Protecting the safety of your baby at birth
A baby deserves the very best protection both inside and outside the womb. Sometimes life-threatening conditions can remain under the radar, surfacing only when it’s too late to prevent disaster. Undetected vasa praevia has a very high risk of stillbirth. Occurring in 1 in 2500 pregnancies, the same prevalence as cot death but yet it in this case, harm to baby and mother is preventable.
About Vasa Praevia
Vasa praevia, although a rare condition, is a serious pregnancy complication that occurs in an estimated 1 in 2,500 pregnancies. It occurs when blood vessels involved in the baby’s circulation grow along the membranes in the lower part of the uterus at the cervical opening. When the condition is not detected in advance, the blood vessels can rupture during labour causing stillbirth.
Known risk factors are assisted reproduction, multiple pregnancy, low lying placenta and bi-lobed placenta.
Surprisingly, antenatal diagnosis is seldom made because there is no screening protocol in the NHS in spite of the fact that death is significantly reduced if the diagnosis is known before delivery.
Vasa praevia usually causes no outward symptoms during the pregnancy but can be accurately diagnosed with colour flow Doppler ultrasound.
To establish if the pregnancy is at high risk can be life-saving and will certainly improve the ongoing monitoring of your pregnancy.
The Vasa Praevia scan
The scan can be carried out from 11 weeks onwards.
We ask that you drink a pint of water before the scan. This makes it easier to see the cervical canal and internal os (cervical opening). On some occasions it is still difficult to see and so we may ask if a more detailed internal ultrasound scan can be done transvaginally. This is a simple procedure and does not cause any pain or harm to the pregnancy.
The scan will:
- use colour flow Doppler ultrasound to identify placental and cord variants
- baby will also be a checked for general well-being and growth.
The Vasa Praevia Scan results
If the condition is seen to exist we will liaise with your healthcare team and hospital to let them know so that you can be carefully monitored, especially for symptoms of vaginal bleeding. A planned delivery under controlled circumstances can also be facilitated to prevent harm to you and the baby and avoid fetal haemorrhage.
Because VP can resolve in up to 15% of cases, the scan should be repeated in the third trimester to confirm the ongoing diagnosis and the need for intervention.
Scanning the cervix to determine a long and closed cervix between 24 and 28 weeks of pregnancy will also provide additional reassurance of the pregnancy well-being.
The scan is performed as an addition to any other screening scan offered.