Dedicated to Providing Trusted Protection
ACOG antenatal dosing guidelines are based on clinical trials1,2:
- 300 μg dose of anti-D at 28 weeks gestation was studied in clinical trials3,4
- This specific dose was expected to ensure 20-30 μg residual anti-D remained in maternal circulation at delivery3
- When calculating the 300 μg dose, a mean elimination anti-D half-life of ~28 days was assumed4
RhoGAM's half-life aligns with ACOG Guidelines5
(Guidelines reaffirmed by ACOG in 2016)
Not All Pregnancies Are Alike
Many factors are beyond your control:
- The timing and amount of fetal-maternal hemorrhage (FMH) is unpredictable and can present without clinical suspicion6,7
- There is natural, individual variability in the anti-D half-life8
- The concentration of anti-D circulating in the maternal bloodstream late in the third trimester varies for each pregnancy8
- The longer the half-life, the greater the residual level in circulation over time9
1. ACOG practice bulletin. Prevention of RhD alloimmunization. Number 4, May 1999. (Reaffirmed 2016). Clinical management guidelines for obstetrician-gynecologists. American College of Obstetrics and Gynecology. Int J Gynaecol Obstet. 1999;66:63-70.
2. McMaster conference on prevention of Rh immunization. Hamilton, Ontario, Canada. 28-30 September, 1977. Vox Sang. 1979;36:50-644.
3. Bowman JM, Chown B, Lewis M, Pollock JM. Rh isoimmunization during pregnancy: antenatal prophylaxis. Can Med Assoc J. 1978;118:623-27.
4. Bowman JM, Pollock JM. Antenatal prophylaxis of Rh isoimmunization: 28-weeks’ gestation service program. Can Med Assoc J. 1978;118:627-30.
5. RhoGAM Ultra-Filtered PLUS Prescribing Information, 2015. Kedrion Biopharma Inc.
6. Sebring ES, Polesky HF. Fetomaternal hemorrhage: incidence, risk factors, time of occurrence, and clinical effects. Transfusion. 1990;30:344-357.
7. Pourbabak S, Rund CR, Crookston KP. Three cases of massive fetomaternal hemorrhage presenting without clinical suspicion. Arch Pathol Lab Med. 2004;128:463-65.
8. Bowman JM, Pollock JM. Failures of intravenous Rh immune globulin prophylaxis: an analysis of the reasons for such failures. Trans Med Rev. 1987;1:101-12.
9. Pelican EW. Half-life. In: Glossary of terms and symbols used in pharmacology. Boston, MA: Boston University School of Medicine. Boston University website. http://www.bumc.bu.edu/busm-pm/academics/resources/glossary/#h. Accessed December 1, 2016.