Mark Denbow

Outcome of fetal pleural effusions treated by thoracoamniotic shunting

Fetal pleural effusions are uncommon, and treatment options for moderate or severe effusions include drainage and thoracoamniotic shunting. However, relatively few records of effusions treated by thoracoamniotic shunting are available in the literature, so our objective was to study the outcome after thoracoamniotic shunting in our unit.

A small-angle neutron scattering and rheology study of the composite of chitosan and gelatin.

The composite chitosan/gelatin solutions and films formed from these solutions were studied by rheological measurements, SANS and tensile tests. The relationship between the inter-molecule interactions with microstructure, rheological behaviour of a solution and eventually the mechanical performance of formed films was established. It was found that the complex formed between chitosan and gelatin was mainly through hydrogen bond but the size of the structure was also affected by electrostatic repulsions. The local structure (correlation length) and the global structure (large inhomogeneous structure size) in the composite solutions were found to be highly correlated to each other. It was also found that the interactions between these two polymers in solution were closely related to the mechanical properties of the formed films. This work will enable one to design films with desired mechanical properties through the combination of different polymers at optimum weight ratios.

Management and outcome of pregnancies with parvovirus B19 infection over seven years in a tertiary fetal medicine unit

Objectives: To determine rates of fetal anaemia and pregnancy outcome in susceptible pregnant women infected with human parvovirus B19 infection in a tertiary fetal medicine department over a 7-year period. Additional features enabling identification of fetuses that progress to severe anaemia were also investigated. Methods: Forty-seven susceptible, pregnant women with confirmed parvovirus infection referred to a regional fetal medicine unit, over a 7-year period (1999–2006), were identified. Where possible maternal serum AFP measurements were obtained from second-trimester serum screening and the presence or absence of echogenic bowel noted. Results: Of the 47 cases, one was excluded. Of the remaining 46 cases, 34 (74%) showed no signs of fetal anaemia and delivered at term. The remaining 12 (26%) showed signs of fetal anaemia. Eight of the 12 developed hydrops and underwent fetal blood sampling and transfusion (median pretransfusion Hb 3.6 g/dl). Seven of the 8 transfused fetuses were thrombocytopenic with a platelet count <150 × 109/l, with 2 fetuses having platelet counts <50 × 109/l. The median gestation age at transfusion was 22 weeks (range 18–27 weeks). The median number of weeks between seroconversion and transfusion was 6 (range 3–12). The signs of anaemia resolved after one transfusion in 5 of the 8 transfused fetuses and they subsequently delivered at term. There were 2 fetal deaths during or shortly after transfusion and one neonatal death following delivery at 28 weeks gestation due to severe pre-eclampsia, 5 days after successful transfusion. Conclusions: Following parvovirus seroconversion, the incidence of significant fetal anaemia requiring transfusion was 17%. Seroconversion after 21 weeks did not result in severe fetal anaemia. Significant anaemia requiring intervention did not occur 12 weeks after maternal seroconversion. We did not demonstrate a correlation with either maternal serum AFP or the presence of fetal echogenic bowel and the development of severe fetal anaemia. Because of the association between fetal anaemia and severe thrombocytopenia, it may be prudent to have compatible platelets available at the time of fetal blood sampling.

Prognosis of Spina Bifida in the Era of Prenatal Diagnosis and Termination of Pregnancy

Objective: To evaluate the current outcome of a selected prenatally diagnosed spina bifida group. Materials andMethods: We analyzed and followed up 74 cases of prenatally diagnosed spina bifida. Results: Termination of pregnancy was chosen in 72% of the cases and 28% were live-born. Chromosomal defects were identified in 16%, although only 1.6% in isolated cases. Of the 21 live births, 3 died in the neonatal period. The other 18 (86%) were all alive after an average follow-up of 3 years and 6 months (range 5 months to 7 years and 4 months). From this group 11% are wheelchair-dependent, 87% of the patients older than 2 years of age are walking, 33% have had cerebral shunting and 72% have normal neurodevelopment. There was a better outcome in patients with closed defects; however, the rates of neuropathic bladder (50%) remain a concern. Conclusions: Even with prenatal diagnosis and a tendency towards apparently less severe defects in the cases in which the pregnancies continue, the prognosis in terms of morbidity needs to remain guarded.

Comparison of different reference values of fetal blood flow velocity in the middle cerebral artery for predicting fetal anemia

To compare different normal reference ranges of fetal blood flow velocity in the middle cerebral artery for predicting fetal anemia.

Optimal Interval between Middle Cerebral Artery Velocity Measurements when Monitoring Pregnancies Complicated by Red Cell Alloimmunization

Objective: To evaluate the optimal interval between middle cerebral artery (MCA) Doppler measurements when monitoring pregnancies complicated by red cell alloimmunization. Methods: Thirty-nine fetal blood samplings (FBS) performed on 24 pregnant women with red blood cell alloimmunization followed up using both MCA peak systolic velocity and time-averaged mean velocity measurements on weekly basis. Results: In total, 65.5 and 37.5% of women with moderate or severe fetal anemia had abnormal MCA Doppler values 1 and 2 weeks, respectively, before FBS was performed. Conclusions: A weekly assessment of women at risk for fetal anemia is optimal in most of the cases even though 35.5% of cases of moderate or severe fetal anemia are expected to have normal Doppler measurements the week before the decision of doing an FBS is made.

Diagnostic accuracy of placental growth factor and ultrasound parameters to predict the small-for-gestational-age infant in women presenting with reduced symphysis-fundus height.

To assess the diagnostic accuracy of placental growth factor (PlGF) and ultrasound parameters to predict delivery of a small‐for‐gestational‐age (SGA) infant in women presenting with reduced symphysis–fundus height (SFH).

Amniotic fluid index in low-risk, post-dates pregnancies.

Objective: To determine normal values for amniotic fluid index (AFI) in uncomplicated post-dates singleton pregnancies and compare it to current reference ranges. Population: Four hundred and forty-eight women with singleton, uncomplicated pregnancies, presenting for post-dates assessment (gestation 40+0 to 42+0 weeks) between January 1, 2004 and June 30, 2005. Methods: Ultrasound assessment of liquor to calculate the AFI. Results: The mean and standard deviation for AFI in the sample was 9.86 (SD 3.4), which is significantly different to the mean of the currently used reference range (mean 11.6, SD 3.9, p < 0.0001). The 5th percentile in this population was 4.6 cm. Conclusions: This study has demonstrated lower mean and 5th percentile values for AFI in post-dates pregnancies than current reference ranges. It has the largest published UK study population, and can therefore be used as a reference range in similar populations, which is likely to reduce unnecessary obstetric interventions.

OP06.12: Use of middle cerebral artery Doppler velocity to time the first invasive procedures in pregnancies affected by red cell alloimmunisation

Group B included 24 subsequent pregnancies, that were managed by weekly administration of IVIG without monitoring platelet counts. The treatment started in the 18th–24th gestational week and was continued until delivery. Group C included 6 pregnancies, in which the women refused treatment despite our counselling. Results: All treated fetuses were delivered by elective c/s, except for three cases, in which vaginal delivery was achieved, after confirming a fetal platelet count above 50,000. The mean platelet count at birth after IVIG treatment was 118,000 (range 11,000–320,000), compared to 25,000 (range 8000–70,000) among the 17 first affected siblings and 24,000 (range 10,000–44,000) among the 6 infants whose mothers refused treatment (p < 0.005). Only 8% (2/24) of the treated fetuses had platelet counts of less than 30,000 at birth compared to 70% (16/23) of the untreated siblings (p < 0.05). None of the treated and nontreated fetuses had an abnormal brain ultrasonographic findings or an intracranial hemorrhage. Conclusions: Non-invasive management of alloimmune thrombocytopenia consisting of only immunoglobulin administration is highly effective and seems safe in women without a history of intracranial hemorrhage. Therefore, the value of performing cordocentesis and platelet transfusions is doubtful in view of its risk for the fetus, and the fact that IVIG therapy so effectively improves the fetal platelet count