Women who undergo gastric bypass surgery for weight loss have a higher risk of delivering dangerously underweight babies.
The operation is thought to be one of the only effective ways for people with severe obesity to lose weight and stay trim.
It involves ‘stapling’ together the stomach to divide it in two, re-routing food past most of the stomach so less is digested.
But despite its benefits, the procedure is also associated with vitamin and mineral deficiencies, as it reduces the body’s ability to absorb micronutrients.
And this is likely the reason for new research showing bariatric surgery patients are more likely to deliver babies 1lb lighter than average.
Women who undergo gastric bypasses are more likely to give birth to babies 1lb lighter
The paper by France’s University Hospital of Angers was presented on Friday at the 55th Annual European Society for Paediatric Endocrinology Meeting.
The findings could lead to different advice and clinical care for pregnant women who have undergone gastric bypass surgery.
‘Maternal obesity can lead to health conditions for the newborn, such as high birth weight and low blood sugar,’ says Maxime Gerard, lead researcher of the study.
‘It can also cause birthing complications, and gastric bypass can prevent these.
‘But our study showed that gastric bypass could have other effects on newborns.’
Women treated with gastric bypass surgery are advised to wait 18 months after the procedure before trying to become pregnant in order to establish a stable, healthy weight.
They must also follow a daily multivitamin supplementation regime and receive regular clinical follow up before, during and after the pregnancy.
Despite these precautions, a team of clinical researchers found that the birth-weight of babies born to gastric bypass mothers was on average 0.7lb lower than average, and that 23 per cent of neonates were small for their gestational age.
The team studied 56 newborns born to gastric bypass mothers who had waited an average of 32 months between surgery and pregnancy, and compared results to 56 controls.
They saw that, despite supplementation, a proportion of gastric bypass mothers were deficient in key nutrients during pregnancy, such as calcium and zinc.
The operation involves ‘stapling’ together the stomach to divide it in two, re-routing food past most of the stomach so less is digested
Analysis of the newborns showed that they also suffered lower than average levels of the same nutrients.
‘These maternal nutrient deficiencies may be the reason for the same deficiencies and low birth weights seen in the newborns,’ continues Gerard.
‘One of our next steps will be to confirm this and determine its impact.’
The team also analysed newborn birth weight in relation to the mothers’ weight, and determined that birth weight was related to the variation in the mother’s weight between the surgery and pregnancy, rather than her weight during pregnancy.
Only preliminary findings were presented, and as the study continues the team’s next key step is to determine if low birth weights have long term consequences for the children in the study.
They would also like to establish optimal nutritional supplementation for mothers who have undergone gastric bypass surgery, to ensure they do not suffer from nutritional deficiencies during pregnancy.