Common Minor Problems /


01 In Brief

A hydrocele is a common finding in a normal newborn baby and is a painless fluid filled sac that surrounds the testis. As the testis descends from its fetal origins in the abdomen near the kidney a sac travels with it to the scrotum allowing fluid to surround the testis. Before birth the sac usually closes off and the fluid is absorbed. In many newborns the absorption of the fluid is not completed and a hydrocele develops. It  does not cause damage to the associated testis, is painless and most resolve by 12 months of age. Occasionally if it is very large or hasn't reduced by 12-18 months, surgery is required.

02 What Do I Need To Know?


  • Probably about 50% of newborn males will have some degree of hydrocele at birth. 
  • They appear as soft swellings in the scrotum and may be quite large to start with. Often the doctor will shine a light on the surface of the scrotum to see if it illuminates or glows like a lantern. They may occur on one or both sides.
  • They do no cause any harm to the underlying testis and do not cause any discomfort.


  • During the latter part of pregnancy (around the 8th month) the testis descends from the abdomen into the scrotum and brings with it a sac (called the processus vaginalis) connected to the abdominal cavity and allows fluid to surround the testicle. 
  • Before birth this sac usually closes and the fluid is absorbed.
  • 2 types are described
    • Non-Communicating: occurs when the connection of the sac to the abdominal cavity closes but the fluid hasn't completely absorbed. This is the commonest type of hydrocele in newborn babies. When the hydrocele is compressed or squeezed, the fluid doesn't escape into the abdomen and the swelling stays the same size. In most cases the fluid is absorbed and the swelling resolves within 12 months. 
    • Communicating: is more common in premature babies and occurs when the connection of the sac to the abdominal cavity doesn't close and the fluid then can flow back and forth from the abdomen. When this type of hydrocele is squeezed or compressed the fluid will slowly go back into the abdomen and the hydrocele will reduce in size. The hydrocele is often smaller in the morning and gets bigger later in the day. It can sometimes be associated with bowel getting caught in the neck of the sac causing a hernia. If the scrotum suddenly appears larger and firmer than usual, consult your doctor urgently.


  • In newborns the large majority a hydrocele will resolve and require no treatment.
  • If it has not resolved by 12 months or has become very large then surgery may be required.

03 What Others Say

 Children's Hospital Boston:  has an excellent easy to read fact sheet  Hydrocele

Texas pediatric Surgical Associates has helpful diagrams TPSA Hydrocele

The information published here has been reviewed by Flourish Paediatrics and represents the available published literature at the time of review.
The information is not intended to take the place of medical advice.
Please seek advice from a qualified healthcare professional.
Read our terms and conditions

Last updated: 20/03/2011 by Dr Elizabeth Hallam*