Circulating levels of adiponectin and leptin at 23-25 weeks of pregnancy in women with impaired placentation and in those with established fetal growth restriction.

Adiponectin and leptin, two adipose-tissue-derived proteins, have been reported to be elevated in women with established PE (pre-eclampsia). The aim of the present study was to investigate whether alterations in adiponectin and leptin levels predate the development of PE and FGR (fetal growth restriction) in women at increased risk of these complications, as assessed by Doppler examination of the uterine arteries during the second trimester of pregnancy. We also sought to investigate the circulating levels of adiponectin and leptin in women with established severe early-onset FGR. The study included three groups of pregnant women at 23-25 weeks: Group A (n=44) with normal uterine artery Doppler waveforms, Group B (n=49) with abnormal Doppler waveforms and normal fetal growth at the time of the examination, and Group C (n=15) with established severe FGR and abnormal Doppler waveforms. All women had plasma adiponectin and leptin measured by sensitive immunoassays. In Group B, 19 women had a normal outcome, 17 delivered infants with FGR and 13 developed PE. The women who developed PE delivered smaller babies earlier than women with a normal outcome (P<0.001). There were no significant differences in adiponectin levels between any of the groups (overall P=0.3). Leptin concentrations, expressed as MoM (multiples of the median) of Group A, were higher in women in Group C, i.e. established severe FGR at 2.5 (1.2-2.7) MoMs (overall P<0.001), compared with all of the other groups and subgroups. In conclusion, we found that, in pregnancies complicated by severe early-onset FGR, the maternal plasma concentration of leptin is twice as high as in normal pregnancies. However, the second trimester levels of maternal plasma adiponectin and leptin in pregnancies that subsequently develop PE and/or FGR are not significantly different from normal and, consequently, it is unlikely that these markers will be useful as predictors of these pregnancy complications.