Premature Rupture of Membranes: (PROM)
A- Definition. Rupture of membranes before the onset of labor, irrespective to gestational age.Epidemiology.
PROM is responsible for 25 to 33% of all of preterm births each year.
Between 13 and 60% of patients with PROM have an intra-amniotic infection.
Between 2 to 13% of patients with PROM have postpartum endometritis.
Etiology.
Intrauterine infection is the major causal factor.
Associated etiologic factors include low socioeconomic status, STDs, prior PROM and preterm delivery, vaginal bleeding, cervical conization, tobacco smoking, uterine overdistention, cervical incompetence and emergency cerclage, trauma as coitus, and malposition and malpresentation.
Evaluation. Diagnosis is usually clinical.
* History: fluid leaking per vagina or excessive vaginal discharge.* examination:A sterile speculum examination is performed to evaluate the fetal membrane status and to inspect the cervix. Avoid vaginal examination unless there is abnormal fetal heart rate or abnormalities in the fetal lie.
Membrane rupture is confirmed by visualization of amniotic fluid in the posterior fornix or by passing of amniotic fluid from the cervical canal.
* if the nature of the fluid is not clear do the following test:
Nitrazine test: The vaginal pH is normally 4.5 to 6.0, and the pH of amniotic fluid is 7.1 to 7.3. Nitrazine paper turns blue with a pH above 6.0 to 6.5. so if the colour change to blue this means that the fluid is amniotic fluid,
False-positive Nitrazine tests result from semen, alkaline
antiseptics, bacterial vaginosis, and blood.
Amniotic fluid from the vaginal pool produces a fernlike pattern on a microscope slide when allowed to dry.
If the patient's history is suggestive of PROM but the sterile speculum examination is equivocal, an amniocentesis can be performed. Amniotic fluid can be sent for Gram stain and culture. In addition, dilute indigo carmine can be instilled into the amniotic fluid. A tampon is then placed in the patient's vagina. After a few hours it is removed. If the tampon is blue, PROM has been confirmed. If the tampon is white, the patient does not have PROM.
* Further tests : Once membrane rupture has been confirmed, digital examination of the cervix should be avoided until labor or induction of labor.
Endocervical samples are obtained for gonorrhea and Chlamydia testing.
Group B Streptococcus cultures are obtained.
A urine specimen is sent for culture.
Fetal heart rate and uterine activity monitoring are used to assess fetal well-being and uterine contraction pattern.
* Ultrasound is performed on admission to assess the
estimated fetal weight and fetal presentation. It revealed oligohydraminous.
Maternal and fetal problems:
Infection: chorioamnionitis occur frequently in patient with
PROM. Its usually diagnosed clinically. Signs include maternal and fetal tachycardia, fever, uterine tenderness with foul vaginal discharge and leukocytosis. The responsible bacteria mostly are normal vaginal flora (ureaplasma urealyticum, mycoplasma, Bacteroids, gardnerella vaginalis, gp B sterpt, E coli, enterococci. It may cause severe neonatal infection and death. Blood test revealed high maternal WBC, and C-reactive proteins, amniotic fluid gram stain and culture with poor fetal biophysical profile.
RDS
Fetal pulmonary hypoplasia.
Abruption placenta.
Fetal congenital anomalies, fetal deformities and fetal distress.
Cord prolapse
Preterm labor and increase prenatal mortality.
Management.
admission to hospital.
Initial evaluation and confirmation of diagnosis and gestational age. Examination ( including general examination for sings of infection, abdominal examination for tenderness, and fetal heart monitoring, then strile speculum examination).
Management plan:
* In the absence of labor, chorioamnionitis, or nonreassuring fetal heart rate testing, neither presence of any maternal medical disease then patients with PROM can be expectantly managed until 34 to 36 weeks' gestation with the followings:
Corticosteroids. A complete course is given from 24 to 34 weeks' gestation.
Broad-spectrum antibiotics. A 7-day course (2 days intravenous, 5 days oral) is given.
3. Fetal well-being is assessed daily with a nonstress test
and a follow-up biophysical profile as needed.
4. Observation chart for vital signs. Frequent measurement
of WBC .
* Chorioamnionitis, labor, or nonreassuring fetal heart rate
testing need delivery at any gestational age. Mode of delivery
depend on gestational age.