Tehran University Medical Journal

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Background: True umbilical cord knot is one of the abnormalities of the umbilical cord. Active fetal movements create cord knotting. True umbilical cord knots are rare but may be associated with fetal distress and stillbirth. True umbilical cord knots are capable of impeding blood flow to the fetus.
Case presentation: A 26-year old primigravid woman was first treated for genital herpes simplex virus (HSV type 2) at 36 weeks of gestational age. She received oral acyclovir (400 mg three times daily for 10 days). At the gestational age of 38 weeks and 5 days, fetal activity decreased and NST was nonreactive. She was delivered by cesarean section and a true umbilical cord knot was found. Four years later, in her second pregnancy, another true knot was seen.
Conclusion: Excessively long umbilical cords are more likely to be associated with true knots. Genetics has an important role in determining cord length and occurrence of true knots.

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Background: Tubal sterilization is the permanent and effective contraception method. This can be performed at any time, but at least half are performed in conjunction with cesarean or vaginal delivery and are termed puerperal. The most complication after tubal ligation is ectopic pregnancy. Ectopic pregnancy is the leading cause of maternal death in first trimester.
Case presentation: We present a 33 years old woman gravida5, para4, all normal vaginal delivery, presented with complaints of delayed menstrual period, pelvic pain and spotting. She underwent tubal ligation for two times. For the first time she had puerperal Pomeroy tubal sterilization after third child delivery. Intra uterine pregnancy occurred three years later. One day after vaginal delivery of fourth child, she underwent post partum tubal ligation with the Parkland method. Tubal pregnancy occurred nine months later. Physical examination identified acute abdomen. Pelvic ultrasound showed no gestational sac in uterine cavity. The sac with fetal pole was in right adnexa. Beta-HCG was 2840mIU/ml. She underwent laparotomy. Surgical management included salpingectomy with cornual resection in both sides. The surgery identified Ectopic pregnancy.
Conclusion: Any symptoms of pregnancy in a woman after tubal ligation must be investigated an ectopic pregnancy should be excluded. Ectopic pregnancy must be considered, in any woman with lower abdominal pain, missed period and vaginal bleed-ing. Conception after tubal sterilization can be explained by fistula formation and re-canalization of fallopian tube.

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Background: Cerebral venous thrombosis (CVT) is uncommon after cesarean section. Although it can be a leading cause of maternal mortality. CVT may occur during pregnancy because of hypercoagulable states such as preeclampsia, thrombophilias, antiphospholipid antibody syndrome and sepsis.
Case presentation: A 31 years old woman G2 Ab1 at 37 weeks gestational age with  premature rupture of membrane underwent cesarean section because breech presentation and preeclampsia. Spinal anesthesia was done for emergent cesarean section. On the second day after cesarean section, she developed headache, vomiting, focal neurologic deficits, paresthesia, blurred vision. Brain magnetic resonance imaging (MRI) showed thrombosis in anterior half of superior sagittal sinus. Treatment consisted of anticoagulation. 
Conclusion: Thrombophilias, pregnancy-related hypertension and cesarean section are the predisposing factors for thromboembolism. Unfractionated heparin and low molecular weight heparin (LMWs) are effective drugs for thromboprophylaxis. It is vital to prevent venous thrombosis to reduce mortality during both intrapartum and postpartum periods. Consideration of cerebral venous thrombosis in similar cases is recommended.

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Background: A variety of endocrine disorders can complicate pregnancy. Diabetes insipidus although uncommon, may have devastating effect on pregnancy outcome, if unrecognized and untreated. The etiology of diabetes insipidus is often unknown, many cases are likely autoimmune, with lymphocytic infiltration of the posterior pituitary gland. Massive polyuria, caused by failure of the renal tubular concentrating mechanism, and dilute urine, with a specific gravity 1.005, are characteristic of diabetes insipidus. The diagnosis of diabetes insipidus relies on the finding of continued polyuria and relative urinary hyposmolarity when water is restricted. Most women require increased doses Desmopressin Acetate during pregnancy because of an increased metabolic clearance rate stimulated by placental Vasopressinase. By this same mechanism, subclinical diabetes insipidus may become symptomatic during pregnancy. Transient diabetes insipidus is associated with acute fatty liver and HELLP syndrome as well as twin gestation. Increased placental Vasopressinase activity, along with insufficient liver degradation in HELLP syndrome and acute fatty liver, may unmask this condition. Diabetes insipidus in pregnancy is rare. The disease results from inadequate or absent antidiuretic hormone (vasopressin) production by the posterior pituitary gland. The increased glomerular filtration rate seen in pregnancy may increase the requirement for antidiuretic hormone. Case presentation: We present a 39 years old woman, gravida3 para3, was admitted to Akbarabadi Teaching Hospital in september 2013. She was admitted due to polyuria, malaise, thirst with slight fever, six days after normal vaginal delivery. The urine volume was 8 lit/day and the specific gravity (S.G.) of the urine was 1.010. The urine osmolarity was lower than the plasma osmolarity. Electrolyte serum examination showed hypernatremia. The patient received 5 µg/day of synthetic vasopressin, in the form of l- deamino-8-Darginine vasopressin (DDAVP). This drug was given as intranasal spray in doses 0.25 mg twice daily. Plasma electrolytes and fluid status monitored carefully with initiation of therapy. DDAVP was used because it was not degraded by vasopressinase. Treatment was continuing, when the symptoms of central diabetes insipidus resolve and urinary concentrating ability was preferred. Maximum urinary osmolality over the next 11 hours was assessed, 730 mosm/kg was considered normal. Conclusion: Close attention to electrolyte and fluid balance is important in the postpartum period. The symptoms of transient vasopressin-resistant diabetes insipidus resolve in few days to a few weeks after vaginal delivery or when hepatic function returns to normal.