We have read with great interest the study by Chevrot et al, which assesses pregnancy outcomes after bariatric surgery (BS), with emphasis on birthweight and the different BS techniques (malabsorptive and restrictive procedures). The authors report a significant reduction in gestational diabetes (GDM) and large-for-gestational-age neonates (LGA) and an overall increase in small-for-gestational-age neonates (SGA).

Galazis et al, in a recent meta-analysis investigating pregnancy outcomes after BS involving 166,134 participants, concluded that, after BS, the incidence of GDM and LGA is halved whereas that of SGA is increased by 80%. Furthermore, the incidence of preeclampsia was decreased significantly after BS compared with obese or body mass index−matched pregnant women. The lack of statistical significance in regard to gestational hypertension/preeclampsia in Chevrot et al is likely a result of the small sample size in their study (139 in the intervention group).

The meta-analysis by Galazis et al also demonstrated that the incidence of SGA was not increased when adjustable gastric banding (a restrictive procedure) was performed compared with obese or body mass index−matched pregnant women with no history of BS. Therefore, the increase of SGA seen after BS is likely to reflect fetal malnutrition secondary to microenvironment nutritional deficiencies associated with the malabsorptive procedures. The authors have suggested that restrictive, rather than malabsorptive, procedures should be preferred in young women planning to have children. This important finding is confirmed by Chevrot et al, who found no significant difference in the incidence of SGA in women who underwent restrictive BS compared with controls (no surgery).

The incidence of obesity is reaching epidemic proportions, with 1 in 3 pregnant women being overweight or obese at the booking antenatal appointment in the United Kingdom. It is thus imperative to assess pregnancy outcomes after BS. So far, the benefits of BS in regard to preeclampsia, GDM, and LGA have been well established. The study by Chevrot et al is valuable because it confirms that restrictive procedures have the aforementioned beneficial effects and, very importantly, do not increase the incidence of SGA, an important drawback of BS, which is associated with significant neonatal and long-term adverse outcomes.

Overall, the findings of Chevrot et al should be regarded as a valuable working document for the growing number of health care professionals (obstetricians, bariatric surgeons, nutritionists, and midwives) involved in the care of obese pregnant women (preconceptually and during pregnancy) and stimulate the development of relevant guidelines.