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CONTEXT Pregnancy affects intravenous paracetamol pharmacokinetics, but there are no studies on covariates of intravenous paracetamol pharmacokinetics around delivery. OBJECTIVES To document the impact of gestational age at delivery on pharmacokinetics of a high intravenous dose of paracetamol. DESIGN Pharmacokinetic study in women shortly after caesarean delivery. This study is an alternative analysis of a previously published study, using the same cohort but with added participants. SETTING Single, tertiary perinatal care centre. PATIENTS Of 36 patients recruited, pharmacokinetics analysis was performed in 34. Shortly following caesarean delivery, women received a loading dose (2 g) of intravenous paracetamol and four (at 1, 2, 4 and 6 h) plasma samples were collected. Of these 36 women, 28 had already been reported, but without further discrimination between preterm and term delivery, or any other covariate. Individual pharmacokinetic profiles were calculated assuming a linear one-compartment model with instantaneous input, first-order output. Covariates of between individual variability (preterm vs. term, maternal disease vs. healthy, twin vs. singleton pregnancy) of individual pharmacokinetics within this cohort were explored (Mann-Whitney U-test). MAIN OUTCOME MEASURES Individual paracetamol pharmacokinetics. RESULTS Mean (SD) paracetamol clearance was 22.4 l h(-1) (9.3) or - when corrected for body surface area - 11.5 l h(-1) m(-2) (4.0). No significant effects of twin pregnancy (n = 8) or maternal co-morbidity (n = 3) were observed, but mean clearance after preterm delivery (n = 12