Fetal and neonatal hypertension in twin-twin transfusion syndrome: a case report.

We report a case of fetal systemic hypertension. This occurred in an ex-donor twin soon after coagulation of chorionic vessels and amniodrainage performed for severe twin-twin transfusion syndrome during the 2nd trimester of pregnancy. Systemic hypertension was suspected because of a high systolic velocity through the tricuspid valve, and Bernoulli's equation was used to estimate the right intraventricular pressure. As both pulmonary arteries and ductus arteriosus were normal, the pressure in the aorta was considered to be equal to that in the right ventricle (60 mm Hg). Fetal systemic hypertension could have happened either because of a dramatic increase in placental resistances in the territory of the ex-donor twin or by reversal of the fetofetal transfusion pathological process.

Twin-to-twin transfusion syndrome: polyhydramnios-associated changes in maternal plasma volume and maternal plasma aldosterone concentrations. A preliminary study.

OBJECTIVE: Our aim was to evaluate the consequences of polyhydramnios on maternal plasma volume and maternal serum aldosterone and atrial natriuretic peptide (ANP) concentrations in monochorionic twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS). METHODS: The maternal plasma volume, ionograms as well as plasma ANP and aldosterone concentrations were compared in normal monochorionic diamniotic twin pregnancies and in TTTS. RESULTS: The maternal plasma volume was normal in TTTS despite severe polyhydramnios. The plasma aldosterone concentration was higher in pregnancies complicated by TTTS. CONCLUSION: The high plasma aldosterone concentration is likely to maintain normal plasma volume despite progressive extravascular volume enhancement. This suggests that TTTS is present early in pregnancy as a chronic phenomenon starting before its clinical expression and may trigger compensatory maternal hyperaldosteronism.

Management of a case of twin-to-twin transfusion syndrome by a combined surgical approach.

OBJECTIVE: The management of a case of severe twin-to-twin transfusion syndrome at 24 weeks of gestation is presented, using a combined surgical and medical approach. METHODS: Operative fetoscopy was used to coagulate placental vessels crossing the intertwin membranes. Repeated intrauterine transfusions were used to correct recurrent anemia in the donor twin. Selective three-dimensional placental angiography and directed histological analysis were used to study the placenta after delivery. RESULTS: Resolution of twin-to-twin transfusion syndrome was obtained by coagulation of placental anastomoses, but was followed by recurrent anemia in the donor twin. This was successfully treated by serial intrauterine blood transfusions, and 2 healthy twins were delivered at 31 weeks of gestation. One artery-to-vein anastomosis was demonstrated to be the only communication left between the two circulations. CONCLUSIONS: This case illustrates the limitations of placental surgery in twin-to-twin transfusion syndrome and highlights the need for ultrasound and Doppler follow-up of these high-risk fetuses to indicate further treatment. Placental anastomoses can be overlooked by macroscopic examination and injection technique, but can be demonstrated by placental angiography.

Influence of pregnancy on the pharmacokinetic behaviour and the transplacental transfer of the piperacillin-tazobactam combination.

The safety/acceptability, blood pharmacokinetics and urinary excretion of the piperacillin-tazobactam (PPR-TZB) combination were studied in six patients between 25 1/7 and 31 5/7 weeks of amenorrhea. The combination was given for a materno-fetal infection due to susceptible organisms i.e. 4/0.5 g/6 h. Whenever possible, the trans-placental transfer (TPT) of the combination was assessed in several sub-compartments of the feto-placental unit i.e. maternal blood sample, cord blood, amniotic fluid, placenta tissue and fetal urine. Two series of nine blood samples were scheduled for each patient, i.e. on D1 (first dose) and D3 (at plateau). Samples were assayed by HPLC and data were analyzed by a non-compartmental method. Safety/acceptability of the treatment proved to be good. The kinetic behavior of both beta-lactams appeared to be identical. Evidence was found during pregnancy of an increase in Vss and Cl of the combination. These increases can be linked to a notable decrease in AUCs. The TPT of the combination was significant. Regarding other accessible compartments (i.e. placenta tissue, amniotic fluid and fetal urine), the ratio of PPR-TZB concentrations was invariably about 8. Maternal circulating levels of PPR-TZB were, by 4 h, less than the MIC of target organisms (i.e. < or = 8 micrograms/ml), both on D1 and at steady state. This raises the question of the pertinence of the dosage regimen. Regarding PPR, it is accepted that antibacterial protection is satisfactory when circulating concentrations are kept at a Css (steady state concentration) of the order of 20 micrograms/ml or more. PPR-TZB combination would be administered by continuous infusion i.e. 8 mg/min to obtain 3 h later a Css of more than 20 micrograms/ml. The daily dosage would then be 12/1.5 g instead of 16/2 g, which is also more satisfactory from a pharmaco-economic standpoint. This proposal must be validated in a sufficient number of patients and, could avoid disqualification of the combination PPR-TZB in the treatment of serious infections during certain pathological pregnancies.

Effect of laser coagulation on placental vessels: histological aspects.

In order to evaluate the effect of laser coagulation on placental vessels and to define the optimal power density that should be used for this procedure, coagulation of placental vessels and histological examination were performed on freshly delivered placentae. This study suggests that 45- to 55-watt (6,000-7,666 J/cm2) shots can cause adequate placental injury. The extent of vascular lesions depends upon incident beam energy, fiber diameter, distance and angle to the vessel.

[Surgical treatment of twin-to-twin transfusion syndrome: coagulation of anastomoses with a Nd:YAG laser, under endosonographic control. Forty four cases]. / Traitement chirurgical du syndrome transfuseur-transfusé: coagulation des anastomoses par un laser Nd:YAG, sous contrôle écho-endoscopique. A propos de 44 cas.

Twin to twin transfusion syndrome occurs in 15% of monozygotic twin pregnancies and is characterized by a hemodynamic imbalance between the two fetuses. Survival is about 10% with expectant management. Our aim is to coagulate the placental vascular anastomoses joining the two fetal circulations on the placenta in order to prevent the consequences on the survivor when one dies in utero. Between November 1993 and April 1996, 44 patients were referred with severe twin to twin transfusion syndrome at less than 28 weeks' gestation. Nd:YAG laser coagulation of the placental vessels crossing the interamniotic membrane was performed under sono-endoscopic control. Forty-one patients have completed their pregnancy and 3 are continuing uneventfully in the third trimester. Fifteen patients (36.5%) delivered 2 healthy infants who survived the neonatal period and are developing normally. Sixteen patients (41.5%) delivered one infant developing, normally after the death of the co-twin in the perinatal period. In ten cases (22%) both twins died in the perinatal period. Among the survivors, 3 (9%) present with neurological handicap at a median age of 9 months. Around 75% (31/41) pregnancies complicated by twin to twin transfusion and treated by fetoscopy delivered at least one healthy baby. These data confirm the feasibility of the technique and that morbidity in-the survivors is relatively low.