Feto-maternal rhesus incompatibility
Feto-maternal rhesus (Rh) incompatibility is a situation when the maternal blood is Rh-negative blood and the fetal blood is Rh-positive (from paternal inheritance). It is a type fetomaternal blood group incompatibility and can, in turn, lead to several complications which classically includes the development of immune hydrops fetalis (IHF).
The incidence rate had decreased worldwide over the years and is currently estimated to be at ~ 6 per 1000 live births (2002) 4-5.
Rhesus incompatibility can lead to rhesus alloimmunisation where maternal antibodies may cross the placenta, bind to antigens present on the fetal erythrocytes and then cause haemolysis.
Doppler ultrasound can be used to detect features of a fetal anaemia.
Treatment and prognosis
In severe cases, blood transfusion in utero is an option. The current day prognosis in a majority of cases is good with perinatal survival rates of more than 90% being reported; the development of hydrops fetalis can reduce the chance for a viable outcome by up to 25%. Prophylactic administration of Rho(D) immune globulin (e.g. RhoGAM) during the delivery for the first pregnancy may reduce the risk for subsequent pregnancies.
- development of immune hydrops fetalis (IHF)
- 1. Merz E, Bahlmann F. Ultrasound in obstetrics and gynecology. Thieme Medical Publishers. (2005) ISBN:1588901475. Read it at Google Books - Find it at Amazon
- 2. Kirkinen P, Jouppila P, Eik-nes S. Umbilical vein blood flow in rhesus-isoimmunization. Br J Obstet Gynaecol. 1983;90 (7): 640-3. - Pubmed citation
- 3. Jones MR. Ultrasonic B-scanning in rhesus incompatibility. J Clin Ultrasound. 1974;2 (3): 185-90. - Pubmed citation
- 4. Moise KJ. Management of rhesus alloimmunization in pregnancy. Obstet Gynecol. 2002;100 (3): 600-11. - Pubmed citation
- 5. Moise KJ. Management of rhesus alloimmunization in pregnancy. Obstet Gynecol. 2008;112 (1): 164-76. doi:10.1097/AOG.0b013e31817d453c - Pubmed citation
- 6. Mari G, Deter RL, Carpenter RL et-al. Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red-cell alloimmunization. Collaborative Group for Doppler Assessment of the Blood Velocity in Anemic Fetuses. N. Engl. J. Med. 2000;342 (1): 9-14. doi:10.1056/NEJM200001063420102 - Pubmed citation