Updated and revised nomenclature for description of early pregnancy events.

The nomenclature used to describe clinical events in early pregnancy has been criticized for lack of clarity and promoting confusion. There is no agreed glossary of terms or consensus regarding important gestational milestones. In particular there are old and poorly descriptive terms such as 'missed abortion' and 'blighted ovum', which have persisted since their introduction many years ago (Robinson, 1975) and have not undergone revision despite the widespread application of ultrasound for accurate clinical assessment and diagnosis. The authors are aware of these shortcomings in terminology and are keen to provide an updated glossary. We hope that this paper will facilitate the introduction of a revised terminology in an attempt to provide clarity and to enhance uptake and use in the literature as well as clinical assessment and documentation.