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Fetal Ovarian cyst torsion & rupture


US scan done on 09/05/09 - 35 weeks female fetus. 

A well defined Cystic lesion with fluid-fluid level (Arrows) noted in the Rt.Iliac fossa


US scan done on 16/05/09  --- 36 weeks female fetus. 

Cyst not seen. Free fluid (Arrow) in the peritonium (Subhepatic region, pelvis & inter loop fluid) with internal echoes.


Diagnosis : Rt. Ovarian cyst with torsion & rupture in female fetus at 35 & 36 weeks gestational age respectively.  


Three physiological cystic lesions in the fetal abdomen  are stomach, gall bladder, urinary bladder. 

Other than these three any cystic lesion in the fetal abdomen is pathological except in female fetus ,

where physiological ovarian follicles or cysts  may be noted.


A cyst in the abdomen of female fetus is most likely ovarian origin due to high level of circulating maternal estrogen.

A follicular cyst typically appears as a unilocular , thin-walled cystic mass in the abdomen of a female fetus.

Importantly, ovarian cysts do not touch the spine as do cysts of renal origin.


Ovarian cysts in the female fetus always present in the abdomen rather than in the pelvis because pelvis is small and fetal ovary is an abdominal organ rather than pelvic organ. Ovarian cysts may be detected high in upper abdomen.

Majority of  fetal ovarian cysts resolve spontaneously over a time.


Hemorrhage is a relatively common complication of ovarian cysts due to torsion. Depending up on age of the bleed, sonographic appearance  of cyst altered. These cysts may appear as diffuse echogenic material, diffuse echoes with visible  fibrin strands, retracting thrombus, and fluid-fluid levels. 


Sonographic observation of cyst hemorrhage is made after the torsion has occurred and any opportunity for operative salvage of the ovary has passed, emergency obstetric intervention is not appropriate.


Ovarian cysts usually have a benign course – regress spontaneously at most require surgical resection after birth.

Ovarian cysts should have a relatively long period of  post natal follow up. Surgical removal is considered only for  those  rare cysts  that do not reduce in size after birth, when there is no further estrogen stimulation .

Prenatal torsed ovary  may undergo atrophy post natally.



A variety of other abdominal cysts should be considered in differential diagnosis 


Three are relatively common :

  • Meconium pseudo cyst – can occur anywhere in the abdomen have invariably calcifications in their walls.

  • Choledochal cyst – seen adjacent to the  inferior surface of right hepatic lobe. 

  • Gut duplication cysts – low amplitude echoes with bright sub mucosa is strongly S/o diagnosis


Other rare cysts are:

  • Mesenteric cysts – midline in location always disclose a loop of bowel that creases the cyst or appears to course directly through the cyst.

  • Meckel’s  Diverticular cysts - found on the right side of the abdomen

  • Urachal cysts  - midline in location abuts superior bladder wall.

Reference : Callen  Ultrasonography in Obstetrics and Gynecology 4th Edition.

Submitted by: Dr.M.Adinarayana Rao, MD.,RD.

                           Dr. D.Prasada Reddy, DMRD.

                           Dr.G.Gowri Sekhar, DMRD., DNB.


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