Commentary - Lyus R, Lohr P, Prager S. Use of Mirena LNG-IUS and Paragard CuT380A intrauterine devices for nulliparous women (Contraception 2010;81:367-371).

摘要

I would like to give some comments regarding the article by Lyus et al. [1]. In 1980, Hasson wrote: "Individual variations in the size and shape of the human uterus are probably greater than variations in the size and shape of the human foot" [2]. Thirty or more years ago, and also more recently, several researchers have shown that there is considerable variation in shape, size and potential capacity of individual uterine cavities. These studies concluded that irritation of the uterine isthmus results if the length of the IUD is equal to that of the endometrial cavity, triggering myometrial contraction that promotes expulsion. Irritation of the lower uterine segment may also result in painful sensations, and if the length of the IUD is greater than the endometrial cavity length and does not slide in the cervical canal, the large device can become impacted in the endometrial cavity. These conditions are manifested clinically as pain, bleeding, expulsion, infection or even perforation. The endometrial cavity length of many nulliparous women is less than 28 mm [3,4]. In a recent study conducted in Brazil, the mean endometrial cavity length was 3.70+-0.03 cm in nulligra-vidae and 3.84+-0.03 cm in parous women, according to ultrasonography. However, their study also showed that one third of the women showed endometrial length shorter than 3.2 cm, confirming previous studies [5].