apollo

Rh Factor in Pregnancy: A Complete Guide for Expecting Parents

Learn everything about Rh factor in pregnancy, including its importance, risks, prevention, and treatment. Understand how RhoGAM can help ensure a healthy pregnancy for Rh-negative mothers.

reviewerImg

Written by Dr. Sonia Bhatt

Last updated on 3rd Jul, 2025

Introduction

When you’re pregnant, your body goes through many changes. While most of these changes are natural and expected, there are also medical factors that can influence your pregnancy and the health of your baby. One such factor is the Rh factor, or Rhesus factor, which is a protein that can be present on the surface of your red blood cells. If you have this protein, you are considered Rh-positive (Rh+). If you do not have this protein, you are considered Rh-negative (Rh-).

Rh factor is important because it can affect your pregnancy, especially if the father of your child has a different Rh factor from you. In most cases, this difference isn’t a problem. However, in some situations, it can lead to complications that may affect your pregnancy or your baby’s health.

This guide explains the importance of Rh factor, its risks, and the available treatments to safeguard both mother and baby.

Why Does Rh Factor Matter in Pregnancy?

The primary concern with Rh factor in pregnancy arises when an Rh-negative mother is carrying an Rh-positive baby. If the baby’s Rh-positive blood enters the mother’s bloodstream, her body might recognise the baby’s blood cells as foreign and start producing antibodies against them. This is known as sensitisation.

Sensitisation occurs when the immune system of an Rh-negative mother creates antibodies in response to the Rh-positive blood cells of the baby. These antibodies can cross the placenta and attack the baby’s red blood cells. This can lead to a condition called haemolytic disease of the newborn (HDN) or erythroblastosis fetalis, which can be serious and even life-threatening.

When Does Rh Sensitisation Happen?

Rh sensitisation typically occurs when an Rh-negative mother is exposed to Rh-positive blood. This exposure may happen during:

  • Childbirth: If you have an Rh-positive baby, some of your baby’s blood can mix with yours during delivery.

  • Miscarriage or abortion: These can also result in blood mixing between you and your baby.

  • Amniocentesis or chorionic villus sampling (CVS): These are diagnostic tests that can occasionally cause blood mixing.

  • Trauma or injury: Any trauma to the abdomen during pregnancy may cause some of your baby’s blood to mix with yours.

In any of these situations, your body may begin producing Rh antibodies, which puts your future pregnancies at risk. This is why Rh factor testing is a standard part of prenatal care.

What Are the Risks of Rh Sensitisation?

When sensitisation occurs, the body’s antibodies may attack the baby’s red blood cells. This can cause:

  • Anaemia: A decrease in red blood cells, which means the baby’s organs don’t get enough oxygen.

  • Jaundice: A yellowish tint to the baby’s skin and eyes, caused by a build-up of bilirubin (a waste product created when red blood cells break down).

  • Severe HDN: In extreme cases, haemolytic disease can lead to organ failure or even death.

However, it’s important to remember that while Rh sensitisation can be serious, it is now preventable and manageable through medical interventions.

How Is Rh Factor Tested During Pregnancy?

Your healthcare provider will likely test your blood early in pregnancy to determine your Rh status. If you’re Rh-negative, your doctor will monitor your pregnancy more closely to ensure that you don’t develop Rh antibodies.

If your partner is Rh-positive, your doctor may recommend further testing to determine the likelihood of Rh incompatibility with your baby. In some cases, your doctor will conduct an ultrasound or other tests to monitor your baby’s condition.

How Can Rh Sensitisation Be Prevented?

Thankfully, Rh sensitisation can be prevented in most cases. The key is to prevent any mixing of Rh-positive blood from the baby into the mother’s bloodstream. The most effective way to do this is by administering a medication called Rho(D) immune globulin (commonly known by the brand name RhoGAM) to the Rh-negative mother. This injection works by preventing the immune system from producing antibodies against the Rh-positive blood cells.

When is RhoGAM Given?

  • At 28 weeks of pregnancy: If you are Rh-negative and the father of your baby is Rh-positive, you’ll likely be given an injection of RhoGAM around 28 weeks. This is a standard part of prenatal care.

  • After delivery: If your baby is Rh-positive, you will be given another dose of RhoGAM within 72 hours of giving birth.

  • After a miscarriage, ectopic pregnancy, or abortion: If you experience any event where there is a risk of blood mixing, RhoGAM may be administered to prevent sensitisation.

  • In cases of trauma: If you experience any injury that might cause bleeding, your doctor may recommend RhoGAM.

What Happens If You Don’t Receive RhoGAM?

If an Rh-negative mother does not receive RhoGAM, the risk of developing Rh antibodies increases. If you become sensitised, it may not affect your first pregnancy, but it could lead to complications in subsequent pregnancies. This is why early screening and the timely administration of RhoGAM is so crucial.

Can Rh Incompatibility Affect Future Pregnancies?

Yes, Rh incompatibility can pose a higher risk to future pregnancies if you’ve been sensitised to Rh-positive blood. If your immune system has already developed antibodies, it will attack the red blood cells of any future Rh-positive babies, potentially causing more severe complications.

However, with proper medical care and the use of treatments like RhoGAM, most Rh-negative women can have healthy pregnancies and healthy babies, even after experiencing an Rh incompatibility in a previous pregnancy.

How Is Rh Sensitisation Treated During Pregnancy?

If you do become sensitised during pregnancy, your doctor may need to closely monitor your baby for signs of HDN. This monitoring may involve:

  • Ultrasound scans: These can detect issues like fluid build-up (hydrops fetalis) or signs of anaemia in the baby.

  • Amniocentesis: A sample of the amniotic fluid can be tested to assess the severity of anaemia or jaundice.

  • Intrauterine blood transfusion: In severe cases, a blood transfusion can be given to the baby while still in the womb to treat anaemia.

The good news is that medical advances have significantly improved the prognosis for babies with Rh incompatibility. With proper treatment, many babies are born healthy, even in the presence of Rh sensitisation.

Final Thoughts: Takeaways for Expecting Parents

  • Rh factor is an important consideration: Knowing your Rh status early in pregnancy is vital. If you’re Rh-negative, work closely with your healthcare provider to manage the potential risks.

  • RhoGAM is key: This injection can prevent Rh sensitisation and is typically given around the 28th week of pregnancy and after delivery if your baby is Rh-positive.

  • Your healthcare team will monitor you closely: With regular check-ups and the right interventions, most women with Rh-negative blood have healthy pregnancies and babies.

  • Talk to your healthcare provider: If you have concerns or questions about Rh factor, don’t hesitate to ask your doctor for more information.

Understanding Rh factor and how it affects pregnancy is essential for ensuring the health and safety of both mother and baby. With the right knowledge and care, Rh incompatibility is manageable, and you can look forward to a healthy pregnancy and a beautiful outcome.

Consult Top Obstetrician-Gynecologists

Dr. Alapati Jyotsna, Obstetrician and Gynaecologist

Dr. Alapati Jyotsna

Obstetrician and Gynaecologist

4 Years • MBBS MS Obstetrics and Gynaecology

Visakhapatnam

Apollo 24|7 Clinic - Andhra Pradesh, Visakhapatnam

499

44 Cashback

Dr Swatika Kumari, Obstetrician and Gynaecologist

Dr Swatika Kumari

Obstetrician and Gynaecologist

19 Years • MBBS, DGO, DNB Obstetrics & Gynaecology

Nashik

Apollo 24|7 Clinic - Maharashtra, Nashik

649

64 Cashback

Dr. Priyanka Surisetty, Obstetrician and Gynaecologist

Dr. Priyanka Surisetty

Obstetrician and Gynaecologist

8 Years • MBBS, DGO

Visakhapatnam

Apollo 24|7 Clinic - Andhra Pradesh, Visakhapatnam

549

54 Cashback

Dr. Parul Sharma, Obstetrician and Gynaecologist

Dr. Parul Sharma

Obstetrician and Gynaecologist

8 Years • MBBS, MS (Obstetrics & Gynaecology)

New Delhi

THE DOCTORS NESST, New Delhi

1000

800

Dr. Sreeparna Roy, Obstetrician and Gynaecologist

Dr. Sreeparna Roy

Obstetrician and Gynaecologist

8 Years • MBBS , MS (OBSTETRICS & GYNAECOLOGY), Fellowship in Infertility, Endoscopy & Ultrasonography), Fellowship in Laparoscopy & Hysteroscopy,DRM

Barasat

Diab-Eat-Ease, Barasat

500

Consult Top Obstetrician-Gynecologists

Dr. Alapati Jyotsna, Obstetrician and Gynaecologist

Dr. Alapati Jyotsna

Obstetrician and Gynaecologist

4 Years • MBBS MS Obstetrics and Gynaecology

Visakhapatnam

Apollo 24|7 Clinic - Andhra Pradesh, Visakhapatnam

499

44 Cashback

Dr Swatika Kumari, Obstetrician and Gynaecologist

Dr Swatika Kumari

Obstetrician and Gynaecologist

19 Years • MBBS, DGO, DNB Obstetrics & Gynaecology

Nashik

Apollo 24|7 Clinic - Maharashtra, Nashik

649

64 Cashback

Dr. Priyanka Surisetty, Obstetrician and Gynaecologist

Dr. Priyanka Surisetty

Obstetrician and Gynaecologist

8 Years • MBBS, DGO

Visakhapatnam

Apollo 24|7 Clinic - Andhra Pradesh, Visakhapatnam

549

54 Cashback

Dr. Parul Sharma, Obstetrician and Gynaecologist

Dr. Parul Sharma

Obstetrician and Gynaecologist

8 Years • MBBS, MS (Obstetrics & Gynaecology)

New Delhi

THE DOCTORS NESST, New Delhi

1000

800

Dr. Sreeparna Roy, Obstetrician and Gynaecologist

Dr. Sreeparna Roy

Obstetrician and Gynaecologist

8 Years • MBBS , MS (OBSTETRICS & GYNAECOLOGY), Fellowship in Infertility, Endoscopy & Ultrasonography), Fellowship in Laparoscopy & Hysteroscopy,DRM

Barasat

Diab-Eat-Ease, Barasat

500

More articles from pregnancy