Thanks for the query.
Sometimes low placental protein can lead to chromosomal abnormalities like down's syndrome.
This may not be seen in all the babies and there is possibility for healthy baby.
The possibility of abnormality will depends on other factors like advanced maternal age
, genetic makeup etc.
So no need to worry.
Continue with regular antenatal checkups as adviced by your doctor.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429