Premature rupture of membranes resident survival guide

Premature rupture of membranes Resident Survival Guide Microchapters
Overview
Causes
Diagnosis
Treatment
Dos
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rinky Agnes Botleroo, M.B.B.S.

Synonyms and keywords:Approach to premature rupture of membranes; PROM; Preterm prelabor rupture of membrane; Preterm premature rupture of membranes; pPROM

Overview

Premature rupture of membranes (PROM) is a condition that occurs in pregnancy when the amniotic sac ruptures before the onset of labor irrespective of gestational age. The term pPROM stands for preterm premature rupture of the membranes which occurs when the rupture happens before 37 weeks of gestation. Risk factors include maternal vaginal infections which ascend to the amniotic membrane, vaginal bleeding during pregnancy and maternal stature among others. Rupture of the membranes typically presents as a large gush of clear vaginal fluid or as a steady trickle. The differential diagnosis includes leakage of urine, excessive vaginal discharge for example physiologic discharge or bacterial vaginosis and cervical mucus (show) as a sign of impending labor.The diagnosis of PROM is done by careful complete history and physical examination, ultrasound is done to confirm oligohydramnios. Once the membranes rupture, delivery is recommended when the risk of ascending infection outweighs the risk of prematurity. When PROM occurs at term, labor typically takes place spontaneously or is induced within 12 to 24 hours.

Causes

Common risk factors in the development of PROM include :

• Maternal risk factors:
  • Sepsis
  • Previous history of PROM, recurrence risk is 16%–32% as compared with 4% in women with a prior uncomplicated term delivery.
  • Chronic steroid therapy
  • Abnormal bleeding during the second trimester or late in the pregnancy.
  • Low body mass index (BMI < 19.8 kg/m2)
  • Smoking and drug abuse
  • Low socioeconomic status
  • Deficiency of copper or vitamin C, along with connective tissue disorders such as Ehlers-Danlos syndrome, Systemic Lupus Erythematosus are also linked to increased risk of PROM.
  • Direct abdominal trauma
  • Preterm labor
  • Anemia

• Uteroplacental Factors:
  • Uterine anomalies (such as uterine septum)
  • Placental abruption
  • Advanced cervical dilation (cervical insufficiency)
  • Prior cervical conization
  • Cervical shortening in the 2nd trimester (< 2.5 cm)
  • Uterine overdistention (Polyhydramnios, Multiple pregnancy)
  • Intra-amniotic infection (Chorioamnionitis)
  • Multiple bimanual vaginal examinations (but not sterile speculum or transvaginal ultrasound examinations)

• Fetal factors include :
  • Multiple pregnancy ( preterm PROM complicates 7%–10% of twin pregnancies)
  • Prematurity
  • Infection
  • Cord prolapse
  • Malpresentation.

Diagnosis

Shown below is an algorithm summarizing the diagnosis of

Abbreviations: BP: Blood pressure; RR=Respiratory rate; HR=Heart Rate, PROM= Premature rupture of membranes; AFV= Amniotic fluid volume

Pregnant woman comes with Premature rupture of membranes

Take complete history

Record the vitals: ❑ Blood pressure ❑ Temperature ❑ Respiratory rate ❑ Heart rate

Take obstetric history : ❑ Date of last menstrual period? ❑ Estimated date of delivery. ❑ Confirm the gestational age, gravidity and parity. ❑ Check if this is a single or multiple gestation.

Ask about previous obstetric history if she was previously pregnant : ❑ Ask about previous pregnancies including miscarriages and terminations. ❑ Length of gestation. ❑ Ask about mode of delivery. ❑ Ask if there was similar complaints during previous pregnancy? ❑ Was there any complications throughout the pregnancy or during delivery such as shoulder dystocia, postpartum haemorrhage ?

Ask the following questions about menstrual history : ❑ Age of menarche ❑ Last menstrual period ❑ Is the menstrual flow normal? How many pads she has to use in a day? ❑ Is there any foul smell or colour change? ❑ How many days does the menstruation stay? ❑ Contraceptive history for example oral contraceptives, intrauterine device

Perform physical examination : ❑ Visualization of amniotic fluid (AF) leaking through the cervix. ❑ Vaginal pooling. ❑ Fern test of dried vaginal fluid seen under microscope. ❑ pH testing : Normal vaginal pH: 3.8 to 4.5 Normal amniotic fluid pH: 7.1 to 7.3 False positives: Blood or semen, alkaline antiseptics or bacterial vaginosis. False negatives: Minimal remaining amniotic fluid following rupture. ❑ Sterile speculum examination to assess dilation.

If above are not conclusive, do the following tests : ❑ Ultrasound for AFV may be helpful but not diagnostic . ❑ Fetal fibronectin is sensitive with high negative predictive value but positive result is not diagnostic. ❑ Amniotic protein tests have high sensitivity for PROM but false-positive rates are high.

Conclusive test – dye instillation : ❑ Intra-amniotic dye instillation is helpful for evaluation of PROM and for genetic amniocentesis in multifetal gestation. Ultrasound guided dye is passed into the vagina and detected with tampon or pad stain. ❑ Indigo carmine is the most used and studied dye which is no longer available. Maternal urine may turn blue following instillation of indigo carmine. ❑ As an alternative, sodium fluorescein is clinically useful but has side effects when used intravenously.the test includes speculum examination of cervix at 15 and 45 minutes post injection using a long-wave ultraviolet light. Yellow-green fluorescent fluid leaking from cervix confirms the diagnosis. Fluorescence will rapidly appear in urine and confusion may be resolved with either visualization of cervical leak or tampon. ❑ Phenol-sulfonphthalein has clinical importance with no maternal, fetal or neonatal side effects. But, it is not currently available in the United States.It is a pH indicator dye, also known as phenol red. ❑ Indocyanine green is used in pregnancy for other indications. ❑ Oral phenazopyridine hydrochloride may lead to a false-positive diagnosis of PROM. ❑ Evans blue and methylene blue have adverse fetal and neonatal outcomes.

Treatment

Shown below is an algorithm summarizing the treatment of premature rupture of membranes.

Abbreviations: PROM: Premature rupture of membranes; ECG=Electrocardiogram ; GBS= Group B Streptococcus, IV= Intravenous; HSV= Herpes Simplex Virus volume; HIV=Human Immunodeficiency Viruse

History suggestive of PROM (leakage of fluid from the vagina)

Physical examination findings confirm PROM •Pooling of fluid •Positive nitrazine and Ferning tests

Sterile speculum examination assess dilation and ultrasound if indicated

PROM ruled-out

PROM confirmed

Check gestational age •Arrange transportation to tertiary care if possible. •Arrange prompt consult with obstetrician. •Fetal non-stress test and ECG to assess well being.

Indications for delivery : ❑ Nonreassuring fetal status and chorioamnionitis. ❑ The decision for delivery depends on fetal status, amount of bleeding, the stability of mother, and gestational age. ❑ If the patient presents with vaginal bleeding, there may be a concern for a placental abruption and delivery should be considered.

Management of PROM ❑ Patients with preterm PROM should be admitted to hospital and periodically assessed for infection, placental abruption, umbilical cord compression, fetal well-being and labor. ❑ Periodic ultrasound evaluation should be performed to monitor fetal growth and fetal heart rate. ❑ Vital signs should be monitored and a rise in maternal temperature should raise suspicion for an intrauterine infection. ❑ Serial monitoring of leukocytes and inflammatory markers are not useful in diagnosing infection as they are nonspecific if there is no clinical evidence of infection. Administration of corticosteroids can cause a transient leukocytosis as well. ❑ Prophylactic tocolytics can cause a longer latency period and a lower risk of delivery within 48 hours. But it is associated with a higher risk of chorioamnionitis in pregnancies before 34 weeks of gestation. ❑ Antenatal corticosteroids after preterm PROM have been shown to reduce neonatal mortality, respiratory distress syndrome, necrotizing enterocolitis, and intraventricular hemorrhage. ❑ Antibiotics prolong pregnancy, reduce maternal and neonatal infections, and reduce fetal morbidity. ❑ Progesterone supplementation should be offered to reduce the risk of spontaneous preterm birth in a woman with previous history of PROM. Management of PROM with infections ❑ HSV infection & PROM •Recurrent active HSV Expectant management is recommended if gestational age is <34w0d. Initiate HSV therapy Corticosteroids Antibiotics Magnesium sulfate Cesarean section if active disease or prodromal symptoms are present at time of delivery. •Primary HSV Management is not clear yet. Cesarean delivery if active lesions are seen. ❑ HIV infection & PROM: •Patient should be seen by a physician with expertise in the management of HIV in pregnancy. •Vertical transmission risk may not be increased if the patient is on highly active antiretroviral therapy with a low viral load and has received antepartum and intrapartum zidovudine. •Expectant management if gestational age is early and patient is on appropriate therapy with a low viral load.

PROM at less than 24 weeks : ❑ Patient counselling must be done and she should be advised about the risks and benefits of expectant management and immediate delivery. •Immediate delivery should be offered as an option. •Consider maternal, fetal and neonatology consultation. ❑ If there is no signs of infection and patient agrees, then expectant management should be started. •Patient can be managed on a outpatient setting following inpatient assessment. •She should be advised to return to hospital immediately if any signs or symptoms of bleeding, labor or infection are noticed. •Patient should be advised to return to hospital at time of viability. ❑ Antibiotics can be offered as early as 20W0D. ❑ A single course of corticosteroids can be given as early as 23w0d due to risk of delivery within 7 days. ❑ Antenatal corticosteroids and latency antibiotics are recommended upon reaching viability. ❑ GBS prophylaxis, tocolysis and neuroprotection (magnesium sulfate) can be considered as early as 23W0D, but these are not recommended prior to viability.

PROM at preterm (24 0/7 – 33 6/7 weeks of gestation) : ❑ Expectant management which includes admitting the patient to the hospital admission and monitored for infection, hemorrhage, placental abruption, umbilical cord compression, fetal assessment and evidence of labor. ❑ If there are maternal or fetal contraindications to expectant management, delivery is recommended. ❑ Single course of antenatal corticosteroids are recommended. ❑ Latency antibiotics can be given. •IV ampicillin 2 g every 6 hours and erythromycin 250 mg every 6 hours for 48 hours followed by oral amoxicillin 250 mg every 8 hours and erythromycin base 333 mg every 8 hours for an additional 5 days (7 days total). •Azithromycin 1 g single dose is a suitable alternative to replace erythromycin if unavailable or poorly tolerated. •Amoxicillin–clavulanic acid is not recommended due to increased risk for necrotizing enterocolitis. ❑ Neuroprotective treatment with magnesium sulfate should be given to women with PROM before 32w0d and imminent delivery. ❑ Vaginal/rectal swab is taken for GBS and GBS prophylaxis can be given as indicated. If the patient is allergic to β-lactam antibiotics consider another agent against GBS based on severity of allergic reaction and susceptibility profiling.

PROM at late preterm (34 0/7- 36 6/7 weeks of gestation) : ❑ Expectant management or immediate delivery. ❑ Administer single-course corticosteroids if •Not previously given. •Delivery expected in >24 hours and ≤7 days. •No chorioamnionitis. ❑ Screen for GBS and administer prophylaxis as indicated. ❑ If chorioamnionitis: treat and plan for delivery.

PROM at early term and term patients (37 0/7 weeks of gestation or more) : ❑ Delivery and Group B Streptococcus prophylaxis should be administered as indicated. •If no spontaneous labor. Induce labor with oxytocin. Allow adequate time (12-18 hours) for latent phase to progress before performing a cesarean section for failed induction of labor. Induction with prostaglandins may have higher risks of chorioamnionitis. There is not sufficient data about cervical ripening with mechanical methods such as a Foley balloon. •Insufficient evidence to recommend antibiotic prophylaxis beyond GBS indications. ❑ If a patient declines delivery and requests expectant management, counsel regarding risks and benefits. ❑ Chorioamnionitis: treat and plan for delivery.

Dos

• GBS prophylaxis should be given based on prior culture results or intrapartum risk factors if cultures not performed or unavailable.
• Patient should be monitored regularly with ultrasound and counsel patients to watch for signs of infection, bleeding or miscarriage.
• Cervical cerclage should be considered for women with the following:
  • Current singleton pregnancy.
  • Prior spontaneous preterm birth < 34 weeks.
  • Cervical length < 25 mm prior to 24 weeks.
• Pregnant women should avoid smoking.

Don'ts

• Tocolytic therapy is not recommended at 34w0d to 36w7d gestation.

References

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