The association between abnormal plasentation and first and second trimester maternal serum homocysteine levels and doppler ultrasound of uterine artery

Some complications of pregnancy such as recurrent spontaneous abortion, ablatio placenta, fetal death, preeclampsia and intrauterine growth restriction are found to be associated with high levels of homocysteine concentration. High homocysteine levels, cause predisposition to the pregnancy complications mentioned above by the following mechanisms: intimal smooth muscle proliferation and thickening, lipid accumulation in the vessel wall, activation of thrombocyte and leukocyte, increment of low density lipoprotein (LDL) oxidation, activation of thromboxane synthesis, increased oxidative stress following the oxidation of homocysteine, and ultimately leads to vascular ischemia. The studies conducted at first and second trimesters revealed that, high levels of homocysteine detected at early stages of pregnancy may be a useful tool in the prediction of pregnancy complications associated with abnormal placentation. Doppler ultrasound (US) is a widely used and non-invasive method, which evaluates the peripheral vascular resistance and flow rate alterations in the fetal and uteroplacental circulation. Some studies reported that, Doppler US applied at early stages of pregnancy may be used estimate the risk of hypertensive diseases associated with pregnancy. In this study, the importance of serum homocysteine level in first and second trimester and uterin artery (UtA) Doppler pulsatility index (PI) in estimation of gestational hypertension, preeclampsia and IUGR; the relationship between homocysteine level and uterin artery Doppler index and Doppler scores are aimed.Homocysteine, folate and vitamine B12 concentrations were measured in maternal blood samples obtained at 11-14th and 20-24th weeks of gestation, and UtA PI was determined with Doppler US at same period of time. The Doppler US parameters were scored due to the system described by Sekizuka and colleagues, in which, the presence of abnormal UtA PI and early diastolic notching were rated as 1 and the lack of former signs were rated as 0. With scoring of the Doppler findings of bilateral UtAs, an ultimate score was obtained between 0 and 4.The significant difference was obtained homocysteine levels in first trimester different Doppler scores. With increasing of Doppler scores, the maternal serum level of homocysteine was increased. There were no difference about pregnancy complications and serum folate, vitamine B12 between Doppler scores. In addition to these findings it has been found a positive correlation between the parameters and the scores of Doppler and homocysteine levels in the first trimester and the homocysteine levels were found to be significantly higher in patients with preeclampsia in the first trimester (preeclampsia; 7,02±2,7 µmol/l, normal; 4,3±1,8 µmol/l, p=0,008). At the end of the first trimester the levels of maternal serum homocysteine were found to be significantly higher in women with abnormal UtA PI (>1,8) (n=35) than in women with normal UtA PI (<1,8) (n=68) (respectively; 5,4±2,5 µmol/l, 3,9±1,3 µmol/l, p=0,001). Nevertheless the homocystein levels in the pregnants who have bilateral early diastolic notch in uterine artery Doppler examination in the first trimester have been found to be significantly higher than in pregnants who have no early diastolic notch (respectively; 5,5±1,9 µmol/l, 4,2±1,9 µmol/l, p=0,03). There could not be found any significant difference about homocysteine level and pregnancy complications between Doppler scores in the second trimester. Mean UtA PI of patients with preeclampsia were significantly higher than normal controls (respectively; 2,05±0,5, 1,03±0,3, p=0,001). Homocysteine levels were not different between preeclampsia and patients with normal controls in this trimester (respectively; 7,5±5,1 µmol/l, 4,8±2,8 µmol/l, p=0,18).As a conclusion, within the both first and second trimesters, determination of UtA Doppler resistance index and serum homocysteine levels have a limited clinical role in the prediction of increased risk of pregnancy complications associated with abnormal placentation. If the serum homocysteine levels and UtA Doppler signs are normal, the risk of developing gestational hypertensive disease is low. The relationship between homocysteine, folate and vitamine B12 levels with UtA Doppler index is not clear. Nevertheless, application of UtA Doppler and homocysteine measurement has a limited clinical role in patients with low grade placental ischemia, they may be useful in determination of severe forms of the diseases.