11 – 13 weeks
Making sure mother & baby are safe and well
Pre-eclampsia happens in about 2% of pregnancies and though usually mild, it can be life-threatening to mother & baby. It is difficult to imagine such catastrophe happening. Sadly, screening by maternal history may detect only about 30% of cases. A simple early pregnancy screening test will identify 90% of pregnancies requiring better monitoring and it is not routinely offered in the NHS.
Pre-eclampsia occurs in around 1 in 50 pregnancies. Medically it is classed as pregnancy induced high blood pressure and is one of the most common life threatening conditions occurring in pregnancy.
Though most cases of pre-eclampsia are mild and cause no trouble, the condition can get worse and become devastatingly serious to both mother and baby. It can cause seizures in mother, reduced growth and development in the baby and in extreme cases even death.
- first pregnancy
- aged 40 or over
- your last pregnancy was more than 10 years ago
- very overweight
- family history of pre-eclampsia
- more than one baby
- previous high blood pressure
- high blood pressure in a previous pregnancy
- chronic kidney disease, diabetes
Approximately only 30% of cases will be identified using the above criteria. However, studies have shown that screening using ultrasound in early pregnancy along with a simple blood test will highlight 90% of pregnancies at risk of early pre-eclampsia and potential early delivery.
This screening test can be added to any pregnancy scan performed between 11 – 13 weeks 6 days.
The pre-eclampsia scan
The uterine artery pulsatility index (PI) ) is determined by performing a blood flow analysis of the uterine artery (which supplies blood to the placenta) between 11 to 13 weeks and used in combination with maternal history, blood pressure and serum PAPP-A maternal blood marker.
The scan will:
- confirm that the gestational age of the pregnancy.
- Color flow is will identify each uterine artery along the side of the cervix and uterus where pulsed wave Doppler is used to obtain a calculation of the mean PI of the left and right arteries.
Along with a blood test and simple question regarding previous family history a risk will be calculated.
Pre-eclampsia scan results
If you screen positive or high-risk for pre-eclampsia it is also important to remember that the chance that you will develop the condition is still low, but it is highly recommended that you are more closely monitored in your pregnancy.
We will inform your healthcare professional and arrange for your routine mid trimester 20+ week scan is performed as close to 20 weeks as possible and that not only baby’s structural development is seen but importantly also baby’s growth is assessed and recorded.
You may also receive simple medical treatment depending upon your current health criteria.
As part of your screen we will then arrange to see you back at one of our clinics for a scan around 23 – 24 week to further check your baby’s growth, your blood pressure and urine. At this stage if everything is alright your midwife will continue to check your blood pressure and urine throughout the pregnancy on a regular basis and you may again if needed be referred for further growth assessment scans.