This leaflet is to help you understand what Placenta Accreta Spectrum Disorder is, what tests you need and the implication of being diagnosed with Placenta Accreta Spectrum Disorders for your baby and your family.
What is Placenta Accreta Spectrum (PAS) Disorder?
his leaflet is designed to help you understand Placenta Accreta Spectrum (PAS), its causes, and what to expect. Placenta accreta spectrum disorder is a rare complication of pregnancy where the placenta attaches to the wall of the uterus (womb) in an abnormal way. The placenta is the organ that provides oxygen and nutrients to the developing fetus. Normally the placenta attaches quite superficially to the wall of uterus but, in PAS, the placenta attaches (adheres) abnormally during the first trimester of pregnancy, pushing too deeply into the muscular layer of the uterus (myometrium).
There are roughly three types of PAS on the spectrum, defined according to the depth the placenta invades into the myometrium:
- Placenta accreta: the placenta adheres too deeply to the uterus but does not invade it;
- Placenta increta: the placenta penetrates deeply into the uterus and invades the uterine wall;
- Placenta percreta: the placenta invades the uterine serosa, i.e. the outer layer of the uterus, and sometimes goes beyond the wall of the uterus to invade adjacent organs such as the bladder.
How does a PAS happen?
PAS is a rare complication, occurring in about 1.7 out of every 10,000 pregnancies. The incidence increases with the presence of risk factors. Risk factors for PAS include: advanced maternal age, multiparity, previous uterine surgery including curettage, assisted reproductive techniques, and previous caesarean delivery. The most common risk factor is a previous caesarean delivery and low-lying placenta or placenta previa.
Should I have more tests done?
In case of suspicion of PAS, you will be referred to a center with expertise for prenatal diagnosis of PAS. Theprenataldiagnosisconsistsofanultrasound,performedespecially fortheevaluation of the uteroplacental interface, the area where the placenta attaches to the uterine wall. This ultrasound should be performed with full bladder and, in some cases, magnetic resonance imaging (MRI) can also be used. An MRI provides a detailed view if the ultrasound is inconclusive.
What are the risks for me at delivery?
This abnormal adherence ofthe placenta prevents the normal separation ofthe placenta atthe time of delivery and can put you at high risk of severe post-partum hemorrhage (bleeding). In some cases, especially with partial placenta accreta, there may be no clinical consequence at delivery.
How are PAS disorders managed?
Management of PAS disorders may differ depending on your specialist center and the degree of invasiveness of the placenta. Some centers perform a caesarean-hysterectomy, where the uterus (womb) is removed during a cesarean delivery of the baby. Other centers use conservative management, which means leaving the placenta in the uterus after delivery, so it can shrink and be absorbed naturally. This may be an option if bleeding is under control and the placenta is not deeply attached. It can preserve the uterus, but requires close monitoring for complications like infection or delayed bleeding. Your care team will work closely with you to ensure the safest plan for delivery in your individual case. Generally, the management of PAS consists of a planned caesarean delivery under general anesthesia.
What does it mean for my baby after it is born?
PAS usually does not harm the baby if the placenta is functioning normally. The possible consequences for your baby are related to moderate prematurity, if caesarean delivery is performed before term, and the risks of general anesthesia. In many cases, delivery will be planned for 35 weeks’ gestational age. In some cases, delivery may need to take place earlier.
Will it happen again?
The recurrence risk for a future pregnancy is around 22% to 29% if uterus was preserved.
|
What other questions should I ask?
|
Last updated: September 2019
Disclaimer: The content of [this leaflet/ our website] is provided for general information only. It is not intended to amount to medical advice on which you should rely. You must obtain professional or specialised individual medical advice relating to your individual position before taking, or refraining from, any action on the basis of the content on [this leaflet/ our website]. Although we make reasonable efforts to update the information on [our leaflets/ website], we make no representations, warranties or guarantees, whether express or implied, that the content on [our leaflet/ website] is accurate, complete or up to date
Download the leaflet:
Placenta accreta spectrum disorder (PAS)