The American College of Obstetricians and Gynecologists (ACOG) has issued a practice bulletin to summarize the risks for obesity in pregnancy and outcomes of pregnancy after bariatric surgery as well as to provide recommendations for management during pregnancy and delivery after bariatric surgery. The new guidelines are published in the June 2009 issue of Obstetrics & Gynecology.
To identify pertinent articles published in the English language between January 1975 and November 2008, the guidelines authors searched the MEDLINE database, the Cochrane Library, and ACOG's own internal resources and documents. The reviewers gave priority to articles reporting findings from original research and also consulted review articles and commentaries, but they did not consider abstracts of research presented at symposia and scientific conferences. Using the method outlined by the US Preventive Services Task Force, the reviewers evaluated the identified studies for methodologic quality.
Recommendations from professional societies including ACOG and the National Institutes of Health were also reviewed. Reference lists from identified articles were used to help identify additional studies. When reliable research findings were not available, the reviewers used expert opinions from obstetrician-gynecologists as a basis for their recommendations.
Specific conclusions and clinical recommendations based on limited or inconsistent scientific evidence (level B) are as follows:
- Because pregnancy rates after bariatric surgery in adolescents are twice that in the general adolescent population, contraceptive counseling is especially important in these patients.
- Administration of hormonal contraception by nonoral routes should be considered in patients with a significant malabsorption component after bariatric surgery because these patients have an increased risk for oral contraception failure.
- Testing drug levels may be necessary for medications in which a therapeutic drug level is critical to ensure a therapeutic effect.
Specific conclusions and clinical recommendations based primarily on consensus and expert opinion (level C) are as follows:
- There should be a high index of suspicion for gastrointestinal tract surgical complications when pregnant women who have had bariatric procedures present with significant abdominal symptoms.
- Bariatric surgery should not be performed with the intention of treating infertility, although fertility may improve in association with rapid postoperative weight loss.
- Bariatric surgery in and of itself does not mandate cesarean delivery, although the rate of cesarean delivery in these patients may approach 62%.
- Despite the lack of consensus regarding the treatment of pregnant patients who have had an adjustable gastric banding procedure, it is suggested that these patients have early consultation with a bariatric surgeon.
- For patients who have had bariatric surgery that may be associated with malabsorption and/or dumping syndrome, alternative testing for gestational diabetes should be considered.
- After conception, consultation with a nutritionist may facilitate adherence to dietary regimens and allow the patient to cope with the physiologic changes of pregnancy.
- For women who have had bariatric surgery, a wide-spectrum assessment for micronutrient deficiencies should be considered at the beginning of pregnancy.
- As a proposed performance measure, the guidelines authors suggest documentation of counseling regarding weight gain and nutrition in pregnancy.
Additional points made by the authors of the practice bulletin include the following:
- Specific complications of obesity in pregnancy include doubling to quadrupling of the risk for stillbirth.
- Waiting 12 to 24 months after bariatric surgery before conceiving may be helpful to avoid exposing the fetus to an environment of rapid maternal weight loss and to allow the patient to achieve full weight loss goals.
- If pregnancy occurs earlier than 12 to 24 months after bariatric surgery, closer surveillance of maternal weight and nutritional status, including ultrasound for serial monitoring of fetal growth, may be beneficial and should be considered.
- After bariatric surgery, there is a reduced risk for hypertension, pregestational diabetes, gestational diabetes, and preeclampsia, as well as of large-for-gestational-age infants and macrosomia.
- After bariatric surgery, the risk for premature rupture of membranes is increased, but the risk for preterm delivery, congenital anomalies, and perinatal death is not increased.