OBESITY PROTOCOL (BMI > 30)

BACKGROUND

The incidence of obesity continues to increase (now 35+% overall) with the percentage of reproductive age women having a BMI > 30 now being approximately 25%. Obesity increases the risk of many obstetrical complications such as miscarriage, gestational diabetes, preeclampsia, venous thromboembolism, induced labor, slow progression of labor, cesarean section, anesthesia problems, fetal anomalies, stillbirth, postpartum hemorrhage, wound complications, macrosomia, wound infection, and NICU admissions/neonatal death. These risks appear increase as the BMI increases. Most of the data appears to be based on the BMI at booking/intake. However, there is some data showing that the risk may be determined by the BMI at delivery. The definition of obesity is as follows

Overweight: 25.0 to < 30.0

Class 1 obesity: 30.0 to < 35.0

Class 2 obesity: 35.0 to < 40.0

Class 3 obesity: 40.0 and above

ANTEPARTUM CARE

  1. Discuss pre-conception folate, 5 mg/day, at least 1 month prior to conception and continue through the 1st trimester since these women are at an increased of having a child with an anomaly, specifically NTD. Women who are obese are less likely to take supplements/vitamins and usually have a less healthy diet. Also their serum folate levels are lower. Odds ratio of NTD based on BMI is 1.22 for BMI 27-30, 1.70 for 30 to 40, and 3. 11 if > 40. Compare this to OR of for someone having a prior affected child
  2. Vitamin D levels are also significantly lower in obese patients. Consider checking vitamin D levels or empirically treating with Vitamin D at 1000 IU (25 ug)/day
  3. Discuss weight gain and individualize based on BMI from recommendations of the IOM
  4. The risk of issues appears to increase when initial BMI is 40. For these patients
  5. Strongly consider antepartum anesthesia consult given the high risk of multiple attempts at epidural along with the high failure rate and more complications with general anesthesia
  6. Discuss low dose aspirin if obese and any other risk factor
  7. Screening HgA1c at intake with appropriate follow up testing based on this number. If normal and no other risk factors, screen at 24-28 weeks
  8. Early ultrasound to confirm dates given the higher incidence of irregular periods / anovulation in this subset of patients
  9. Anatomy scan at 20 weeks
  10. Due to the poor correlation of fundal height to EFW, monthly ultrasounds starting at 28 weeks until delivery
  11. The risk of IUFD is increased in obese patients compared to non-obese with that risk directly related to BMI. Consider fetal testing if any other risk factors present
  12. If BMI exceeds 40, unclear if patient is a candidate for midwifery/family medicine care. This should prompt a consult with OB or MFM to review for possible other risk factors which may then require transfer of care
  13. Success with TOLAC is reduced with all levels of obesity and risk of uterine rupture increases when BMI exceeds 40. Counsel appropriately!!!!

INTRAPARTUM CARE

  1. Need to have appropriate equipment to allow for laboring and operating on these patients (appropriate OR table, hovercrafts ?, sky cranes ?, MD anesthesia if BMI exceeds 40
  2. Risk of pulmonary thromboembolism in patients with BMI > 30 is 2.65. All patients should receive have sequential compression devices. If there is obesity with BMI 30 – 40, along with 2 other risk factors, patient should receive pharmacological thromboprophylaxis. If the BMI is > 40.0, patient should receive pharmacological thromboprophylaxis regardless of mode of delivery and continue for 1 week
  3. Low transverse skin incision is the prefer incision for cesarean section. There is less blood loss, greater chance of a low transverse uterine incision, better outcomes in future pregnancies with less risk of uterine rupture.