MicroRNA changes in maternal serum from pregnancies complicated by twin-twin transfusion syndrome: A discovery study.

OBJECTIVE: MicroRNAs (miRNAs) are used as biomarkers in cardiovascular disease and cancer. miRNAs are involved in placental development but have not previously been investigated in twin-twin transfusion syndrome (TTTS). Our aim is to explore the miRNA profile of TTTS pregnancies. METHOD: Initial miRNA profiling was performed using a reverse transcription polymerase chain reaction (RT-PCR) panel on maternal serum samples taken from five women prior to fetoscopic laser ablation for TTTS and compared with serum samples from five women with uncomplicated monochorionic diamniotic twin pregnancies. Validation RT-PCR was performed in an additional cohort of eight TTTS pregnancies and eight uncomplicated pregnancies. RESULTS: Median gestational age at sampling in the TTTS and control groups was 20+0  weeks (interquartile range [IQR], 19+4 -20+0 ) and 20+2  weeks (IQR, 20+0 -20+2 ), respectively. All samples passed quality control. One control sample was excluded as a biological outlier. Thirty-one of 752 miRNAs were significantly different: 17 were upregulated and 14 downregulated in the TTTS group, although they did not remain significant following Benjamini-Hochberg correction for multiple testing. The six miRNAs chosen for validation demonstrated no significant difference. CONCLUSION: This is the first study to investigate miRNA changes in TTTS pregnancies. We did not demonstrate a statistically significant difference in miRNAs in TTTS pregnancies, but further investigation is required.

Congenital urinary tract obstruction.

Congenital bladder neck obstruction (or lower urinary tract obstruction [LUTO]) describes a heterogeneous group of congenital anomalies presenting with similar prenatal ultrasonographic findings of dilated posterior urethra, megacystis, hydronephrosis, oligohydramnios and often with associated renal dysplasia. Untreated LUTO has high rate of perinatal morbidity and mortality from associated pulmonary hypoplasia and early-onset renal failure in infancy. Ultrasonographic features and prospective fetal urinalysis may help in predicting the overall prognosis of congenital LUTO. Currently, fetal vesicoamniotic shunt (of various designs), and fetal cystoscopy and fulguration of the obstruction are potential prenatal interventions. Retrospective and prospective cohort studies and a relatively small randomized controlled trial have demonstrated these treatments may possibly improve perinatal survival. Despite this, concerns remain as to the high rates of renal impairment observed in paediatric survivors. A clinical prospective scoring/staging system may improve prenatal diagnostic criteria and case selection for fetal therapy.

Prenatal thoraco-amniotic chest drain insertion to manage a case of fetal hydrops secondary to FOXC2.

Lymphoedema-distichiasis is an inherited autosomal dominant disorder of the lymphatic system. Rarely, it is associated with fetal hydrops; the risk and severity of which increases with successive generations. The causative gene is a member of the forkhead transcription factor family (FOXC2). We describe a fetus presenting with early-onset, rapidly progressing body wall oedema, bilateral pleural effusions and a pericardial effusion in a mother with known FOXC2 mutation. First trimester chorionic villus sampling confirmed FOXC2 mutation in the fetus when there was only a large nuchal translucency. As the phenotype progressed, the couple consented to in utero ultrasound-guided insertion of sequential bilateral pleuro-amniotic chest drains (at 23 weeks) which successfully drained the pleural effusions. The fetus was delivered at 39 weeks gestation by elective caesarean section in good condition. The shunts were removed postnatally, and the baby was discharged after 7 days. This is the first case described of a fetus with severe early-onset fetal hydrops secondary to FOXC2 mutation successfully treated by the prenatal insertion of bilateral pleuro-amniotic shunts.