The nurse is aware that uterine rupture is considered an obstetric emergency.
Which of the following patients is at an increased risk for uterine rupture?

Choice A rationale

Prostaglandin gels, like Prepidil, primarily function by modifying the cervical tissue, not by directly stimulating the amniotic membranes to rupture. Amniotomy, the artificial rupture of membranes, is a separate procedure often performed once the cervix is favorable, but it is not the direct effect of prostaglandin administration. This medication's mechanism is focused on tissue changes to prepare the cervix.

Choice B rationale

Prostaglandin gels do not have a direct mechanism of action to increase amniotic fluid volume. Amniotic fluid volume is primarily regulated by fetal renal function, swallowing, and placental exchange. The purpose of this medication is to facilitate cervical ripening, which is a prerequisite for labor induction, not to alter the fluid environment surrounding the fetus.

Choice C rationale

Prostaglandins do not enhance uteroplacental perfusion. This medication's primary pharmacological effect is localized to the cervix, where it causes cervical softening and effacement by breaking down collagen fibers and increasing water content. Uteroplacental perfusion is a complex circulatory process that ensures adequate oxygen and nutrient exchange, and it's not the target of this drug.

Choice D rationale

Prepidil, which contains dinoprostone, is a prostaglandin E2 analog. Its primary action is to promote cervical ripening by stimulating the breakdown of collagen and increasing the water content of the cervix. This leads to cervical softening, effacement, and dilation, making the cervix more favorable for subsequent induction with oxytocin. The goal is to prepare the cervix for the mechanical forces of labor.

Choice A rationale

A fern pattern on a microscope slide is the definitive diagnostic sign of premature rupture of membranes (PPROM). This occurs when amniotic fluid, which contains sodium chloride, dries on the slide, forming a crystalline, fern-like pattern. This positive "ferning" test confirms the presence of amniotic fluid, indicating that the membranes have ruptured.

Choice B rationale

White vaginal discharge is a common finding during pregnancy and is not indicative of PPROM. This discharge, known as leukorrhea, is a result of increased estrogen production and blood flow to the vaginal area. It is a normal physiological change and does not signify ruptured membranes.

Choice C rationale

A negative fetal fibronectin test indicates a low probability of preterm birth within the next one to two weeks. It does not diagnose PPROM. While PPROM often leads to preterm birth, the fFN test is a predictive tool for labor, whereas ferning is a direct diagnostic test for membrane rupture.

Choice D rationale

The pH of vaginal fluid is typically acidic, ranging from 3.8 to 4.5. Amniotic fluid, however, is alkaline, with a pH of 7.0 to 7.5. Therefore, a vaginal fluid pH of 4.5 would be considered normal and would not indicate the presence of alkaline amniotic fluid, which would raise the pH to above 6.5.