Human placental lactogen (hPL; chorionic somatomammotropin) is a 21,000 KD polypeptide produced during pregnancy by placental trophoblastic cells. The level of hPL in maternal serum is directly related to placental function and fetal well-being. hPL is detected at about 6 weeks after conception and its concentration increases gradually to peak levels (without decreases) until about the 34th week where it remains stable for the remainder of the pregnancy. Consistently low levels throughout pregnancy or a sudden drop in serial determinations are an indication of fetal distress. After normal delivery, the hPL concentration falls rapidly to an undetectable level. The hPL levels in serum of women with multiple placenta pregnancies generally exceeds that of single placenta pregnancies. This is generally noted from the 2nd trimester to delivery.

Gold serum separator (SST) tube

Immediately following collection, thoroughly mix sample by gently inverting 5 times

1. Allow sample to clot for a minimum of 30 minutes
2. Spin within two (2) hours of sample collection
3. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
4. Freeze

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Red serum vial/tube, 5 mL

1. Allow sample to clot
2. Spin 
3. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum, within two (2) hours of sample collection
4. Freeze

Frozen (preferred) - 90 days

Refrigerated - 24 hours

Ambient - 4 hours

• Samples received at room temperature

Enzyme-linked Immunosorbent Assay (ELISA)

An interpretive report will be provided