OBESITY IN PREGNANCY FOR UNDERGRADUATES Max Brinsmead MB

OBESITY IN PREGNANCY FOR UNDERGRADUATES Max Brinsmead MB BS Ph. D January 2020

Definition & Incidence BMI > 30 Class 1 obesity = BMI 30 - 35 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

Risks and Complications Increased maternal risk of: Miscarriage Thromboembolism (10 -fold) Gestational diabetes (4 -fold) Pre eclampsia (3 -fold) Dysfunctional labour (1. 3 x 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

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

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 12 w Don’t rely on self estimates of height & weight

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

Gestational Diabetes 75 G GTT recommended for all obese patients at 24 - 28 weeks Manage as per existing guidelines for gestational diabetes Follow up postpartum with GTT at 3 m and annually thereafter screen for cardiovascular risk factors

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

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

Role for Bariatric Surgery In a retrospective case controlled study of 326 women undergoing bariatric surgery in NSW between their 1 st and 2 nd pregnancy (BJOG 2020): Less hypertension (OR=0. 39, CI 0. 29 -53) Fewer spontaneous preterm (OR=0. 37, CI 0. 16 -0. 86) Fewer LGA infants (OR=0. 63, CI 0. 44 -0. 88) Fewer SCN/NICU admissions (OR=0. 64, CI 0. 46 -0. 90) SGA rate was 8. 3% (non significant increase in risk) Rate gestational diabetes 11. 4%

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