Objective: Maternal lifestyle factors are potential predictors of pregnancy complications. We examined relations between modifiable factors and delivery complications.
Design: Prospective cohort.
Setting: University hospital antenatal clinic, Oslo, Norway.
Sample: A cohort of 553 women followed through pregnancy and delivery.
Main outcome measures: Pre-specified birth complications: cesarean section (CS), operative vaginal deliveries (VDs), third and fourth degree of perineal lacerations and hemorrhage (> or =1,000 ml).
Methods: Univariate and multiple logistic regression analyses were performed. Besides high birthweight (> or =4,200 g), modifiable predictors (high body mass index (BMI), fasting glucose and physical inactivity) and non-modifiable predictors (parity, maternal age, gestational age, and gender) were considered.
Results: Significant predictors for induction of labor were parity (odds ratio (OR): 2.1; 95% CI 1.3-3.5), maternal age (OR: 2.0; 1.2-3.4), gestational age (OR: 1.9; 1.1-3.1), and BMI > or =30 (OR: 4.2; 2.2-7.8, p<0.01). High birthweight and high BMI were overrepresented among CSs. Emergency CS was associated with birthweight (OR: 3.7; 1.7-8.1), parity (OR: 3.5; 1.7-7.2), maternal age (OR: 2.6; 1.3-5.3), and induction of labor (OR: 4.8; 2.6-9.1). After excluding CS, operative VD was associated with parity (OR: 8.7; 3.8-20) and gender (OR: 2.2; 1.2-14.1). Perineal laceration was associated with pre-gestational physical inactivity (OR: 6.1; 1.6-22.9) and operative VD (OR: 5.1; 1.5-17.6). Hemorrhage was associated with high birthweight (OR: 4.2; 1.2-4.7) and BMI > or =30 (OR: 4.6; 1.2-17.7).
Conclusions: Pre-gestational physical inactivity increased the risk of perineal lacerations and male infants were associated with higher risk of vaginal operative delivery.