Correspondence

Ruptured interstitial pregnancy caused by inactive chorionic villi presenting with negative serum B -hCG

To the Editor,

We read with interest the article by Kim et al [1]. They reported a case of an interstitial pregnancy resulting in uterine rupture with a false-negative urine pregnancy test and highly positive serum b-human chorionic gonadotropin (hCG). A negative urine pregnancy test certainly does not negate the possibility of interstitial pregnancy, but the serum b-hCG concentration is completely sensitive [1]. Indeed, serum b-hCG test findings will be positive when the chorionic villi are exuberant [2-5]. We present an unusual case in which inactive chorionic villi caused uterine rupture after expectant management for the interstitial pregnancy with negative results for serum b-hCG and urine preg- nancy tests.

A 32-year-old multiparous woman, who presented with a mild right-sided discomfort at 9 weeks of gestation, was referred to our hospital with suspicion of an interstitial pregnancy. A Transvaginal ultrasound examination showed an Intrauterine pregnancy and a gestational sac (GS) located in the right interstitial segment; a low echoic lesion surrounded it. The empty GS measured 7 mm in diameter. Neither ultrasound nor gadolinium-enhanced magnetic reso- nance imaging detected clear villi. A urine pregnancy test gave negative results and serum b-hCG concentration was

1.84 mIU/mL. Diagnosis of an interstitial pregnancy of the

right uterine cornu was made. Repeated ultrasound exami- nations showed no change in GS size. The serum b-hCG level gradually decreased to 0.53 mIU/mL. On the 13th day of hospitalization, an acute abdomen with ascites occurred. An emergent laparotomy revealed the rupture of the interstitial pregnancy. The affected lesion was resected wedgewise; consequent histopathological examination showed necrotic villi with neutrophil infiltration.

Kim et al [1] warned that interstitial pregnancy should not be excluded, even with a negative urine pregnancy test,

when a woman of childbearing potential visits the emer- gency department presenting with shock of unknown origin. In addition, we report this case of a ruptured interstitial pregnancy with negative results for both a urine pregnancy test and a serum b-hCG test. In the present case, the pathological finding suggests that Inflammatory changes caused the uterine rupture. Interstitial pregnancy is the gravest type of Ectopic pregnancy. The patient with a negative hCG should be carefully observed because an interstitial pregnancy with inactive chorionic villi may result in rupture.

References

1. Kim SW, Ha YR, Chung SP, Kwon OY. Ruptured interstitial pregnancy presenting with negative beta-hCG and hypovolemic shock. Am J Emerg Med 2003;21:51.
2. Jafri SZ, Loginsky SJ, Bouffard JA, Selis JE. Sonographic detection of interstitial pregnancy. J Clin Ultrasound 1987;15:253-7.
3. Shalev E, Peleg D, Tsabari A, Romano S, Bustan M. Spontaneous resolution of ectopic tubal pregnancy: natural history. Fertil Steril 1995; 63:15-9.
4. Trio D, Strobelt N, Picciolo C, Lapinski RH, Ghidini A. Prognostic factors for successful expectant management of ectopic pregnancy. Fertil Steril 1995;63:469-72.
5. Cunningham G, Grant NF, Leveno KJ. Ectopic pregnancy. In: Cunningham G, Grant NF, Leveno KJ, editors. Williams obstetrics. 21st ed. New York (NY)7 McGraw-Hill; 2001. p. 883-910.

Koji Nishijima MD Ken-ichi Shukunami MD Hideaki Tsuyoshi MD Yuka Hattori MD

Yoshio Yoshida MD Fumikazu Kotsuji MD, PhD

Department of Obstetrics and Gynecology University of Fukui, Fukui 910-1193, Japan

E-mail address: [email protected]

0735-6757/$ - see front matter D 2005 Elsevier Inc All rights reserved. doi:10.1016/j.ajem.2004.01.006