#5268 PREGNANCY OUTCOMES IN DIALYSIS PATIENTS: A TEN-YEAR SERIES FROM A TERTIARY CENTER
Authors: Costa Claudia , Silva Bernardo , Godinho Iolanda , Pinto Luísa , Lopes José António , Nogueira Estela 
Published: June 2023

Abstract

Background and Aims
Pregnancy in dialysis patients was almost prohibited a decade ago, as fetal and maternal outcomes were very poor. In the last years, there has been a paradigm shift, as the introduction of intensive hemodialysis (HD) schedules has been associated with an impressive improvement on fetal outcomes, making motherhood a possibility in these women. Nevertheless, pregnancy in women on dialysis remains associated with a high incidence of complications and is extremely demanding for both patients and clinicians. We describe the maternal, obstetric, and perinatal outcomes of pregnancies in women on dialysis followed at the Nephro-Obstetric Clinic at Centro Hospitalar Universitário Lisboa Norte (CHULN).

Method
Retrospective analysis of pregnancies in women on dialysis and surveilled at the Nephro-Obstetric Clinic at CHULN from 2011 to 2022.

Results
We considered 17 pregnancies from 16 women. One of the women accounted was submitted to voluntary termination of pregnancy. Mean age was 31.5 ± 6.1 years; 70.6% were Black (n = 11) and 29.4% (n = 5) Caucasian; 58.8% were nulliparous (n = 10). All patients had chronic hypertension (HTN), although only 75.0% were under therapy (12/16). Additionally, 3/16 patients had diabetes and 2/16 hyperthyroidism. The mean of overall renal replacement therapy (RRT) duration was 9.1 ± 8.2 years (dialysis and renal transplantation time), being on dialysis program 43.7 ± 37.5 months before gestation. One patient was on peritoneal dialysis (PD) and two patients started HD during pregnancy. Five patients (31.2%) were exposed to teratogenic drugs during gestation. Pregnancy diagnosis occurred at 13.4 ± 5.6 weeks; 70.6% of the patients were on low dose acetylsalicylic acid (n = 12). HD mean time per week according to each trimester was 13.7 ± 2.8 hours/week, 24.5 ± 7.3 hours/week and 28.0 ± 8.0 hours/week during the 1st/2nd/3rd respectively. Mean pre-dialysis urea was 62.1 ± 28.0 mg/dL during gestation. Regarding maternal outcomes, worsening HTN occurred in 62.5% (n = 10) of patients during the 1st (4/10) and 2nd trimester (7/10) and pre- eclampsia (PE) occurred in 6/16 patients (1 with HELLP syndrome). One patient developed polyhydramnios and another one cholestasis of pregnancy. Premature rupture of membranes (PRM) occurred in 3 patients (at 17, 25 and 36 weeks); One patient asked for medical termination of pregnancy due to severe growth restriction and oligohydramnios at 20 weeks. Stillbirth occurred in 4 gestations (cervical insufficiency in a twin pregnancy, severe congenital fetal cardiopathy in a patient with PE, severe growth restriction and premature rupture of membranes (PRM). In the 2 patients with early PRM, the neonates died in the following week due to severe prematurity complications. Labor was induced in 9 patients, mainly due to PE (7/9). Cesarean was performed in 10/17 patients and mean gestation age at delivery was 29.8 ± 6.6 weeks. Extreme prematurity (&lt;28 weeks) occurred in 3 pregnancies and there were three term babies. Mean birth weight was 1554.0±613.6 grams with 4 newborns having extremely low birth weight (&lt;1000g) and 6 requiring neonatal care.

Conclusion
Our study reveals that pregnancy in women on dialysis is challenging and still associated with significant maternal, obstetric and perinatal complications. This population was highly heterogenous, with a significant number of patients living under unfavorable social conditions, and with significant comorbidities. The diagnosis of pregnancy took place mainly during the 2nd trimester, preventing early initiation of intensive dialysis schedules which could have significantly improved outcomes. Pregnancy planning, early diagnosis and management by a multidisciplinary experienced team are of paramount importance to improve outcomes and reduce complications.