The Impact of Maternal Ketonuria on Fetal Test Results in Patients with Post-term Pregnancy

Background: Post-term pregnancy is currently defined as a pregnancy progressing to ≥42 weeks (294 days) of gestation. It is associated with increased risk of maternal and fetal complications. Ketonuria in the context of post-term pregnancy is associated with an increased risk of maternal and fetal outcomes.

Aim of the study: The objective of this study was to assess the effect of maternal ketonuria on fetal surveillance outcomes, specifically non-stress test (NST) and biophysical profile (BPP) results, in post-term pregnant women

Patients and methods: The current cross-sectional study was conducted in the Obstetrics and Gynecology Department at Al-Diwaniyah Maternity and Pediatric Teaching Hospital, Iraq, between February 2024 and September 2024. The study enrolled 50 pregnant women with post-term pregnancy, with an age range between 18 and 40 years old. Urine was collected (3-5ml) in a clean, dry container and transported to the laboratory within 30 minutes. The dipstick was dipped for 1–2 seconds in urine, and the color of the strip was then compared to the color chart on the strip container approximately1 minute after immersion.

Results: Ketonuria was detected in 15 women (30.0%). Of these, 8 (16.0%) had mild (+), 3 (6.0%) moderate (++), and 4 (8.0%) severe (+++) ketonuria. Significant differences were observed in non-stress test (NST) reactivity (reactive, p = 0.002; non-reactive, p = 0.001), while equivocal results were not significant (p = 1.000). Intrapartum decelerations occurred more frequently in women with ketonuria compared to those without (40.0% vs. 11.4%). The relative risk (RR) of decelerations in ketonuric women was 3.51 (95% CI: 1.05–11.7, p = 0.048). No significant associations were found between ketonuria and liquor color (RR = 1.26, 95% CI: 0.57–2.77, p = 0.558) or Doppler findings (RR = 1.00, 95% CI: 0.29–3.44, p = 1.000).

Conclusion: Ketonuria was seen in 30% of post-term women and was associated with significantly worse non-stress test (NST) and biophysical profile (BPP) results, but not with liquor color or Doppler findings. Routine ketonuria screening may help identify high-risk fetuses in prolonged pregnancies.