Inflammation is associated with poor pregnancy outcomes. There is a much higher prevalence of chronic infections among Indigenous populations compared with non-Indigenous people. We aimed to investigate if maternal inflammation and infection assessed during pregnancy were associated with prematurity and birth weight in a cohort of Indigenous Australian women participating in the Gomeroi gaaynggal research program. The effects of cigarette smoke (measured as cotinine levels) and chronic inflammation (assessed as levels of C reactive protein; CRP) were determined in relation to gestational age at birth and birth weight.
Serum cotinine was detected in 75% of the mothers. Also CRP levels were ≥ 3 mg L1 in 75% of women. They were positively associated with pre-pregnancy BMI (P < 0.001). Compared with non-Indigenous women of child-bearing age, our cohort had 10 times the prevalence of antibodies to H. pylori (33% v. 3%).
For all infants (male and female) serum cotinine levels were negatively associated with birth weight (BW, r = -0.39, P < 0.001) and gestational age at delivery (GA, r = -0.212, P= 0.016). For male infants, cotinine was negatively associated with both BW (P = 0.001) and GA at birth (P = 0.005) but there was no association with CRP. For female infants, cotinine was negatively associated with BW (P = 0.017) but not GA. CRP was negatively associated with GA (P < 0.001) but not BW. Linear multiple regression found that cotinine, CRP and GA at delivery were associated with birth weight (model: r = 0.688, P=0.045).
These data highlight the importance of putting programs in place to reduce cigarette smoke exposure in pregnancy and to treat women with recurring chronic infections such as H. pylori in order to improve pregnancy outcomes.