Results
We approached 105 pregnant women (n=85 with BMI≥30kg/m2 and n=20 with BMI 20-25kg/m2) and of those, 70 obese and 16 normal BMI women agreed to take part. Those who attended at least two out of the three research visits, with known pregnancy outcome, were included in the study which comprised 64 women with BMI≥30kg/m2 and 14 women with normal BMI. All women delivered a live, phenotypically normal neonate. The maternal characteristics and pregnancy outcomes of the study population are given in Table 1. There were no significant differences in the maternal demographic characteristics between the study groups except for maternal booking BMI, as expected.

Haemodynamic function

Compared to the normal BMI group, women with obesity had higher systolic BP, diastolic BP and HR in each trimester and in the overall analysis. Similarly, CO and SV were higher and PVR lower in the obese compared to the normal BMI group, in each trimester and overall (Table 2, Table S1 and Figure 1). SV and CO trended up in both groups with a significant increase in CO from the first to the third trimester (Table S2).