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The Chinese RingA Contraceptive Intrauterine Device

Taylor L. MacDonald, MS, Eugenio O. Gerscovich, MD,John P. McGahan, MD, Maria Fogata, MD

he stainless steel ring (SSR; Figure 1) is a commonly used Chinese intrauterine

device (IUD) that has a typical appearance when shown on sonography.Considering the large number of Chinese immigrants coming to the UnitedStates and the 2.7 million Chinese-born immigrants currently living here, it is

not surprising that many family practitioners, obstetricians, sonographers, and sonol-ogists will see the SSR at some point in their careers. 1 General knowledge about theeffectiveness, risks, and sonographic appearance of the SSR is important for physicianswho may encounter this particular IUD in their practices. To the best of our knowledge,no previous reports of the sonographic appearance of the SSR have been reported inthe English language imaging literature.

Received November 2, 2005, from Kirksville Collegeof Osteopathic Medicine, Kirksville, Missouri USA(T.L.M.); and Department of Radiology, University ofCalifornia, Davis Medical Center, Sacramento,California USA (E.O.G., J.P.M., M.F.). Manuscriptaccepted for publication November 15, 2005.

Address correspondence to Eugenio O.Gerscovich, MD, Department of Radiology,University of California, Davis, 4860 Y St, Suite 3100,Sacramento, CA 95817 USA.

E-mail: eugenio.gerscovich@ucdmc.ucdavis.edu

AbbreviationsIUD, intrauterine device; SSR, stainless steel ring

Case Report

A 41-year-old Chinese woman, immigrant to this coun-try, went to her family practitioner for a yearly wellwoman examination. On questioning, the patient statedshe had been having regularly timed menses with occa-sional heavy flow. This had been occurring since place-ment of an IUD, inserted approximately 8 years beforewhile she was still living in China. The device was placedafter an uneventful delivery of her first pregnancy. Thepatient denied any pregnancies since the IUD was insert-ed, despite being sexually active. A thorough physicalexamination was performed, including a pelvic examina-tion with a speculum. The pelvic examination revealedno gross abnormalities; however, the primary care physi-cian was unable to identify an IUD string. In light of thelack of visual evidence of an IUD, the provider assumedthe IUD had been lost and ordered pelvic sonographyto confirm. Transabdominal sonography was per-formed, which showed a curvilinear strong echogenic-ity in the lumen of the patients uterus. Endovaginalsonography showed the echogenicity as correspondingto a ringlike structure in the endometrial cavity (Figure 2).

2006 by the American Institute of Ultrasound in Medicine J Ultrasound Med 2006; 25:273275 0278-4297/06/$3.50

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The interpreting radiologist identified the objectas a Chinese SSR IUD, and the primary carephysician was notified. The risks associated withthe device were explained to the patient, whoultimately declined removal of the SSR for thetime being, with possible reevaluation if men-strual bleeding increased or anemia developed.

Discussion

The SSR is an IUD that has been used as the mainmethod of birth control in China, accounting for90% of all IUD use. One reason for the highprevalence of the SSR is the low cost associatedwith production, estimated to be less than onefourth the price of the Copper T IUD.2 Low cost

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The Chinese Ring

Figure 2. Endovaginal sonograms of the uterus with the SSR in place. AC, Coronal views at different levels of the IUD. D, Sagittalview. Observe the circular configuration of the IUD. Arrows indicate SSR and U, uterus.

BA

C D

Figure 1. Stainless steel ring. Courtesy of Jeff Bradley, RDMS,OBGYN.net (http://www.obgyn.net/us/us.asp?page=/us/pre-

sent/9808/Bradley, accessed October 21, 2005). Photography of

IUDs provided by Joseph S. K. Woo, MBBS, FRCOG.

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combined with national family-planning practicepolicy encouraging maternal IUD insertion afterthe first child for population control purposes hasresulted in more than 50 million Chinese womenusing the SSR.2 However, both physician andpatient should be aware of the significant risksassociated with the SSR. One study performed bythe China State Family Planning Commissionshowed 12-month failure rates of 10.6% for theSSR compared with rates of 1.7% for the Copper Tand 2.1% for the Copper V.3A second study con-firmed these high rates of undesired pregnancy(IUD failure), showing an 8% failure rate at 2 yearsfor the SSR versus rates of 2.1% and 1% for theCopper V and T, respectively.4 The same studyalso showed expulsion rates of 12.6% for the SSR,whereas the Copper T had a 1.7% rate, and the

Copper V had a 1.6% rate.4 This high rate of expul-sion is worrisome, especially given the fact thereis no IUD string attached; therefore, there is noway on speculum to check to see whether theIUD is in place. Thus, in questionable cases,sonography may be used as a method to checkthe location of this IUD. In light of the higher ratesof complications, it is not surprising that the gov-ernment of China decided to convert from theSSR to the TCu220C and TCu380A devices begin-ning in 1993. By doing so, it is estimated thatmore than 55 million pregnancies, including 35.6

million induced abortions, will have been avoid-ed over the last decade.5

Despite the change, the early marriage rates andencouragement of IUD insertion after the birth ofthe first child result in millions of Chinese womenof child-bearing age still using the SSR. With morethan 2.7 million Chinese immigrants living in theUnited States as of 2000, there is a high likelihoodthat practitioners with obstetric and gynecologicpatients will encounter a patient at reproductiveage with the SSR.1

Proper identification of the SSR with its distinctappearance, a ringlike hyperechoic structure onsonography without a string for removal, is diag-nostic. Risks and benefits of retaining the device,including substantial failure rates, should be dis-cussed with the patient, as well as plans for futurecare. Removal via endocavitary instrumentationis possible, and cases have been described involv-ing successful removal early in gestation with theuse of a stone clamp under sonographic guid-ance.6 The technique described in these caseswas similar to the technique used for transcervi-cal chorionic villous sampling.7

References

1. US Census Bureau. 2000 Census of Population and

Housing: Population and Housing Unit Counts. United

States Summary. Washington, DC: US Census Bureau;

2004.

2. Kaufman J. The cost of IUD failure in China. Stud Fam Plann

1993; 24:194196.

3. State Family Planning Commission of China. A clinical trial

of three commonly used IUDs. In: Condensed Summary of

Family Planning Scientific Research Results During the Sixth

Five Year Plan. Beijing, China: State Family Planning

Commission of China; 1985:1921.

4. Gao J, Shen H, Zheng S, et al. A randomized comparative

clinical evaluation of the Steel Ring, VCu200 and TCu220C

IUDs. Contraception 1986; 33:443454.

5. World Health Organization Special Program of Research.

China changes from the stainless steel ring to modern IUDs.

Prog Hum Reprod Res 1993; 27:7.

6. Sachs BP, Gregory K, McArdle C, Pinshaw A. Removal of

retained intrauterine contraceptive devices in pregnancy.

Am J Perinatol 1992; 9:139141.

7. Rodeck CH, Mossman JM, Nicholaides KH, McKenzie C,

Gosden CM, Gosden JR. A single-operator technique for

first trimester chorion biopsies. Lancet 1983; 2:13401341.

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