Background <p>Early CKD may affect pregnancy outcomes, but identifying women at most risk remains challenging. We aimed to understand the predictive role of clinical parameters in early-mid pregnancy in women with early stage CKD.</p> Methods <p>Women with CKD stage 1–3 with a pregnancy &gt; 20&#xa0;weeks gestation between 2018 and 2023 were evaluated for ‘red flag’ markers previously linked with risk of adverse pregnancy outcomes: failure of ≥ 10% fall in serum creatinine; urinary protein: creatinine ratio (uPCR) ≥ 30&#xa0;mg/mmol in second trimester; lack of physiological fall in blood pressure by mid-pregnancy. The relationship between these red flags and a composite adverse pregnancy outcome of gestational age &lt; 37&#xa0;weeks, birth weight &lt; 2500&#xa0;g and pre-eclampsia was determined.</p> Results <p>Of 38 mothers with 47 deliveries, 72% of pregnancies were in women with stage 1 CKD, 38% had hypertension and 19% had pre-eclampsia. Infants had median birth weight 2895&#xa0;g (IQR: 2460–3170) and median gestational age 37.3&#xa0;weeks (IQR 35.8–38). Serum creatinine did not fall ≥ 10% in 66% (<i>n</i> = 27/41) of women, uPCR was ≥ 30&#xa0;mg/mmol in 69% (<i>n</i> = 24/35) and blood pressure did not fall in 73% (<i>n</i> = 24/33). Eighty-six percent had one or more ‘red flags’. The composite adverse pregnancy outcome occurred in 49% (<i>n</i> = 22/45). Women exhibiting any early-mid pregnancy red flags did not have increased rates of composite adverse pregnancy outcome (no creatinine fall, composite adverse pregnancy outcome <i>n</i> = 15, <i>p</i> = 0.176; proteinuria <i>n</i> = 15, composite adverse pregnancy outcome <i>p</i> = 0.066; no blood pressure fall, composite adverse pregnancy outcome <i>n</i> = 12, <i>p</i> = 1.00).</p> Conclusions <p>The high rate of composite adverse pregnancy outcome in early stage CKD was not associated with traditional mid-pregnancy red flags. Best models of care for this cohort remain uncertain.</p> Graphical abstract <p></p>