INCREASED FETOPLACENTAL ANGIOGENESIS DURING FIRST-TRIMESTER IN ANEMICWOMEN

Background epidemiological studies describe an association between rel ative size of the placenta at delivery and cardiovascular morbidity an d mortality during adult life. Some determinants of placental size, su ch as maternal anaemia, have been acknowledged, but no plausible mecha nism has been advanced to explain the initial of postnatal disease. Me thods Placental villous vascularisation in anaemic women (Hb<90 g/L) w as assessed in the first and third trimesters of pregnancy by immunohi stochemical identification bf villous capillaries and compared with th at of gestational age-matched groups of women with normal (Hb>110 g/L; control group) concentrations of haemoglobin, and an intermediate gro up (Hb 90-110 g/L). Findings Anaemia, especially in the first trimeste r, was associated with increased numbers of capillaries per villous cr oss section (mean 11.70 [SE 0.35] vs 4.14 [0.27]) located mainly in th e outer third of the stroma beneath the trophoblast (94% [1.15] vs 67% [1.82]) and with increased numbers of villous macrophages and of prol iferating MIB-1-positive cells compared with the control group. Interp retation Maternal anaemia in early pregnancy seems to influence the pa ttern of placental vascularisation. Such changes might alter placental vascular impedance during early fetal life, thereby exerting importan t effects on cardiovascular development.