Description of the condition

Obesity is associated with poor health. Maternal obesity (defined as a body mass index (BMI) of equal to or greater than 30 in pregnancy), especially extreme obesity (BMI of equal to or greater than 50), is associated with higher rates of adverse pregnancy outcomes including gestational diabetes (odds ratio (OR) for extremely obese 15.7, 95% confidence interval (CI) 4.75 to 51.8) (CMACE 2010; CMACE 2011; Knight 2010), hypertensive disorders (OR 7.35, 95% CI 3.07 to 17.6 for nulliparous women with extreme obesity) (CMACE 2010; CMACE 2011; Knight 2010), reduced mobility and thromboembolism (CMACE 2010; CMACE 2011), delivery by caesarean section (OR 3.50, 95% CI 2.72 to 4.51) (CMACE 2010; Knight 2010; Usha Kiran 2005), postpartum haemorrhage (OR 1.5, 95% CI 1.2 to 1.8) (CMACE 2010; CMACE 2011; Usha Kiran 2005), fetal macrosomia (birthweight greater than 4.5 kg) (OR 5.23, 95% CI 2.81 to 9.74) (Knight 2010; Usha Kiran 2005), congenital malformations (including neural tube defects (OR 1.87, 95% CI 1.62 to 2.15), cardiovascular abnormalities (OR 1.30, 95% CI 1.12 to 1.51), and orofacial clefts (OR 1.20, 95% CI 1.03 to 1.40) (Stothard 2009), stillbirth (Salihu 2011) and maternal mortality (CMACE 2011). It has been reported that limiting gestational weight gain to less than 15 lb (approximately 7 kg) might reduce the incidence of adverse outcomes (Guelinckx 2009; Jensen 2005; Kiel 2007), but the evidence supporting this is not conclusive (Dodd 2010), and any limitation of gestational weight gain has to be balanced against the potential harms.

Description of the intervention

LAGB is a well‐established treatment for extreme obesity (Colquitt 2009) with proven safety and efficacy in achieving significant weight loss and improved health (Chapman 2004). The procedure involves laparoscopic placement of an adjustable band containing a fluid‐filled balloon around the upper portion of the stomach. This band acts to reduce stomach capacity, by creating a small upper stomach pouch and limiting passage of food into the lower digestive portion of the stomach, resulting in early satiation; aiding weight loss by reducing food intake. The volume of the balloon can be adjusted by addition or removal of fluid through a subdermal port positioned at the time of surgery. In this way nutritional intake, and thus body weight, can be influenced. Potential maternal and perinatal benefits of limiting weight gain in pregnancy have to be set against theoretical risks of leaving the balloon inflated. The reduction in nutritional intake from an inflated gastric band balloon might have adverse consequences. In general, reduced nutritional intake and low maternal weight gain are known to be associated with lower birthweight (OR 1.66, 95% CI 1.44 to 1.92) (Guelinckx 2009; Stotland 2006; Strauss 1999), and preterm labour (although this was a more significant finding in underweight ((OR 6.7, 95% CI 1.1 to 40.6) and normal‐weight (OR 3.6, 95% CI 1.6 to 8.0) women than overweight women (OR 1.6, 95% CI 0.7 to 3.5)) (Schieve 2000). Similarly, a systematic review did not find limiting gestational weight gain to be associated with small‐for‐gestational age in obese and overweight women (Siega‐Riz 2009). Recognised complications of LAGB also include gastric perforation, gastric necrosis, gastric prolapse, band leakage, and band migration and slippage (Chevallier 2004; Forsell 1999). The incidence of band migration and slippage of the band is increased in pregnancy because of raised intra‐abdominal pressure (Guelinckx 2009). Band migration often presents with nausea and vomiting and as these are common in normal early pregnancy, so band migration might go unrecognised initially, resulting in avoidable significant maternal morbidity. For these reasons, many advocate routine deflation of the band balloon at the beginning of pregnancy, but this might later result in excessive maternal weight gain and its associated complications, such as pregnancy complications (hypertensive disorders, gestational diabetes) (OR 2.10, 95% CI 1.74 to 2.54), caesarean delivery (OR 1.29, 95% CI 1.09 to 1.54) and increased birthweight (weight difference 206.45 g, 95% CI 178.82 to 234.08) (Mamun 2011).

Because of the controversy over appropriate gestational weight gain and concerns over band complications, management of gastric bands in pregnancy is inconsistent. Some clinicians advocate deflation of the gastric band balloon for the entire pregnancy allowing sufficient intake of nutrients to allow for fetal growth and development and potentially reducing the risk of band complications. This might, however, result in excessive gestational weight gain (defined by Institute of Medicine 2009 as 20 lbs or 9 kg for obese women) and its associated complications (Mamun 2011). Others promote a policy of leaving the balloon inflated for the duration of pregnancy with deflation only if significant complications such as band migration or severe nausea and vomiting occur (Lapolla 2010; Sheiner 2009). Another approach that has been employed is to deflate the balloon in the early part of pregnancy with re‐inflation at the beginning of the second or third trimesters (Dixon 2001), or selective adjustment of the balloon according to tolerance and gestational weight gain (Carelli 2011; Dixon 2005; Martin 2000; Skull 2004; Weiss 2001). These approaches might reduce the risk of aggravating symptoms of nausea and vomiting in early pregnancy and allow sufficient intake of crucial micronutrients during organogenesis, and yet still limit excessive gestational weight gain and its associated complications in later pregnancy.

How the intervention might work

Leaving the balloon deflated throughout pregnancy would allow sufficient intake of nutrients for maternal and fetal health while potentially reducing the rate of nausea and vomiting and more serious complications such as band slippage and nutritional deficiencies.

Maintaining inflation of the balloon for the duration of pregnancy might limit gestational weight gain (Carelli 2011), and so reduce adverse maternal and perinatal outcomes (CMACE 2010).

Why it is important to do this review

With the growing prevalence of obesity, the incidence of pregnant women who have undergone LAGB procedures is increasing (Maggard 2008). Currently, no guidance exists for maternity healthcare workers on how best to manage gastric bands to achieve optimum maternal and neonatal outcomes (Maggard 2008).