Antenatal Prophylaxis with Anti-D

Patient Experience

  • Reference Number: HEY-978/2018
  • Departments: Maternity Services
  • Last Updated: 1 January 2022


This leaflet has been produced to give you information about Antenatal prophylaxis with anti-D.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and your doctor, but may act as a starting point for such a discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What does rhesus factor mean?

All human beings are unique and so is their blood and its characteristics. There are 4 blood groups A, B, AB and O. The other important characteristic is the Rhesus Factor.

People who are Rhesus positive have a substance called D antigen on the surface of their blood cells, and are said to be RhD positive. People who are Rhesus negative do not have this D antigen on their blood cells. They are said to be RhD negative.

An individual’s blood group and Rhesus factor are inherited from their parents. Around 85% of people are Rhesus Positive and 15% are Rhesus Negative.

RhD status matters if a woman who is RhD negative becomes pregnant with a baby who is RhD positive. This can only happen if the baby’s father is RhD positive. However, not all children who have an RhD positive father will be RhD positive, because the father may have both RhD positive and RhD negative genes.

What causes rhesus disease?

If any blood cells from a Rhesus positive baby cross over into the blood stream of a Rhesus negative mother, she will react to the D antigen in the baby’s blood and produce antibodies. This process is called Rhesus sensitisation and can lead to Rhesus Disease.

Rhesus disease is a condition where antibodies in a pregnant woman’s blood destroy her baby’s blood cells. Rhesus disease does not harm the mother but can cause the baby to become anaemic and develop Haemolytic Disease of the Newborn (HDN).

If sensitisation occurs, the next time the woman is exposed to RhD positive blood, the antibodies in the mother’s blood can cross the placenta and attack the blood cells of the RhD positive unborn baby causing HDN.

The most common time for sensitisation is at the time of birth. However other examples of occurrence are:

  • After a miscarriage
  • After an abortion
  • Following investigations such as amniocentesis
  • Following any vaginal bleeding
  • Following an abdominal injury

Anti-D (Rhophylac©) should be given within 72 hours when any of the above happens.

HDN can be very mild, but it can also be more serious and cause the baby to be still born, severely disabled or be anaemic (lack of iron in the blood) and jaundiced.

The most common time for a baby’s blood cells to get into the mother’s blood is at the time of birth.

The antibodies can continue attacking the baby’s red blood cells for a few months after birth.

All women who are known to be Rhesus negative will be offered antenatal protective treatment (prophylaxis) Anti–D immunoglobulin (Rophylac©) at 28 weeks of pregnancy.

Why do I need Anti-D if I am rhesus negative?

During pregnancy the placenta acts as a barrier between the red blood cells of the mother and the baby.  Occasionally small amounts of the baby’s blood can cross over into the mother’s blood stream.

Prophylaxis is a word given to a medicine to prevent something happening. Anti- D prophylaxis means giving Anti-D immunoglobulin (Rhophylac©) to prevent a woman producing antibodies against RhD positive blood cells and so to prevent the development of Haemolytic Disease of the Newborn (HDN)  in an unborn baby.

Can there be any complications or risks?

There can be a rare allergic reaction to Anti- D (Rophylac©)

Anti-D immunoglobulin is made from a part of the blood celled plasma that is collected from donors.

The production of Anti-D (Rhophylac©) as a blood product, is very strictly controlled to ensure the chance of a known virus being passed from the donor to the person receiving Anti-D (Rhophylac©) is very low – it is estimated to be 1 in 10 billion doses.

How do I prepare for the Anti-D prophylaxis

Please read the information leaflet.  Share the information it contains with your partner and family (if you wish) so that they can be of help and support.  There may be information they need to know, especially if they are taking care of you following the procedure.

What will happen?

Your appointment will be at the Antenatal Clinic, Women and Children’s Outpatient Department, with one of the midwives.

The midwife will discuss fully at this appointment the benefits and risks of having Anti-D (Rhophylac©)

At your appointment, the midwife will administer the Anti-D (Rhophylac©) injection with your consent, into the muscle in the upper arm. You may experience mild discomfort during and for a short time following the injection. This is completely normal and to be expected

You will be expected to remain within the department for 15 minutes following your injection to ensure you have not had a reaction to the Anti-D (Rhophylac©)

What happens afterwards?

After your appointment you should be able to return to work and resume normal duties.

You will not require Anti-D (Rhophylac©) again during your pregnancy, unless you experience any vaginal bleeding or abdominal injury.

More information about prophylaxis Anti-D (Rhophylac©) can be found at:

Reactions to this injection are rare, however if you experience any of the following: high temperature, feeling unwell, undue swelling or redness around the injection site, we would recommend that you contact the Antenatal Day Unit on (01482) 382729 24 hours, or the Antenatal Clinic during office hours Monday-Friday on (01482) 382623 for advice.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Antenatal Clinic Department on tel no: 01482 382623

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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