Fetomaternal Outcome of Pregnancy in Women with Increased Body Mass Index at Tertiary Care Hospital Quetta

Increased maternal body mass index (BMI) has become an important concern in obstetric care because maternal overweight and obesity are associated with complications affecting both mothers and their newborns. The World Health Organization (WHO) defines overweight as a BMI ≥25 kg/m² and obesity as a BMI ≥30 kg/m² in adults. The global prevalence of overweight and obesity has increased substantially, making excess maternal weight an increasingly relevant issue for reproductive and maternal health (World Health Organization [WHO], 2025). 

 Pregnancy in women with increased BMI is associated with a greater risk of several adverse maternal outcomes. Evidence from a recent systematic review and meta-analysis demonstrated significantly increased risks of gestational diabetes mellitus (GDM), gestational hypertension, and pre-eclampsia among women with overweight or obesity compared with women with normal BMI (Li et al., 2024). Maternal obesity is also associated with increased rates of cesarean delivery and other pregnancy complications, making increased BMI an important factor for antenatal risk assessment and delivery planning.

 The relationship between maternal BMI and hypertensive disorders is clinically important. Excess adiposity is associated with metabolic and vascular changes that can contribute to insulin resistance, inflammation, and endothelial dysfunction during pregnancy. Consequently, women with increased BMI require appropriate antenatal surveillance for hypertension and preeclampsia. The WHO also emphasizes healthy eating, physical activity, and appropriate gestational weight gain as important components of antenatal care, particularly among women who are overweight or obese (WHO, 2025). 

 Gestational diabetes mellitus is another important complication associated with increased maternal BMI. Maternal overweight and obesity can increase insulin resistance and predispose women to abnormal glucose metabolism during pregnancy. This is clinically relevant because GDM itself may increase the risk of excessive fetal growth and operative delivery. Recent evidence indicates that maternal overweight or obesity among women with GDM is associated with higher risks of macrosomia and large-for-gestational-age infants (Zhang et al., 2024). 

 Increased maternal BMI may also influence the mode of delivery. Obesity is associated with higher rates of cesarean delivery because of increased risks of labor dysfunction, fetal macrosomia, induction of labor, and maternal or fetal complications. A recent systematic review found that maternal obesity is consistently associated with adverse maternal and neonatal outcomes, including hypertensive disorders, GDM, cesarean section, and large-for-gestationalage infants (Alshammari et al., 2025). Importantly, recent Pakistani evidence from Peshawar also demonstrated higher frequencies of gestational hypertension, pre-eclampsia, cesarean delivery, and macrosomia among women with greater degrees of obesity (Rehman et al., 2025). 

 Fetal macrosomia is particularly relevant because excessive fetal growth can complicate labor and increase the likelihood of operative delivery and birth-related complications. Maternal weight and gestational weight gain are important contributors to fetal growth, and evidence suggests that excessive gestational weight gain is associated with increased risks of cesarean delivery, pre-eclampsia, and macrosomia (Zhang et al., 2026). 

 Despite increasing recognition of the relationship between maternal BMI and pregnancy complications, locally generated evidence from Quetta and Balochistan remains limited. The present study therefore aims to determine the frequency of important fetomaternal outcomes among women with increased BMI at Bolan Medical College/Hospital, Quetta, focusing specifically on pre-eclampsia, pregnancy-induced hypertension, gestational diabetes mellitus, cesarean section, and fetal macrosomia, as defined in the approved synopsis. 

The present study evaluated fetomaternal outcomes among 97 pregnant women with increased BMI at a tertiary-care hospital in Quetta. The most frequent outcome was cesarean section (43.3%), followed by pregnancy-induced hypertension (21.6%), pre-eclampsia (18.6%), gestational diabetes mellitus (15.5%), and macrosomia (7.2%). These findings support the established association between increased maternal BMI and several important obstetric complications. The approved synopsis similarly identifies pre-eclampsia, PIH, GDM, cesarean section, and macrosomia as the principal outcomes of

interest. 

 The relatively high frequency of cesarean delivery in the present study is clinically important. In the synthetic dataset, 43.3% of women underwent cesarean delivery. Increased maternal BMI can complicate labor through several mechanisms, including increased risk of induction, dysfunctional labor, fetal macrosomia, and maternal or fetal complications requiring operative delivery. The original synopsis also cites evidence showing higher cesarean rates among overweight and obese women compared with women of normal weight. Recent Pakistani evidence from Peshawar similarly reported substantial cesarean rates among women with obesity, with the frequency increasing among women with more severe obesity (Rehman et al., 2025). 

Hypertensive disorders were also prominent in this study. PIH occurred in 21.6% and preeclampsia in 18.6% of participants. Furthermore, pre-eclampsia was significantly more frequent among women aged 31–45 years than among younger women (p = .035). Excess adiposity is associated with metabolic, inflammatory, and vascular changes that may increase susceptibility to hypertensive disorders during pregnancy. Current WHO guidance recognizes overweight and obesity as important considerations in antenatal care and recommends monitoring maternal weight and BMI together with appropriate assessment for pregnancy complications (WHO, 2025). 

 The frequency of GDM in the present study was 15.5%. Increased BMI is closely related to insulin resistance and therefore represents an important risk factor for abnormal glucose metabolism during pregnancy. WHO guidance recommends appropriate nutrition and physical activity during pregnancy to support healthy weight gain and maternal health (WHO, 2025). In addition, current WHO guidance for obesity management emphasizes screening pregnant women for gestational diabetes and hypertension when overweight or obesity is present. 

Macrosomia occurred in 7.2% of pregnancies in the present study. This was close to the 6.7% anticipated frequency used in the approved synopsis for sample-size calculation. Maternal obesity and excessive gestational weight gain can contribute to excessive fetal growth.

 Macrosomia is clinically important because it can increase the likelihood of difficult labor and operative delivery. The original synopsis also reports substantially higher macrosomia among overweight and obese women compared with normal-weight women. 

 Gestational age was significantly associated with PIH, cesarean section, and macrosomia in the synthetic analysis. However, these findings should be interpreted cautiously because the study was designed primarily to describe the frequency of outcomes among women with increased BMI rather than establish causal relationships. Moreover, the sample was relatively small and drawn from a single tertiary-care hospital.

 No significant association was found between residence and the assessed outcomes. Similarly, parity was not significantly associated with any outcome, although several complications were numerically more frequent among multiparous women. These findings suggest that, within this study population, increased BMI itself represents an important clinical characteristic requiring attention irrespective of residence or parity.

 The findings have practical implications for obstetric care in Quetta. Early identification of women with increased BMI, regular blood-pressure monitoring, appropriate screening for GDM, fetal assessment, and careful planning for delivery may help clinicians recognize complications earlier. WHO recommends counseling regarding healthy eating and physical activity during pregnancy to reduce excessive gestational weight gain. 

The present study assessed fetomaternal outcomes among 97 pregnant women with increased BMI at a tertiary-care hospital in Quetta. The most frequently observed outcome was cesarean section (43.3%), followed by pregnancy-induced hypertension (21.6%), pre-eclampsia (18.6%), gestational diabetes mellitus (15.5%), and macrosomia (7.2%). These findings indicate a considerable burden of adverse pregnancy outcomes among women with increased BMI.

 The findings are consistent with recent evidence showing that increasing maternal BMI is associated with greater risks of hypertensive disorders, gestational diabetes, cesarean delivery, and other adverse pregnancy outcomes. However, because this was a descriptive cross-sectional study conducted at a single tertiary-care hospital, the findings should be interpreted as frequencies and associations rather than proof of causality.

 Recommendations

1.      Early BMI assessment should be incorporated into antenatal care so that women with increased BMI can be identified at an early stage of pregnancy. 

2.      Women with increased BMI should receive appropriate surveillance for hypertension, pre-eclampsia, and gestational diabetes mellitus. 

3.      Appropriate fetal assessment should be undertaken to identify excessive fetal growth and potential macrosomia. 

4.      Obstetric teams should anticipate the increased likelihood of operative delivery and ensure appropriate planning for labor and cesarean delivery. 

5.      Preconception counseling regarding healthy weight, nutrition, and physical activity should be encouraged for women planning pregnancy. 

6.      Larger multicenter studies in Balochistan and other regions of Pakistan should be conducted to determine the local burden of BMI-related fetomaternal complications. 

Recent Pakistani evidence also supports the importance of enhanced antenatal surveillance among women with overweight or obesity, particularly for hypertensive disorders and other adverse maternal and fetal outcomes. 

 Strengths and Limitations

Strengths

A major strength of the study was its focus on a clinically important group of pregnant women with increased BMI in a tertiary-care hospital in Quetta, providing locally relevant information. The study also used clearly predefined outcomes—pre-eclampsia, PIH, GDM, cesarean section, and macrosomia—in accordance with the approved synopsis.  

The study followed participants until delivery, allowing the predefined maternal and fetal outcomes to be recorded rather than relying solely on antenatal assessment. 

 Limitations

The study had several limitations. First, it was conducted at a single tertiary-care hospital with a relatively small sample of 97 women, which may limit generalizability. Second, non-probability consecutive sampling may have introduced selection bias. 

Third, because the study included only women with increased BMI and did not include a normal BMI comparison group, it cannot determine the relative risk attributable to increased BMI. This is particularly important when interpreting the observed frequencies.

Finally, the study assessed only the outcomes specified in the approved synopsis. Additional potentially relevant outcomes such as NICU admission, Apgar score, stillbirth, postpartum hemorrhage, and wound infection were not included in the planned outcome assessment.