Factors associated with acute kidney injury during delivery or the postpartum period: A case control study

To investigate the incidence of risk factors associated with acute kidney injury(AKI) occurring during the intrapartum or the immediate postpartum period.

A retrospective case control study in a tertiary UK hospital of pregnant women identified with AKI in labour or in the postpartum period between July 2019 and June 2020 was carried out. Women identified with pregnancy related AKI (pr-AKI) in labour or postpartum were compared with a matched cohort of women with no evidence of pr-AKI, using multiple regression analysis.

In 4600 births, 71 women with pr-AKI and 142 control women were identified. The antenatal and intrapartum risk factors strongly associated with pr-AKI were pre-eclampsia, prolonged ruptured membranes, delivery by emergency caesarean section and greater blood loss at delivery (all p < 0.001 in multivariable regression).

Pr-AKI is relatively common, occurring in 1.5 % of our cohort. Women who are overweight, have prolonged rupture of the membranes, an emergency caesarean section and/or a postpartum haemorrhage are at greatest risk. Clinicians should be check renal function before prescribing non-steroidal medication for postpartum pain relief if there are risk factors for AKI.