A British Medical Association Lecture on the Diagnosis and Treatment of Placenta Praevia
Authors: J. Barris
Journal: BMJ (1926)

THE subject of the diagnosis and treatment of placenta praevia is not only one of the greatest practical importance, but one much debated and upon which opiniion is still divided. DIAGNOSIS.It is first necessary to ascertain whether the blood comes rough the cervical canal or from disease of the lower genital tract-as, for instanice, carcinoma of the cervix.his can be determined by examination with the finger and iith tlhe speculum.If the blood be found to come through te canal we have then to decide between a diagnosis of jcidental haemorrhage or of placenta praevia.The presence of placenta praevia may be conjectured if the haemorrhage has been repeated owing to the gradual Zretching of the' lower uterine segment and resultant paration of it from the placenta.The existence of a- Ialposition of the foetus, or the fintding of the feetal head too high or.unengaged,more especially in a primigrav;i(la St or near term in whom the pelvis is not contracted, is also suggestive of the condition.It is possible that if the woman is very thin the placenta may be-palpable as a boggy mass at the pelvic brim on abdominal examination, or that the head may be felt more clearly one side than in the other.An unusually loud uterine souffle over this area has sometimes been noted.Vaginal examination may reveal a spongy resistance in-the fornices obscuring the presenting part.The absence of albuminuria is also suggestive; it is much more commonly present in accidental 4iaemorrhage, although several cases have now been recorded iM which this condition has been found in association also iith placenta praevia.-If,therefore, there is bleeding but no malposition, if she head is engaged an-d albumin is present, a diagnosis of accidental haemorrhage is suggested.If, on the other land, the bleeding has been repeated, the head is Eigh, here is a malposition, and albumin is absent,.placenta .raevia is the more probable diagnosis.But none of.these*ymptoms or physical signs is of itself sufficient to eniable is to establish a, diagnosis.-Theonly certain way to iagnioso placenta praevia is to.feel.theplacenta through the cervical canal; if then the spongy placenta can be felt tho diagnosis is certain.Blood clot or a vesicular mole may be mistaken for the placenta; the former is distin- guished by its friability and the ease with which the finger cain be pushed through it.A vesicular mole is moro diffil cult to distinguish, but the bleeding usually occurs-far earlier .inpregnancy; the undue size of the uterus: in rela- tion.to the Period of amenorrhoea and the inability, to feel ,a foetus on abdominal palpation' or to obtain internal ballottement serve to distinguish between the two con- ditions.It is rare that the cervix will not admit the Fnger; but if the cervix is closed, or if when open. the sxamining finger cannot reach the placenta, the diagniosis gust still remain in doubt.Now early diagnosis is an essenitial part of the treat- ent of placenta praevia.It has therefore been suggested hat if, during the later weeks of pregnancy, the cervix he closed, an attempt shtuld be made to establish the liagnosis by passing a metal dilator tlhrough the canal, foi if on withdrawing it bleeding occurs the presence of the ilacenta can certainly be inferred.In almost all cases, owever, the cervix will allow the finger to be passed if -are and gentleness are employed.TM~Duna L MEIDICAL JOUBEAS TREATMENT.We may first review the principles upon which the treatment must be based.