Women with a booking body mass index of 50 kg/m² or higher face higher risks of severe pregnancy complications, Cureus reported.
A retrospective clinical audit at Luton and Dunstable Hospital examined 124 patients who delivered between January 2025 and June 2026, comparing outcomes evenly across four distinct weight categories.
The facility evaluated 31 women from each body mass index bracket. The cohorts spanned normal weight individuals at 18.5 to 29.9 kg/m², moderately increased levels at 30 to 39.9 kg/m², severely elevated measures at 40 to 49.9 kg/m², and extreme cases at 50 kg/m² and above. Bedfordshire Hospitals NHS Foundation Trust oversaw the project as a local service evaluation.
Patients in the highest bracket recorded a 32.3 percent rate for gestational diabetes mellitus. That compares with 29 percent for the 40 to 49.9 kg/m² group, 12.9 percent for moderately increased cases, and 9.7 percent for normal weight participants. Pre-eclampsia reached 19.3 percent among patients with a body mass index of 50 or greater.
Chronic hypertension similarly concentrated in the extreme group at 12.9 percent. Researchers said that current smokers comprised 16.1 percent of the highest weight cohort. Mean booking measurements reached 55.9 kg/m² for the top tier, compared to 42.6 kg/m², 33.6 kg/m², and 24.1 kg/m² for the remaining groups.
Gestational diabetes appeared proportionally highest among South Asian, Asian, and Middle Eastern participants at 28.6 percent. Black and Black African-Caribbean patients experienced a 26.7 percent rate for the condition. White British individuals recorded 17.9 percent, while European participants showed 11.1 percent.
Pre-eclampsia clustered heavily among Black and Black African-Caribbean individuals at 20 percent. White British patients experienced a 7.1 percent rate. South Asian, Asian, and Middle Eastern participants recorded 5.7 percent, and European individuals showed 5.6 percent.
Caesarean births occurred in 67.7 percent of deliveries within the highest body mass index category. Induction of labour peaked in the 40 to 49.9 kg/m² group at 35.5 percent. Elective procedures contributed substantially to overall surgical deliveries in the top two weight brackets.
Postpartum haemorrhage exceeding 500 millilitres affected 61.2 percent of patients in the extreme weight tier. Wound infections reached 9.7 percent for that same group. No blood transfusions or venous thromboembolism events occurred across the entire cohort.
Large-for-gestational-age infants accounted for 16.1 percent of births in the extreme category.
Neonatal unit admissions reached 19.4 percent for infants born to mothers with a body mass index of 50 or higher. Specialist and joint-care referrals covered extreme weight participants.
Researchers said that surgical delivery rates were multifactorial rather than tied to weight alone. Primary indications included previous uterine scars, failed inductions, foetal heart rate concerns, and malpresentation.
The project was strictly a descriptive local audit without inferential statistical testing or adjustment for confounders. Authors said that larger prospective trials are required to confirm these observations.
The hospital evaluated 124 maternity records divided evenly into four cohorts of 31 participants. Data collection ran from January 2025 to June 2026.
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