Placenta Flashcards
Low lying placenta is..?
when the placental edge is less than 20mm from internal os
If low lying placenta, when to reassess?
32 weeks
If still low rescan at 36 weeks to plan MOD
Should women with placenta praevia/low lying placenta get steroids?
Offer at 34-36 weeks as they have a higher risk of pre-term delivery
When should delivery be planned in low lying placenta/praevia?
If bleeding or risk factors 34-37 weeks
If uncomplicated praevia 36-37w
Things to consider at CS for placenta praevia
May need to convert to GA
Use cell salvage, consider cross match
Consider vertical skin/uterine incisions when fetus is transverse lie to avoid placenta, particularly <28w
Consider using US to determine placental location
If placenta is transected, immediately clamp cord to minimise blood loss
If pharmacological measures fail to control haemorrhage, initiate intrauterine tamponade/surgical haemostatic techniques.
Consider use of IR techniques
Early recourse to hysterectomy
Risk factors for placenta accreta?
Previous accreta
Previous caesarean(s)
Previous uterine surgery, inc repeated endometrial curettage
How should imaging be use in placenta accreta?
If previous CS and anterior placenta, need specific USS to assess for accreta
MRI can be used to complement USS to assess depth of invasion and lateral extension of myometrial invasion
Risks of caesarean section for placenta accreta for consent form?
Massive obstetric haemorrhage
Lower urinary tract damage
Hysterectomy
Surgical approach for placenta accreta
Caesarean hysterectomy with placenta in situ is preferable to attempting to separate it from uterine wall
IF the placental implantation area is accessible and fully visible can consider uterus preserving surgery
IF hysterectomy is not acceptable to woman, can consider leaving placenta in situ!
What should you do if you open the abdomen at an elective CS and notice placenta accreta?
DELAY CS until appropriate staff and resources and blood available
May involve closing maternal abdomen and transferring to specialist unit
What is vasa praevia and why is it a concern?
Fetal vessels run through the free placental membranes. Unprotected by placental tissue or Wharton’s jelly of the umbilical cord, a vasa praevia is likely to rupture in active labour, or when amniotomy is performed to induce or augment labour, in particular when located near or over the cervix, under the fetal presenting part.
Types of vasa praevia?
Vasa praevia is classified as type I when the vessel is connected to a velamentous umbilical cord, and type II when it connects the placenta with a succenturiate or accessory lobe
Signs of vasa praevia?
On vaginal examination, detecting the pulsating fetal vessels inside the internal os. Or by the presence of dark-red vaginal bleeding and acute fetal compromise after spontaneous or artificial rupture of the placental membranes (fetal mortality rate of 60%).
Can be detected on USS, but not routinely screened
How to manage undiagnosed vasa praevia at delivery?
EMCS and neonatal resus with possible blood trasnfusion required.
Should women with a diagnosis of vasa praevia be hospitalised
Consider from 30-32 weeks
Especially if RFs like antenatal bleeding, threatened pre-term labour
