• Pillar I
• Pillar II
• Pillar III
• Pillar IV

Optimal timing and mode of delivery for women with obesity

Obesity during pregnancy poses a significant risk to both mother and baby and is becoming increasingly prevalent. Clear evidence for optimal maternity care of this population remains elusive. Two key uncertainties that affect pregnancies complicated by obesity are:

1. ideal gestational age for delivery; and
2. ideal mode of delivery for patients.

Elective deliveries, including vaginal delivery following induction of labour and C-section delivery with or without induction of labour, may help to avoid common adverse infant outcomes associated with deliveries among individuals with obesity. However, the inherent risks of elective delivery to both mother and baby must be considered. Induction of labour, particularly in nulliparous women with severe obesity (≥35kg/m²), is often a prolonged process that results in C-sections. Furthermore, the risks of C-section delivery during labour are increased compared to a pre-labour caesarean section.

In this pillar, we are using BORN Ontario registry data to conduct population-based retrospective cohort studies that explore the optimal timing and mode of delivery for women across various categories of obesity and gestational weight gain.

We are also conducting a partially randomized preference trial to determine the optimal mode of delivery for improving health outcomes for individuals with obesity and their babies.

Findings from this pillar will be used to inform development of a large-scale study that will provide definitive evidence on the optimal care for these women and facilitate patient counselling so that an informed decision can be made.