Association of serum asymmetric dimethylarginine, homocysteine, and l-arginine concentrations during early pregnancy with hypertensive disorders of pregnancy.

BACKGROUND: Our previous study suggested that a lower l-arginine level (<70µM) at early gestation is associated with pregnancy-induced hypertension. The maternal asymmetric dimethylarginine (ADMA) and homocysteine (Hcy) concentrations also have been reported to be increased in hypertensive disorders of pregnancy (HDP). These molecules have a key role in metabolism of nitric oxide. The aim of this study is to determine the most useful predictor of HDP at early gestation. METHODS: The concentrations of ADMA and Hcy at each of three periods in normal pregnancy were determined, and the values compared between the normal pregnancy and HDP groups. Moreover, the possible risk factors for the development of HDP also were evaluated using a multivariate logistic regression model and propensity score (PS). RESULTS: The maternal ADMA concentration was significantly elevated with advance of gestational age, while Hcy concentration was decreased from early to mid-gestation and increased from mid- to late-gestation in normal pregnancy. The maternal Hcy concentration at early gestation was significantly higher in the HDP group compared to that in the normal group. A higher maternal Hcy level (>7.2µM) in early pregnancy was independently associated with the development of HDP (PS-adjusted odds ratio=4.47, 95% confidence interval=1.51-12.82), as well as pre-pregnancy overweight [body mass index (BMI)>25kg/m2], primipara status, and a lower maternal l-arginine level (<70µM). CONCLUSIONS: The risk factors, such as overweight (BMI>25kg/m2) before pregnancy, primipara status, higher Hcy (>7.2µM), and lower l-arginine (<70µM) concentration in early pregnancy, for development of HDP were detected.

Is the serum l-arginine level during early pregnancy a predictor of pregnancy-induced hypertension?

The objective of this study was to determine the concentration of serum l-arginine in healthy pregnant women and infant cord blood and to compare them with those in patients with pregnancy-induced hypertension (PIH). The serum concentration of l-arginine in normal pregnant women at early gestation (n = 186) was determined and analyzed based on maternal factors such as the age, pre-pregnancy body mass index (BMI), smoking and alcohol habits before pregnancy. Similarly, the concentration of cord blood of the newborns (n = 142) was also analyzed. These values were compared with those in the PIH group (n = 21). The potential risk factors for PIH were also estimated. The serum concentration of l-arginine at early gestation in normal pregnant women (88.65 ± 19.96 µM) was not affected by the maternal age and BMI before pregnancy. A lower l-arginine concentration at early gestation (<70 µM) significantly elevated PIH risk [adjusted odds ratio (OR) = 4.26, 95% CI 1.29-14.50]. In addition, either women with large body mass before pregnancy (BMI>25 kg/m(2)) or primipara women also showed a significant association with PIH risk [adjusted OR = 10.55 (2.95-40.68); 5.25 (1.72-19.15), respectively]. In conclusion, a lower l-arginine concentration at early gestation, overweight before pregnancy (BMI>25 kg/m(2)) and primipara could predict to the development of PIH.