Ammiotic fluid in created by the baby's wee. The kidneys process the wee, turns it into amniotic fluid, which in turn, develops the lungs. Kidney problems are quite common and have a broad range of severity.

DS1 had polycystic kidney disease. He had overlarge kidneys full of cysts. They could not produce enough fluid, so his lungs did not develop. One working kidney gives your baby a much better chance.

i recently read an article about an American Senator whose baby had Potters Syndrome (no kidneys). It's normally fatal, but they added saline to increase the fluid and helped develop the lungs. Baby also had steroid shots. That baby was born early but survived.

i'd talk to a neonatologist about what it means for your baby, especially as you're carrying twins. It may mean a watch and see approach. They may offer steroids for lung development. Many people live a full life with only one kidney. It may mean keeping an eye on blood pressure and no contact sports.