///2013 Abstract Details
2013 Abstract Details2019-08-02T16:57:45-05:00

The use of saliva kits for ADRB2 genotyping in preeclampsia: mothers and premature babies

Abstract Number: F 35
Abstract Type: Original Research

Ruth Landau MD1 ; Dominique Van Dyk MD2; Michelle Arcache MD3; Jean-Louis Blouin PhD4; Robert Dyer PhD5

Background

Management of maternal hemodynamics is an ongoing challenge during cesarean delivery in severe preeclampsia, since spinal anesthesia may result in hypotension requiring vasopressors. While maternal and fetal genotypes appear to influence vasopressor requirement and neonatal acidosis (1), the effect of phenylephrine on placental perfusion in preeclampsia has not been clarified. One of the aims of this ongoing project is to investigate the impact of genetic variants on maternal hemodynamics and neonatal acidosis at delivery in preeclampsia. Gathering blood samples for neonatal DNA analysis can be challenging, and no study has evaluated the feasibility of using saliva kits for DNA collection in neonates.

Methods

Women with severe preeclampsia requiring a cesarean delivery with a standardized spinal anesthetic are randomized to receive ephedrine or phenylephrine for management of spinal hypotension. Saliva is collected within 48 h of delivery by an anesthesiologist trained to use the DNAgenotek™ kits, with OG-500 tubes for maternal samples, and OG-250 tubes for neonatal samples (OG-250 uses 5 tiny sponges to absorb neonatal saliva, compared with 2 mL collected in adults using OG-500). ADRB2 haplotype distribution is performed as previously described (1). Data presented as mean ± SD.

Results

Genetic data from 22 normotensive mothers/babies (controls) and 54 preeclamptic mothers/babies (PE) has been analyzed. Mean birth weight was 3134g (± 447) in controls vs 1834g (± 663) in PE (p<0.001). DNA yield was 3.8μg (± 3.2) in controls vs 5.4μg (± 4.8) in PE babies (p=0.255), and was overall 40.6μg (± 40.8) in mothers (n=76). The DNA yield did not correlate with the neonatal birth weight (Pearson correlation -0.48, Figure). Genotyping was possible in all controls, and technically impossible in 9/54 preeclamptic neonates. Neonatal ADRB2 haplotype distribution is presented (Figure).

Discussion

Although collecting saliva from premature neonates may appear technically impossible, the DNA yield with commercially available saliva kits was remarkably good. These findings confirm the feasibility of DNA collection and genotyping in premature newborns, which offers exciting perspectives for future studies that can explore genomic/pharmacogenomic associations in the context of obstetrics, anesthesia and perinatology.

1 Anesth Analg 2011;112(6):1432-7



SOAP 2013