FetRef is a unique database that incorporates the majority of the published reference range data on various measurements of fetal organs, size and physiology. The database was built by a maternal-fetal medicine specialist following a thorough literature search and data mining. All data were extracted and compiled manually by a single person. We are aware that the database is not complete, nor it is error-proof. We are investing a continuous and persistent effort in broadening the database's extent and improving its quality.
Inclusion criteria for the different articles were:
- The article must appear on PubMed
- The article must include a table of week-by-week percentiles of a specific fetal measurement, or alternatively the mean and the standard deviation of a measurement
We did not include articles that have only graphic representation of measurements.
Regarding papers that did not include percentiles, but included mean and standard deviation – in order to make things simple and usable we assumed a normal distribution. Then, we calculated mean – 2SD (we called it 2.5 percentile instead of 2.1 percentile, for the sake of simplicity) and mean + 2SD (we called it 97.5 percentile instead of 97.9 percentile, again for the sake of simplicity).
Each measurement parameter in the database is classified according to :
- Its organ system
- The (sub)organ it pertains to
- The part of the organ that was measured
- Parameter field relates to what exactly was measured in the specified body part
- Specification is how the measurement was taken (eg for BPD – outer-inner or outer-outer)
- Measurement field denotes what measurement was taken (length, velocity, volume etc)
- Modality field relates to which modality was used – 2D/3D ultrasound, 4D-STIC, Doppler or MRI
- Singleton/twins
- Male/female
- Population characteristics enables the user to restrict the search to only normal cases or to include also articles that included mixed-risk populations
- The user can choose a specific country or a combination of countries in order to better match the chosen reference to the patient
Some fields are mandatory and are denoted by a red asterisk * in the input form
Wherever possible we included the number of fetuses per week and the total number of fetuses in the entire study. Each article's methodology was cited so that the user will be able to reproduce the same measurement exactly as the authors did. We also added remarks that represent our own perspective regarding the quality of dating, the normalcy of the population, the quality of data presentation, methodology, study design and any other details that seemed important.
We hope you find this database useful and helpful. If you do – we would appreciate spreading the word to your colleagues by any means you find suitable (WhatsApp, Facebook, Twitter, Instagram etc). We would like to encourage you to give us feedback and send comments and suggestions in order to make this database even better, and more user-friendly in the future.
The FetRef project is a personal initiative and is not externally funded.
Who am I ?
My name is Shay Porat and I am a maternal-fetal medicine specialist. I am an attending physician at Hadassah-Hebrew University Medical Center in Jerusalem and director of the obstetric-gynecologic ultrasound unit. I am board certified in Obstetrics, Gynecology and Infertility. My PhD thesis deals with the role of glucose metabolism in pancreatic beta cell proliferation and mass. I completed a fellowship in MFM at Mount Sinai Hospital, Toronto (2009-2012).
In the past I created phenotip.com - a database of the sonographic phenotype of syndromes, in collaboration with two friends and colleagues of mine (Dr. David Baud and Dr. Tim Van Mieghem).
I have been working on FetRef project for the past several years driven by an internal passion to somehow combine the wealth of information and the technology that enables retrieval of such information within a few clicks. I identified a need in the field of references and hope this endeavor will help close the gap.