Maternal serum heat-stable alkaline phosphatase. In normal and high-risk pregnancies

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Biochemical Markers in Pregnancy

Background:

• Heat-stable alkaline phosphatase (HSAP) is a placental enzyme.
• Its potential as a marker for placental function and fetal well-being has been investigated.
• Serial measurements may offer insights into pregnancy progression.

Purpose of the Study:

• To evaluate the specificity of maternal serum HSAP as an indicator of placental function.
• To assess the correlation of HSAP levels with fetal status in normal and high-risk pregnancies.
• To determine the clinical utility of serial HSAP measurements.

Main Methods:

• Serial maternal serum HSAP levels were measured in 76 normal and 161 high-risk pregnancies.
• A total of 1272 determinations were analyzed.
• HSAP levels were correlated with various pregnancy conditions and outcomes.

Main Results:

• A curvilinear rise in HSAP levels was observed starting around 28 gestational weeks.
• No significant relation was found between HSAP levels and mild hypertension, gestational diabetes, or non-toxemic placental insufficiency.
• HSAP levels were elevated in proteinuric hypertension and low-normal in insulin-dependent diabetics. Neonatal and intrauterine deaths occurred across a range of HSAP values.

Conclusions:

• Serial maternal serum HSAP values are not a specific indicator of placental function.
• HSAP levels do not reliably predict fetal status in high-risk pregnancies.
• The clinical utility of HSAP as a standalone marker for pregnancy complications is limited.