An interdisciplinary team from University Hospitals Cologne and Bonn announced on Mar. 13 the results of a prospective study showing that very early intervention in unborn children with congenital lower urinary tract obstruction (cLUTO) can improve survival rates and kidney function. The study, published in "The Lancet Child & Adolescent Health" to coincide with World Kidney Day, examined the effects of implanting vesicoamniotic shunts during the first trimester in pregnancies affected by severe fetal megacystis.
This research is significant because cLUTO can cause serious complications before birth, including damage to developing kidneys and insufficient lung development due to lack of amniotic fluid. Early diagnosis and innovative treatments are crucial for improving outcomes for affected children.
The study included 40 pregnancies where a vesicoamniotic shunt was implanted in the first trimester. Of these, 75 percent of children were born alive, and 68 percent survived their first year. Among the survivors who received active treatment, most did not require dialysis during their first year, and many had normal or only slightly impaired kidney function. Dr Stefan Kohl, Specialist at the Department of Paediatric and Adolescent Medicine at University Hospital Cologne, said: "In cLUTO, the unborn child's urine flow is blocked. The resulting pressure causes significant overstretching of the urinary tract while still in the womb. The permanently increased pressure can damage the developing kidneys at an early stage. At the same time, there is a lack of amniotic fluid, which consists mainly of foetal urine and is essential for normal lung maturation. Insufficient lung development has therefore often been associated with high mortality after birth."
Previous interventions performed later in pregnancy have not shown clear benefits for kidney function or survival. Dr Eva C. Weber, Deputy Head of Prenatal Medicine and Foetal Surgery at University Hospital Cologne, explained: "The strategy examined here starts much earlier: With the help of a novel foldable vesicoamniotic shunt that can be inserted through a smaller needle, the procedure could be performed safely at the end of the first trimester of pregnancy – at a stage when the foetus is about the size of a hen's egg." She added that early treatment led to good chances for survival and preserved kidney function if no other severe malformations were present.
Dr Weber also said: "Our aim was to examine whether we could protect the sensitive phase of kidney development by relieving pressure on the urinary tract at a very early stage... If we succeed in stabilizing kidney development at an early stage, we can not only improve survival rates but also reduce long-term consequences such as the need for dialysis." Professor Christoph Berg, Head of Foetal Surgery at University Hospital Cologne, commented: "In early pregnancy, the kidney is in a particularly sensitive phase of development... By providing relief at a very early stage, we try to protect this critical phase of kidney development."
The study enrolled pregnancies between June 2019 and January 2024 and followed clinical outcomes up to each child's first birthday. It was supported by internal research funding from University of Cologne's Faculty of Medicine as well as additional grants received by Dr Kohl.
Professor Dr Jörg Dötsch concluded: "Such projects make it possible to provide patients with interdisciplinary support from prenatal findings to long-term care."
