2019
Fetal megacystis: a lot more than LUTO
Publication
Publication
Ultrasound in Obstetrics and Gynecology , Volume 53 - Issue 6 p. 779- 787
ABSTRACT
Objective Fetal megacystis presents a challenge in terms
of counseling and management because of its varied
etiology and evolution. The aim of this study was to
present a comprehensive overview of the underlying
etiologies and structural anomalies associated with fetal
megacystis.
Methods This was a retrospective multicenter study of cases referred to the fetal medicine unit of one of the eight academic hospitals in The Netherlands with a diagnosis of fetal megacystis. For each case, data on and measurements of fetal urinary tract and associated structural anomalies were collected. All available postmortem examinations and postnatal investigations were reviewed in order to establish the final diagnosis. In the first trimester, fetal megacystis was defined as longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during an extended ultrasound examination lasting at least 40 min.
Results Of the 541 pregnancies with fetal megacystis,
it was isolated (or solely accompanied by other signs
of lower urinary tract obstruction (LUTO)) in 360
(67%) cases and associated with other abnormal
ultrasound findings in 181 (33%) cases. The most
common associated ultrasound anomaly was an increased
nuchal translucency thickness (22%), followed by single
umbilical artery (10%) and cardiac defect (10%). A
final diagnosis was established in 418 cases, including
222 (53%) cases with isolated LUTO and 60 (14%)
infants with normal micturition or minor isolated
urological anomalies. In the remaining 136 (33%) cases,
concomitant developmental or chromosomal abnormality
or genetic syndrome was diagnosed. Overall, 40
chromosomal abnormalities were diagnosed, including
trisomy 18 (n = 24), trisomy 21 (n = 5), Turner syndrome
(n = 5), trisomy 13 (n = 3) and 22q11 deletion (n = 3).
Thirty-two cases presented with anorectal malformations
involving the anus, rectum and urogenital tract. In cases
with confirmed urethral and anal atresia, megacystis
occurred early in pregnancy and the bladder appeared
severely distended (the LBD (in mm) was equal to or
greater than twice the gestational age (in weeks)). Fetal
macrosomia was detected in six cases and an overgrowth
syndrome was detected in four cases, comprising two
infants with Beckwith–Wiedemann syndrome and two
with Sotos syndrome. Megacystis-microcolon-intestinal
hypoperistalsis syndrome was diagnosed in five (1%) cases
and prenatally suspected only in one case.
Conclusions Although the main cause of fetal megacystis is LUTO, an enlarged fetal bladder can also be present as a concomitant finding of miscellaneous genetic syndromes, developmental disturbances and chromosomal abnormalities. We provide an overview of the structural anomalies and congenital disorders associated with fetal megacystis and propose a practical guide for the differential diagnosis of genetic syndromes and chromosomal and developmental abnormalities in pregnancies presenting with fetal megacystis, focusing on the morphological examination of the fetus.
Additional Metadata | |
---|---|
doi.org/10.1002/uog.19182, hdl.handle.net/1765/117797 | |
Ultrasound in Obstetrics and Gynecology | |
Organisation | Department of Gynaecology & Obstetrics |
Fontanella, F., Maggio, L., Verheij, J, Duin, L.K., van Scheltema, P. N. A., Cohen-Overbeek, T., … Bilardo, C. M. (2019). Fetal megacystis: a lot more than LUTO. Ultrasound in Obstetrics and Gynecology, 53(6), 779–787. doi:10.1002/uog.19182 |