) in comparison to the women after spontaneous conception. With increasing number of oocytes retrieved PAPP-A decreased and inhibin A increased. In women pregnant after assisted conception without ovarian stimulation (transfer of frozen-thawed embryo or in spontaneous cycle) the marker levels were not significantly different from those in women after spontaneous conception.

CONCLUSIONS

The presence of multiple corpora lutea may be responsible for the changes in marker levels. In spite of the differences in marker levels, the screen-positive rate for T21 is not significantly increased in women after assisted conception.