#2130 Pregnancy in patients with chronic kidney disease stage 3 to 5: what to expect?
Authors: Da Costa José Oliveira , Marchão Natália , Peres Nadiesda , Godinho Iolanda , Centeno Mónica , Lopes José António , Pinto Luisa , Nogueira Estela 
Published: May 2024

Abstract

Background and Aims
Chronic Kidney disease (CKD) has long been recognized as a risk factor for adverse pregnancy outcomes. Advanced CKD is also associated with decrease fertility, raising the importance of an early approach of pre- menopausal CKD women to discuss pregnancy planning and avoid long term kidney function deterioration or prematurity sequelae in their child-to-be.

Method
Retrospective analysis of maternal, obstetric and perinatal outcomes of patients with CKD stage 3 to 5, followed by the Nephro-obstetric clinical team between 2011 until 2023.

Results
We evaluated 31 gestations in 28 patients, with mean age of 32 years [19-43], 21 Caucasian and 7 African, 15 nulliparous, 21/28 with hypertension (HTN), 6/28 diabetic, 2/28 with HIV and 3/28 with systemic lupus erythematosus (SLE). CKD diagnosis occurred during pregnancy in 4/28 patients. Mean pre-pregnancy SCr was 2,1 ± 1 mg/dL [1,1-4,3] and mean proteinuria was 1535 ± 1874 mg/day [5 - 6000], and 11 patients had proteinuria &gt;1 g/day. At gestation baseline, patients evaluated in each pregnancy were in CKD stage 3a (9/31), 3b (10/31), 4 (8/31) and 5 (4/31). CKD etiologies were heterogenous, with most common diagnosis being hereditary nephropathies (7/28), Diabetic nephropathy (6/28) and lupus nephritis (3/28). Exposure to teratogenic therapy occurred in 10/31 gestations (mean time of 11 weeks; 2 - 15), generally ACE/ARBs. Medical termination of pregnancy occurred in 3 gestations due to active SLE and severe growth restriction, 1 abortion at 16 weeks and 1 stillbirth due to cervical insufficiency. HTN aggravation occurred in 16/31 (52%) gestations and de novo proteinuria or proteinuria increase occurred in 7/31(22,5%) and 20/31 (64.5%) gestations, respectively due to pregnancy hyperfiltration, active lupus nephritis and preeclampsia.
Considering pregnancies that progressed, renal function (RF) deterioration occurred 10/19 (53%) patients in CKD stage 3 with 20%/60%/20% with full/partial and no RF recovery, respectively. In CKD4 6/7 patients (86%) had RF aggravation with 17% and 83% with partial or no RF recovery. Of the 2 Patients in CKD stage 5 with gestation &gt;20 weeks, 1 started dialysis during pregnancy and the other 4 months postpartum. Dialysis was initiated in 3 patients during pregnancy (2 CKD stage 4 and 1 CKD stage 5) due to urea level &gt;100 mg/dL. RF deterioration was mainly due to pregnancy hyperfiltration and preeclampsia (11/26 gestations; 42%).
Mean gestation age at delivery was 34 ± 4 weeks (28-41), with 73% and 53,8% pregnancies with gestational age &lt;37 and 34 weeks, respectively. Mean birth weight was 1866 ± 707 g (555–3095 g), with 73% low birth weight (&lt;2500 g). Mean Apgar 1/5/10 was 9/10/10, respectively. Cesarean was performed in 53,8% gestations and 61,5% newborns were admitted to the neonate care unit (NICU) due to prematurity

Conclusion
CKD patients with stage 3 to 5 are at increased risk of worse maternal outcomes, namely HTN aggravation (52%), de novo or increase proteinuria (87%) and RF deterioration (53% stage 3 and 86% stage 4) with significant permanent loss of kidney function. Obstetric and perinatal results were also significantly worse with a high incidence of preeclampsia (42%), prematurity (73%), low birth weight (73%) and the need of NICU (61.5%). It is of sum importance, that advanced CKD patients are previously counseled about those risks and are managed in a multidisciplinary feto- maternal clinic experienced in CKD pregnancy care that has a dialysis unit.