Dr. Hansa Dhar MD

Specialist Department of Obstetrics / Gynaecology
Rustaq Referral Hospital, South Batinah Region
Ministry of Health, Sultanate of Oman.
PO Box 349, P.C 329, Al Rustaq Oman.
Tel: (00) (968) 95256945, (00) (968) 25449489
E-mail: hansad10@hotmail.com, hansad10@rediffmail.com
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ABSTRACT Unicornuate uterus with rudimentary horn is a rare type of uterine malformation associated with obstetrical complications. It is difficult to diagnose early, and rupture of the pregnant rudimentary horn is the usual presentation resulting in severe haemoperitoneum with increased maternal morbidity and at times mortality. Case of ruptured rudimentary horn pregnancy in a G2P1 24 years is reported along with signs and symptoms of acute adnexal pathology. Explanatory laparotomy revealed ruptured rudimentary horn pregnancy 14 weeks with haemoperitoneum. Excision of accessory horn was done.

Keywords: : Rupture, Rudimentary horn, Ectopic Pregnancy.
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Unicornuate uterus with rudimentary horn is a result of abnormal mullerian duct development. The prevalence of unicornuate uterus with rudimentary horn is very rare 1:100,000(1) . The rudimentary horn may consist of a functional cavity, or it may be a small solid lump of uterine muscle with no functional endometrium. It is usually associated with endometriosis and pregnancy complications including miscarriage, ectopic pregnancy, uterine rupture, preterm labour and malpresentations. Renal anomaly is found in 36% of cases(2) .

The uterine anomalies present few problems in absence of pregnancy, provided there is no obstruction to menstrual flow. Pregnancy in a rudimentary horn is rare. Reported figures in literature are between 1 : 76000 and 1 : 140,000 pregnancies(3) .

A 24 year old Omani patient married for the last 4 years was referred from the local Health Centre to Rustaq Referral Hospital with acute onset of abdominal pain and bleeding per vaginum for the last three hours. She was at 14 weeks gestation and was G2P1. She had a previous caesarean section for breech presentation at another hospital. No records of previous delivery, of the patient were present. . Patient on arrival was afebrile. Heart rate was 110 / min, Blood pressure 90 / 44 mmHg. Pallor was present. Abdominal examination revealed tenderness with guarding. Bi manual pelvic examination revealed. a soft cervix, uterus size could not be made out. Bleeding per vaginum was present. Her investigations showed Haemoglobin 11.39 / dl with normal blood counts, urea, creatinine, electrolytes and coagulation profile were within normal limits.

Abdomino-pelvic ultrasound revealed free fluid with a fetus with no cardiac activity. Patient was taken for emergency laparotomy after arranging 4 units of blood. On laparotomy haemoperitoneum was encountered. About 2000 cc blood in abdomino pelvic cavity, with a dead fetus, was seen. Presence of ruptured left rudimentary horn of uterus with placenta in situ was found. The ruptured rudimentary horn was excised. The left tube and ovary was attached to the uterus. Patient was managed initially in ICU and then shifted to the ward. She made an uneventful recovery and was discharged after 10 days in hospital. Patient had ultrasound examination of renal system which showed no abnormality. She was counseled regarding birth spacing.

Pregnancy in the rudimentary horn arises either from a small communication with the uterine cavity or by transperitoneal migration of the fertilized ovum from the contra lateral side (4) . The usual outcome of the rudimentary horn pregnancy is rupture of the rudimentary horn with severe intra peritoneal bleeding and shock. Most pregnancies in the rudimentary horn rupture in the first or second trimester.
Early diagnosis of rudimentary horn pregnancy remains challenging, few cases of early (first-trimester) pre rupture sonographic diagnosis of this condition, have been reported(5,6).
Fedelle et al(7) have found ultrasonography a useful tool in determining the presence of rudimentary horn.

In this case the patient presented with acute abdomen but due to no medical record of previous pregnancy, suspicion of rupture of rudimentary horn was remote. According to Shah and Khan(8) every pregnant lady with unexplained abdominal pain should be suspected to have ectopic pregnancy until proved otherwise.

Soundarajan and Rai(9) reported a case of rudimentary uterine horn pregnancy mimicking an ectopic pregnancy. In this case horn was removed laparoscopically. Excision is usually carried out at laparotomy, but has been increasingly successfully carried out at laparotomy in unruptured cases.

Laparoscopy is said to be the most accurate diagnostic tool by certain authors, with significant advantages in efficient surgical management and therapy avoiding laparotomy(10) .
All cases of rudimentary horn pregnancy should be investigated, for any associated urinary anomalies, because of high incidence of associated urinary anomalies in the presence of genital anomalies. In this case no associated renal anomaly was seen.

Rupture of rudimentary horn pregnancy is one of the remote causes of acute abdomen. However missing the diagnosis can lead to fatal complications. Early detection on the other side can reduce the eventual morbidity and mortality. If ultrasonography remains inconclusive, use of magnetic resonance imaging (MRI) may be useful in centres where facilities for MRI are available.