Gestation in women with kidney disease: prognosis and management

Reflux nephropathy and the risk of preeclampsia and of other adverse pregnancy-related outcomes: a systematic review and meta-analysis of case series and reports in the new millennium

BACKGROUND

Reflux nephropathy is a common urinary tract malformation, and a substantial cause of morbidity in women of childbearing age. While recent studies provide further new information on pregnancy-related outcomes, their results are heterogeneous and a systematic meta-analysis may help the interpretation. The aim of this review was to analyze pregnancy-related outcomes in the recent literature on reflux nephropathy (2000-2016), to perfect the estimation of risks, and to identify specific research needs.

METHODS

We searched Medline, EMBASE and the Cochrane review databases for the period 2000-2016 (PROSPERO registration no. 42016042713).

SELECTION CRITERIA

all case series and case reports dealing with reflux nephropathy and reporting on at least one pregnancy outcome. Data were extracted from eligible case series (≥ 6 cases). For the outcomes preeclampsia (PE), pregnancy-induced hypertension (PIH), preterm birth, and newborns small for gestational age, we employed as a control group the low-risk pregnancies from a multicenter database including 1418 live-born singletons. Case reports were analyzed narratively.

RESULTS

The search retrieved 2507 papers, of which 7 case series and 4 case reports were retained. The series report on 434 women with 879 pregnancies; no study reported controls. Compared to the low-risk controls, the meta-analysis showed an increased risk of PIH (odds ratio, OR 5.55; confidence interval, CI 3.56-8.66), PE (OR 6.04; CI 2.41-15.13), and all hypertensive disorders combined (OR 10.43; CI 6.90-15.75). No difference was observed in preterm delivery and caesarean sections. A higher incidence of stillbirth was reported in one paper. Conversely, the 4 case reports (on 10 pregnancies) alert us to a potentially severe complication, hydro(uretero)nephrosis with or without infection.

CONCLUSION

Reflux nephropathy is associated with an increased risk of PIH and PE, but not of preterm delivery, suggesting the occurrence of late 'maternal' PE. The finding of a higher incidence of stillbirths in one series requires further analysis. Strict follow-up of these women is needed, in particular in late pregnancy stages, to avoid and manage in particular hypertensive pregnancy complications.

Specific controversies concerning the natural history of renal disease in pregnancy

Whether or not pregnancy adversely affects the natural course of underlying primary renal disease, and whether fetal outcome is influenced by the type of renal disease per se are controversial issues. We retrospectively analyzed the fetal and maternal outcome in 148 women with various, biopsy-proven histological types of primary chronic glomerulonephritis (GN), including IgA GN (52 patients), membranous GN ([MGN] 20 patients), membranoproliferative type 1 GN ([MPGN] 58 patients), focal and segmental glomerulosclerosis ([FSGS] 13 patients), and minimal change nephrotic syndrome ([MCNS] 22 patients), who were pregnant (with a total of 290 pregnancies) after the clinical onset of GN, and in 104 women with reflux nephropathy (with a total of 254 pregnancies). Fetal outcome was poor in the presence of uncontrolled hypertension, nephrotic range proteinuria, and/or impaired renal function at conception or early in gestation, whatever the type of renal disease. An accelerated, more rapid than expected, worsening of maternal renal function was observed in five GN patients of whom four (two IgA, two MPGN) had serum creatinine (Scr) levels greater than 160 mumol/L (1.8 mg/dL) early in gestation, and in five patients with reflux nephropathy whose Scr at conception ranged from 180 to 490 mumol/L (2.0 to 5.5 mg/dL).(ABSTRACT TRUNCATED AT 250 WORDS)

An overview of pregnancy in women with underlying renal disease

This is a report of a retrospective study of the effects of preexisting glomerular disease and pregnancy on each other. Two hundred forty pregnancies in 166 Japanese women who delivered between 1970 and 1988 were analyzed. There were 206 (86%) live births, 14 (6%) perinatal deaths, and 20 (8%) spontaneous abortions. Perinatal loss was greatest in women with hypertension and/or glomerular filtration rate (GFR) less than 70 mL/min before conception. Pregnancy did not appear to adversely affect the underlying glomerular disease if GFR was greater than 70 mL/min and blood pressure was below 140/90 mm Hg. However, with moderately impaired renal function (creatinine greater than 124 mumol/L [1.4 mg/dL] or GFR less than 50 mL/min), the long-term prognosis was poorer, despite generally favorable obstetrical outcomes. Gravidas with membranoproliferative glomerulonephritis had the highest rates of hypertension (29%) and decreased renal function (33%) at final follow-up, ie, the type and severity of glomerulonephritis had a major impact on clinical course.

National High Blood Pressure Education Program Working Group Report on High Blood Pressure in Pregnancy

This consensus report focuses the presentation, pathophysiology, and management of the hypertensive disorders of pregnancy expanding on recommendations first presented in 1988 by the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. Practicing physicians should determine whether a patient's hypertension during pregnancy falls into the classification of (1) chronic hypertension, (2) preeclampsia, (3) preeclampsia superimposed on chronic hypertension, or (4) transient hypertension. The distinction, for management considerations, is made between hypertension that is present before pregnancy (chronic and preexisting) and that occurring as part of the pregnancy-specific condition preeclampsia. When maternal blood pressure reaches diastolic levels of 100 mm Hg or greater, treatment should be instituted to avoid hypertensive vascular damage. The report includes a discussion of antihypertensive therapy specific to the chronic or acute hypertension occurring concomitantly with pregnancy. The roles of calcium supplementation and low-dose aspirin to prevent preeclampsia and chronic and transient hypertension are under investigation.