Altered neurodevelopmental DNA methylation status after fetal growth restriction with brain-sparing.

It is under debate how preferential perfusion of the brain (brain-sparing) in fetal growth restriction (FGR) relates to long-term neurodevelopmental outcome. Epigenetic modification of neurotrophic genes by altered fetal oxygenation may be involved. To explore this theory, we performed a follow-up study of 21 FGR children, in whom we prospectively measured the prenatal cerebroplacental ratio (CPR) with Doppler sonography. At 4 years of age, we tested their neurodevelopmental outcome using the Wechsler Preschool and Primary Scale of Intelligence, the Child Behavior Checklist, and the Behavior Rating Inventory of Executive Function. In addition, we collected their buccal DNA to determine the methylation status at predefined genetic regions within the genes hypoxia-inducible factor-1 alpha (HIF1A), vascular endothelial growth factor A (VEGFA), erythropoietin (EPO), EPO-receptor (EPOR), brain-derived neurotrophic factor (BDNF), and neurotrophic tyrosine kinase, receptor, type 2 (NTRK2) by pyrosequencing. We found that FGR children with fetal brain-sparing (CPR <1, n = 8) demonstrated a trend (0.05 < p < 0.1) toward hypermethylation of HIF1A and VEGFA at their hypoxia-response element (HRE) compared with FGR children without fetal brain-sparing. Moreover, in cases with fetal brain-sparing, we observed statistically significant hypermethylation at a binding site for cyclic adenosine monophophate response element binding protein (CREB) of BDNF promoter exon 4 and hypomethylation at an HRE located within the NTRK2 promoter (both p <0.05). Hypermethylation of VEGFA was associated with a poorer Performance Intelligence Quotient, while hypermethylation of BDNF was associated with better inhibitory self-control (both p <0.05). These results led us to formulate the hypothesis that early oxygen-dependent epigenetic alterations due to hemodynamic alterations in FGR may be associated with altered neurodevelopmental outcome in later life. We recommend further studies to test this hypothesis.

TRIDENT-2: National Implementation of Genome-wide Non-invasive Prenatal Testing as a First-Tier Screening Test in the Netherlands.

The Netherlands launched a nationwide implementation study on non-invasive prenatal testing (NIPT) as a first-tier test offered to all pregnant women. This started on April 1, 2017 as the TRIDENT-2 study, licensed by the Dutch Ministry of Health. In the first year, NIPT was performed in 73,239 pregnancies (42% of all pregnancies), 7,239 (4%) chose first-trimester combined testing, and 54% did not participate. The number of trisomies 21 (239, 0.33%), 18 (49, 0.07%), and 13 (55, 0.08%) found in this study is comparable to earlier studies, but the Positive Predictive Values (PPV)-96% for trisomy 21, 98% for trisomy 18, and 53% for trisomy 13-were higher than expected. Findings other than trisomy 21, 18, or 13 were reported on request of the pregnant women; 78% of women chose to have these reported. The number of additional findings was 207 (0.36%); these included other trisomies (101, 0.18%, PPV 6%, many of the remaining 94% of cases are likely confined placental mosaics and possibly clinically significant), structural chromosomal aberrations (95, 0.16%, PPV 32%,) and complex abnormal profiles indicative of maternal malignancies (11, 0.02%, PPV 64%). The implementation of genome-wide NIPT is under debate because the benefits of detecting other fetal chromosomal aberrations must be balanced against the risks of discordant positives, parental anxiety, and a potential increase in (invasive) diagnostic procedures. Our first-year data, including clinical data and laboratory follow-up data, will fuel this debate. Furthermore, we describe how NIPT can successfully be embedded into a national screening program with a single chain for prenatal care including counseling, testing, and follow-up.

Prediction model of postnatal renal function in fetuses with lower urinary tract obstruction (LUTO)-Development and internal validation.

OBJECTIVE: To develop a prediction model of postnatal renal function in fetuses with lower urinary tract obstruction (LUTO) based on fetal ultrasound parameters and amniotic fluid volume. METHODS: Retrospective nationwide cohort study of fetuses with postnatally confirmed LUTO and known eGFR. Fetuses treated with fetal interventions such as vesico-amniotic shunting or cystoscopy were excluded. Logistic regression analysis was used to identify prognostic ultrasound variables with respect to renal outcome following multiple imputation of missing data. On the basis of these fetal renal parameters and amniotic fluid volume, a model was developed to predict postnatal renal function in fetuses with LUTO. The main study outcome was an eGFR less than 60 mL/min * 1.73 m2 based on the creatinine nadir during the first year following diagnosis. Model performance was evaluated by receiver operator characteristic (ROC) curve analysis, calibration plots, and bootstrapping. RESULTS: Hundred one fetuses with a confirmed diagnosis of LUTO were included, eGFR less than 60 was observed in 40 (39.6%) of them. Variables predicting an eGFR less than 60 mL/min * 1.73m2 included the following sonographic parameters: hyperechogenicity of the renal cortex and abnormal amniotic fluid volume. The model showed fair discrimination, with an area under the ROC curve of 0.70 (95% confidence interval, 0.59-0.81, 0.66 after bootstrapping) and was overall well-calibrated. CONCLUSION: This study shows that a prediction model incorporating ultrasound parameters such as cortical appearance and abnormal amniotic fluid volume can fairly discriminate an eGFR above or below 60 mL/min * 1.73m2 . This clinical information can be used in identifying fetuses eligible for prenatal interventions and improve counseling of parents.

Differential placental DNA methylation of VEGFA and LEP in small-for-gestational age fetuses with an abnormal cerebroplacental ratio.

BACKGROUND: In Fetal Growth Restriction 'fetal programming' may take place via DNA methylation, which has implications for short-term and long-term health outcomes. Small-for-gestational age fetuses are considered fetal growth restricted, characterized by brain-sparing when fetal Doppler hemodynamics are abnormal, expressed as a cerebroplacental ratio (CPR) <1. We aimed to determine whether brain-sparing is associated with altered DNA methylation of selected genes. METHODS: We compared DNA methylation of six genes in 41 small-for-gestational age placentas with a normal or abnormal CPR. We selected EPO, HIF1A, VEGFA, LEP, PHLDA2, and DHCR24 for their role in angiogenesis, immunomodulation, and placental and fetal growth. DNA methylation was analyzed by pyrosequencing. RESULTS: Growth restricted fetuses with an abnormal CPR showed hypermethylation of the VEGFA gene at one CpG (VEGFA-309, p = .001) and an overall hypomethylation of the LEP gene, being significant at two CpGs (LEP-123, p = .049; LEP-51, p = .020). No differences in methylation were observed for the other genes. CONCLUSIONS: VEGFA and LEP genes are differentially methylated in placentas of small-for-gestational age fetuses with brain-sparing. Hypermethylation of VEGFA-309 in abnormal CPR-placentas could indicate successful compensatory mechanisms. Methylation of LEP-51 is known to suppress LEP expression. Hypomethylation in small-for-gestational age placentas with abnormal CPR may result in hyperleptinemia and predispose to leptin-resistance later in life.

The impact of national prenatal screening on the time of diagnosis and outcome of pregnancies affected with common trisomies, a cohort study in the Northern Netherlands.

BACKGROUND: To evaluate the impact of the introduction of prenatal screening on time of detection and pregnancy outcome for trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13). METHODS: We performed a retrospective, population-based cohort study in the Northern Netherlands including 503 trisomy cases born between 2005 and 2012. Screening tests and invasive procedures, timing of diagnosis and pregnancy outcome were compared between the period before (2005-2006) and after introduction (2007-2012) using X 2 tests. RESULTS: There was an increase in proportion of women who had a prenatal screening and/or invasive test, from 62% in 2005-2006 to 84% in 2010-2012 (p < 0.01), while the proportion of prenatally diagnosed cases did not change (60% overall). In women < =35 years 47% of the cases were diagnosed prenatally vs 73% in women >35 years (p < 0.01). More T13/T18 cases were diagnosed <24 weeks after introduction (62% vs 84%; p < 0.01). In T13/T18 intra-uterine death decreased (26% vs 15%), while terminations increased: 55% vs 72%. CONCLUSION: The introduction of prenatal screening had limited impact on the time of detection and outcome of the most common trisomies. The introduction of the 20-week anomaly scan has resulted in more trisomy cases diagnosed <24 weeks and a shift from fetal death to terminations.

Outcome of infants presenting with echogenic bowel in the second trimester of pregnancy.

OBJECTIVE: Fetal echogenic bowel (FEB) is a soft marker found on second trimester sonography. Our main aim was to determine the outcome of infants who presented with FEB and secondarily to identify additional sonographic findings that might have clinical relevance for the prognosis. DESIGN: We reviewed all pregnancies in which the diagnosis FEB was made in our Fetal Medicine Unit during 2009-2010 (N=121). We divided all cases into five groups according to additional sonographic findings. Group 1 consisted of cases of isolated FEB, group 2 of FEB associated with dilated bowels, group 3 of FEB with one or two other soft markers, group 4 of FEB with major congenital anomalies or three or more other soft markers, and group 5 consisted of FEB with isolated intrauterine growth restriction (IUGR). RESULTS: Of 121 cases, five were lost to follow-up. Of the remaining 116 cases, 48 (41.4%) were assigned to group 1, 15 (12.9%) to group 2, 15 (12.9%) to group 3, 27 (23.2%) to group 4, and 11 (9.5%) to group 5. The outcome for group 1 was uneventful. In group 2 and 3, two anomalies, anorectal malformation and cystic fibrosis, were detected postnatally (6.7%). In group 4, mortality and morbidity were high (78% resp. 22%). Group 5 also had high mortality (82%) and major morbidity (18%). CONCLUSIONS: If FEB occurs in isolation, it is a benign condition carrying a favourable prognosis. If multiple additional anomalies or early IUGR are observed, the prognosis tends to be less favourable to extremely poor.

Prediction of miscarriage and stillbirth at 11-13 weeks and the contribution of chorionic villus sampling.

OBJECTIVES: To derive models for estimating risk of miscarriage and stillbirth from maternal characteristics and findings of first-trimester screening for aneuploidies and to define the procedure-related risk of chorionic villus sampling (CVS) after adjusting for these factors. METHOD: We examined 33 856 singleton pregnancies at 11(+0) to 13(+6) weeks, and in 2396 CVS was carried out. Logistic regression analysis was used to examine the factors contributing to miscarriage and stillbirth. RESULTS: There were 33 310 (98.4%) livebirths, 404 (1.2%) miscarriages and 142 (0.4%) stillbirths. Models combining maternal characteristics, nuchal translucency, pregnancy-associated plasma protein-A (PAPP-A) and flow in the ductus venosus detected 36.9% of miscarriages and 35.2% of stillbirths, at a 10% false-positive rate. The risk of miscarriage and stillbirth increased with maternal age and weight, in women of African racial origin, in those with previous miscarriages or stillbirths and in those with low serum PAPP-A and reversed A-wave in the ductus venosus. The risk of miscarriage increased in women with pre-existing diabetes mellitus, in those conceiving on ovulation-induction drugs and in those with high fetal nuchal translucency, and the risk of stillbirth increased in women with chronic hypertension and in cigarette smokers. The expected number of miscarriages and stillbirths in the CVS group and the models derived from the non-CVS group were 45 (95% prediction intervals 32-58) and 18 (95% prediction intervals 9-26), respectively. These expected numbers were not significantly different from the observed 44 and 15 cases (p = 0.881 and 0.480), respectively. CONCLUSION: A high proportion of fetal losses can be predicted at 11 to 13 weeks. A model for such predictions can be used to assess the procedure-related risks from CVS.

Women's opinions on the offer and use of nuchal translucency screening for Down syndrome.

OBJECTIVE: To study the attitude of Dutch women to the offer and subsequent (non)use of nuchal translucency (NT) screening for Down syndrome in the first trimester of pregnancy, in a country where screening is not routinely offered under 36 years of age. METHODS: An experimental NT screening programme offered to pregnant women, together with a series of questionnaires to be completed before and after the offer and (non)use of screening, in 12 midwife practices in three different health districts. PARTICIPANTS: Cohort of pregnant women who had their first prenatal care visit in the participating midwife practices between 1 June 1999 and 1 January 2001. MAIN OUTCOME MEASURES: Women's knowledge and understanding of prenatal screening tests; attitude towards screening offer; perceived freedom of choice; satisfaction with information given; change in attitude over time. RESULTS: Eighty-six percent of women accepted the offer of NT screening. Seventy percent had previous knowledge of NT screening and 92% considered the information given before screening clear and sufficient. Thirty-nine percent of women felt worried to some extent after being given the information, but only 3% would have preferred not to have been informed at all. Ninety percent of women (including 68% of decliners) agree that information on Down syndrome screening should be extended to all pregnant women and feel competent in deciding on screening participation. CONCLUSION: When NT screening is offered as a new screening strategy its concept is understood and well accepted. The large majority of women, including the decliners, are in favour of its standard offer.