Adjective
(of a woman or female animal) That has never given birth.
(of a mosquito or other female insect) That has never yet laid eggs.
Source: en.wiktionary.orgIn addition to T-shaped IUDs, there are also U-shaped IUDs (such as the Multiload) and 7-shaped Gravigard Copper 7 (with a mini version for nulliparous women introduced in the 1980s). Source: Internet
Overall, IUDs are safe and acceptable also in young nulliparous women. citation The same is likely the case for virgin women, unless there is a microperforate hymen that obstructs any insertion of the IUD. Source: Internet