From 6-11 weeks of pregnancy.
Rhesus Negative Test
Rhesus Negative Test
Your Baby's Blood Group and Anti D
As part of your routine booking, at the beginning of your pregnancy, your blood group will be checked. Aproximately 15% of women are Rhesus negative. This is not a concern unless the baby is Rhesus positive. In this case, where mum is Rhesus negative and baby is Rhesus positive there is a small chance that if baby’s blood cells cross to the mother’s circulation an antibody response can occur which can be dangerous to the baby. To prevent this occuring, Rhesus negative women will be offered a dose of Anti D at 28 weeks and also if Mum has a bleed during pregnancy at anytime after 12 weeks.
The routine injection for all Rhesus negative mothers has been necessary because until recently it was different to know the baby's blood group when still in the womb. If we are unaware of baby's blood group, it is possible that the baby is also Rhesus negative and therefore the Anti D may be given unnecessarily.
However, the technology which gives us NIPT(Non-Invasive Parental Testing) for Down's syndrome can now also be used to determine the baby's blood group. This is done by taking a simple blood sample from the mother and sending it to a specialised NHS labratory.
FAQ
The blood sample is processed by an NHS laboratory and the results take between 10 and 14 days. The result will be emailed to you on a report. This laboratory report should then be added to your primary care notes e.g your NHS pregnancy records.
If your unborn baby is predicted to be RhesusD negative, please discuss the results with your primary care midwife who will recommend that you do not have anti-D injections before or after giving birth.
If your blood test report predicts that your unborn baby is Rhesus positive, or the result is inconclusive, your primary care team will offer an anti-D injection. The injection is very safe and will not harm your baby.
The Rhesus blood test is very good at determining baby's blood group. However in 2 out of every 100 tests that are taken, the report may predict that baby is Rhesus negative but then the baby may be found to be Rhesus positive at birth. In this case you will be offered an anti-D injection with 72 hours of birth by your hospital.
For more information: Rhesus disease - Prevention
The test is performed from 12 weeks of pregnancy. If you have not had a scan with us in the pregnancy, please ensure that you bring your latest pregnancy scan report and your NHS or Hospital number along with you. The sample will not be accepted by the accepted by the laboratory without these patient identification references.
Our team are very experienced in blood draws, however there are many factors which can affect the success of a blood draw. Please ensure you are well hydrated and warm at the time of your appointment. If you are anxious, you may find some meditation useful. If our team are unable to draw your sample, we may require you to attend a phlebotomy clinic or the TDL laboratory which is a short walk from the clinic. On some occasions we may require you to return at a different time to draw the sample. We always aim to provide the highest levels of care with the least inconvenience, however clinical procedures in nature vary from patient to patient.
The Birth Company always ensure that Rhesus Blood Test samples are couriered at the earliest possible time, any delays and test failures are communicated to patients at the earliest opportunity. The Birth Company does not accept responsibility for delays and test failures.
Explore other tests
Early Pregnancy Scan
Panorama NIPT
From 9 weeks of pregnancy.
Non-Invasive Prenatal Test (NIPT)
From 10 weeks of pregnancy