Placental tissue samples were collected directly after the third stage of labour. The samples were obtained from four macroscopically unaffected parts of the placenta, one from each of the four quadrants of the decidua basalis – the maternal surface of the placenta. The samples were placed in a tube and stored at -86°C to maintain integrity until analysis. RNA isolation, then reverse transcription, and finally, Real-Time PCR were conducted to determine the expression of the mRNA of the target genes.