Tailoring of Fincoid-350 insertions--experience with Hasson's Wing Sound 1 Cavimeter.

The total uterine and endometrial cavity lengths of 212 nulliparous and 331 parous women were measured with Hasson's Wing Sound 1 Cavimeter prior to insertion of IUDs. A rather poor correlation between these two measurements was established, indicating that the total uterine sound measurement does not give reliable information about the endometrial cavity length. Furthermore, the cavimetric measurements showed that a majority of both nulliparous and parous uterine cavities were less than 35 mm in length. Consequently, the devices of standard size on the market are too long for most uterine cavities. The results of 543 tailor-made insertions showed that the tailoring of IUD length according to the endometrical cavity length produces better clinical performance. In particular, the continuation rates improved whereas the pregnancy rates remained practically unchanged.