Is it Dangerous for the Bariatric Surgical Patient to Conceive?

Cynthia Buffington, Ph.D.

Beyond Change, January 2004

Recently, several of our bariatric patients were asked to be guests on a talk show to discuss their personal experiences with gastric bypass surgery (which the host incorrectly referred to as  ‘stomach stapling’). As often happens, the host had preconceived notions concerning the risks of obesity surgery. One statement the host made was that it was his understanding a woman should not become pregnant after having bariatric surgery because it is extremely dangerous to do so. 

Is this statement true? Should a woman who has had a bariatric surgical procedure avoid becoming pregnant? Does bariatric surgery increase the incidence of maternal complications or have adverse effects on the health and well-being of the child? What are the maternal/fetal risks of the morbidly obese before, as compared to after, weight loss surgery? 

Studies have found that obesity - even mild obesity – substantially increases the risk for maternal complications and poor pregnancy outcomes  (see references 1-6 below). The obese as compared to the normal weight female has a much higher risk during pregnancy of developing gestational diabetes, pre-eclampsia, and genital and urinary tract infections. The obese female also has an increased risk for blood clots and pulmonary emboli (blood clots that break loose from the veins and lodge in major vessels of the lungs with serious and, sometimes, deadly consequences).

Labor abnormalities and post-delivery hemorrhage are more common with obesity, as is the need for cesarean delivery. Furthermore, during and following cesarean section, the obese woman is more likely to develop complications. Studies have reported that obesity lengthens surgical time, is associated with greater blood loss, a higher risk for developing blood clots or pulmonary emboli, and a greater incidence of post-surgical infection.

In addition to maternal complications, obesity also adversely affects pregnancy outcome. Maternal obesity increases the risk for miscarriage, stillbirths, pre-term deliveries, and neural tube defects. And, obese women are more likely to have large infants who, according to studies, will be at increased risk for subsequent childhood obesity and its deleterious health consequences.

Are obesity-associated maternal/fetal complications improved with weight loss surgery? Do bariatric procedures cause surgery-specific complications that can endanger the health or well-being of mother or child?

Most studies have found that neither the mother nor child are unduly endangered by pregnancy following bariatric surgery (5-9, 13, 15-16). In fact, studies that have examined complication rates of pregnancies of morbidly obese patients before and after bariatric surgery have found significant reductions in maternal risks (5-7)  – significant reductions in rates of gestational diabetes, pre-eclampsia, infections, blood clots, and other complications. Pregnancy outcomes are also substantially improved with bariatric surgery – more pregnancies are carried full-term, most delivers are vaginal instead of cesarean, and the incidence of large infants is substantially lowered. 

If studies have found that bariatric surgery is highly beneficial in reducing pregnancy risks, where does the notion come from that pregnancy after bariatric surgery is dangerous?

An earlier surgery, the jejunoileal bypass, was associated with low birth weight infants and metabolic problems (10). Such problems occurred because of the severe vitamin and mineral deficiencies that this particular procedure caused. The jejunoileal bypass, however, has since been abandoned and replaced by far safer and more effective surgeries, including the gastric bypass, the duodenal switch, the adjustable gastric band and vertical banded gastroplasty.

A few isolated cases of nutrient deficiencies occurring with pregnancy following these surgical procedures have been reported (11-14).  Maternal iron deficiency anemia requiring additional iron therapy has been reported following gastric bypass, without harm to the infant (11). An increased risk for neural tube defects, presumably due to a folate deficiency, has also been reported with gastric bypass (12-13). And, in another case, a 10-month old male infant who was exclusively breastfed developed a vitamin B12 deficiency from the mother who unknowingly had a B12 deficit (14). 

The anatomy of the gastric bypass procedure is such that an individual has an increased risk of developing iron, vitamin B12, folate, and possibly other vitamin deficits. However, the risk of such nutrient deficits is resolved or substantially reduced if the bariatric patient adheres to the daily post-operative vitamin and mineral supplement regimen recommended by their surgeon and nutritional staff before pregnancy and if they continue to follow this regimen during pregnancy IN ADDITION to taking prenatal vitamins.  

The greatest risk for nutrient deficits following gastric bypass or any other bariatric procedure occurs during the rapid weight loss period when calorie intake is low (6,13). Because of the high risk for nutrient deficits during this period, it is strongly RECOMMENDED that an individual NOT BECOME PREGNANT for at least one year after surgery. The concerns are: 1) the baby will be unhealthy in this relatively semi-starvation state, 2) the mother will suffer nutrient deficits from the additional nutrients her body will require to support the developing fetus, and 3) early pregnancy will reduce the long-term weight loss success of the surgery. 

Although it is certainly NOT advisable for a bariatric patient to become pregnant during the first postoperative year, there are studies showing that gastric bypass patients, as well as individuals having had gastric restrictive surgeries (the adjustable band), who conceived during the first postoperative year gave birth to infants that were as healthy as those who conceived later (15-16). Nonetheless, to become pregnant within the first postoperative year is not advisable and can increase the risk for maternal and fetal nutrient deficiencies and associated adverse health consequences.

Was the talk show host correct in stating that ‘it is dangerous for women who have had baritaric surgery to become pregnant’. Absolutely not!

Pregnancy complications and fetal risks are significantly and dramatically reduced in women who have had weight loss surgery. There are a few isolated case reports of nutrient deficiencies adversely affecting maternal health or fetal well-being. However, the risk for nutrient deficits during pregnancy are low if the bariatric patient: 1) avoids becoming pregnant during the first postoperative year, 2) adheres to their daily bariatric vitamin and mineral supplement regimen before, during and following pregnancy, 3) takes, in addition to their regular vitamins and minerals, the prenatal vitamins prescribed by their obstetrician, and 4) eats healthfully and does not attempt to diet or lose weight during the gestational period (6, 13).

For more information regarding nutrient management during pregnancy for bariatric patients, see the article by the bariatric nutritionist, Sally Myers, entitled ‘Pregnancy after Roux-en-Y Gastric Bypass’ in the November 2003 issue of
Beyond Change. 

References:

• Lu GC et al.  Am J Obstet Gynecol 2001; 185:845-9.

• Sebire NJ, et al.  Int J Obes Relat Metabol 2110; 25:1175-82.

• Norman RJ and AM Clark.  Reprod Fertil Dev 1998; 10:55-63.

• Baeten JM et al.  Am J Public Health 2001;91:436-40.

• Deitel M et al.  J Am Coll Nutr 1988; 7:147-53.

• Wittgrove AC, et al.  Obes Surg; 1998; 8:461-4.

• Richards DS et al.  J Reprod Med 1987; 32:172-6.

• Bilenka B et al.  Acta Obstet Gynecol Scand 1995; 74:42-4.

• Printen KJ  and  D Scott.   Am Surg 1982; 48:363-5.

• Knudsen LB and B Kallen.   Acta Obstet Gynecol Scand 1986; 65:831-4.

• Gurewitsch ED et al.  Obstet Gynecol 1996; 88:658-61.

• Martin L et al.  Lancet 1988; 1:640-1.

• Deitel M.  Obes Surg 1998; 8:465

• Grange DK and JL Finlay.   Pediatr Hematol Oncol 1994; 11:311-8.

• Rand  CS, Macgregor AM.  S Med J  1989;  82:1319-20.

• Martin LF et al.  Obstet Gynecol 2000; 95:927-30.