To the Editor: A 33-year-old woman, who had borne five children and had had previous caesarean sections, presented in her eighth pregnancy with worsening malabsorption after biliopancreatic diversion for morbid obesity, performed 3 years earlier. Before surgery, she had weighed about 130 kg (height,161 cm; body mass index [BMI], 46 kg/m2); she had gradually reduced her weight to 67 kg.

Her surgery had created intestinal malabsorption resulting from the intestinal bypass and from dietary restriction because of gastroplasty. The physiological stress associated with pregnancy worsened her anaemia from protein and vitamin deficiencies, especially fat-soluble vitamins and calcium. She required frequent hospitalisation for intravenous fluids to compensate for dehydration from vomiting and diarrhoea. She was taking oral iron, folate, vitamin D, a calcium supplement, vitamin B12, and having vitamin K injections. Her total weight gain in pregnancy was poor (from 71 kg to 74 kg).

At 32 weeks she presented with premature labour and a persistent low fetal baseline heart rate of 90 beats per minute and an unstable lie. She had an emergency caesarean section and delivered a baby boy with a birth weight of 2095 g (average for gestational age). Apgar scores were 7 and 8 at 1 and 5 minutes, respectively; the baby required ventilation for hyaline membrane disease and phototherapy for jaundice, although his blood profile was normal. His clinical course thereafter was uneventful.

Obesity (BMI > 30 kg/m2), has become the epidemic of the 21st century, with one in two Australian women being overweight or obese. 1 Morbid obesity (BMI > 40kg/m2) is associated with a 6–12-fold increase in mortality.2

A multifaceted approach is essential for treatment in all patients with obesity, but unfortunately, medical treatment mostly produces short-term weight loss. Thus, bariatric surgery is being performed more frequently.

Biliopancreatic diversion has two components:

• a limited gastrectomy results in reduction of oral intake, inducing weight loss, especially during the first postoperative year; and

• the construction of a long limb Roux-en-Y anastomosis with a short common “alimentary” channel of 50 cm length, which maintains weight loss long term.

Scopinaro, who pioneered this technique, has published long-term results reporting 72% excess body weight loss maintained for 18 years.3 He documented 239 pregnancies in 1136 patients who had undergone biliopancreatic diversion, 25% of whom had been infertile before the operation. During pregnancy, 20% required parenteral nutrition and had fetuses that were small for gestation age. The women had a mean weight gain of 6 kg during their pregnancies, and 80 % delivered babies at term with a mean birth weight of 2.8 kg. 4

From the patient’s perspective, the great advantage of biliopancreatic diversion is the ability to eat a normal diet and still achieve excellent, long-term weight loss. The most serious potential complication is protein malnutrition, with a need to take supplemental calcium and vitamins, particularly vitamin D, lifelong. Because of this potential for significant complications, patients who have had biliopancreatic diversion require lifelong follow-up and pregnancy should be avoided. Ideally this operation should be performed in women who have completed their childbearing.