| Abstract|| |
A rare case of antenatal fetus is seen in urinary bladder on MRI on T1WI & T2WI.
In sagittal section of MRI, a communication was noticed between uterus and urinary bladder which had resulted due to previous multiple caesarian section surgery for deliveries. On operation, dead fetus was located in urinary bladder & some tissue of placenta was removed from uterine cavity. The rent was repaired. Post operative event was normal.
Keywords: Abdominal pregnancy, Urinary bladder, MRI
|How to cite this article:|
Sharma O P. Secondary abdominal pregnancy in urinary bladder. Indian J Radiol Imaging 2006;16:815-8
| Introduction|| |
Normal pregnancy is confined to uterine cavity and site of pregnancy other than uterine cavity is usually referred to as ectopic pregnancy which usually results from the conditions causing obstruction or slow passage of a fertilized ovum through Fallopian tube More Details to uterus. This may be caused by a physiological blockage of the tube or by failure of tubal endothelium to move the zygote down the tube into the uterus. Most such cases are a result of scarring caused by previous tubal infection or tubal surgery. Upto 50% of women with ectopic gestation have a medical history of salpingitis or pelvic inflammatory disease. Some ectopic gestations can be traced to congenital tubal abnormalities, endometriosis, tubal scarring and kinking caused by a ruptured appendix or scarring caused by previous pelvic surgery and prior ectopic pregnancy. Sometimes a woman conceives even after elective tubal sterilization. The risk of an ectopic pregnancy occurring in this situation may reach 60%. The woman who have had surgery to reverse previous tubal sterilization in order to become pregnant also have an increased risk of ectopic pregnancy. Available global medical references on MEDLINE revealed the evidence of primary abdominal pregnancy like primary hepatic pregnancy (Luwuliza - Kirunda J. M. 1978) in state of lithopedian, live complicated primary hepatic pregnancy (Mitchell & Teare 1984), pregnancy in Sigmoid colon (Kazerooni et al 1998), Splenic pregnancy & Pregnancy in Omentum, large and small intestine (Kalof A. N. et al 2004), Abdominal pregnancy (Malian & Lee 2001); but nothing has been reported about urinary bladder pregnancy which is first of it's kind under the head of abdominal pregnancy. We are reporting possibly the first case of pregnancy in urinary bladder in a 32 years old female from state of Uttar Pradesh of India.
| Case History|| |
A 32 years old female resident of Ghazipur, U.P. (India), housewife by profession presented with history of: Amenorrhoea for 5 months, On & off Vaginal bleeding for 1.5 weeks, passing the fetal limbs and mass per vagina, retention of urine and pain in lower abdomen for one day. Following passage of fetal limbs and mass per vagina; vaginal bleeding increased in frequency & amount. When patient tried to pass urine, she could pass only small amount of blood stained urine.
Obstetric History Revealed: G3P2L2 L1 = 6 year old healthy male child, delivered by LSCS
L2 = 3 year old healthy male child, delivered by LSCS
Patient had earlier consulation with a local doctor in Ghazipur with history of amenorrhea of 5 months and on & off vaginal bleeding (1.5 weeks). She was advised for USG examination which was performed by a local sonologist and the report revealed a single live fetus in uterine cavity but she continued to bleed. Following which, the patient was referred to Institute of Medical Sciences, B.H.U. Varanasi, where she was advised MRI abdomen, by department of Obstetric and Gynecology to look for cause of retention of urine & persistent vaginal bleeding. MRI revealed fetus (without cardiac activity) in urinary bladder.
Patient had twins, one of which was aborted per vagina & the other passed in urinary bladder possibly through vesico-uterine fistula, as a result of weakened myometrium due to previous two lower segment caesarean section. MRI confirmed the presence of a dead fetus in urinary bladder and a communication between anterior uterine wall and posterior wall of urinary bladder [Figure - 1],[Figure - 2],[Figure - 3].
| Discussion|| |
Most common site of ectopic implantation is within the fallopian tube (95.5%). Approximately 1.3% of all ectopic pregnancy is abdominal pregnancy and occurs with direct implantation onto the peritoneal surface. Primary abdominal pregnancy has been reported in various extra pelvic organs like omentum, liver, large and small intestine and spleen. Incidence of abdominal pregnancy is 1:8000 birth; and carries maternal mortality rate of 5.1/1000 cases which is 7.7 times higher than the risk from other ectopic pregnancies and approximately 90 times higher than those associated with intrauterine pregnancy.
Abdominal pregnancies are classified as either primary or secondary. The later is much more common and is associated with tubal rupture followed by implantation at a second site i.e. peritoneal surface. Primary abdominal pregnancy occurring as a result of fertilization of an ovum within the peritoneal cavity is extremely rare. Studdiford (1942) laid down the following criteria for primary abdominal pregnancy -
(1) Fallopian tubes and ovaries are grossly normal and show no evidence of recent injury.
(2) No evidence of uteroplacental fistula.
(3) A pregnancy of no more than 12 weeks gestation with trophoblastic elements related exclusively to a peritoneal surface. This ensures that the pregnancy is immature to exclude the possibility of secondary implantation to the peritoneal cavity after primary tubal pregnancy rupture.
Associated risk factors are prior history of pelvic inflammatory disease, kinking caused by ruptured appendix, ectopic gestation, endometriosis, infertility with subsequent in - vitro fertilization and previous tubal surgery, or pelvic surgery.
In the present case, single dead fetus was identified in the urinary bladder on T1WI & T2WI image on MRI. There was history of previous two caesarian sections which have resulted into vesicouterine fistula and through this fistulous tract, the fetal parts have migrated from uterus and placental tissue was observed in uterine cavity and the findings were confirmed on laparotomy. This suggested secondary abdominal pregnancy in the urinary bladder which gave the patient a feeling of mass lesion in lower abdomen; and patient was bleeding per vagina as a result of earlier abortion. MRI in this case helped not only to confirm the pregnancy but also delineated the exact anatomical location of fetal parts and placental tissue separately in urinary bladder and uterine cavity respectively and helped in planning the surgery.
MRI shows its importance when one finds diagnostic, suspicious equivocal, questionable & negative result on other investigation, signal intensity of haemetoma and ascites was clearly confirmed. The predominant signal intensity of tubal haematoma was an intermediate signal on T1WI & low signal on T2WI. Ascites showed signal intensity higher than that of urine on T1WI in 100%. MRI, hence, of course with use of I.V. Contrast allows a specific diagnosis of tubal pregnancy, recognizing tubal wall enhancement and fresh tubal haematoma (Kataoka et al 1999).
Transvaginal sonography is the imaging modality of choice however due to intrinsic limitations in tissue characterization; it can not always produce a definite diagnosis of tubal localization of pregnancy (Kataoka et al 1999).
MR imaging was scored to indicate whether a tubal pregnancy was demonstrated & with that confidence as follows:
(1) Diagnostic (definite tubal pregnancy - presence of wall enhancement of dilated fallopian tube filled with haematoma or GS like structure).
(2) Suspicious (dilated enhancing tube filled with only a nonspecific fluid or only presence of haematosalpinx, cylindrical bloody structure with enhancement).
(3) Equivocal (haematoma or GS like structure without identifiable tubal finding).
(4) Questionable (only ascites).
Sometimes between uterus and the urinary bladder, haematoma is seen with intermediate signal on T1 WI & distinct low signal intensity on T2WI without any evidence of enhancement (Kataoka et al 1999)
| Conclusion|| |
Single nonviable fetus was well demonstrated on MRI study. Simultaneously a tract was also demonstrated between uterus and urinary bladder through which one fetus passes out from uterus to urinary bladder who could not be survived in the presence of urine and died. Some hematoma tissue was also demonstrated in uterine cavity. Thus it is concluded that though the sonography is the choice of investigation in the elevation of normal as well as abnormal pregnancy but MRI scored over ultrasound as it provided further detail regarding the fetus in urinary bladder presenting as mass in lower abdomen and also resulting into retention of urine. Also it nicely demonstrated the uterovesical fistulous tract through which uterine pregnancy could migrate to urinary bladder. Vaginal bleeding was the result of loss of one of the twin fetuses.
| References|| |
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|9.||Studdiford, W.E. : Primary peritoneal pregnancy, Am J. Obst. Gynae 44: 487-491, 1942. |
O P Sharma
7FF, Old Medical Enclave, Banaras Hindu University, Varanasi-221005
[Figure - 1], [Figure - 2], [Figure - 3]