PRETERM PRELABOUR RUPTURE OF MEMBRANE
The precious fluid around the baby is an important fluid which i refer to as the water of life or the golden fluid. Its presence cannot be quantified in relation to its significance in the survival of the baby in the mother’s uterus. The bag that keeps this fluid is called a membrane in medical terms and its rupture has a positive and negative impact on the baby. Rupture of membrane during pregnancy can be divided into different types, the membrane that rupture early in pregnancy or at maturity of the pregnancy or during labour. The approaches to management of the different types are totally unique.
Preterm prelabour rupture of membrane previous called Premature rupture of membrane is a term that refers to the rupture of membrane (leakage of amniotic fluid) before 37 weeks of gestation. This medical condition is noted to complicate approximately 3 percent of pregnancies and leads to one third of preterm births.
Causes / Risk Factors
The causes of prelabour rupture of membrane are interwoven with the risk factors. This include underlying infection in the vaginal canal or in the mother’s system, others are previous prematurity, excessive amniotic fluids (polyhydramnios), abnormality of the uterus in shape. Rupture of membrane can occur following procedures such as amniocentesis (procedure whereby samples of the fluids is taken for analysis during pregnancy), cervical cerclage (used to correct cervical incompetence), previous cervical surgeries such as cone biopsy or conization which lead to incompetence cervix with resultant gap at cervical outlet when pregnancy advances.
Social habits have been attributed to risk factors for rupture of membrane such as cigarette smoking and recreational drugs (narcotics). Abdominal trauma which can arise from domestic or motor accident and in some situation domestic violence are causative factors of membrane rupture.
The diagnosis of preterm prelabour rupture of membrane can be evaluated from the symptoms, signs and examination which are done in the hospital. The symptoms presented comprises of leakage of fluid or sudden gush of fluid from the vagina in which the patient will perceived as wetness of the perineal region. If the patient is not observant or delayed presentation to the hospital the presentation or symptoms complained about may include, fever, heavy or foul- smelling vaginal discharge, abdominal pain, which at this time is a pointer to intraamniotic infection which is called Chorioamnionitis.
The diagnostic examination procedure comprises the physical examination which involve a general examination that also involve listening to the baby’s heart beat that could be faster than expected which is called fetal tachycardia.
A vaginal examination with the use of an instrument called speculum, investigative kits called nitrazine paper, aminosense pad, and ultrasound guided amniocentesis dye test for confirmation can be employed.
The vaginal speculum will show the egress of amniotic fluid escaping from the cervix or in the alternatively the presence of the vernix (white waxy substance that severs as skin coat for the baby) or meconium which is the baby’s poo.
Further evaluation can be done with the use of investigative tool such as nitrazine paper which changes colour to blue indicating alkalinity which is synonymous to the amniotic fluid status. Also the vaginal fluid can be spread on glass slide looking for a fern like pattern that also imply amniotic fluid. The use of a perineal pad called amniosense pad which changes colour to blue indicating probable amniotic fluid leak, differentiate the fluid from urine that is yellow after wearing it for about 30 minutes. However, it is be noted that there are limitations to the tests due to false positivity. Confirmatory test can be done with the use of amniocentesis dye test and also evaluation of the amniotic fluid volume under ultrasound guidance.
Blood and urine analysis are adjuvant investigations that are used in the management.
The complications that arise from preterm prelabour rupture of membrane include prematurity with resultant comorbidity. Others are infection of the amniotic fluid called chorioamnionitis, umbilical cord compression, prolapse, abruptio placentae, increased in caesarean section rate and foetal demise.
The treatment plan for mothers with rupture can be divide into expectant management, and immediate management. The age of the pregnancy and complications play key roles in the line of management which are individualised. Administration of erythromycin (antibiotics), steroids and magnesium sulphate are some of the management armamentarium which are used.
Women with prelabour premature rupture of membrane in established labour or having a planned birth within 24 hours are offered intravenous magnesium sulphate as neuroprotection for the baby between the gestational age of 24 – 29+6 weeks
In an uncomplicated condition pregnancy after 24 weeks of age of viability with no other contraindication, they can be offered expectant management up till the 37 weeks of gestation.
Complicated pregnancy can be expedited by induction of labour or emergency caesarean section.
Tanya M, Medina MD, D.Ashley Hill MD, JM, Moore ML. Preterm premature rupture of membrane: Diagnosis and Management. Am Fam Physician, 2006 Feb 15;73(4): 659-664
MSD manual Professional version https://www.msdmanuals.com/
RCOG Guideline 73 Care of Women Presenting with Suspected Preterm Prelabour Rupture of membrane from 24+0 weeks of gestation