High-Risk Pregnancy Is Associated With Increased Alpha-Fetoprotein Concentrations in the Amniotic Fluid and Foal Plasma.

This research investigates a correlation between high-risk pregnancies in horses and increased levels of alpha-fetoprotein (AFP) in amniotic fluid and foal plasma. The study utilized three distinct groupings of mare pregnancies: normal (Group 1), normal pregnancies yielding sick foals (Group 2), and high-risk pregnancies yielding sick foals (Group 3). Findings suggest that high-risk pregnancies and those with pathological fetal membranes have higher AFP concentrations, hinting at its potential use as an indicator for pregnancy complications.

Participant Groupings

• Pregnancy conditions in this study were divided into three distinct groups: Group 1 (normal pregnancies resulting in healthy foals), Group 2 (normal pregnancies resulting in sick foals), and Group 3 (high-risk pregnancies resulting in sick foals).
• High-risk pregnancies were identified by history of premature udder development/lactation or variations in the combined thickness of the uterus and placenta, vulvar discharge, or systemic illness in mares.
• Sick foals suffered from neonatal encephalopathy, prematurity/dysmaturity, sepsis, or hypoxic-ischemic encephalopathy.

AFP Measurements

• AFP concentrations were measured in the plasma of mares, amniotic fluid, and in the foals’ plasma.
• The researchers used a commercially available immunoassay, previously validated for use in horses, to make these measurements.

AFP Concentration Results

• The study revealed no significant AFP changes in the mare’s plasma across the three groups during the last 15-20 days of pregnancy.
• In contrast, amniotic fluid and foal’s plasma demonstrated increased AFP concentrations in Group 3 pregnancies.
• Furthermore, an observed strong association between AFP in amniotic fluid and foals’ plasma suggests the presence of AFP in fetal urine.

AFP and Fetal Membranes

• The research also unveiled a correlation between AFP levels and the state of the fetal membranes. Higher AFP was found in pregnancies with pathological fetal membranes (PFM) compared to those with normal fetal membranes (NFM).
• Such results suggest a distinction between pregnancies with normal placental barriers and pregnancies where this barrier is compromised.

Potential Implications

• An increase of AFP concentration observed in amniotic fluid and the plasma of high-risk foal pregnancies implies possible upregulation of AFP. This finding potentially sets ground for more targeted future research.
• AFP levels, therefore, may serve as potential biomarkers to indicate complications in horse pregnancies.