Prenatal presentation of transient central diabetes insipidus.

INTRODUCTION: Nephrogenic diabetes insipidus (DI) in the foetus has been described as a rare presentation of severe polyhydramnios. DISCUSSION: We report a case of foetal central DI, characterised by severe polyhydramnios. Significant polyuria was noted at birth. Serum AVP level was un-measurable (<0.5 pg/ml). A dramatic response to intravenous dDAVP (desmopressin) was noted confirming central DI. Further investigations did not reveal a recognised cause for central or nephrogenic DI. The infant thrived well on a small dose of oral desmopressin until the age of 12 months. At 13 months, a water deprivation test revealed a normal ability to concentrate urine without desmopressin, and subsequently, the infant has thrived without further treatment. The transient nature of the central DI remains obscure but could be explained by a maturational delay in the tissues involved in AVP synthesis or release, during intrauterine life and infancy. CONCLUSION: Both nephrogenic and central DI should be considered as a cause of severe polyhydramnios. This may help to guide prompt intensive management and investigation, with attention to vascular access, central venous pressure, urine output monitoring and replacement.

The use of culture-independent tools to characterize bacteria in endo-tracheal aspirates from pre-term infants at risk of bronchopulmonary dysplasia.

Although premature infants are increasingly surviving the neonatal period, up to one-third develop bronchopulmonary dysplasia (BPD). Despite evidence that bacterial colonization of the neonatal respiratory tract by certain bacteria may be a risk factor in BPD development, little is known about the role these bacteria play. The aim of this study was to investigate the use of culture-independent molecular profiling methodologies to identify potential etiological agents in neonatal airway secretions. This study used terminal restriction fragment length polymorphism (T-RFLP) and clone sequence analyses to characterize bacterial species in endo-tracheal (ET) aspirates from eight intubated pre-term infants. A wide range of different bacteria was identified in the samples. Forty-seven T-RF band lengths were resolved in the sample set, with a range of 0-15 separate species in each patient. Clone sequence analyses confirmed the identity of individual species detected by T-RFLP. We speculate that the identification of known opportunistic pathogens including S. aureus, Enterobacter sp., Moraxella catarrhalis, Pseudomonas aeruginosa and Streptococcus sp., within the airways of pre-term infants, might be causally related to the subsequent development of BPD. Further, we suggest that culture-independent techniques, such as T-RFLP, hold important potential for the characterization of neonatal conditions, such as BPD.

Molecular microbiological characterization of preterm neonates at risk of bronchopulmonary dysplasia.

The role of infection in bronchopulmonary dysplasia (BPD) is unknown. We present an observational study of 55 premature infants born weighing less than 1.3 kg within two level III neonatal intensive care units. Endotracheal aspirates (ETA) and nasogastric aspirates (NGA) were studied with denaturing gradient gel electrophoresis (DGGE) profiling to elucidate the total bacterial community, and species-specific PCR was used to detect the presence of Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum. DGGE identified bacterial species in 59% of NGA and ETA samples combined. A diverse range of species were identified including several implicated in preterm labor. Species-specific PCR identified M. hominis in 25% of NGA and 11% of ETA samples. Among the 48 infants surviving up to 36 wk-postconceptual age, ordinal logistic regression showed the odds ratio for BPD or death where Ureaplasma was present/absent as 4.80 (95% CI 1.15-20.13). After adjusting for number of days ventilated, this was reduced to 2.04 (0.41-10.25). These data demonstrate how the combined use of DGGE and species-specific PCR identifies a high exposure in utero and around the time of birth to bacteria that might be causally related to preterm delivery and subsequent lung injury.

Anti-C(w) alloimmunization presenting as hydrops fetalis.

UNLABELLED: C(w) is a low frequency red cell antigen that belongs to the Rh blood groups system. While not uncommon, anti-C(w) is rarely associated with clinically significant haemolytic disease of the newborn (HDN). When it does occur, it is often subclinical or of mild to moderate clinical severity. In the majority of pregnancies it is considered to be a naturally occurring antibody and has not been reported to cause hydrops fetalis or stillbirth. We report a case of anti-C(w) alloimmunization, which was associated with significant anaemia and hydrops fetalis, presenting at 35 wk gestation. CONCLUSION: Pregnancies affected by anti-C(w) merit closer scrutiny. Consideration should be given to performing more frequent antenatal ultrasound assessments to detect hydrops fetalis. This may help to support the need for more invasive procedures (cordocentesis and intrauterine transfusions).