When I was pregnant I was told to drink lots of fluids, this is the most efficient way to increase amniotic fluid levels.

If you have a low level of amniotic fluid during pregnancy,
the condition is referred to as “Oligohydramnios”. Your doctor will need to
conduct testing to determine if you are suffering from this condition. If the
testing confirms the fact that your amniotic levels are too low, there are a
few different treatments that may be appropriate for you.

The first step, as
mentioned in a previous answer, is to increase your fluid intake. You may also
be able to schedule an IV that will successfully hydrate your body. You may
also increase the amount of foods that you consume during your pregnancy that
contain water in them. Watermelon is an excellent option.

If your doctor determines that you are experiencing low
amniotic levels prior to delivery and labor, they may elect to inject fluids
into your body quickly. This process is called “Amniocentesis”. Furthermore, a
catheter may be used for the process called “Amnio-Infusion” in order to place
fluids around where the umbilical cord is.