| |
Placenta
previa is implantation of the placenta at or near the cervix
(Figure 12.1).
If you suspect placenta previa, do not perform a vaginal examination unless preparations
have been made for immediate caesarean section.
| 1 |
Perform
a careful speculum examination to rule out other causes
of bleeding such as cervicitis, trauma, cervical polyps
or cervical malignancy. The presence of these, however,
does not rule out placenta previa. |
| 2 |
Assess
the amount of bleeding. |
| 3 |
Restore
blood volume by infusing IV fluids (normal saline or
Ringer’s
lactate). |
| 4 |
If
bleeding is heavy and continuous, arrange for caesarean
delivery, irrespective of fetal maturity. |
| 5 |
If
bleeding is light or if it has stopped and the fetus
is alive but premature, consider expectant management
until delivery or heavy bleeding occurs:
| • |
Keep
the woman in the hospital until delivery |
| • |
Correct
anaemia with oral iron therapy |
| • |
Ensure
that blood is available for transfusion, if required |
| • |
If
bleeding recurs, decide management after weighing
benefits and risks
for the woman and fetus of further expectant management versus delivery. |
|
Confirming
the diagnosis
If a reliable ultrasound examination can be performed, localize the placenta. If
placenta previa is confirmed and the fetus is mature, plan delivery.
If ultrasound is not available or the report is unreliable and the pregnancy
is less than 37 weeks, manage as placenta previa until 37 weeks.
If ultrasound is not available or the report is unreliable and the pregnancy
is 37 weeks or more, examine under double set-up to exclude placenta previa, with
the woman in the operating theatre with the surgical team present.
The double set-up prepares for either vaginal or caesarean delivery, as follows.
| 1 |
Ensure
IV lines are running and crossmatched blood is available. |
| 2 |
Use
a sterile vaginal speculum to see the cervix:
| • |
If
the cervix is partly dilated and placental tissue
is visible, the diagnosis
is confirmed; plan caesarean delivery |
| • |
If
the cervix is not dilated, cautiously palpate the
vaginal fornices:
– If you feel spongy tissue, confirm placenta previa and plan caesarean
delivery
– If you feel a firm fetal head, rule out major placenta previa and
proceed to deliver by induction |
| • |
If
a diagnosis of placenta previa is still in doubt,
perform a cautious
digital examination:
– If you feel soft tissue within the cervix, confirm placenta previa and
plan delivery (below)
– If you feel membranes and fetal parts both centrally and marginally,
rule out placenta previa and proceed to deliver by induction. |
|
Women
with placenta previa are at high risk for postpartum haemorrhage
and placenta accreta/increta, a common finding at the site
of a previous caesarean scar.
If delivered by caesarean section and there is bleeding from the placental site:
| 1 |
Under-run
the bleeding sites with sutures. |
| 2 |
Infuse
oxytocin 20 units in 1 L IV fluids (normal saline or
Ringer’s lactate) at 60 drops per minute.
|
| 3 |
If
bleeding occurs during the postpartum period, initiate
appropriate management. This may include artery uterine
ligation or hysterectomy. |
|
|
|
