Ante Part Um Haemorrhage

ANTEPARTUM HAEMORRHAGE:PLACEN TA PREVIA

Definition/Introduction Antepartum haemorrhage is bleeding from the genital tract that occurs between the age of fetal viability(28th week of pregnancy) and the delivery of the fetus. It is an obstetric emergency and also a significant cause of both maternal and perinatal morbidity and mortality. It occurs in about 3% of all pregnant women. In UPTH, it accounted for 4.8% of admissions into the Ante-natal Ward in 2003 (Annual Report).

Causes of APH  

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Placenta praevia Placental abruption (abruptio placenta) Local causes: cervical polyps, cervicitis, cancer of the cervix, postcoital genital laceration Vasa praevia Unknown

PLACENTA PRAEVIA  

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Literally means afterbirth first It is the location of the placenta either partially or completely in the lower uterine segment. It is believed to occur due to a delay in implantation of the blastocyst in the uterine cavity. The extent of the attachment to the lower uterine segment determines both the management and prognosis. Incidence varies between 0.4-0.8%. In UPTH- 2.8% in 2003.

Aetiology .Cause unknown .Multiparity .Multiple pregnancy .Previous Caesarean delivery .Previous myomectomy .Previous induced abortion .Older women .Cigarette smoking/cocaine use .Uterine fibroids/other uterine abnormalities

Pathophysiology 

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Placenta praevia typically occurs as a result of abnormally low implantation believed to result from abnormal endometrial vascularisation related to atrophy or scarring from prior trauma or inflammation. The margins of the abnormally implanted placenta are altered as the lower uterine segment thins out in late pregnancy. Various degrees of placental detachment may develop with ensuing maternal haemorrhage from the intervillous spaces. In the absence of the decidua basalis, the placenta can attach directly to the myometrium (Accreta), invade the myometrium (Increta),or penetrate it (percreta). Placenta accreta occurs in ~ 1 in 2500 deliveries and the rate is increased to 10% in women with placenta praevia.

CLASSIFICATIONS 

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Type I- the placenta is located in the lower uterine segment but does not reach the internal os Type II- it is attached to the lower uterine segment with its lower margin reaching the internal os but does not cross it to the opposite side. IIA- anterior, IIB- posterior. Type III- the placenta is in the lower uterine segment and covers the internal os but not completely Type IV- the placenta is centrally placed and completely covers the internal os Placenta praevia types I and IIA may also be classified as Minor degree placenta praevia and types IIB-IV as Major degree. Another method of classification labels the occurrence of placenta praevia as i) Marginal when the placenta approaches the border of the internal os, ii) Partial when it partially covers the internal os and iii) Total when the internal os is completely covered.

Differential Diagnosis     

Abruptio placenta Cervicitis Cervical laceration Heavy show Vasa praevia