TNF-alpha gene polymorphism and fetal Doppler velocimetry in intrauterine growth restriction.

OBJECTIVES: The intrauterine growth restriction (IUGR) frequently is a cause of fetal morbidity and mortality, and influences perinatal outcome. Several genes have been identified to explain aetiology of IUGR, beside others the gene coding for tumour necrosis factor alpha (TNF-alpha).

DESIGN: To investigate frequency of AlwI polymorphism of TNF-alpha gene and its correlation with TNF-alpha level in maternal serum, Doppler velocimetry and perinatal outcome in pregnancies suspected for IUGR.

SETTING: 42 pregnancies with IUGR and 50 matched healthy pregnant women were included in the study. Maternal venous blood samples were investigated in relationship to blood flow Doppler velocimetry in umbilical (UA) and middle cerebral (MCA) arteries. AlwI polymorphism was analysed using PCR/RFLP assays. TNF-alpha level was evaluated by immunoelectophoretic method.

RESULTS: A higher frequency of mutated -238A alleles (13.1% vs. 7.0%) and genotypes containing at least one mutated -238A allele (23.8% vs. 14.0%) were found in the IUGR group. The tendency to the higher TNF-alpha level in IUGR subgroups with the presence of at least one mutated A allele (258.9+/-231.3 vs. 174.1+/-145.6 pg/ml) was detected. No statistical differences were detected for PI values in UA and MCA arteries considering particular genotypes (GG vs. GA + AA) separately in IUGR group.

CONCLUSION: Increased UA vascular impedance and signs of brain sparing in MCA are related to IUGR and increased TNF-alpha level in maternal serum. AlwI polymorphism might play a role in IUGR aetiology and influence TNF-alpha expression in maternal serum, but was not related to Doppler velocimetry or with perinatal outcome.