Noninvasive prenatal screening for RHD: the Stockholm study

The Determination of Fetal RhD Status from Maternal Blood in Serbia

The aim of this research was to demonstrate: The specificity, sensitivity, the positive and negative prediction value of the PCR method in the detection of the fetal RhD status from maternal blood in various weeks of gestation. Which was the earliest gestational week, when is possible to get a reliable result? How did the presence of RhD antibodies in sensitized mothers affect the results? This was a prospective clinical study within a multidisciplinary project approved by the Ministry of Science of the Republic of Serbia, 2011. The study was approved by the Ethics Committee of the Medical Faculty in Belgrade. Ninety six RhD negative patients had participated in the study, with written consent. The sensitivity of the determination of the RhD status of the fetus from the mother's blood after the 7th GW in our sample was 98.6%, with a specificity of 92%. The positive predictive value of the test was 97% and the negative predictive value was 95.6%. False positive results were detected in 2.6% of cases and 4.5% of cases were false negative. This is a reliable test which should be used in monitoring of pregnancies of RhD negative mothers.

Haemolytic disease of the fetus and newborn

Haemolytic Disease of the Fetus and Newborn (HDFN) is caused by maternal alloimmunization against red blood cell antigens. In severe cases, HDFN may lead to fetal anaemia with a risk for fetal death and to severe forms of neonatal hyperbilirubinaemia with a risk for kernicterus. Most severe cases are caused by anti-D, despite the introduction of antental and postnatal anti-D immunoglobulin prophylaxis. In general, red blood cell antibody screening programmes are aimed to detect maternal alloimmunization early in pregnancy to facilitate the identification of high-risk cases to timely start antenatal and postnatal treatment. In this review, an overview of the clinical relevance of red cell alloantibodies in relation to occurrence of HDFN and recent views on prevention, screening and treatment options of HDFN are provided.