Trajectories of Fetal Adipose Tissue Thickness in Pregnancies After Gastric Bypass Surgery

Abstract

Purpose Recent studies showed that women after surgery are at higher risk of delivering small-for-gestational infants. Thus, this study aims to investigate longitudinal changes of fetal subcutaneous adipose tissue thickness (FSCTT) of fetuses conceived after gastric bypass surgery as compared to BMI-matched controls. Methods Retrospective cohort study measuring ultrasound-derived longitudinal trajectories of abdominal FSCTT in 41 singleton pregnancies after gastric bypass surgery compared to 41 BMI-matched controls and 64 obese mothers.Results FSCTT was significantly lower in fetuses of women after GB as compared to BMI-matched controls in the second (mean difference 1.38 mm, p < 0.001) and third trimester of gestation (mean difference 3.37 mm, p < 0.001). Longitudinal analysis revealed significant differences in mean FSCTT trajectories between offspring's in GB mothers, BMI-matched, or obese controls. The ratio of FSCTT and abdominal circumference remained constant in the BMI-matched control group whereas it significantly decreased in fetuses of women after GB. Despite remarkable differences were observed in longitudinally assessed FSCTT, further analyses in the GB subgroup revealed that FSCTT were not influenced by OGTT mean or 120 min glucose values, biochemically hypoglycemia, time since bariatric surgery, or weight loss since surgery. Conclusion In fetuses of mothers with history of bariatric surgery, abdominal FSCTT was markedly reduced. While the underlying mechanisms are not fully understood, a multifactorial genesis including nutritional deficiencies and altered metabolism after bariatric surgery is assumed.

Fetal Growth and Adipose Fat Tissue Trajectories in Twin Pregnancies after Gastric Bypass Surgery

“…However, the growth pattern of other fetal growth parameters in this study, such as the AC, showed only marginal differences. This is in contrast to previous observations but may be a consequence of the lower sample size in this very special study population [5,6]. While a causal relationship between glycemic alterations and fetal development is obvious, we are convinced that the intrauterine growth restriction in twins in women with history of GB surgery is more complex and subject to other additional processes as it is for singletons.…”

“…Longitudinal assessment of ultrasound-derived FSCTT was performed retrospectively from the second trimester onward after recalibration of the image. For that purpose, the abdominal circumference level (AC) has been used for all measurements since it is a standardized cutting plane (according to ISUOG guidelines) [13], for unification and therefore having a continuity and equality within the measurements as reported in our previous study [6] with measure points of FSCTT (measured in millimeters [mm] between the outer and inner margin of the echogenic subcutaneous tissue after magnifying the area of interest) on (i) the anterior abdominal wall in front of the intrahepatic tract of the umbilical vein, (ii) on the left side next to the stomach, and (iii) on the exact opposite right side of the abdomen. Medical records were used to collect data on BMI before pregnancy or before bariatric surgery and time between operation and pregnancy.…”

“…In this context, we demonstrated in previous studies a continuous decline in fetal growth throughout singleton pregnancy after bariatric surgery [5] and second a markedly decline of fetal subcutaneous adipose tissue thickness (FSCTT) of fetuses of mothers with a history of bariatric surgery [6]. Although the pathophysiological mechanisms remain unclear, it is believed that fetal growth restriction and low FSCTT are more likely caused by nutrient deficiency and by multifactorial genesis with altered metabolism as the most important factor, rather than by growth restriction due to placenta etiology or preeclampsia (PE) [7].…”

Maternal overweight and obesity and its association with metabolic changes and fetal overgrowth in the absence of gestational diabetes mellitus: A prospective cohort study

“…Fetal subcutaneous tissue thickness was measured in millimeters at the level of the abdominal plane at three different points after magnification of the region of interest, from the outer to the inner margin of the echogenic fetal subcutaneous tissue: (i) at the level of the left lateral abdominal wall near the stomach, (ii) at the level of the right lateral abdominal wall symmetrically to the left side caliper, (iii) anterior as near as possible to the umbilical vein entrance into the abdomen. For the analysis, we considered the mean value of the three measurements for each fetus if available 15 …”

“…For the analysis, we considered the mean value of the three measurements for each fetus if available. 15 …”