What Causes Fetal Megacystis?
Feb 10, 2022
Source: Cainiu Health
Dr. Ma Yan
Introduction
This condition may result from chromosomal abnormalities or genetic factors. Second, inadequate development of the fertilized egg can also lead to the disease. Third, infants have relatively low immunity and may temporarily exhibit functional issues, which typically improve gradually over time. Fourth, the disease may be triggered by external factors such as environmental noise and an unhealthy diet.
Fetal megacystis primarily refers to the measurement of the fetal bladder’s longitudinal diameter via ultrasound examination between 10 and 14 weeks of gestation. A diagnosis of megacystis is made when the fetal bladder’s longitudinal diameter is equal to or greater than 7 mm. Below, we address the underlying causes of fetal megacystis.
What Causes Fetal Megacystis?
This condition may result from chromosomal abnormalities or genetic disorders. Second, inadequate development of the fertilized egg can also lead to this condition. Third, infants with relatively low immunity may exhibit transient functional issues that gradually improve over time. Fourth, external factors—including environmental noise and an unhealthy diet—may contribute to the condition. During the second trimester, more accurate assessments can be obtained via ultrasound; however, the majority of cases carry a poor prognosis, leading most families to opt for pregnancy termination. In a minority of cases, megacystis occurs in isolation without associated structural anomalies.
Fetal megacystis most commonly manifests during early pregnancy. Pregnant women may experience heightened morning sickness, increased irritability, and loss of appetite. Dietary adjustments—including consumption of foods that promote appetite and strengthen the spleen—can help improve mood and nutritional intake. High-quality protein intake is essential, as the early embryo cannot synthesize amino acids independently and relies entirely on maternal supply. Insufficient amino acid or protein availability may impair fetal growth and even contribute to congenital malformations. Maternal protein intake should be no less than 40 grams per day to meet physiological demands.
Comprehensive evaluation—including detailed fetal anatomical assessment and urinalysis—can be performed. If no significant abnormalities are detected, dynamic observation may be appropriate, as spontaneous resolution is possible. In cases where bladder enlargement results from urinary tract obstruction accompanied by oligohydramnios—but with confirmed normal renal function—urethral stenting may be considered to relieve the obstruction. Neonates with normal renal function, serum creatinine levels, and creatinine clearance generally have a favorable prognosis.
The above outlines the potential causes of fetal megacystis. We hope this information is helpful to you.
