Greater fetal crown-rump length growth with the use of in vitro fertilization or intracytoplasmic sperm injection conceptions after thawed versus fresh blastocyst transfers: secondary analysis of a prospective cohort study

OBJECTIVE

To compare first-trimester fetal crown-rump length (CRL) measurements in pregnancies obtained after thawed blastocyst transfer versus fresh blastocyst transfer after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective longitudinal cohort study of CRL Z scores with adjustment for major confounders.

SETTING

University-affiliated obstetrics, fetal medicine, and fertility units.

PATIENT(S)

Singleton gestations conceived via IVF/ICSI and fresh or thawed blastocyst transfer with ultrasound performed at 6-14 weeks of gestational age.

INTEVENTION

None.

MAIN OUTCOME MEASURE(S)

CRL Z scores.

RESULT(S)

A total of 365 IVF/ICSI pregnancies were recruited (fresh: 161; thawed: 204). The mean CRL Z score at 6-14 weeks was significantly greater in thawed versus fresh transfers. Different growth trajectories between thawed and fresh transfers were detected: Mean CRL Z score was 0 at 65 days in fresh versus 80 days in frozen. Comparisons of both fresh and thawed transfers with reference values from the general population confirmed significantly lower CRL Z scores in both IVF/ICSI groups (P<.001). The risks of CRL <5th percentile in fresh versus thawed were, respectively 68% vs. 40% at 6 weeks and 2% vs. 1% at 14 weeks. A significant positive correlation between CRL Z scores and birth weight Z scores was found only for fresh transfers, not for thawed.

CONCLUSION(S)

At 6-14 weeks, thawed blastocyst transfers after IVF/ICSI conceptions present greater CRLs compared with fresh, and both IVF/ICSI groups show smaller CRLs than the general population. This effect is particularly evident before 9 weeks and it may favor birth weight difference of thawed versus fresh BT pregnancies.

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.

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.

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.

The placenta: phenotypic and epigenetic modifications induced by Assisted Reproductive Technologies throughout pregnancy

Today, there is growing interest in the potential epigenetic risk related to assisted reproductive technologies (ART). Much evidence in the literature supports the hypothesis that adverse pregnancy outcomes linked to ART are associated with abnormal trophoblastic invasion. The aim of this review is to investigate the relationship between epigenetic dysregulation caused by ART and subsequent placental response. The dialogue between the endometrium and the embryo is a crucial step to achieve successful trophoblastic invasion, thus ensuring a non-complicated pregnancy and healthy offspring. However, as described in this review, ART could impair both actors involved in this dialogue. First, ART may induce epigenetic defects in the conceptus by modifying the embryo environment. Second, as a result of hormone treatments, ART may impair endometrial receptivity. In some cases, it results in embryonic growth arrest but, when the development of the embryo continues, the placenta could bring adaptive responses throughout pregnancy. Amongst the different mechanisms, epigenetics, especially thanks to a finely tuned network of imprinted genes stimulated by foetal signals, may modify nutrient transfer, placental growth and vascularization. If these coping mechanisms are overwhelmed, improper maternal-foetal exchanges occur, potentially leading to adverse pregnancy outcomes such as abortion, preeclampsia or intra-uterine growth restriction. But in most cases, successful placental adaptation enables normal progress of the pregnancy. Nevertheless, the risks induced by these modifications during pregnancy are not fully understood. Metabolic diseases later in life could be exacerbated through the memory of epigenetic adaptation mechanisms established during pregnancy. Thus, more research is still needed to better understand abnormal interactions between the embryo and the milieu in artificial conditions. As trophectoderm cells are in direct contact with the environment, they deserve to be studied in more detail. The ultimate goal of these studies will be to render ART protocols safer. Optimization of the environment will be the key to improving the dialogue between the endometrium and embryo, so as to ensure that placentation after ART is similar to that following natural conception.

Longer time-to-pregnancy in spontaneously conceived pregnancies is associated with lower PAPP-A and free β-hCG in first trimester screening for Down syndrome

OBJECTIVE

The aim of this study was to investigate whether subfertility, measured as longer time-to-pregnancy (TTP) in spontaneously conceived pregnancies, affects the first trimester levels of pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotrophin (β-hCG) and hence the risk estimates in Down syndrome screening.

METHODS

The study included a cohort of 10 469 singleton pregnant women who underwent first trimester combined screening and responded to a questionnaire regarding TTP. PAPP-A and free β-hCG levels were measured between gestational week 8 + 0 and 13 + 6 and were related to TTP.

RESULTS

The median PAPP-A and free β-hCG MoMs were significantly lower in women with a TTP ≥24 months compared with the reference group with a TTP <6 months (PAPP-A: 0.96 vs 1.06 MoM, p = 0.003; free β-hCG: 1.04 vs 1.12 MoM, p = 0.03). This led to an increased odds for trisomy 21 risk ≥1 : 300 for TTP ≥24 months compared with TTP <6 months, but when adjusting for potential confounders, the odds ratio (OR) lost significance (OR 1.4, 95% confidence interval; 0.8-2.4).

CONCLUSION

Time-to-pregnancy ≥24 months in spontaneously conceived pregnancies is associated with decreased levels of PAPP-A and free β-hCG.

First trimester PAPP-A MoM values predictive for breech presentation at term of pregnancy

INTRODUCTION

Our aim was to state the role of first trimester pregnancy-associated plasma protein A (PAPP-A)-multiple of the median (MoM) value as a predictor for breech presentation at term of pregnancy.

MATERIALS AND METHODS

In this retrospective study, we present data for 1100 singleton full-term deliveries that took place in a third-level hospital setting in northeast Italy between January 2004 and July 2007. For each case, PAPP-A, free beta-human chorionic gonadotropin and nuchal translucency were measured during prenatal trisomies screening (between 11 weeks and 13 weeks and 6 d). A wide range of predictive factors for breech presentation at term of pregnancy and other confounding elements were considered.

RESULTS

Of the 1100 singleton deliveries at term considered in our study, 40 babies were in breech presentation. Using bivariate analysis and multivariate logistic regression, a lower PAPP-A MoM than 0.63 (first quartile of our distribution) in the first trimester (OR 2.41, CI.95 1.25-4.67), and placental index at term higher than the median value (OR 2.04, CI.95 1.00-4.17) were proven to be associated with breech presentation at term.

CONCLUSIONS

A low PAPP-A during the first trimester was a predictive factor for breech presentation at term of pregnancy. Acknowledging and acting on this predictor could enable improved management of breech foetuses in the future.

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.