The role of fetal karyotyping from unconventional sources

Short- and long-term outcome following thoracoamniotic shunting for fetal hydrothorax

OBJECTIVES

To assess short- and long-term outcome in a cohort of fetuses diagnosed with hydrothorax (FHT) which underwent thoracoamniotic shunting in utero, and to examine the antenatal predictors of survival and of survival with normal neurodevelopmental outcome.

METHODS

This was a retrospective analysis of 132 fetuses that underwent thoracoamniotic shunting at our center between 1991 and 2014. Data were extracted from hospital obstetric and relevant neonatal intensive care and neonatal developmental follow-up databases. Outcomes included survival to discharge and survival with normal neurodevelopmental outcome beyond 18 months. Information on malformations, syndromes and genetic abnormalities were obtained from antenatal, postnatal and pediatric hospital records or by parent report. We compared pregnancy characteristics among those who survived vs non-survivors and among those with normal neurodevelopmental outcome vs those who were abnormal or died. We explored whether there was a trend in survival over the study period.

RESULTS

The mean gestational age at diagnosis of FHT was 25.6 weeks. The fetus was hydropic at diagnosis in 61% of cases, 69% had bilateral effusions and 55% had bilateral shunts inserted. Other diagnoses were present in 24% of cases, two-thirds of which were discovered only postnatally. There were 16 intrauterine and 30 neonatal deaths, with a 65% survival rate overall. The mean gestational age at delivery of liveborns was 35.4 (range, 26.9-41.6) weeks, and 88/116 (76%) were preterm (< 37 weeks). Of 87 liveborn at the treatment center, 75% experienced some respiratory and/or cardiovascular morbidity after birth, many with a lengthy hospital stay (mean, 36 (range, 1-249) days). Overall, 84% of survivors were developmentally normal beyond 18 months and outcomes were better when pleural effusions were isolated, 92% of these cases being neurodevelopmentally normal. There was no trend in survival or neurodevelopmental outcome over time. Despite the presence of FHT and neonatal respiratory issues, most (89%) of the 55 survivors with relevant follow-up had no long-term pulmonary complications. Gestational age at delivery was the only factor independently predictive of both survival and survival with normal neurodevelopmental outcome.

CONCLUSIONS

FHT is associated with other pathologies in a quarter of cases and carries a significant risk of prematurity, mortality and neonatal morbidity. The outcome is good in survivors but is best in isolated cases. Predictors of outcome at diagnosis are poor. Future improvement in diagnostics at time of identification of FHT may help to identify those that would benefit most from thoracoamniotic shunting. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal outcome following fetal chest shunt insertion for pleural effusion

OBJECTIVE

To evaluate perinatal outcome of fetuses with primary pleural effusions following pleuroamniotic shunting.

METHODS

This was a retrospective study of 88 fetuses with large pleural effusions referred to a tertiary fetal medicine unit between 1991 and 2008 which, after a thorough work-up, underwent pleuroamniotic shunting.

RESULTS

At presentation, 59 (67.0%) fetuses were hydropic and 67 (76.1%) had bilateral effusions. In 17 (19.3%) fetuses, pleural fluid was aspirated prior to shunting and in 71 (80.7%), shunts were inserted directly as the first procedure. Mean gestational age at shunting was 27.6 (range, 18-37) weeks and at delivery 34.2 (range, 19-42) weeks. Seventy-four (84.1%) babies were born alive, of whom 52 (70.3%) survived the neonatal period. Of 59 hydropic fetuses, 10 (16.9%) died @ in utero and 18 neonates (30.5%) died, resulting in perinatal survival of 52.5%, whereas of 29 non-hydropic fetuses, perinatal survival was 72.4%. Hydrops resolved following shunting in 28 fetuses, of whom 71% survived, compared to 35% survival in 31 fetuses where hydrops persisted (P = 0.006). Of 22 neonatal deaths, seven were related to pulmonary hypoplasia, five to genetic syndromes, two to aneuploidy and one to a congenital anomaly (truncus arteriosus). Overall 13 (14.8%) were diagnosed with a chromosomal, genetic or other condition, several of which could not have been diagnosed antenatally.

CONCLUSION

Carefully selected fetuses with primary pleural effusions can benefit from pleuroamniotic shunting, allowing hydrops to resolve with a survival rate of almost 60%.

Fetal pleural effusions

The clinical course of primary fetal hydrothorax is unpredictable. Whereas smaller unilateral effusions might remain stable or even regress, this is rarely the case with larger collections. Bilateral effusions, hydrops, preterm delivery and the lack of antenatal therapy are all associated with poor outcome. Once structural and chromosomal anomalies have been excluded, optimal management depends on gestational age, rate of progression, the development of hydrops and associated maternal symptoms. For very large effusions with mediastinal shift, hydrops and/or hydramnios, or when there is rapid enlargement of the effusion, fetal intervention is warranted. Survival can be maximized by pleuroamniotic shunting, which can reverse hydrops and hydramnios and prevent pulmonary hypoplasia. Pleuroamniotic shunting can also be used for the treatment of other large cystic lung lesions, such as a macrocystic congenital cystic adenomatoid malformation or bronchopulmonary sequestration, especially when associated with hydrops.

Prenatal diagnosis from cystic hygroma fluid: the value of fluorescence in situ hybridization

OBJECTIVE

We sought to determine the optimal approach to the prenatal chromosome analysis of cystic hygroma fluid using traditional cytogenetic analysis and fluorescence in situ hybridization.

STUDY DESIGN

A retrospective evaluation of our experience with traditional cytogenetic and fluorescence in situ hybridization analysis on cystic hygroma fluid was performed through a systematic review of the Genzyme Genetics database from January 1995 to July 2000. Information on gestational age, sample volume, clinical ultrasound findings (including fetal viability), cytogenetic results, fluorescence in situ hybridization results, and turn-around-time were queried.

RESULTS

Eighty-three specimens were included in the investigation. The mean gestational age was 18.1 weeks (range, 13-27 weeks), and the mean sample volume was 20.7 mL (range, 0.1-101 mL). Of the 72 samples in which > 5 mL of cystic hygroma fluid was available, the success rate for cytogenetic analysis was 76% (55/72 samples). In 11 specimens of < or = 5 mL of cystic hygroma fluid, cytogenetic analysis was successful in only 1 case (9%). Fluorescence in situ hybridization was attempted on 23 samples, 18 of which were successful (78%), including 6 of 9 cases of cell culture failure (67%). Both traditional cytogenetic analysis and fluorescence in situ hybridization were performed in 21 instances when a sample of > 5 mL was available. A successful result was obtained by either cytogenetic testing or fluorescence in situ hybridization analysis or both in 19 of 21 of these cases (90%). Samples of > 5 mL from viable fetuses had a higher cytogenetic success rate (80%) and fluorescence in situ hybridization success rate (89%) than samples from fetuses with intrauterine death (38% and 50% cytogenetic and fluorescence in situ hybridization success rates, respectively.) The mean turn-around time was 8.2 days (range, 4-17 days). Results were available in < or = 12 days in 91% of cases. There was a 91% aneuploidy rate identified, with 45,X occurring in 86% of the samples.

CONCLUSION

We conclude that the optimal approach for the prenatal diagnosis of chromosome abnormalities from cystic hygroma samples is to perform both traditional cytogenetic studies and interphase prenatal fluorescence in situ hybridization evaluation for the most common aneuploidies that involve chromosomes 13, 18, 21, X, and Y. With this combined approach, our data indicate that, in viable pregnancies with a fluid sample of >5 mL, a 90% diagnostic success rate can be achieved.

Cystic hygroma in the fetus and newborn

Cystic hygromas are developmental abnormalities of the lymphoid system that occur at sites of lymphatic-venous connection, most commonly in the posterior neck. They are frequently associated with karyotypic abnormalities, various malformation syndromes, and several teratogenic agents. The disease course of an infant with cystic hygroma is unpredictable. When diagnosed prenatally, the overall prognosis is poor. Cystic hygroma diagnosed after birth is usually associated with a good prognosis. This article reviews the embryologic, genetic, and pathologic correlates of these lymphatic system abnormalities, as well as the clinical course and outcome of the fetus and newborn with a cystic hygroma. Management strategies are reviewed, including newer nonsurgical therapies for the neonate with a cystic hygroma.