Pregnancy after bariatric surgery for obesity

ACOG Issues Guidelines on Managing Obesity in Pregnancy CME/CE

News Author: Laurie Barclay, MD
CME Author: Désirée Lie, MD, MSEd

June 9, 2009 — 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 issue of Obstetrics & Gynecology.

"Obesity is associated with reduced fertility primarily as a result of oligo-ovulation and anovulation," write Michelle A. Kominiarek, MD, and colleagues from the ACOG. "The increased risks for gestational diabetes, preeclampsia, cesarean delivery, and infectious morbidity associated with obesity are well established....Obese patients are more likely to be admitted earlier in labor, need labor induction, require more oxytocin, and have longer labor."

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.
"As the rate of obesity increases, it is becoming more common for providers of women's health care to encounter patients who are either contemplating or have had operative procedures for weight loss, also known as bariatric surgery," the guidelines authors write. "The counseling and management of patients who become pregnant after bariatric surgery can be complex. Although pregnancy outcomes generally have been favorable after bariatric surgery, nutritional and surgical complications can occur and some of these complications can result in adverse perinatal outcomes."

Obstet Gynecol. 2009;113:1405-1413.

Clinical Context

Obesity is associated with adverse outcomes of pregnancy, and the incidence in reproductive-age women has increased in the United States by 70% from 1994 to 2003. Bariatric surgery is the most effective treatment of morbid obesity for improvement of comorbidities and quality of life but has consequences for subsequent pregnancy.

This is a review of the risks associated with obesity and recommendations on care of pregnant women who have previously undergone bariatric surgery.


Study Highlights

Increased maternal body mass index increases the risk for stillbirth by 2.1 to 4.3 times and increases the risk for gestational diabetes, preeclampsia, cesarean delivery, and infectious morbidity but not the risk for preterm delivery.

Bariatric surgery is available to women with a body mass index of 40 kg/m2 or higher or 35 kg/m2 or higher and other comorbidities.

The procedure may have restrictive and malabsorptive effects.
The number of bariatric procedures per year has increased from 12,480 in 1998 to 113,500 in 2005, and 80% are performed in women, with one half of them performed in women with a mean age of 40 years.
Operative complications of bariatric surgery include anastomotic leaks, bowel obstructions, internal or ventral hernias, band erosion, and band migration; all gastrointestinal tract problems occurring after surgery should be evaluated for these complications.
Dumping syndrome with associated nausea, weight loss, cramps, bloating, and distension may occur.
Rapid weight loss follows bariatric surgery with improvement in fertility, but bariatric surgery is not considered a treatment of infertility.
Women undergoing bariatric surgery are more likely to have had previous cesarean delivery (15.4% vs 10.5%; P = .006), gestational diabetes (9.4% vs 5.0%; P < .001), preeclampsia, and given birth via cesarean delivery (25.2% vs 12.2%; P < .001).

After bariatric surgery, the risk for hypertension, pregestational diabetes, gestational diabetes, and preeclampsia is reduced.
Although the risk for premature rupture of membranes is increased after bariatric surgery, the risk for preterm delivery is not increased.
Some authorities recommend waiting 12 to 24 months after bariatric surgery before conceiving to minimize exposure of the fetus to rapid maternal weight loss.
Should pregnancy occur before this timeframe, closer surveillance of nutritional status is recommended.

The rate of congenital anomalies and perinatal death after bariatric surgery is not increased.
After bariatric surgery, there is a lower rate of large-for-gestational-age infants and macrosomia.
The ACOG recommends the following for women after bariatric surgery:
Contraceptive counseling is important especially for adolescents because pregnancy rates double after bariatric surgery.
Nonoral administration of hormonal contraception should be considered because of a higher failure rate with oral contraception because of malabsorption.
Medications may not be well absorbed, and testing for therapeutic levels may be indicated.
During pregnancy, there should be a high index of suspicion for gastrointestinal tract symptoms being complications of the bariatric surgery.
Counseling for weight gain and nutrition should be offered during pregnancy.
Because of dumping syndrome, an alternate method to the 50-g glucose load to screen for gestational diabetes should be considered.
Bariatric surgery is not an indication for cesarean delivery, although the rate of cesarean delivery may be as high as 62%.
There is no consensus on management of pregnant patients who have had an adjustable gastric banding procedure, but early consultation with a bariatric surgeon is recommended.
Nutrition consultation is recommended because of macronutrient and micronutrient effects of surgery because of malabsorption.
An evaluation for micronutrient deficiencies at the beginning of pregnancy should be considered.

Clinical Implications

Bariatric surgery is associated with a reduced risk for preeclampsia, hypertension, pregestational and gestational diabetes, and an increased incidence of cesarean delivery in pregnant women.
In pregnant women with a history of bariatric surgery, some of the ACOG recommendations include: contraceptive counseling for adolescents, prenatal care assessment for nutritional deficiencies, and non-oral administration of hormonal contraception.