Premature Rupture of The Membranes

Premature rupture of the membranes is a spontaneous break or tear in the amniotic sac before onset of regular contractions, resulting in progressive cervical dilation. This common abnormality of parturition occurs in nearly 10% of all pregnancies over 20 weeks' gestation, and labor usually starts within 24 hours; more than 80% of these infants are mature.

The latent period (between membrane rupture and onset of labor) is generally brief when the membranes rupture near term. When the infant is premature, the latent period is prolonged, which increases the risk of mortality from maternal infection (amnionitis, endometritis), fetal infection (pneumonia, septicemia), and prematurity.

Causes

PROM's causes aren't thoroughly understood, but taking certain steps may help reduce your risk. Smoking increases the risk of PROM, so quit now. Get early, regular prenatal care so that certain complications of pregnancy that increase the risk of PROM, such as uncontrolled high blood pressure, can be detected and treated. You also are at increased risk of PROM if you are pregnant with twins

Signs and Symptoms

A patient who has experienced premature rupture typically reports gushing or leaking of blood-tinged amniotic fluid containing vernix particles. Inspection during sterile speculum examination shows amniotic fluid in the vagina

Diagnostic tests

A characteristic passage of amniotic fluid confirms the rupture. Slight fundal pressure or Valsalva's maneuver may expel fluid through the cervical os. The following diagnostic tests support the diagnosis:

• Alkaline pH of fluid collected from the posterior fornix turns nitrazine paper deep blue. (The presence of blood can give a false-positive result.) Staining the fluid with Nile blue sulfate reveals two categories of cell bodies. Blue-stained bodies represent sheath fetal epithelial cells; orange stained bodies originate in sebaceous glands. Incidence of prematurity is low when more than 20% of cells stain orange.
• A smear of fluid, placed on a slide and allowed to dry, takes on a fernlike pattern (because of the high sodium and protein content of amniotic fluid). This positive finding confirms that the substance is amniotic fluid.
• Vaginal probe ultrasonography may be done to yisualize the amniotic sac.
• Differential diagnosis excludes urinary incontinenre and vaginal infection.

Treatment

Fetal age and the risk of infection are considered in determining the course of treatment for premature rupture of the membranes.

In a term pregnancy, if spontaneous labor and vaginal delivery aren't achieved within 24 hours after the membranes rupture, inducement of labor with oxytocin is usually necessary; if inducement fails. cesarean delivery is usually necessary. Cesarean hysterectomy is recommended with gross uterine infection.

Management of a preterm pregnancy of less than 34 weeks is controversial; with advanced technology a conservative approach may be effective. With a preterm pregnancy of 28 to 34 weeks, treatment includes hospitalization and observation for signs of infection (maternal leukocytosis or fever and fetal tachycardia) while awaiting fetal maturation. If clinical status suggests infection, baseline cultures and sensitivity tests are appropriate. If these tests confirm infection, labor must be induced, followed by I.V. administration of antibiotics. A culture should also be made of gastric aspirate or a swabbing from the neonate's ear because antibiotic therapy may be indicated for him as well.

During delivery, resuscitative equipment and ares thesia should be available. A pediatrician should be present to treat neonatal distress.

Prevention

Unfortunately, there is no way to actively prevent PROM. However, this condition does have a strong link with cigarette smoking and mothers should stop smoking as soon as possible.