Fetal megacystis and trisomy 18 association: case report

Objective

We aimed fetal megasistis existance,which is frequently seen together chromosomal anomalies,to discuss a case report.

Case(s)

The pregnancy of a patient who is 31 years old and whose pregnancy is detected fetal megasistis in 14 weeks and detected trisomy 18 by amniosynthesis which is made in 16 weeks is terminated in Ağrı Maternity and Children Hospital. Situation: Ağrı Maternity and Children Hospital.

Conclusion

İn Fetal Megasistis,it is detected 25 chromosomal defects of fetuses whose fetal bladder longitudinal diamater between 715mm.From this defects the most frequently seen are Trisomy 13 and likely in our case Trisomy 18.90 of the cases recover not to develop any sequela or adverse effects in chromosomally normal group.İn this case report,we discussed a case which is cooperated withfetal megasistis and Trisomy 18.

Keywords

Fetal megacystis, ultrasonography, trisomy 18

Introduction

Fetal megasistis which is >7 mm of fetal bladder longitudinal diamater is seen in 1/5000 births. Bladder is an organ in abdomen which is diagnosed simply and fastly with stomach.(1)The routine anomaly screening of pregnancy between 18-20 weeks in 15-20 minutes,the bladder is always seen in all cases.A normal fetus mictures regularly but never definitely empty and always contain somehow residue urine(2)
Fetal megasistis is two main reason.İn the first reason ,there must be a problem in the urine output,this case is oluşur in the men mainly the result of the false development of the urethra.The spectrum of the anomalies changes complete urethral atresia to urethral valves that oluşan of etrafında membraneus/prosthetic urethra (3).Bladder obstruction of women is usually the result of the complex defects of the development of the urogenital system and called 'anomalies of the cloacal bed'.Second group is bladder growth due to nonobstructive factors.These are heterogen group because of the underlying complex pathologies.Among of these neuropathic bladder,obsruction of the small intestines due to düz muscle degeneration,megacystic microcolon intestinal hyperperistalsis syndrome and Prune Belly syndrome(4).

Case(s)

There isn't an of the patient who first başvuran in 14. weeks;in 31 years gravida 5,parity 4,live 4.There isn't an in family anemnesis and laboratory tests were normal.The fetal bladder longitudinal diamater was 19mm and amniotic fluid was normal in the obstetric ultrasonography.(picture 1)NT measurement was 3.2mm. There isn't another özellik in ultrasonography. Because of the detection of the same results of the patient's ultrasonographic examination which is made in 16 gestational weeks,amniosynthesis process is performed. Because of the result of the amniosynthesis Trisomy 18,the pregnancy of the patient is terminated by getting permission of the family.

Discussion

İn the %25 of the fetuses whose bladder longitudinal diamater is 7-15mm in 10-14 weeks of the pregnancy,it is detected chromosomal defects.Among of these defects the most seen are Trisomy 13 and like our case Trisomy 18.İn the chromosomally normal group %90 percent of the cases is improved not to develop any sequela or adverse effect.İn the contrary,in the cases of the bladder diamater>15mm the chromosomal anomaly ratio is %10; but the chromosomally normal cases in this group always together progressive obstructive uropathy.(5) The treatment of the megasistis changes depend of the underlying pathology.İf the megasistis develop in the early period of the pregnancy,usually the cause is urethral atresia and these cases are fatal.The being of the obstruction partial or complete effect the treatment.İn the detection of the obstruction the best method is measuring of the amniotic fluid level.The obstruction is getting increase the amniotic fluid miktarı is getting decrease.İn the cases of the oligohydramnios the bladder is emptied by making vesico-amniotic shunt.This perform can be make 3-4 times. it is protected from pulmoner hypoplasia which develops in the cases of the oligohydramnios.İn the group of the amniotic fluid level is normal,the treatment of the bekleme can be make.Assessing the neuropathic causes of the bladder distension is is harder and the worth of the inutero treatment of this causes isn't open and it is needed long time randomised studies in this topic.(1,6) Megasistis is in the %75 of the chromosomally abnormal cases and in the %30 of the chromosomally normal cases along with the increased NT.The underlying mechanism of the increasing NT in the fetal megasistis may be thoracic compression.(5) İn the cases of megasistis which bladder 7-15mm,if the fetal caryotype is normal it is told to parents megasistis will improve in the %90 percent of the cases not to cause any adverse effect of kidney development and function.Because of the bladder smooth muscles and autonomic innervation develop after the 13.week;in the pregnancies less than 13 weeks bladder wall is oluşur connective tissue no epithelium and contractile element.For this reason,the assesment of this group patients is left to 14.weeks which the bladder completely develop.

Conclusion

In Fetal Megasistis,it is detected %25 chromosomal defects of fetuses whose fetal bladder longitudinal diamater between 7-15mm.From this defects the most frequently seen are Trisomy 13 and likely in our case Trisomy 18.%90 of the cases recover not to develop any sequela or adverse effects in chromosomally normal group.İn this case report,we discussed a case which is cooperated withfetal megasistis and Trisomy 18.

References

1) McHugo J, Whittle M.Enlarged fetal bladders:aetiology,management and outcome.Prenat Diagn 2001;21:958-63.
2) Chih-Ping C,Chin Yuan T, Wayseen W.Prenatal diagnosis of cystic bladder distention secondary to obstructive uropathy.Prenat Diagn 2000;20: 260-63.
3) Michael G P,Jacquelyn B,Joseph RW,Angelina C.Enlarged Fetal Bladder:Differential Diagnosis and Outcomes..J Clin Ultrasound 2003;31: 6-14.
4) Sebire NJ,.Von K,Rubio,R.J. Snijders M, Nicolaides KH.Fetal Megacystis at 10-14 weeks of gestation.Ultrasound Obstet Gynecol 1996; 8: 387-90.
5) Liao AW, Sebire NJ, Geerts N, Cicero S, Nicolaides KH.Megacystis at 10-14 weeks of gestation:chromosomal defects and outcome according to bladder length.Ultrasound Obstet Gynecol 2003;21:338-41.

	File/Dsecription
	Picture 1. Appearance of the fetus.