American journal of obstetrics and gynecology
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Am. J. Obstet. Gynecol. · May 1998
The Preterm Prediction Study: recurrence risk of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
We sought to estimate the risk of spontaneous preterm birth in parous women by use of obstetric history, fetal fibronectin, and sonographic cervical length. ⋯ The recurrence risk of spontaneous preterm birth varies widely according to fetal fibronectin and cervical length. Cervical length and fetal fibronectin results had distinct and significant effects on the recurrence risk of preterm birth. Predicted recurrence risk is increased by twofold to fourfold in women with a positive compared with a negative fetal fibronectin, and it increases as cervical length shortens in both fetal fibronectin-positive and fetal fibronectin-negative women. These data may be useful to care for women with a history of preterm birth and to design studies to prevent recurrent premature delivery.
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Our purpose was to compare the biochemical composition of the fluid contained in pathologic and physiologic cavities in early pregnancy. ⋯ The composition of vesicular fluid in complete mole reflects a possible origin from the maternal plasma, yolk sac, and trophoblast, whereas the composition of nuchal and cystic hygroma fluid suggests a leakage from the fetal circulation.
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Am. J. Obstet. Gynecol. · Apr 1998
Randomized Controlled Trial Clinical TrialDoes magnesium sulfate given for prevention of eclampsia affect the outcome of labor?
The purpose of this study was to determine whether magnesium sulfate given for prevention of eclampsia affected labor outcomes compared with phenytoin, which is not known to impede uterine activity when given in anticonvulsant doses. ⋯ Compared with phenytoin, magnesium sulfate given for intrapartum treatment of pregnancy-induced hypertension does not significantly affect labor outcomes.
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Am. J. Obstet. Gynecol. · Mar 1998
Plasma concentrations of asymmetric dimethylarginine, a natural inhibitor of nitric oxide synthase, in normal pregnancy and preeclampsia.
We investigated the change in the plasma concentration of asymmetric dimethylarginine, an endogenous inhibitor of nitric oxide synthase, in early-, mid-, and late-gestation normotensive pregnancies and in gestational age-matched preeclamptic pregnancies and compared the observed changes with changes in blood pressure. ⋯ It is well recognized that blood pressure falls in early normal pregnancy and rises again toward term. These studies show that the early fall in blood pressure is accompanied by a significant fall in the plasma asymmetric dimethylarginine concentration. Later in pregnancy circulating concentrations increase and, when pregnancy is complicated by preeclampsia, concentrations are higher than in the nonpregnant state. Our data support a role for both asymmetric dimethylarginine and nitric oxide in the changes in blood pressure seen in both normal and preeclamptic pregnancy.