Thank you for your query.
If the fluid around the baby is inadequate, ultimately it can lead to asphyxiation ( death ) of the baby, so it is a grave , ominous sign.
ALso, since you have had previous 4 miscarriages, you need to investigate yourself thoroughly.
Causes could be genetic causes, uterine abnormalities in shape and size, intra uterine infections, hormonal
disturbances or autoimmune conditions.
Also, ideally the tissue of previous 4 abortions should have been sent for analysis.
Even in absence of a known cause, you should be taking maximum support for this pregnancy
, including progesterone
supplements and blood thinner injections.