gynecology and obstetrics
Prelabor Rupture of Membranes (PROM)
Diagnosis
Vaginal pooling of amniotic fluid or visible vernix or meconium Evaluation of vaginal fluid showing ferning or alkalinity (blue color) on Nitrazine paper Sometimes ultrasound-guided amniocentesis with dye for confirmation Sterile speculum examination is done to verify PROM, estimate cervical dilation, and obtain samples for cervical cultures. Digital pelvic examination, particularly multiple examinations, increases risk of infection and is best avoided unless imminent delivery is anticipated. Fetal position should be assessed. If subclinical intra-amniotic infection is a concern, amniocentesis (obtaining amniotic fluid using sterile technique) can confirm this infection. If prelabor rupture of membranes is suspected, avoid doing digital pelvic examinations unless delivery seems imminent. The diagnosis of PROM is assumed if one of the following is present: Amniotic fluid appears to be escaping from the cervix. Vernix or meconium is visible. Other less accurate indicators include vaginal fluid that ferns when dried on a glass slide or turns Nitrazine paper blue, indicating alkalinity and hence amniotic fluid; normal vaginal fluid is acidic. Nitrazine test results may be false positive if blood, semen, alkaline antiseptics, or urine contaminate the specimen or if the woman has bacterial vaginosis. Oligohydramnios, detected by ultrasonography, suggests the diagnosis. If the diagnosis is questionable, indigo carmine dye can be instilled using ultrasound-guided amniocentesis. Appearance of the blue dye on a vaginal tampon or peripad confirms the diagnosis. If the fetus is viable, women are typically admitted to the hospital for serial fetal assessment. 