Fetal reduction of triplet pregnancy: one or two?

OBJECTIVE: To review outcomes following reductions in trichorionic triplet pregnancies at our institution. METHOD: Retrospective analysis of the outcome of trichorionic triamniotic triplets reduced to singletons (group I, n = 44) or twins (group II, n = 136) at 10 and 12 weeks of gestation. RESULTS: Reduction to one or two was based on parent's preference, hence unrelated to any specific obstetrical or maternal issue. Early fetal loss rate (e.g. <24 weeks) was 9.1% in group I versus 5.1% in group II (p = 0.83). In group I, the take-home baby rate was 86.4% versus 91.9% in group II (p = 0.8). In group I, 17.5% of the women gave birth between 33 and 36(+6) weeks of gestation versus 40.6% in group II (p = 0.026). Delivery beyond 37 weeks was 72.5% in group I and 46.9% in group II (p = 0.01). Intrauterine growth restriction rate was 27.0% in group I versus 45.0% in group II (p = 0.049). CONCLUSION: Reduction to one rather than two fetuses led to significantly higher term delivery rate without significant differences in fetal loss rate or take-home baby rate.

[Fetoscopic laser coagulation in 100 consecutive monochorionic pregnancies with severe twin-to-twin transfusion syndrome]. / Coagulation laser en fœtoscopie des anastomoses vasculaires placentaires: étude observationnelle de 100 grossesses gémellaires monochoriales consécutives compliquées de syndrome transfuseur-transfusé sévère.

OBJECTIVES: To report pre- and post-surgical datas of large series of severe twin-to-twin transfusion syndrome (TTTS) managed with laser ablation surgery in our centre, to evaluate the incidence of complications, perinatal outcome and to compare with other cohorts. PATIENTS AND METHODS: Observational study of 100 cases of TTTS consecutively treated with fetoscopic laser coagulation between January 2004 and April 2010 in CMCO-SIHCUS of Schiltigheim. RESULTS: There are nine stage I, 49 stage II, 38 stage III and four stage 4. Median gestation at time of laser is 20.6 weeks (14-29) whereas median gestation at delivery is 32.6 weeks (16.3-39). Overall perinatal survival rate is 68.5% (137 children over 200). Eighty-five percent have one or more surviving twins. The survival rate is the same for donors and for recipients. Preterm premature rupture of the membranes are observed in 17% of cases and the median gestational age for this complication is 30 weeks (20-34). Cerebral abnormalities are present in 7% of newborns. CONCLUSION: Our results for the management of severe TTTS are comparable to the other reported series. There are still many questions remaining concerning the optimal management of TTTS.

[First trimester screening for Down syndrome: five years prospective experience]. / Dépistage combiné de la trisomie 21 au premier trimestre : à propos de cinq ans d'expérience prospective multicentrique.

First trimester screening for Down syndrome is yet to become the first intention strategy in France. This screening program at 11-14 weeks of gestation using maternal age, fetal nuchal translucency, maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A has already been validated for a long time by many international studies. It seems to improve detection rate and decrease false positive rates. We report here five years prospective experience.

Clinical and placental characteristics in four new cases of twin anemia-polycythemia sequence.

We report and analyze four new cases of spontaneous twin anemia-polycythemia sequence (TAPS) and discuss antenatal management by fetoscopic laser coagulation for this uncommon form of chronic intertwin transfusion. The clinical course and placental characteristics of four pairs of monochorionic-diamniotic (MCDA) twins with spontaneous TAPS, of which one was treated with fetoscopic laser surgery, are described. For the three cases that did not undergo intrauterine intervention, serial Doppler measurement revealed a gradual increase in the middle cerebral artery peak systolic velocity (MCA-PSV) in the donor and a concomitant decrease in the recipient. These twins were born at between 32 and 34 weeks' gestation by Cesarean section. At birth, the donor twins were severely anemic and the recipient twins were polycythemic. Placental injection studies revealed a few small arteriovenous (AV) and venoarterial anastomoses. In the fourth case, because of the high suspicion of TAPS on MCA-PSV data at 24 weeks' gestation, fetoscopic laser coagulation of three small AV anastomoses was successfully performed. No hematological abnormalities were detected at birth. TAPS is a newly described form of chronic twin-to-twin transfusion associated with chronic anemia in the donor and polycythemia in the recipient, without twin oligo-polyhydramnios sequence (TOPS). The monitoring of MCDA pregnancies should include measurement of MCA-PSV in both fetuses even in the absence of intertwin discordance in amniotic fluid volume. Early detection of TAPS could indicate fetoscopic laser coagulation of AV anastomoses.

Nuchal translucency and cystic hygroma colli in screening for fetal major congenital heart defects in a series of 12,910 euploid pregnancies.

OBJECTIVE: Many studies have shown that an increased nuchal translucency (NT) may be a good marker of fetal heart malformation, but the extent to which NT is suitable for identifying the population at risk remains unclear. We aimed to determine the value of NT measurement and of the presence of cystic hygroma colli in the screening of euploid fetuses for congenital heart defects (CHD). METHODS: We carried out a retrospective analysis of 12 910 euploid pregnancies examined between January 1995 and August 2007 at our institution. The screening performance of NT measurements in identifying fetuses with CHD was assessed, with comparison between the use of cut-offs defined as absolute values, multiples of the median (MoM) and percentiles. The presence of cystic hygroma colli was also assessed in the prediction of CHD. RESULTS: The incidence of major CHD was 3.4 per thousand (44/12 910). The sensitivity of NT measurement in screening for major CHD was 54.5% if the threshold was set at the 95(th) percentile, 45.4% if it was set at 3 mm, 27.3% for 3.5 mm, 50.0% for 1.5 MoM and 45.5% for 1.75 MoM. The false-positive rates for these thresholds were 8.4, 6.6, 1.7, 8.9 and 6.3%, respectively. The incidence of major CHD was 1.2% (10/813) in cases of thick NT (> 95(th) centile) and 4.3% (13/304) in cases of hygroma colli. CONCLUSIONS: NT measurement during the first trimester is potentially useful for screening for fetal major CHD. Screening performance is consistent whether NT values are expressed as MoMs, percentiles or absolute values. The incidence of major CHD seems to be higher in cases of cystic hygroma colli.

Use of Z-scores to select a fetal biometric reference curve.

OBJECTIVE: Fetal biometric data are a major part of prenatal ultrasound screening in the general population. The aim of this study was to analyze the effect of choice of reference curve on the quality of screening for growth abnormalities, using a statistical tool based on Z-scores. METHODS: The biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were measured in 9699 ultrasound scans during the second trimester (20-24 weeks of gestation) and 8100 scans during the third trimester (30-34 weeks of gestation). These biometric data were all transformed retrospectively into Z-scores, calculated using five reference curves: those published by Snijders and Nicolaides (1994), Chitty et al. (1994), Kurmanavicius et al. (1999) and Salomon et al. (2006), and curves used at our ultrasound unit generated from a sample of the local population. The Z-score distribution was compared with the expected normal distribution by calculation of the mean and SD, and using the Kolmogorov-Smirnov test. The sensitivity and specificity of each reference curve were calculated to determine the capacity of these curves to identify fetuses with measurements < 5(th) percentile or > 95(th) percentile for each parameter. RESULTS: Most of the distribution curves determined from the Z-scores of the measurements taken differed significantly from a non-skewed standard normal curve (mean of 0 and SD of 1). In our population, the Chitty reference curves gave the best results for identifying fetuses with abnormal (< 5(th) percentile or > 95(th) percentile) BPD (sensitivity, 100%; specificity, 97.24%), HC (sensitivity, 96.07%; specificity, 98.89%) and FL (sensitivity, 96.46%; specificity, 98.80%). The best reference for AC was the Salomon curve (sensitivity, 72.25%; specificity, 99.64%). CONCLUSIONS: Checking for good concordance between the study population and chosen reference data is a key initial step in quality control. Z-scores are a simple tool for evaluating the performance of each reference curve for a given population in order to optimize the sensitivity and specificity of screening for fetal growth abnormalities.

The role of fetal nuchal translucency and ductus venosus Doppler at 11-14 weeks of gestation in the detection of major congenital heart defects.

OBJECTIVE: To determine whether, in a selected high-risk population, Doppler velocimetry of the ductus venosus can improve the predictive capacity of increased nuchal translucency in the detection of major congenital heart defects in chromosomally normal fetuses at 11-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood velocity waveforms were obtained prospectively at 11-14 weeks of gestation in 1040 consecutive singleton pregnancies. Waveforms were classified either as normal in the presence of a positive A-wave, or as abnormal if the A-wave was absent or negative. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. In 484 cases karyotyping was performed. Those fetuses found to be chromosomally normal by prenatal cytogenetic analysis, and which had abnormally increased nuchal translucency and/or abnormal ductus venosus Doppler velocimetry, underwent fetal echocardiography at 14-16 weeks of gestation. Ultrasound examination was repeated at 22-24 weeks of gestation in all women. The sensitivity, specificity and positive and negative predictive values for the detection of major cardiac defects of increased nuchal translucency thickness alone, ductus venosus Doppler alone and increased nuchal translucency thickness in association with abnormal ductus venosus Doppler were determined. RESULTS: In 29 of 998 fetuses presumed to be chromosomally normal, reversed or absent flow during atrial contraction was associated with increased (> 95(th) centile for crown-rump length) nuchal translucency. Major cardiac defects were observed in 9 of these 29 fetuses. No other major cardiac abnormalities were found in chromosomally normal fetuses in spite of the presence of either increased nuchal translucency alone or abnormal ductus venosus velocimetry. A total of 25 cardiac malformations were observed in the population. Fifteen were associated with aneuploidy and 10 fetuses had a normal karyotype. Nine of the 10 had major cardiac anomalies and one had a ventricular septal defect. The nine cases with normal karyotype and major cardiac anomalies had both increased nuchal translucency and abnormal ductus venosus flow velocity waveforms. CONCLUSION: In chromosomally normal fetuses with increased nuchal translucency, assessment of ductus venosus blood flow velocimetry could improve the predictive capacity for an underlying major cardiac defect.