Improved technical success, postnatal outcome and refined predictors of outcome for fetal aortic valvuloplasty.

OBJECTIVES: Fetal aortic valvuloplasty (FAV) may prevent progression of mid-gestation aortic stenosis to hypoplastic left heart syndrome (HLHS). The aim of this study was to evaluate whether technical success and biventricular (Biv) outcome after FAV have changed from an earlier (2000-2008) to a more recent (2009-2015) era and identify pre-FAV predictors of Biv outcome. METHODS: We evaluated procedural and postnatal outcomes in 123 fetuses that underwent FAV for evolving HLHS at Boston Children's Hospital between 2000 and 2015. The primary outcome measure was circulation type (Biv vs single ventricle) at the time of neonatal hospital discharge. Classification and regression tree (CART) analysis was performed to construct a stratification algorithm to predict Biv circulation based on pre-FAV fetal variables. RESULTS: The FAV procedure was technically successful in 101/123 (82%) fetuses, with a higher technical success rate in the more recent era than in the earlier one (49/52 (94%) vs 52/71 (73%); P = 0.003). In liveborn patients, the incidence of Biv outcome was higher in the recent than in the earlier era, both in the entire liveborn cohort (29/49 (59%) vs 16/62 (26%); P = 0.001) and in those in whom the procedure was technically successful (27/46 (59%) vs 15/47 (32%); P = 0.007). Independent predictors of Biv outcome were higher left ventricular (LV) pressure, larger ascending aorta, better LV diastolic function and higher LV long-axis Z-score. On CART analysis, fetuses with LV pressure > 47 mmHg and ascending aorta Z-score ≥ 0.57 had a 92% probability of Biv outcome (n = 24). Those with a lower LV pressure, or mitral dimension Z-score < 0.1 and mitral valve inflow time Z-score < -2 (n = 34) were unlikely to have Biv (probability of 9%). The remainder of the patients had an intermediate (∼40-60%) likelihood of Biv circulation. CONCLUSIONS: The proportion of patients achieving Biv outcome after FAV has increased, probably owing to an improved technical success rate and modified selection criteria. Fetal factors, including LV pressure, size of the ascending aorta and diastolic function, are associated with likelihood of Biv circulation after FAV. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Origin of extraembryonic mesoderm in experimental animals: relevance to chorionic mosaicism in humans.

Confined chorionic mosaicism, a discordance in the karyotype between the fetus and placenta, occurs in 1% of chorionic villus sampling (CVS) cases. While the cytogenetic discrepancies occurring between different fetal tissues may pose clinical dilemmas, they can also be viewed as a natural experiment to determine early cell lineage relationships in the human. We reviewed extensive data in experimental animals to define the origin of the human extraembryonic mesoderm. The extraembryonic mesoderm in humans is an important component of the CVS culture preparation. Previously, the extraembryonic mesoderm was thought to originate in the cytotrophoblast or primitive streak. More recent evidence supports its origin from the yolk sac, which does not always correlate with the fetal karyotype. We formulated a model of early human cell lineage and employed it to clarify clinical cases of chorionic mosaicism in two large published studies.

Fluorescence in situ hybridization for the detection of aneuploidy from archived fetal cells.

BACKGROUND: In perinatal settings, fluorescence in situ hybridization has the potential to provide specific chromosome evaluation when full karyotype analysis is not possible because there are no dividing cells. CASE: Based on clinical features, cases of fetal and neonatal demise were selected for evaluation with chromosome-specific probes. Sources of nondividing cells included deparaffinated tissue sections, disaggregated tissue biopsies, and archived, Giemsa-stained slides. CONCLUSION: Diagnostic information was obtained by fluorescence in situ hybridization in three settings: 1) postmortem trisomy 21 identification from paraffin sections following unsuccessful tissue culture, 2) postmortem trisomy 18 confirmation in disaggregated cells from macerated fetal tissues, and 3) retrospective documentation of a cryptic deletion (22q-) in archived metaphase spreads. We encourage familiarity by obstetricians with fluorescence in situ hybridization for chromosomal assessment using archived fetal material.

The effect of obstetric practice change to reduce early term delivery on perinatal outcome.

OBJECTIVE: To investigate whether the national emphasis on attaining 39 weeks gestation has altered obstetric practice, and if so whether this has affected perinatal morbidity. STUDY DESIGN: We examined trends in gestational age, neonatal morbidity, maternal complications and stillbirth for a retrospective cohort of singleton, live births between 37+0 and 39+6 weeks of gestation over a 5-year period at a single tertiary care center. RESULT: There were 21 343 eligible deliveries. The proportion of deliveries in the early term (<39 weeks) decreased from 47.8 to 40.2% (P<0.01). The reduction was most pronounced for elective inductions (27.5 to 8.0%; P<0.01) and scheduled cesareans (56.9 to 24.9%; P<0.01), although a similar trend was seen for nonelective inductions (51.2 to 47.9%; P=0.03). In multivariable analysis, there was a 10% decreased odds of early term delivery per year (P<0.01). There were no changes in the rates of neonatal intensive care unit (NICU) evaluation (29.8 to 28.1%; P=0.11), pre-eclampsia (7.6 to 8.5%; P=0.06) or stillbirth (11.5 to 14.4 per 10 000; P=0.55). CONCLUSION: A 10% annual decline in the odds of early term delivery was not accompanied by significant changes in perinatal morbidity.

Factors affecting technical success of fetal aortic valve dilation.

OBJECTIVE: We have reported previously that valve dilation enhances growth of cardiac structures and may prevent hypoplastic left heart syndrome (HLHS) in fetuses with critical aortic stenosis. We aimed to investigate maternal/fetal factors which may affect the technical success of fetal valvuloplasty, and to describe perinatal complications of the procedure. METHODS: This was a descriptive series of 22 fetuses diagnosed with critical aortic stenosis developing into HLHS which underwent intervention by valvuloplasty. Initially this was attempted using a percutaneous approach; reassessment after our first five attempts, only one of which was successful, led to the introduction of the option of laparotomy. Technical success was defined as balloon inflation across the aortic annulus and a broader jet through the aortic valve as assessed by Doppler. Data collected included body mass index, demographic variables, ultrasound findings and postprocedure interventions. RESULTS: Technical success increased significantly if maternal laparotomy was an option (83.3% vs. 20.0%, P = 0.017). Laparotomy was performed in 66.6% (12/18) of cases. There was a learning curve that showed an increase in success rate and decrease in need for laparotomy over the 3-year study period. Neither the need for laparotomy nor the chances of technical success were predictable by gestational age, body mass index or placental location. Tocolysis was limited to perioperative prophylaxis; one woman experienced wound infection and fluid overload. Postoperatively, three fetuses died and two delivered prematurely, 2 and 7 weeks after intervention. CONCLUSION: Fetal aortic valvuloplasty can be performed with technical success, with low fetal loss rate and few maternal complications. While the need for laparotomy cannot be predicted, having it available as an option improves the technical success rate.