Fatal fetal hemorrhage and placental pathology. Report of three cases and a new setting.

We report three cases of late third trimester fetal death in utero consequent to fetal exsanguination from the chorionic vasculature. In general, fetal hemorrhage is unusual, exsanguination is rare and the location and basis of the hemorrhage varies widely. Intragestational and intrapartum hemorrhage is far more often of maternal rather than fetal origin. Even when severe, the former is almost always manageable whilst the latter may be clinically obscure, intractable, catastrophic and fatal. In this presentation, we review and characterize fetal hemorrhage by anatomical location and on the basis of its underlying origins. In our first two cases, the chorionic vascular failure is understood on the basis of mechanical factors, such as tearing by the presenting part or an amniotomy hook. Our third case demonstrates the first reported instance in which a severe chorionic vasculopathy has damaged a placental surface vessel sufficiently to permit spontaneous rupture and fetal exsanguination.

Identification of a candidate membrane protein for the basolateral peptide transporter of rat small intestine.

A candidate protein for the basolateral peptide transporter of rat jejunum is described. Vascular perfusion of the photoaffinity label, [4-azido-D-phe]-L-ala (2.5mM), had no effect on the transepithelial transport of the non-hydrolysable dipeptide D-phe-L-gln (1mM) from the lumen, its mucosal accumulation or wash-out into the vascular perfusate. When the label was perfused luminally, the transepithelial transport of D-phe-L-gln was inhibited by 38% (P<0.001) and accumulation increased by 62% (P<0.05). These data are consistent with those of a basolateral transporter that is strongly asymmetric in its substrate binding and transport properties. Labelling of basolateral membrane vesicles with [4-azido-3,5-3H-D-phe]-L-ala revealed that the majority of label was incorporated into a single protein of M(r)112+/-2 kDa and pI 6.5. MALDI-TOF analysis of tryptic digests of the protein followed by database searches established that this protein was novel with no obvious similarity to PepT1, the apical membrane transporter.