Outcome of antenatally diagnosed cystic hygroma - Lessons learnt

This study is carried out to characterize the prognosis and outcome of antenatally diagnosed cystic hygroma in a series of registered pregnancies.

This is a prospective cohort study, carried out over a period of 4 years (Jan 2016-Sept 2019). All the pregnancies referred from the department of obstetrics with antenatally detected cystic hygroma or increased nuchal thickness on level II ultrasonography suggestive of lymphangiomas were registered in the Pediatric Surgery outpatient department. Amniocentesis, fetal ECHO and fetal MRI (if indicated)were done. Prognosis was explained to the family and mode of delivery was planned as per the obstetric indications. Postnatal evaluation included general physical examination along with ultra sound (USG)doppler of the lesion. The neonates were admitted in neonatal surgical ICU for the administration of intralesional bleomycin in a dose of 0.3 IU/kg under strict observation. All the babies were followed up at 3, 6 and 12 months. Results were segregated as excellent, good and still in follow up cohort as per the final outcome. The fetal neck masses detected antenatally and the age at first dose of bleomycin were compared with the number of sclerotherapy doses required to achieve good response.

Only nine patients out of 626 registered pregnancies (1.4%) were diagnosed with cystic hygroma. One antenatal mother opted for termination of pregnancy at 19 weeks of gestation and another patient was lost to follow up after receiving two doses of bleomycin in postnatal period. Maternal hypothyroidism was noted in two pregnancies. Antenatal USG shows increased nuchal thickness in 2 cases (first trimester) and 6 cases in level II scan. Amniocentesis shows normal fetal karyotyping in all these pregnancies. Fetal ECHO suggests normal biventricular function in 100% cases while fetal MRI done in one case completely ruled out any aerodigestive compromise. Mode of delivery is found to be planned elective LSCS in 57% of cases while normal vaginal delivery attained in 43% of cases as per the obstetric guidelines. Six cases achieved good response with >50% reduction in size out of which 4 cases received the dose at the first 10 days of life. Complete disappearance of lesion at the end of 6 months of follow up were seen in two babies.

Antenatal screening for early detection of fetal cystic hygroma with possible associated congenital aneuploidies helps in prognostication and planning the mode of delivery. A multimodality approach during intra and postpartum increases safety margin. Even huge neck masses without associated anomalies carry fair prognosis. Intralesional bleomycin is safe and prevents surgical morbidity.