#2289 Pregnancy outcomes in patients with congenital abnormality of the urinary tract: experience of a tertiary Portuguese center
Authors: Peres Nadiesda , Da Costa José Oliveira , Marchão Natália , Godinho Iolanda , Jorge Sofia , Rodrigues Márcia , Gonçalves Sara , Fonseca José , Centeno Mónica , Lopes José António , Pinto Luisa , Nogueira Estela 
Published: May 2024

Abstract

Background and Aims
Congenital abnormalities of the urinary tract (CAKUT) represent a broad range of disorders that occur due to abnormal kidney development. Maternal, obstetric, and perinatal outcome in pregnant woman with CAKUT have not been extensively evaluated, although small series report an increased incidence of urinary tract infections (UTI) and obstructive uropathy.

Method
Retrospective analysis of maternal, obstetric, and perinatal outcomes in pregnant patients with CAKUT (including genetic cystic kidney disease) that were surveilled in our tertiary center by a nephro-obstetric team between 2011 and June 2023. Information was obtained from medical records.

Results
We evaluated 47 gestations in 41 patients, with mean age of 31 ± 5 years [17-40], 89% were Caucasian, 11% black; 40% were nulliparous, 36% had hypertension (HT) and 42% a previous history of UTI. Regarding CAKUT specificity, 17/41 patients had genetic cystic diseases, 10/41 ureteropelvic junction obstruction (UPJ), 4/41 duplicate collecting system, 5/41 vesicourethral reflux, 2/41 ectopic kidney, 3/41 renal hypoplasia. Genetic testing was done before, during or after pregnancy in 2/4/4 patients, respectively. Teratogenic therapy exposure occurred in 25% of gestations. Most patients were CKD stage 1 (33/41), with 2/4/1/1 with patients in CKD stage 2/3/4/5, respectively. Mean baseline SCr was 0.99 ± 0.8 mg/dL [0.4-4.6] and mean proteinuria was 194 ± 357 mg/g [22-1500]. Renal function (RF) deterioration occurred in 9/47 (19%) women due to pre-eclampsia (PE), pregnancy hyperfiltration (PH) and hydronephrosis in 3/3/3 patients, respectively. Urologic intervention was needed in 2 patients due to hydronephrosis, and one of the patients required transient dialysis. All patients fully recovered RF except for the 1 CKD stage 3 patients that had partial RF recovery. De novo and worsening proteinuria occurred in 7/47 gestations due to PE (3/7) and PH (4/7). De novo or aggravation of HTN occurred in 25% gestations, UTI in 19% and PE in 6% gestations.
Regarding fetal outcomes, mean duration of gestation was 38 ± 2 weeks [32-41] and mean birth weight 2910 ± 634 g [1360-4600]. There was 1 miscarriage and 1 medical termination of pregnancy at 17 weeks (neural tube defect). Cesarean was performed in (8/47, 17%) gestations and 10/47 (17%) newborns were admitted to the neonatal care unit (NICU) mainly due to prematurity, sepsis and feeding intolerance.

Conclusion
Our cohort of CAKUT patients was very heterogenous and only 19.5% had CKD stage 2-5. Still, we found a significant incidence of maternal, obstetric, and perinatal complications, namely HT UTI, PE, and the need for NICU. UPJ obstruction can evolve with RF deterioration and the need for intervention during pregnancy. This study underlines the importance of the management of these patients by a multidisciplinary team.