In this study, we investigated the incidence, risk factors, and outcomes associated with obesity in parturient women, with a specific emphasis on those who conceived following bariatric surgery (post-BS). Unprecedented in Qatar, this research involved a classification of participants into four groups, leading to six unique comparisons. The study revealed that advanced maternal age, Parity > 1, diabetes, and hypertension were significant risk factors, particularly in the context of post-BS.
Within three vital comparison groups (obese vs. overweight, obese vs. normal, and overweight vs. normal), our findings unequivocally demonstrated a heightened risk of maternal and neonatal adverse outcomes with increasing BMI index [39]. Noteworthy outcomes included gestational diabetes, caesarean deliveries, and labour induction, aligning seamlessly with extensive epidemiological studies and National Institute for Health and Care Excellence (NICE) guidelines for managing obesity in pregnancy [40–42]. Our findings contribute not only to the Qatari context but also provide a valuable benchmark for global discussions on the impact of obesity on pregnancy outcomes.
In the realm of post-BS comparison groups (BS vs. obese, BS vs. overweight, BS vs. normal), a profound reduction in the risk of gestational diabetes among post-BS women stood out prominently. The significance of this reduction was stark when compared to both the obese group with no history of BS and the overweight group with no history of BS. The findings also shed light on a significant reduction in assisted birth among post-BS women, an aspect that has been notably underexplored in existing literature.
Comparing our GDM reduction results with other meta-analyses revealed intriguing nuances. While our estimated reduction in the odds of GDM post-BS (aOR = 0.39, CI: 0.29–0.54, P < 0.001) paralleled some studies, it also showcased variations compared to others [30, 31, 43]. This discrepancy emphasizes the importance of contextual factors and warrants further investigation into the underlying reasons for such variations. Notably, our study identified a paucity of epidemiological investigations on the five other comparison groups, signaling a critical gap in understanding the comprehensive spectrum of outcomes in post-BS women.
In addition, post-BS women showed a significant reduction in assisted birth (4% vs. 9%, aOR = 0.46, CI 0.21–0.99, P < 0.05). Numerous studies proved GDM risk reduction for women who conceived following BS [5, 30, 31, 39, 40, 43–45], however, we identified a shortage of epidemiological studies concerning assisted birth specifically [46].
Despite the evident reduction in GDM risk, our study calls attention to the need for vigilant monitoring of post-BS women for potential complications inadequately mitigated by bariatric surgery. Cesarean delivery and other risks, including term low birth weight, low birth weight, stillbirth, and preterm neonates, demand particular consideration. These results may be due to nutritional deficiency and rapid weight loss [5].
Our findings concur with a substantial body of evidence indicating an increased risk of preterm deliveries, stillbirth, and low birth weight neonates among post-BS women[4, 5, 15, 26, 30, 31, 44, 47–56]. However, the scarcity of studies on low birth weight among term babies underscores the imperative for further investigation. Conflicting results on cesarean delivery [44, 57, 58] highlight the multifaceted nature of this outcome among post-BS women, necessitating extended research to unravel its underlying complexities. These findings indicate the need for extended research on CS and BS complications that are not fully understood and may be related to other factors, such as changes in maternal anatomy, fetal growth patterns, or other severe maternal complications.
Despite the invaluable insights garnered from this study, certain limitations must be acknowledged. The retrospective nature of the study introduces inherent biases and limits the establishment of causal relationships. Additionally, the study's focus on a specific timeframe (2017) might not capture evolving trends or changing demographics. The generalizability of findings beyond the Qatari population warrants cautious interpretation, necessitating further research in diverse settings. However, the study included multinational and multi-ethnic populations which can give indications on other ethnic groups.
The strength of our study lies in its pioneering nature as the first in Qatar to comprehensively examine various risk factors in pregnant women post-BS compared to obese, overweight, and normal-weight counterparts. The detailed examination of multiple comparison groups enriches the existing literature on obesity and pregnancy outcomes.