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Updated: Jun 10, 2026
10:02
State of the Art Cranial Ultrasound Imaging in Neonates
Published on: February 2, 2015
Fetal transient occipital bone protuberance during early pregnancy
1Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. ori.nevo@sunnybrook.ca
Prenatal Diagnosis
|July 27, 2010
Summary
Transient occipital bone protuberance (TOBP) identified on early pregnancy ultrasounds typically resolves before birth. Postnatal skull examinations are normal in these rare cases.
Area of Science:
- Prenatal diagnosis
- Fetal development
- Medical imaging
Background:
- Transient occipital bone protuberance (TOBP) is a rare finding during early pregnancy.
- Accurate prenatal diagnosis is crucial for appropriate management and parental counseling.
Purpose of the Study:
- To document the sonographic characteristics of TOBP in fetuses.
- To assess the pregnancy outcomes for fetuses diagnosed with TOBP.
- To evaluate the resolution of TOBP during gestation.
Main Methods:
- Retrospective review of five fetal cases diagnosed with TOBP via ultrasound between 14-15 weeks gestation.
- Serial prenatal ultrasound examinations to monitor the protuberance.
- Postnatal examination of neonates to assess skull normality.
Main Results:
- TOBP was identified in five fetuses during routine early pregnancy ultrasounds.
- The occipital bone protuberance resolved spontaneously in all five cases by 24 weeks gestation.
- All neonates exhibited normal skull structure upon postnatal examination.
Conclusions:
- Isolated TOBP is an uncommon prenatal finding with a typically benign course.
- Ultrasound surveillance is recommended for cases of TOBP.
- Complete resolution of TOBP before birth is expected, with normal postnatal skull development.
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