L/S ratio, biochemical and clinical changes after ritodrine intravenous infusion.

The effects of ritodrine hydrochloride on the L/S ratio, the clinical and biochemical status of the mother, and the amniotic fluid were studied in a total of 46 women between the 28th and 35th wk of their pregnancy. An increase in the L/S ratio and creatinine levels in the amniotic fluid, significant changes in the maternal serum levels of potassium, sodium, alpha 1-antitrypsin and glucose were found, whereas the urea levels remained unchanged. Maternal hyperglycemia and hypokalemia in both maternal serum and amniotic fluid, were more pronounced when the ritodrine was infused in 5% dextrose. The findings from monitoring the cardiovascular systems of both mother and fetus, agreed with previous reports. It was concluded that ritodrine hydrochloride has a positive effect on the fetal lung maturation, probably by accelerating the release of surfactant. Its administration, however, should be under laboratory control.