Atrial natriuretic factor in amniotic fluid and in maternal venous blood of pregnancies with fetal cardiac malformations and chromosomal abnormalities

Abstract

Objective: We evaluated the levels of atrial natriuretic factor (ANF) in amniotic fluid and in maternal venous blood in pregnancies with fetal cardiac malformations and chromosomal abnormalities.Method: Between the 16th and 18th week of pregnancy, 151 women were divided into three groups. Group A included patients at lowest risk, carrying a fetus with a normally developing heart andnormal karyotype (control group). Group B included women with a fetus suffering from cardiac malformations, with or without associated chromosomal abnormalities. Group C included women carrying a fetusaffected with chromosomal abnormalities without congenital cardiopathies. ANF was evaluated by radioimmunoassay.Results: In maternal venous blood, the mean levels of ANF were 42.1, 53.1 and38.7 pg/ml in groups A, B and C, respectively. In amniotic fluid, the mean levels of ANF were 34.2, 101.8 and 35.8 pg/ml in groups A, B and C, respectively. In group A (control group) there was no statisticaldifference in ANF levels across the gestational age range of 16-18 weeks, either in amniotic fluid or in maternal venous blood. A significant difference of ANF content in maternal venous blood was revealedin comparing group A with group B (p < 0.01), and group C with group B (p < 0.01). A statistically significant difference in ANF levels was also found in amniotic fluid between groupA and group B (p < 0.01), and between group C and group B (p < 0.01). No statistically significant differences were found between group C and group A in comparing ANF levels in maternalvenous blood and amniotic fluid.Conclusion: ANF levels in amniotic fluid and in maternal venous blood are increased early in the case of fetuses with cardiac malformations, with or without associatedkaryotype alteration. Chromosomally abnormal fetuses without heart malformations have normal ANF levels. These results could be useful for elucidating fetal pathophysiology mechanisms.