Bariatric surgery to manage obesity continues to increase. In Australia, bariatric procedures doubled between 2005 and 2015 with 80% performed on women of child bearing age [1]. Pregnancy following bariatric surgery is associated with mixed maternal and fetal outcomes. Lower rates of hypertensive disorders (HDP) and gestational diabetes (GDM) but higher rates of small for gestational age (SGA) infants and pre-term delivery are reported predominantly from women with previous roux-en-y gastric bypass [2]. Limited data are available regarding pregnancy outcomes after laparoscopic sleeve gastrectomy. This data-linkage project analysed the pregnancy and neonatal outcomes of women who delivered between 2013-2018 following bariatric surgery, against matched controls within Queensland, Australia.
A statewide hospital and perinatal data register linked cohort matched study was performed. In total, 2,018 births in 1,677 women with prior maternal bariatric surgery were registered in the Queensland Hospital Admitted Patient Data Collection and matched with deliveries during 2013-2018 in the Perinatal Data Collection. The first pregnancy following bariatric surgery for each woman was used for analysis. Women were excluded if BMI was missing or if bariatric surgery procedures had been reversed, revised or ambiguously coded. Only singleton pregnancies were included. A total of n=1282 cases and n=12820 controls were analyzed matched on BMI, smoking, age and parity. Continuous variables were analyzed using paired t-tests and categorical variables were analyzed using the Chi-square or Fishers exact test.
Of 1282 women with a singleton delivery after bariatric surgery, 89% had undergone laparoscopic sleeve gastrectomy. In women with previous bariatric surgery, the proportion of assisted reproductive technology use was higher (10.7% vs 8.0%, p<0.001), proportion of preterm birth (<37 weeks) were higher (10.5% vs 7.8%), absolute birthweight was lower (3223g ± 605g vs 3418g ± 595g; p<0.001), lower percent of large for gestational age (LGA) (8.6% vs 14.1%; p<0.001) and higher rates of SGA infants (10.7% vs 7.3%; p<0.001) than in matched women. Percent of GDM and HDP were lower in women with previous bariatric surgery (15% vs 20%; p<0.001) and (4% vs 5%; p=0.01). There were no other differences between groups.
Screening methods for GDM following surgery are not evidence-based which may contribute to lower numbers of women being appropriately identified. Our results suggest that pregnancy outcomes following maternal bariatric surgery differ from matched controls in a cohort of women with primarily gastric sleeve surgery.