SAN FRANCISCO — Pregnancy soon after bariatric surgery does not appear to pose safety concerns for the mother or newborn, Dr. Tuoc N. Dao reported at the annual meeting of the American Society for Bariatric Surgery.
Surgeons have generally recommended that bariatric surgery patients should not become pregnant until 12–18 months after the procedure because of a perceived risk to the fetus or the woman during the period of large weight loss and limited calorie and nutrient intake following the surgery, said Dr. Dao, a surgical resident at Baylor University Medical Center at Dallas.
Although her review of 24 patients indicated that “the desire for pregnancy should not be a deterrent for Roux-en-Y gastric bypass as a weight-loss procedure,” Dr. Dao and her colleagues continue to recommend that most bariatric surgery patients wait 12–18 months before becoming pregnant “due to the psychological component of trying to undergo all of these changes at one time. Trying to lose weight and deal with a pregnancy at the same time, I think, would be too much for people.”
Several previous studies have not reported any major adverse events or outcomes in women who became pregnant after bariatric surgery.
In a study of 298 deliveries, no adverse perinatal outcomes were reported in women who had restrictive or malabsorptive surgery, although Roux-en-Y gastric bypass (RYGB) was associated with an increased risk of premature rupture of membranes, labor induction, and fetal macrosomia (Am. J. Obstet. Gynecol. 2004;190:1335–40).
A separate review of 18 pregnancies after gastric bypass showed few metabolic problems or deficiencies in vitamin B12 or iron (South. Med. J. 1989;82:1319–20).
In another group of 46 deliveries, four of seven preterm infants were born to mothers who became pregnant within 16 months of their surgery. Pregnancy was safe outside of that time period (Am. Surg. 1982;48:363–5).
Pregnancy during the period of rapid weight loss immediately after surgery can cause deficiencies in iron, folate, calcium, and vitamin B12.
It also has been questioned whether women will be able to lose additional weight post partum during the early postoperative phase.
Fetal and maternal deaths have been reported in a few cases of postoperative small bowel herniations and ischemia, but other reports have recorded good outcomes with early detection and treatment of this complication, Dr. Dao said.
In her review of 2,532 patients who underwent RYGB at Baylor during 2001–2005, 24 became pregnant within 1 year after the surgery.
These patients were 32 years old with a body mass index of 49 kg/m
At the time of delivery, the women were 34 years old and had gained a mean of 0.3 pounds during pregnancy, although this varied widely from losing 70 pounds to gaining 45 pounds.
The patients' mean body mass index dropped from 34 kg/m
Only one patient failed to sustain their excess weight loss.
The 24 women had 26 pregnancies, 2 of which were early miscarriages in women who soon became pregnant again and carried to term. Of three other miscarriages, two occurred in the first trimester and one at a gestational age of 20 weeks.
Another patient had an ectopic pregnancy.
One patient had mild iron deficiency during pregnancy that resolved with iron supplementation.
One patient had symptomatic cholelithiasis and underwent laparoscopic cholecystectomy after the delivery of her baby.
An internal hernia in one patient was detected early and repaired without any incident.
Another patient with a gastrogastric fistula was treated conservatively until her delivery.
Two patients had preterm labor. One patient had preeclampsia and one had mild hypertension that was much improved since her last pregnancy before bariatric surgery.
The 21 babies (including one set of twins) had an average birth weight of 2,874 g. Three neonates, including the twins, had a low birth weight (less than 2,500 g). One infant had intrauterine growth restriction (born to the mother with an internal hernia).
Another infant had intrauterine growth restriction plus a low birth weight (born to the mother with a gastrogastric fistula).
No infants had any congenital or developmental defects.
In five of the women who had pregnancies before their RYGB surgery, there were fewer instances of diabetes, hypertension, and complications during postsurgery pregnancies than in those that occurred before the operation.
Dr. Dao did not know how many of the other patients who received RYGB in the cohort were lost to follow-up, but she said that patients who report pregnancy at clinical visits or on follow-up surveys are interviewed to gather information.