1. obesITY IN pregnanCY FOR UNDERGRADUATES
Max Brinsmead MB BS PhD
October 2016

2. Definition & Incidence
BMI > 30
Class 1 obesity = BMI
Class 2 " = BMI 35 – 40
Class 3 “ = BMI >40
Also called morbid obesity
Incidence has doubled in the past decade
Now ≈ 20% of patients in first world societies
Most of what follows refers to BMI >35

3. Risks and Complications
Increased maternal risk of:
Miscarriage
Thromboembolism (10-fold)
Gestational diabetes (4-fold)
Pre eclampsia (3-fold)
Dysfunctional labour (1.3x length of labour)
Caesarean section (2-fold)
Wound infection (2-fold)
Anaesthetic complications
Maternal mortality
NB Most studies demonstrate a linear relationship between risk and BMI

4. Risks and Complications (2)
Increased fetal risk of:
Congenital malformation (1.6 fold)
Fetal macrosomia (3-fold)
Shoulder dystocia
Stillbirth (2-fold)
Neonatal death (2-fold)
Neonatal morbidity i.e. NICU admission
Reduced rates of breast feeding

5. Management Recommendations (RCOG)
Optimise weight before pregnancy
Educate & advise all women with BMI>30 to lose weight before conception
Weight loss >4.5 Kg before pregnancy reduces the risk of gestational diabetes by 40%
Dietary Supplementation
Folic acid 5 mg/day for -1 to +3 months of pregnancy
Vitamin D 10 ug/day (? Required for a sun-loving Aussie)
Measure and calculate BMI at first ANV
Preferably before 12w
Don’t rely on self estimates of height & weight
Dietary Advice

6. Management Recommendations (2)
Recommend daily physical activity & reinforce
Provide detailed, accurate and specific pregnancy risk advice to all women with BMI>30
Not suitable for homebirth or Midwife-led care
Discuss & document intrapartum risks and plans management
Induction of delivery only for obstetric indications
Requests for VBAC require individual assessment
IV access in labour if difficulty is expected
Active management third stage
Subcutaneous suture if Caesarean is required
Special education and support for breastfeeding should begin antenatally
Encourage postnatal weight loss and or refer

7. Gestational Diabetes
75G GTT recommended for all obese patients at weeks
Manage as per existing guidelines for gestational diabetes
Follow up postpartum with GTT at 3m and annually thereafter screen for cardiovascular risk factors

8. Pre eclampsia Use the appropriate-sized cuff for BP measures
Consider increased surveillance if there is another risk factor present i.e.
Primigravida
Age >40 years
More than 10 years since the last baby
Family history of preeclampsia
Booking BP >80 diastolic
Multiple pregnancy
Chronic hypertension, thrombophilia, diabetes, renal disease
These patients may benefit from low dose aspirin

9. For Women Whose BMI > 40
Antenatal review by anaesthetist to develop an anaesthetic plan
Plan for manual handling/skin care, TED stockings etc.
Experienced obstetrician & anaesthetist available for labour
Notify both when admitted in labour
Alert theatre for all patients >120 Kg
One to one midwifery care required
Offer postpartum thomboprophylaxis

10. Any Questions or Comments?
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