Risk factors for cesarean delivery at presentation of nulliparous patients in labor.

Objective: To identify risk factors that place a term nulliparous patient in labor at risk for cesarean delivery.

Methods: This was a case-control, chart review study of 325 nulliparous patients presenting in labor at term with singleton vertex fetuses with either cesarean (patients) or vaginal (controls) delivery. Dichotomous variables were analyzed by chi(2) or Fisher exact tests; continuous variables were assessed by the Wilcoxon two-sample test.

The effect of an elevated maternal lysine concentration on placental lysine transport in pregnant sheep.

Objectives: In a previous study, the coinfusion into the maternal circulation of lysine and several other amino acids failed to increase significantly lysine umbilical uptake. The purpose of this study was to determine whether umbilical lysine uptake can be increased by infusing a lysine solution that does not contain any other amino acid.

Study Design: Six late-gestation ewes were studied on 2 consecutive days.