Women who become pregnant after bariatric surgery should experience fewer complications and adverse outcomes than if they had remained obese if managed appropriately, according to experts.

“There's more risk for obese patients who become pregnant than for pregnant patients who've had bariatric surgery and lost weight,” said Dr. Jacques S. Abramowicz, codirector of the fetal and neonatal medicine program, professor of obstetrics and gynecology, and director of ob.gyn. ultrasound at Rush University Medical Center in Chicago.

“Once women have had the bariatric surgery, as long as they make an effort to wait the recommended year before getting pregnant, we are more than happy to take care of them,” agreed Dr. Laura Riley, director of labor and delivery at Massachusetts General Hospital and a high-risk obstetrician.

Dr. Riley chaired the committee that wrote the American College of Obstetricians and Gynecologists Committee Opinion (#315) on Obesity in Pregnancy in 2005. It recommends that women wait 12–18 months after bariatric surgery before conceiving to allow time for weight loss and postsurgical adjustment, she said in an interview (see box).

“I do a fair number of prepregnancy consultations, and I've seen many women who at 6 months after bariatric surgery are not ready to become pregnant because they haven't yet gotten the full effect of the surgery, so their obesity-related risks are essentially the same as before the surgery,” Dr. Riley said.

Also, it takes time to figure out which foods and how much of them they can eat. “It's important to allow time for surgical healing,” she said.

Nutritional issues are acute in the early postsurgical phase, but this risk is never eliminated entirely, Dr. Abramowicz said in an interview: “Both malabsorptive and restrictive bariatric surgery can cause deficiencies in folic acid, iron, vitamin B₁₂, and calcium—so supplementation and nutritional counseling are important.” The greatest risk lies with unintended pregnancies, he said. “If it's a planned pregnancy, [the women] can take supplements from the start, but what happens often, if they are not warned, is that—because they lose so much weight—their fertility returns unexpectedly, and they become pregnant but do not realize it because they are used to irregular cycles.”

At least one study suggests “patient and physician anxiety over poor outcome of pregnancy during the first year can be allayed” (Am. J. Surg. 2006;192:762–6). A retrospective review of 21 pregnancies conceived within 1 year of bariatric surgery and 13 conceived after 1 year found “no significant episodes of malnutrition, adverse fetal outcomes, or intrauterine growth retardation” in either group. However, compared with the group that conceived later, patients in the early group did have a significantly higher miscarriage rate (24% vs. 0%), which was also higher than the 15%–20% incidence seen in the general population, noted Dr. Tuoc N. Dao and colleagues from the department of surgery at Baylor University Medical Center in Dallas.

Studies on post-bariatric surgery pregnancies are sparse in the obstetric literature, but in one comparison of all pregnancies with (298) and without (158,912) a history of bariatric surgery between 1998 and 2002 at Soroka University Medical Center, Beer-Sheva, Israel, Dr. Eyal Sheiner and colleagues found no association between the surgery and adverse perinatal outcomes (Am. J. Obstet. Gynecol. 2004;190:1335–40).

Dr. Abramowicz participated in a subsequent study with Dr. Sheiner, which included pregnancies with gestational diabetes from the first study, comparing 28 pregnancies with a history of bariatric surgery with 7,986 pregnancies without such a history. “Perinatal outcome was comparable between the groups, and no significant differences were noted with regard to complications such as perinatal mortality, congenital malformations, and low Apgar scores at 1 and 5 minutes,” they wrote (Am. J. Obstet. Gynecol. 2006;194:431–5).

A government report released in January shows a ninefold increase from 1998 to 2004 in the number of bariatric surgeries performed in the United States (from 13,386 to 121,055). “We're doing a better job of making women aware of the extreme pregnancy complications if they are obese—and they are turning to bariatric surgery more than they did in the past,” said Dr. Riley.

Four Points to Reinforce

The ACOG Committee Opinion #315 on Obesity in Pregnancy recommends that women who have undergone bariatric surgery require the following counseling before and during pregnancy:

▸ Patients with adjustable gastric banding should be advised that they are at risk of becoming pregnant unexpectedly after weight loss following surgery.

▸ All patients are advised to delay pregnancy for 12–18 months after surgery to avoid pregnancy during the rapid weight-loss phase.

▸ Women with a gastric band should be monitored by their general surgeons during pregnancy because adjustment of the band may be necessary.

▸ Patients should be evaluated for nutritional deficiencies and vitamin supplementation when necessary.

Managed Properly, Postbariatric Pregnancy Is Safe