韓國婦人에 對한 lippes loop와 ota ring의 避姙效果에 關한 硏究

Abstract

[한글]

[영문]

Introduction

Various types of intra-uterine contraceptive devices (IUD) have recently been invented and evaluated clinically by many investigators. In oriental countries such as Japan, Korea, and Taiwan, the Ota ring has been used for many years by a considerable number of women, while the Lippes loop was first introduced into this country in 1962. The latter is now being widely used as a recommendable contraceptive method in Korea.

However, comparative studies on the effectiveness of the two IUD have been meager in this country, and the purpose of this study is to make a comparative study between the two different types of intrauterine devices-Lippes loop and Ota ring-in order to find out whether there are any differences in the contraceptive effectiveness in terms of 1) pregnancy rate,2) expulsion rate, 3) removal rate, and 4) side effects.

Materials and Methods

From among the residents in Kimchum City and Kumnung County in Kyungsang Pukdo Province, healthy and married multiparous women who had desire for contraception were subjected to this study. One of the two IUD was inserted at the choice of clients who visited our clinic.

In this study two kinds of the devices were used; namely,

a. Lippes loop; Plastic one, size No. 4 (27.5mm). A string, attached to the loop, is to be retained in vagina. Dilatation of the cervical canal is not necessary for its insertion.

b. Ota ring; made of plastic and medium sized (24mm). It is completely inserted in the uterine cavity, and it is necessary for its insertion to dilate the cervical canal by Hegar's No.8.

IUD was inserted any time of a menstrual cycle. In some cases the insertion was also made during amenorrhea after delivery or abortion. In all cases the hemoglobin level was measured prior to insertion.

Following insertion, observation was made at the first and second month after insertion, and later once every third month, and results were computed by the Tietze-Potter's life table method for a comparison.

Summary of Findings

During the Period from December 1964 to December 1966, the loop was inserted in 208cases and the ring in 144 cafes in order to make a comparative study of the effectiveness and side effects of both methods, and a brief summary of findings was as follows:

1. The two study groups were comparable in terms of age distribution, number of previous pregnancies, and number of living children.

2. The cumulative pregnancy rate at the end of 18 months was 5.2 per hundred first insertions in the group of women using the Lippes loop and 2.2 per hundred first insertions with the Ota ring.

3. Cumulative expulsion rate was 5.3 per hundred loop insertions after one year, but only1,4 per hundred for Ota ring insertions after 18 months if unnoticed expulsion with pregnancy was included in expulsion rate. This indirates a lower expulsion rate in the Ota ring group than among the loop wearers.

4. The removal rate for the loop was higher than that of ring after the first year-19.5 for the loop vs. 13.7 for the ring per hundred insertions. However, after 18 months the rates were similar-21.7 for the loop vs. 21.6 for the ring. The main reason for removal of loops was pain (64.3%) whereas the main reason for removal of rings was bleeding(46.5%).

5. In 12.2% of the cases where loops were removed because of pain and in 16.7% of those cases where they were removed due to bleeding the loops were very badly deformed. This warping of the loop can be classified into six separate types of deformation and may have been the cause of pain and/or bleeding. The cause of this deformation is not known, however it can be assumed that the loop was being carried in its misshapen form and was at least partially responsible for the causes leading to removal. One fact which strengthens this assumption is that no loops removed due

to neurosis and other non-medical reasons in this study were deformed.

6. The average length of irregular bleeding (discounting menses) after insertion was 5.3days for the loop and 6.1 days for the ring in cases where such bleeding occurred.

7. Although a lower hemoglobin level prior to IUD insertion did not lead to a higher amount of bleeding, it was found that those women who were anemic and experienced a high rate of bleeding were most likely to request removal. This indicates that women who were predisposed to anemia were more worried about bleeding. This worry, in turn, led to a higher removal rate. This phenomena was observed mast in the ring which was more frequently the cause of bleeding.

In short the ring group experienced a lower rate of pregnancy and expulsion than the loop users. However the difficulties involved in insertion and extraction and the extreme cases of aggravation of the endometrium mitigate against recommending

the ring as compared to the loop. The loop is therefore recommended for greater use than the ring in any large scale program.

It is further recommended that quality control of loop production in order to insure the retention of adequate elasticity be increased. Technical training of personnel for loop insertion in order to avoid deformation or improper location

during initial insertion is also recommended. In addition follow-up treatment especially for anemic women who experience bleeding is urged.