Symptoms of hydrops fetalis can occur during pregnancy or after the baby is born. During pregnancy, symptoms of hydrops fetalis may include: large amounts of amniotic fluid. thickened placenta.

When do hydrops develop?

If infection develops during the first 12 weeks of gestation, the risk of hydrops ranges from 5%–10%. If infection occurs during weeks 13 through 20, the risk decreases to 5% or less. Infection after the 20th week of gestation is associated with a fetal hydrops risk of 1% or less.

How early can fetal hydrops be detected?

More than half of all babies with the condition die before birth or soon after delivery. The risk is highest for those who are diagnosed with hydrops fetalis early (less than 24 weeks into pregnancy) and for those who have a structural abnormality, such as a heart defect.