FFinalistSouthampton · 2027
Obstetrics & gynaecology
AKT · Obstetrics & gynaecology/Antenatal & medicallow yield

Obesity in pregnancy

Maternal BMI ≥30

Overview

Maternal obesity (BMI ≥30) raises risks across pregnancy: gestational diabetes, pre-eclampsia, VTE, macrosomia, shoulder dystocia, caesarean, and anaesthetic/wound complications. Managed with extra surveillance and prophylaxis.

Recognise

  • BMI ≥30 at booking
  • Increased risk of GDM, pre-eclampsia, VTE, fetal macrosomia, difficult delivery
  • Higher rates of caesarean and anaesthetic complications

Red flags

  • Comorbid pre-eclampsia/GDM; VTE

Differentials & how to tell them apart

Other GDM/pre-eclampsia risk factorsobesity is one of several — assess all

Investigations

OGTT (GDM screening), BP/urine surveillance for pre-eclampsia, VTE risk assessment, anaesthetic review if BMI very high.

Management

5 mg folic acid + vitamin D + risk-based aspirin/LMWH

  1. 1Pre-conception/early: 5 mg folic acid, vitamin D, dietary advice; OGTT for GDM.Gate: Aspirin from 12 weeks if obesity PLUS another pre-eclampsia risk factor; LMWH thromboprophylaxis per VTE score
  2. 2Consultant-led care, anaesthetic review, growth surveillance, active management of comorbidities.
High-dose folic acid 5 mg — pre-conception/first trimester (neural tube risk)
Vitamin D supplementation — recommended
Aspirin from 12 weeks — if additional pre-eclampsia risk factors
LMWH thromboprophylaxis — per VTE risk score

Key points

Higher folic acid dose (5 mg) because of increased neural tube defect risk. Obesity compounds multiple other risks — surveillance is the theme.

Monitor & prognosis

Glucose, BP/proteinuria, growth, VTE risk through pregnancy.

Good with proactive surveillance.

Source: RCOG; NICE