Fetal megacystis and triploidy: a case diagnosed at 14th week of gestation

Objective

We reported this case that megacystis plus triploidy because of the low incidence

Case(s)

Fetal megacystis is defined as a longitudinal diameter of the fetal bladder greater than 7 mm in the first trimester One case was reported with megacystis plus triploidy in the literature The fetal longitudinal bladder diameter was detected 34 mm at 14 th gestational age by ultrasonography

Conclusion

Chorionic villus sampling prosedure was performed The result was reported as triploidy 69 XXY The fetal termination was performed by vaginaly

Keywords

Fetal megacystis, triploidy, early gestation

Introduction

Fetal megacystis is defined as expanded bladder higher than normal limits in any gestational period. While it appears as a temporary phenomenon in some cases, it can be an early indicator of lower urinary system obstruction.(1 )While megacystis diagnosis is assessed subjectively at second and third trimester, longitudinal bladder diameter about 7 mm and over in first trimester (10th-14th gestational week) is defined as fetal megacystis.(2 8)- 11 mm bladder diameter is classified as Grade 1 (light), between 12-15 mm is classified as Grade 2 (medium), and over 15 mm is classified as Grade 3 (severe) in first trimester. While many rates were reported in different studies about megacystis prevalence within first trimester, Sebire et al found 15 (1/1633) cases with fetal megacystis in their study in which they examined 24.492 ultrasonography examinations.(2) In this article, we presented a rare case who had megacystis and triploidy together.

Case(s)

Our case was found during a routine antenatal observation in an association which is a university hospital and training center. Our case was 25 years old and her husband was 33 years old. Her gravida was 2 and her parity was 0. The patient had D&C history applied due to one year ago. There was no consanguineous marriage between individuals. Gestational sac with 199 mm large in diameter was found in ultrasonographic examination performed on the 6th gestational week of the patient. Nuchal translucency was found as 1.6 mm in the ultrasonographic examination performed on the 11th gestational week. Ultrasonographic diagnoses compatible with gestational week were observed. Fetal megacystis was found in ultrasonographic examination performed on the 14th gestational week. Longitudinal bladder diameter was measured as 34 mm (Figures 1 and 2). 
The patient was examined in high risky gestation unit. After taking her informed consent, chorionic villus sampling (CVS) was applied. Afterwards, gestation termination was performed by misoprostol 200 mcg / 6 hours protocol by taking informed consent of the patient (cytotec 200 mcg blister, by vaginal way). The termination process was completed at 36th hour after 6 doses (total dose: 1200 mcg). While the abdomen was observed as distended in the macroscopic examination of fetus, pathological examination was evaluated as urethral atresia. As a result of culture from chorionic villus sampling, karyotyping of fetus was reported as 69 XXY (Triploidy). Maternal and paternal karyotyping was evaluated as normal.
 

Discussion

The patient was examined in high risky gestation unit. After taking her informed consent, chorionic villus sampling (CVS) was applied. Afterwards, gestation termination was performed by misoprostol 200 mcg / 6 hours protocol by taking informed consent of the patient (cytotec 200 mcg blister, by vaginal way). The termination process was completed at 36th hour after 6 doses (total dose: 1200 mcg). While the abdomen was observed as distended in the macroscopic examination of fetus, pathological examination was evaluated as urethral atresia. As a result of culture from chorionic villus sampling, karyotyping of fetus was reported as 69 XXY (Triploidy). Maternal and paternal karyotyping was evaluated as normal.

Conclusion

While longitudinal bladder diameter was 34 mm in 14th gestational week in our case, chromosomal analysis result was found as triploidy. Its association with fetal triploidy megacystis is very rare.

References

1. Sepulveda W, Megacystis in the first trimester. Prenatal Diagnosis 2004; 24: 144–9.
2. Sebire NJ, Von Kaisenberg C, Rubio C, Nicolaides K, Fetal megacystis at 10-14 weeks of gestation. Ultrasound Obstet Gynecol 1996; 8: 387-90.
3. Favre R, Kohler M, Gasser B, Muller F, Nissand I. Early fetal megacystis between 11 and 15 weeks of gestation. Ultrasound Obstet Gynecol 1999; 14: 402- 6.
4. Liao AW, Sebire NJ, Geerts L, Cicero S, Nicolaides K,. Megacystis at 10- 14 weeks of gestation: Chromosomal defects and outcome according to bladder length. Ultrasound Obstet Gynecol 2003; 21:338-41.

	File/Dsecription
	Figure 1. Fetal megacystis: longitudinal appearance of fetal bladder.
	Figure 2. Fetal megacystis: transverse appearance of fetal bladder.