[Liveborn birth-weight of single and uncomplicated pregnancies between 28 and 42 weeks of gestation from Burgundy perinatal network]

The hypomethylation of imprinted genes in IVF/ICSI placenta samples is associated with concomitant changes in histone modifications

Although more and more children are born by Assisted Reproductive Technologies (ART), ART safety has not fully been demonstrated. Notably, ART could disturb the delicate step of implantation, and trigger placenta-related adverse outcomes with potential long-term effects, through disrupted epigenetic regulation. We have previously demonstrated that placental DNA methylation was significantly lower after IVF/ICSI than following natural conception at two differentially methylated regions (DMRs) associated with imprinted genes (IGs): H19/IGF2 and KCNQ1OT1. As histone modifications are critical for placental physiology, the aim of this study was to profile permissive and repressive histone marks in placenta biopsies to reveal a better understanding of the epigenetic changes in the context of ART. Utilizing chromatin immunoprecipitation (ChIP) coupled with quantitative PCR, permissive (H3K4me3, H3K4me2, and H3K9ac) and repressive (H3K9me3 and H3K9me2) post-translational histone modifications were quantified. The analyses revealed a significantly higher quantity of H3K4me2 precipitation in the IVF/ICSI group than in the natural conception group for H19/IGF2 and KCNQ1OT1 DMRs (P = 0.016 and 0.003, respectively). Conversely, the quantity of both repressive marks at H19/IGF2 and SNURF DMRs was significantly lower in the IVF/ICSI group than in the natural conception group (P = 0.011 and 0.027 for H19/IGF2; and P = 0.010 and 0.035 for SNURF). These novel findings highlight that DNA hypomethylation at imprinted DMRs following ART is linked with increased permissive/decreased repressive histone marks, altogether promoting a more permissive chromatin conformation. This concomitant change in epigenetic state at IGs at birth might be an important developmental event because of ART manipulations.

Singleton fetal growth kinetics depend on the mode of conception

OBJECTIVE

To study the impact of in vitro fertilization, with or without intracytoplasmic sperm injection (IVF/ICSI), frozen-embryo transfer (FET), and intrauterine insemination (IUI) on fetal growth kinetics throughout pregnancy and to compare the different modes of conception.

DESIGN

Retrospective cohort study.

SETTING

University.

PATIENT(S)

A total of 560 singleton pregnancies were included (96 IVF, 210 ICSI, 121 FET, and 133 IUI).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We compared crown-rump length (CRL) at the first trimester (T1: 11-13 weeks of gestation [WG] + 6 days), estimated fetal weight (EFW) at the second (T2: 21-23 WG + 6 days) and third (T3: 31-33 WG + 6 days) trimesters, and birth weight (BW) z-scores with those in the reference curves (Papageorghiou for T1, and Ego M2 for T2, T3, and birth). Multivariate analyses were performed.

RESULT(S)

For T1, the CRL was longer than the reference curve whatever the assisted reproductive technique (ART). For T2, EFW was significantly greater for all groups compared with the reference curve, and for T3 only FET singletons had a greater EFW. ICSI, IVF, and IUI singletons had a significantly lower BW compared with reference curves. For all ART fetuses, growth kinetics differed from T2. Only FET fetuses maintained their significantly above-reference growth values. The proportion of fetuses for which at least one period of growth loss was observed from T2 to birth was higher after IVF, ICSI, and IUI than after FET.

CONCLUSION(S)

For the first time, we have highlighted that fetal growth kinetics differed from T2 depending on the ART protocols used. They could have an impact on trophoblastic invasiveness and might lead to long-term health effects.

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.

Customized and non-customized live-born birth-weight curves of single and uncomplicated pregnancies from the Burgundy perinatal network. Part I - methodology

OBJECTIVES

To establish non-customized and customized birth-weight curves of single and uncomplicated pregnancies according to gestational age.

MATERIALS AND METHODS

We used data for 64,173 mother-infants pairs from the Burgundy perinatal network database (France) over the period 2005-2013. A validated procedure was used to link mothers with their newborns, and maternal and fetal pathologies likely to affect birth weight were excluded. Multiple regression analysis with covariate selection was used to build a customized growth curve with maternal and fetal parameters.

RESULTS

Using this methodology, three different curves were generated: an unadjusted curve for birth weight, named B0, an curve adjusted for fetal gender, named B1 and a curve adjusted for fetal and maternal parameters (fetal gender, maternal height, weight and parity), named B2.

CONCLUSION

We present curves showing an original distribution of birth weights for the French population in order to improve the diagnosis of small for gestational age. These curves are not based on the Gardosi in utero growth model but on actual birth weights, thus limiting bias. Nevertheless, the minimum gestational age was 25weeks as there was an insufficient number of live-borns in small gestational ages.

Perinatal health inequalities and accessibility of maternity services in a rural French region: closing maternity units in Burgundy

Maternity unit closures in France have increased travel time for pregnant women in rural areas. We assessed the impact of travel time to the closest unit on perinatal outcomes and care in Burgundy using multilevel analyses of data on deliveries from 2000 to 2009. A travel time of 30min or more increased risks of fetal heart rate anomalies, meconium-stained amniotic fluid, out-of-hospital births, and pregnancy hospitalizations; a positive but non-significant gradient existed between travel time and perinatal mortality. The effects of long travel distances on perinatal outcomes and care should be factored into closure decisions.

Fetal growth and childhood acute lymphoblastic leukemia: findings from the childhood leukemia international consortium

Positive associations have been reported between the measures of accelerated fetal growth and risk of childhood acute lymphoblastic leukemia (ALL). We investigated this association by pooling individual-level data from 12 case-control studies participating in the Childhood Leukemia International Consortium. Two measures of fetal growth-weight-for-gestational-age and proportion of optimal birth weight (POBW)-were analysed. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression, and combined in fixed effects meta-analyses. Pooled analyses of all data were also undertaken using multivariable logistic regression. Subgroup analyses were undertaken when possible. Data on weight for gestational age were available for 7,348 cases and 12,489 controls from all 12 studies and POBW data were available for 1,680 cases and 3,139 controls from three studies. The summary ORs from the meta-analyses were 1.24 (95% CI: 1.13, 1.36) for children who were large for gestational age relative to appropriate for gestational age, and 1.16 (95% CI: 1.09, 1.24) for a one-standard deviation increase in POBW. The pooled analyses produced similar results. The summary and pooled ORs for small-for-gestational-age children were 0.83 (95% CI: 0.75, 0.92) and 0.86 (95% CI: 0.77, 0.95), respectively. Results were consistent across subgroups defined by sex, ethnicity and immunophenotype, and when the analysis was restricted to children who did not have high birth weight. The evidence that accelerated fetal growth is associated with a modest increased risk of childhood ALL is strong and consistent with known biological mechanisms involving insulin-like growth factors. © 2013 UICC.

A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants

Background

The aim of this study was to revise the 2003 Fenton Preterm Growth Chart, specifically to: a) harmonize the preterm growth chart with the new World Health Organization (WHO) Growth Standard, b) smooth the data between the preterm and WHO estimates, informed by the Preterm Multicentre Growth (PreM Growth) study while maintaining data integrity from 22 to 36 and at 50 weeks, and to c) re-scale the chart x-axis to actual age (rather than completed weeks) to support growth monitoring.

Methods

Systematic review, meta-analysis, and growth chart development. We systematically searched published and unpublished literature to find population-based preterm size at birth measurement (weight, length, and/or head circumference) references, from developed countries with: Corrected gestational ages through infant assessment and/or statistical correction; Data percentiles as low as 24 weeks gestational age or lower; Sample with greater than 500 infants less than 30 weeks. Growth curves for males and females were produced using cubic splines to 50 weeks post menstrual age. LMS parameters (skew, median, and standard deviation) were calculated.

Results

Six large population-based surveys of size at preterm birth representing 3,986,456 births (34,639 births < 30 weeks) from countries Germany, United States, Italy, Australia, Scotland, and Canada were combined in meta-analyses. Smooth growth chart curves were developed, while ensuring close agreement with the data between 24 and 36 weeks and at 50 weeks.

Conclusions

The revised sex-specific actual-age growth charts are based on the recommended growth goal for preterm infants, the fetus, followed by the term infant. These preterm growth charts, with the disjunction between these datasets smoothing informed by the international PreM Growth study, may support an improved transition of preterm infant growth monitoring to the WHO growth charts.

Neonatal anthropometric charts: the Italian neonatal study compared with other European studies

BACKGROUND AND OBJECTIVE

This was a nationwide prospective study carried out in Italy between 2005 and 2007, involving 34 centers with a neonatal intensive care unit. The study reports the Italian Neonatal Study charts for weight, length, and head circumference of singletons born between 23 and 42 gestational weeks, comparing them with previous Italian data and with the most recent data from European countries.

PATIENTS AND METHODS

Single live born babies with ultrasound assessment of gestational age within the first trimester, and with both parents of Italian origin. Only fetal hydrops and major congenital anomalies diagnosed at birth were excluded. The reference set consists of 22,087 girls and 23,375 boys.

RESULTS

At each gestational age, boys are heavier than girls by about 4%. Later-born neonates are heavier than firstborn neonates by about 3%. The effects of sex and birth order on length and head circumference are milder. No differences were observed between babies born in central-north Italy and southern Italy. A large variability emerged among European neonatal charts, resulting in huge differences in the percentage of Italian Neonatal Study neonates below the 10th centile, which is traditionally used to define small-for-gestational-age babies. In the last 2 decades prominent changes in the distribution of birth weight emerged in Italy and in the rest of Europe, in both term and preterm neonates.

CONCLUSIONS

The existing European neonatal charts, based on more or less recent data, were found to be inappropriate for Italy. Until an international standard is developed, the use of national updated reference charts is recommended.