Aim: Obesity is a risk factor for many adverse pregnancy outcomes, and bariatric surgery (BS) is an effective treatment option for obesity. This study assessed whether BS reduces obesity-related adverse outcomes in women diagnosed with gestational diabetes mellitus (GDM) by comparing pregnancy outcomes between women with a prior history of BS and women with elevated body mass index (BMI) but without undergoing BS.
Method: A retrospective cohort study on women with GDM delivered between 2016 and 2021 at Liverpool Hospital (NSW, Australia) was conducted. A total of 29 women had previously undergone BS, and 655 women with a pre-pregnancy BMI≥35kg/m2 who had not undergone BS were the control. Pregnancy outcomes were analysed and compared between the two groups.
Results: Women in the BS group were older and had lower BMI compared to the control group. Approximately 72.4% of bariatric women tolerated the 75g-oral glucose tolerance test (OGTT). Mean HbA1c at screening and fasting blood glucose levels (BGL) on OGTT were significantly lower in the BS group compared to control. BS group had higher 1-hour BGL but lower 2-hour BGL on OGTT; more bariatric women had 2-hour BGL<4.0mmol/L than the control group. During pregnancy, women from both groups had comparable weight gain and there was no difference in the need for insulin therapy. However, newborns born to BS group had lower birthweight; there was also a trend towards fewer large-for-gestational-age neonates, but more small-for-gestational-age neonates when compared to control. There was no statistically significant difference in other pregnancy outcomes between the two groups.
Conclusions: Compared to women with elevated BMI who had not undergone BS, women with GDM after BS had more favourable diabetic measures and gave birth to lower birthweight neonates. Other obesity-related outcomes were comparable between the two groups.
|
Outcomes |
BS(n=29)* |
Control(n=655)* |
P value |
|
Maternal age(years) |
33.8±4.6 |
31.2±5.6 |
0.016 |
|
Pre-pregnancy BMI(kg/m2) |
34.1±7.0 |
40.9±5.2 |
<0.001 |
|
OGTT:fasting BGL(mmol/L) |
4.8±0.6 |
5.4±0.7 |
<0.001 |
|
OGTT:1-hour BGL(mmol/L) |
11.6±1.2 |
9.7±1.9 |
<0.001 |
|
OGTT:2-hour BGL(mmol/L) |
6.1±2.3 |
7.3±1.7 |
<0.001 |
|
2-hour BGL<4.0mmol/L on OGTT |
6(28.6) |
8(1.4) |
<0.001 |
|
HbA1c(%) |
5.2±0.4 |
5.4±0.5 |
0.018 |
|
Insulin requirement |
13(44.8) |
391(60.3) |
0.096 |
|
Metformin requirement |
5(17.2) |
131(20.2) |
0.701 |
|
Gestational weight gain(kg) |
11.5±9.4 |
9.3±9.7 |
0.269 |
|
Hypertension |
1(3.4) |
82(12.6) |
0.140 |
|
Pre-eclampsia |
1(3.4) |
32(6.4) |
0.605 |
|
Caesarean delivery |
8(27.6) |
257(41.4) |
0.139 |
|
Preterm delivery |
3(10.3) |
75(12.0) |
0.784 |
|
Birthweight(g) |
3195.2±523.9 |
3470.3±611.3 |
0.018 |
|
Birthweight<2500g |
4(13.8) |
33(5.3) |
0.056 |
|
Birthweight>4000g |
1(3.4) |
103(16.7) |
0.058 |
|
Neonatal intensive unit admission |
4(13.8) |
115(18.6) |
0.511 |
|
Neonatal hypoglycaemia |
4(13.8) |
110(17.9) |
0.573 |
|
Intrauterine/neonatal death |
0 |
5(0.8) |
0.627 |
*Data are presented as Mean±SD/frequency(%).