Signiicantly impaired renal function is accompanied by subfertility that may be corrected with chronic renal replacement therapy-either hemodialysis or peritoneal dialysis (Hladunewich, 2016b; Shahir, 2013). Not unexpectedly, these pregnancies can be complicated. In one review of 131 cases, mean fetal birthweights were higher in women who conceived while undergoing dialysis-1530 g versus 1245 g-than in women who conceived before starting dialysis (Chou, 2008). his was also true for 77 pregnancies described by J esudason and coworkers (2014). Similar outcomes from several reports are shown in Table 53-5.
Outcomes are similar with either hemodialysis or peritoneal dialysis. hus, for the woman already undergoing either method, it seems reasonable to continue that method with consideration for its increasing frequency. In the woman who has never been dialyzed, the threshold for initiation during pregnancy is unclear. Lindheimer and colleagues (2007a) recommend dialysis when serum creatinine levels are between 5 and 7 mg/ dL. Because it is imperative to avoid abrupt volume changes that cause hypotension, dialysis frequency may be extended to five to six times weekly (Reddy, 2007).
Certain protocols emphasize attention to replacement of substances lost through dialysis Qim, 2016). Multivitamin doses are doubled, and calcium and iron salts are provided along with suicient dietary protein and calories. Chronic anemia is treated with erythropoietin. To meet pregnancy changes, extra calcium is added to the dialysate along with less bicarbonate.
Maternal complications are common and include severe hypertension, placental abruption, heart ailure, and sepsis. In a review of 90 pregnancies in 78 women, as well as those shown in Table 53-5, high incidences of maternal hypertension and anemia, preterm and growth-restricted infants, stillbirths, and hydramnios were reported (Piccoli, 2010b).
Previously termed acute renal ailure, acute kidney injury (AKI) is now used to describe suddenly impaired kidney function with retention of nitrogenous and other waste products normally excreted by the kidneys (W aikar, 2015). Severe AKI associated with pregnancy is less frequent today. For example, in a 6-year period, the overall incidence at the Mayo Clinic was 0.4 percent (Gurrieri, 2012). It is even less common for women who require dialysis-1 case per 10,000 births (Hildebrand, 2015). But, it still occasionally causes signiicant obstetrical morbidity, and women who require acute dialysis have increased maternal mortality rates (Kuklina, 2009; Van Hook, 2014). Outcomes are available from four older studies comprising a total of 266 women with renal failure (Drakeley, 2002; Nzerue, 1998; Sibai, 1990; Turney, 1989). Nearly 70 percent had preeclampsia, 50 percent had obstetrical hemorrhage, and 30 percent had a placental abruption. Almost 20 percent required dialysis, and the maternal mortality rate was 15 percent.