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Obesity in Pregnancy

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Obesity in Pregnancy, Overweight in Pregnancy

  • See Also
  1. Weight Gain in Pregnancy
  • Epidemiology
  1. Obesity affects more than one third of women of child bearing age in U.S. (20 to 39 years)
  • Management
  • Weight Gain Guidelines
  1. See Weight Gain in Pregnancy
  2. Precautions
    1. Avoid weight loss (or weight gain below these guidelines)
    2. Even in Obesity, weight loss or inadequate gain is associated with Small for Gestational Age infants
    3. Excessive weight gain above guidelines is associated with Fetal Macrosomia, operative delivery, gestational DM
  3. Overweight at conception (BMI 25 to 29)
    1. Total weight gain: 7 to 11 kg (15 to 25 lb)
    2. Gain 1st trimester: 1 to 2 kg (2 to 4 lb) per month
    3. Gain 2nd/3rd: 0.5 kg (1 lb) per week
  4. Morbidly Overweight at conception (BMI >=30)
    1. Total weight gain: 5 to 9 kg (11 to 20 lb)
    2. Gain 2nd/3rd: 0.22 kg (0.5 lb) per week
  • Management
  • Preconception
  1. Target weight loss of 5-10% before pregnancy
    1. Reduces perinatal complications (see below)
  2. Lifestyle recommendations
    1. Healthy Nutrition with a broad array of nutritious foods
    2. Moderate intensity Exercise 150 minutes/week
    3. Resistance Training
  3. Preconception guidance regarding medications
    1. See Preconception Counseling
    2. See Medications in Pregnancy
    3. Anti-Obesity Medications are contraindicated in pregnancy and Lactation
    4. Prenatal Vitamins with 400 mcg Folic Acid taken when trying to conceive
  • Management
  • First Trimester
  1. Confirm dates with early Ultrasound
    1. Obesity is often associated with Ovulatory Dysfunction (e.g. PCOS)
  2. Medications
    1. Early initiation of Prenatal Vitamins with 400 mcg Folic Acid
  3. Metabolic assessment
    1. Blood Pressure
    2. Obstructive Sleep Apnea screening (e.g. STOP-Bang Questionnaire)
    3. Pregestational Diabetes Screening (e.g. Hemoglobin A1C)
  • Management
  • Second Trimester
  1. Congenital malformation screening (higher risk in Obesity)
    1. Aneuploidy Screening
    2. Cell-Free DNA is often inconclusive in Obesity (increased plasma volume, decreased fetal fraction)
  2. Gestational Diabetes Screening
    1. Glucose Challenge Test (at 24 to 28 weeks)
  • Management
  • Third Trimester
  1. Fetal Macrosomia screening after 32 weeks gestation
    1. May offer cesarean delivery if fetal weight >5000 g (>4500 g if Gestational Diabetes)
  2. Increased Stillbirth risk
    1. Fetal Assessment weekly as of 37 weeks in Class II Obesity (as of 34 weeks in Class III Obesity)
  3. Intrapartum
    1. Obesity is NOT an indication for early induction <39 weeks
    2. First stage of active labor may be 2 hours longer for Class III Obesity
    3. Early epidural placement if desired (allows for emergent cesarean delivery)
  • Management
  • Postpartum
  1. Observe for infectious complications of operative delivery
    1. Endometritis
    2. Wound dehiscence and infections
  2. Venous Thromboembolism prophylaxis following cesarean delivery
    1. Early mobilization or
    2. Pneumatic compression device or
    3. LMWH for up to 6 weeks postpartum
  3. Lactation Counseling
    1. Encourage Lactation and provide support
    2. Lower rates of continued Breast Feeding in Obesity
  4. Contraception
    1. Caution with Oral Contraceptives (VTE Risk)
    2. Caution with Contraceptive Patch (lower efficacy in BMI >30 kg/m2)
  5. Screen for Postpartum Depression
    1. Class III Obesity is associated with Postpartum Depression rates as high as 40%
  • Complications
  • Adverse Pregnancy and Neonatal Outcomes Related to Obesity
  1. Spontaneous Abortion
  2. Congenital Anomaly
  3. Gestational Diabetes
  4. Hypertensive Disorders of Pregnancy
  5. Stillbirth (esp. BMI >=40 kg/m2 at which RR 3)
  6. Prolonged labor times
  7. Cesarean Delivery
  8. Postpartum Hemorrhage
  • References
  1. (2021) Obstet Gynecol 137(6):e128-e144 +PMID: 34011890 [PubMed]
  2. McKenna (2026) Am Fam Physician 113(3): 208-9