Reassuring pregnancy outcomes in women with mild COL4A3-5-related disease (Alport syndrome) and genetic type of disease can aid personalized counseling

Individualized pre-pregnancy counseling and antenatal care for women with chronic kidney disease (CKD) require disease-specific data. Here, we investigated pregnancy outcomes and long-term kidney function in women with COL4A3-5 related disease (Alport Syndrome, (AS)) in a large multicenter cohort. The ALPART-network (mAternaL and fetal PregnAncy outcomes of women with AlpoRT syndrome), an international collaboration of 17 centers, retrospectively investigated COL4A3-5 related disease pregnancies after the 20th week. Outcomes were stratified per inheritance pattern (X-Linked AS (XLAS)), Autosomal Dominant AS (ADAS), or Autosomal Recessive AS (ARAS)). The influence of pregnancy on estimated glomerular filtration rate (eGFR)-slope was assessed in 192 pregnancies encompassing 116 women (121 with XLAS, 47 with ADAS, and 12 with ARAS). Median eGFR pre-pregnancy was over 90ml/min/1.73m2. Neonatal outcomes were favorable: 100% live births, median gestational age 39.0 weeks and mean birth weight 3135 grams. Gestational hypertension occurred during 23% of pregnancies (reference: 'general' CKD G1-G2 pregnancies incidence is 4-20%) and preeclampsia in 20%. The mean eGFR declined after pregnancy but remained within normal range (over 90ml/min/1.73m2). Pregnancy did not significantly affect eGFR-slope (pre-pregnancy β=-1.030, post-pregnancy β=-1.349). ARAS-pregnancies demonstrated less favorable outcomes (early preterm birth incidence 3/11 (27%)). ARAS was a significant independent predictor for lower birth weight and shorter duration of pregnancy, next to the classic predictors (pre-pregnancy kidney function, proteinuria, and chronic hypertension) though missing proteinuria values and the small ARAS-sample hindered analysis. This is the largest study to date on AS and pregnancy with reassuring results for mild AS, though inheritance patterns could be considered in counseling next to classic risk factors. Thus, our findings support personalized reproductive care and highlight the importance of investigating kidney disease-specific pregnancy outcomes.

FC 012PRIMARY KIDNEY DISEASE IMPACTS OUTCOME IN CKD PREGNANCIES: COMPLICATIONS IN COL4A3-5 RELATED DISEASE (ALPORT SYNDROME) VS OTHER CKD PREGNANCIES

Background and Aims

Chronic kidney disease (CKD) affects approximately 3% of pregnant women. CKD increases the risk of pregnancy complications such as prematurity, low birthweight and pre-eclampsia. Also, kidney function can deteriorate more quickly due to pregnancy. There is limited knowledge on pregnancy outcomes in specific kidney diseases. The aim of the ALPART network is to study pregnancy outcomes differentiated by CKD aetiology. We have started with COLA3-5 related disease (Alport syndrome), which is one of the most prevalent monogenic kidney diseases. Comparing outcomes in COLA3-5 related disease to pregnancies with other CKD aetiologies allows us to investigate whether this specific diagnosis impacts outcome in CKD pregnancies.

Method

The ALPART network is an international 15-center network, which aims to include ∼200 COLA3-5 related disease pregnancies. In this intermediary analysis, we present data on 109 pregnancies from 68 women with COLA3-5 related disease. We compared outcomes to a cohort of 457 CKD stage 1-2 patients (a similar CKD stage as our cohort) of diverse aetiology from a 2015 Italian study and 159,924 women from the general Dutch population.

Results

The main pregnancy and kidney outcomes are presented in Figure 1. Foetal outcomes were better in COLA3-5 pregnancies than in pregnancies of women with CKD stage 1-2 of diverse aetiology. We saw less prematurity (17% vs 36% respectively) and a higher mean birthweight of 3216 ± 663 gram compared to 2768 ± 680 in the Italian cohort. Maternal kidney outcomes should be interpreted with caution (>30% missing data): proteinuria (73%) and hypertension (30%) were more frequent in COLA3-5 pregnancies than the Italian cohort. In the ALPART cohort, 10% developed severe hypertension. Median eGFR was not impacted by pregnancy and decline of eGFR before and after pregnancy were not significantly different between groups.

Conclusion

Fetal outcomes in pregnancies with COLA3-5 related disease seem to be more favorable than in a cohort with mixed cause of CKD. In this intermediary analysis, proteinuria levels and frequency of new-onset hypertension in pregnancy are higher. There is no significant eGFR loss during pregnancy or increased eGFR deterioration in the long-term. The differences between COLA3-5 and general CKD pregnancies underscore the importance of investigating pregnancy outcomes in specific kidney disease phenotypes to ensure adequate (pre-) pregnancy counselling and care.