Despite widespread use of prenatal biochemistry, evaluation of amniotic fluid by the amniotic fluid index remains a reproducible and inexpensive method to predict renal function in cases of bilateral obstructive uropathy of any origin. It retains its validity not only in severe, but also in milder reductions. Conversely, intact amniotic fluid mostly invariably predicts normal renal function at long-term evaluation. For a better understanding of the disease such information is to be promptly conveyed to the prospective parents at each prenatal consultation.

Objective To compare procedure-related pregnancy loss after second-trimester genetic amniocentesis in women given an antibiotic prophylaxis and controls.Methods Prospective, open randomised controlled single-centre study between January 1999 and December 2005 at Artemisia Fetal Maternal Medical Centre. A follow-up within 4 weeks after the procedure was done.Of 36 347 eligible women, 1424 refused to participate and 34 923 were enrolled and randomised with unequal chance of selection, 21 991 were assigned to treatment group and 12 932 were assigned to the control group, and did not receive any placebo. Oral azithromycin, 500 mg per day, was administered 3 days before amniocentesis. The primary endpoint was the procedure-related pregnancy loss. The secondary endpoint was the rate of preterm premature rupture of membranes. ResultsThe rate of abortion related to the amniocentesis was 7/21 219 women (0.03%, 95% CI 0.009-0.057) in the intervention group, and 36/12 529 (0.28%, 0.28-0.30) in controls (p = 0.0019). The rate of preterm premature rupture of membranes was 14/21 219 (0.06%, 0.031-0.101) in the intervention group, and 140/12 529 (1.12%, 0.94-1.30) in the control group (p = 0.001).Conclusions Antibiotic prophylaxis before second-trimester amniocentesis reduced the risk of abortion and of rupture of the membranes.

Introduction: recent studies have proposed the introduction of cell-free fetal DNA testing (NIPTNon Invasive Prenatal Testing) in routine clinical practice emphasizing its high sensibility and specificity. In any case, false positive and false negative findings may result from placental mosaicism, because cell-free fetal DNA originates mainly from placenta. Case: we report six cases of women who underwent chorionic villus sampling (CVS) or amniocentesis to confirm the results from NIPT: two Turner syndromes, two Triple X, one Patau syndrome, one Edward syndrome. Results: using classic cytogenetic analysis and, also, Array -Comparative Genomic Hybridization (Array CGH) the karyotype of all 5 fetuses was found to be normal. Conclusion: results from NIPT must always be confirmed by invasive prenatal diagnosis. It is mandatory to inform the patient that the CVS and amniocentesis still represent the only form of prenatal diagnostic test available.

Objective: Prenatal diagnosis of urinomas has long been established with underlying obstructive uropathy generally responsible for urinary extravasation. Because urinoma formation represents a pop-off mechanism in cases of posterior urethral valves, the number of affected males greatly exceeds the number of females. Fetal urinoma has rarely been reported without obstruction and in females it has only been described as a consequence of a complicated amniocentesis. Methods: Three cases of fetal urinoma in female fetuses without any dilatation of the urinary tract are described. Since the fetus remained healthy, they were all conservatively managed. Results: Two urinomas resolved after birth and 1 exhibited significant regression. In the second case, a compressed kidney was visualized with fetal MRI. Renal function was impaired in cases 1 and 3 and absent in case 2 (the kidney was no longer visualized). Conclusions: Fetal urinomas can occur even in the absence of urinary tract obstruction and in a low-pressure system as is found in female fetuses. Fetal MRI may help both visualize the ipsilateral kidney and differentiate the mass from other conditions. In a healthy fetus, fetal urinomas can be conservatively managed, but renal function after birth is often absent or impaired. Whether or not in utero aspiration may be beneficial for the preservation of renal function remains unclear.

Objective: Oligohydramnios (OA) is nowadays regarded as one of the best markers of renal function (RF) impairment in bladder outlet obstruction (BOO) detected in utero. As such, its onset is usually early and progressive because of decline in fetal urine production. A series of acute OA complicating pregnancies with BOO has never been reported. Methods: Over a 7-year period, 5 fetuses with in utero suspicion of BOO exhibited an abrupt decrease of amniotic fluid after the 30th week of gestation. Results: All fetuses were delivered by cesarean section: diagnosis was posterior urethral valves in 3 cases, urethral atresia in 1, and prune-belly syndrome in 1. Urologic work-up demonstrated a unilateral vesicoureteral reflux dysplasia (VURD syndrome) in all 5 fetuses. RF at 1 year was normal in 4 fetuses and impaired in 1. Conclusions: Besides obstetrical reasons, OA may also have acute onset occurring in the presence of anomalies of the urinary tract; although diagnosis is almost always BOO, functional and anatomical characteristics of the urinary tract are those of VURD syndrome with a non-functioning, refluxing renal unit. The associated acute OA/VURD syndrome may represent a milder expression of a pop-off mechanism advocated in this syndrome with a more favorable prognosis than progressive OA detected early in pregnancy.