Aim: To identify women with preconception chronic kidney disease (CKD) and assess the impact on maternofoetal pregnancy outcomes.
Background: Pregnancy is a key goal and aspiration for many women with CKD. While pregnancy outcomes for women with advanced kidney disease including those treated with dialysis or kidney transplantation is well defined, there is significantly less data on the cohort of women with earlier stages of CKD.
Methods: We linked state-wide perinatal datasets (containing births with gestation ≥20 weeks and weight ≥400g) to pathology data, ANZDATA and other administrative health datasets between 2005-2019. We included all women ≥18 years with ≥1 maternal serum creatinine within 5 years prior to conception (and up to 30 days post-conception) to identify pre-existing stages of CKD. We also followed mothers for up to 2 years postpartum.
Results: Of the total 79,694 pregnancies (in 46,891 women) during the study period, we included 32,240 (in 26,010 women). Of these, 2,607 (8.1%) had CKD, the majority stage 1 or 2. On multivariable analysis, pre-eclampsia (aOR 1.34 [1.07-1.65], p=0.008) was more likely in women with pre-existing CKD. There was no difference in the likelihood of an induced delivery, gestational hypertension, gestational diabetes or delivery by caesarean.Babies of women with CKD were more likely to be born prematurely (≤37 weeks’ gestation, aOR 1.22 [1.08-1.38], p=0.001) and require special care nursery admission (aOR 1.14 [1.00, 1.30], p=0.044), but there was no difference in live birth rates, low birth weight or congenital abnormalities. Only 3% of women had pre-pregnancy urine measurement of albumin or protein prior, and therefore it is difficult to comment on the association with proteinuria and outcomes. In the 16,250 individuals with at least one post pregnancy serum creatinine measurement, there was no significant creatinine change in patients with CKD compared to those without CKD up to 2-year postpartum.
Conclusion: Women with early stages of CKD and their babies are at an increased risk of adverse maternal and baby outcomes including pre-eclampsia, premature delivery and requiring special care nursery admission. Women do not appear to be at increased risk of worsening kidney function up to 2 years postpartum, however it should be noted that our CKD cohort largely consisted of CKD stage 1 and 2. This information is highly valuable in helping patients and clinicians make informed, shared, and patient-centered decisions around the motherhood journey.