Second Trimester Amniotic Fluid Angiotensinogen Levels Linked to Increased Fetal Birth Weight and Shorter Gestational Age in Term Pregnancies

Dionysios Vrachnis; Alexandros Fotiou; Aimilia Mantzou; Vasilios Pergialiotis; Panagiotis Antsaklis; George Valsamakis; Sofoklis Stavros; Nikolaos Machairiotis; Christos Iavazzo; Christina Kanaka-Gantenbein; George Mastorakos; Petros Drakakis; Nikolaos Vrachnis; Nikolaos Antonakopoulos

doi:10.3390/life14020206

Second Trimester Amniotic Fluid Angiotensinogen Levels Linked to Increased Fetal Birth Weight and Shorter Gestational Age in Term Pregnancies

Life (Basel). 2024 Jan 31;14(2):206. doi: 10.3390/life14020206.

Authors

Affiliations

¹ National and Kapodistrian University of Athens Medical School, 11527 Athens, Greece.
² Aghia Sophia Children's Hospital, National and Kapodistrian University of Athens, 11527 Athens, Greece.
³ First Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens Medical School, Alexandra Hospital, 11527 Athens, Greece.
⁴ Second Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens Medical School, Aretaieion Hospital, 11527 Athens, Greece.
⁵ Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens Medical School, Attikon Hospital, 11527 Athens, Greece.
⁶ Department of Gynecologic Oncology, Metaxa Memorial Cancer Hospital of Piraeus, 18537 Piraeus, Greece.
⁷ Unit of Endocrinology, Diabetes Mellitus and Metabolism, National and Kapodistrian University of Athens Medical School, Aretaieion Hospital, 11527 Athens, Greece.
⁸ Vascular Biology, Molecular and Clinical Sciences Research Institute, St George's University of London, London SW17 0RE, UK.
⁹ Department of Obstetrics and Gynecology, University Hospital of Patras, Medical School, University of Patras, 26504 Patra, Greece.

Abstract

Background: Despite the considerable progress made in recent years in fetal assessment, the etiology of fetal growth disturbances is not as yet well understood. In an effort to enhance our knowledge in this area, we investigated the associations of the amniotic fluid angiotensinogen of the renin-angiotensin system with fetal growth abnormalities.

Methods: We collected amniotic fluid samples from 70 pregnant women who underwent amniocentesis during their early second trimester. Birth weight was documented upon delivery, after which the embryos corresponding to the respective amniotic fluid samples were categorized into three groups as follows: small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). Amniotic fluid angiotensinogen levels were determined by using ELISA kits.

Results: Mean angiotensinogen values were 3885 ng/mL (range: 1625-5375 ng/mL), 4885 ng/mL (range: 1580-8460 ng/mL), and 4670 ng/mL (range: 1995-7250 ng/mL) in the SGA, LGA, and AGA fetuses, respectively. The concentrations in the three groups were not statistically significantly different. Although there were wide discrepancies between the mean values of the subgroups, the large confidence intervals in the three groups negatively affected the statistical analysis. However, multiple regression analysis revealed a statistically significant negative correlation between the angiotensinogen levels and gestational age and a statistically significant positive correlation between the birth weight and angiotensinogen levels.

Discussion: Our findings suggest that fetal growth abnormalities did not correlate with differences in the amniotic fluid levels of angiotensinogen in early second trimester pregnancies. However, increased angiotensinogen levels were found to be consistent with a smaller gestational age at birth and increased BMI of neonates.

Keywords: amniotic fluid; angiotensinogen; birth weight; fetal growth; large for gestational age (LGA); renin–angiotensin system (RAS); second trimester of pregnancy; small for gestational age (SGA); third trimester of pregnancy.

Grants and funding

This research received no external funding.