During gestation, the fetus is present amniotic sac or amniotic membranes along with the amniotic fluid which nourishes him/her. When the labor begins, the amniotic membrane ruptures. The rupturing of the membrane at term occurs due to cell death, action of various enzymes and mechanical forces that act on the membrane. Premature rupture of membranes occurs due to early activation of the above pathways, which results in spontaneous onset of labor. However, in certain cases labor has to be induced. It is not a frequently occurring condition and occurs in less than 15% of pregnancies.
Preterm Premature Rupture of Membranes
In this condition rupture of membranes occurs before 37 weeks of pregnancy. It is a serious complication which can lead to infection and even death of the fetus.
Risk factors
The risk factors are:
- Infections in the uterus, vagina or cervix
- Smoking cigarettes
- Drug abuse
- Hydramnios (increased amount of amniotic fluid)
- If you are pregnant with more than one baby
- Bleeding during pregnancy
- Nutritional deficits
- Cervical insufficiency
- Being underweight
- Belonging to the low socio economic status
Symptoms
The main symptoms of premature membrane rupture include leakage or sudden rush of fluid from the vagina.
How is it diagnosed?
It is diagnosed by the following clinical signs:
- Leaking amniotic fluid through the cervix and visual pooling of amniotic fluid in posterior part of vagina.
- Alkaline pH of the discharge from the cervix and vagina (It is detected by nitrazine test where yellow nitrazine paper turns blue at alkaline pH).
- Microscopic ferning test where the cervicovaginal discharge is allowed to dry and observed under the microscope to see if it exhibits fern like patterns.
- Decreased amniotic fluid volume.
Complications of Premature Rupture of Membranes
Neonatal Complications
The neonatal complications depend on the gestational period when the premature membrane rupture has occurred. If it occurs before term then the risk of neonatal mortality increases by 3 fold and the risk of the baby developing respiratory distress syndrome is also high. If you suffer from preterm premature rupture, you have a 1-2% chance of losing your baby due to infections and cord accidents. It also increases risk of infections of the amniotic sac, incomplete development of lungs and skeletal deformities in the baby, cord prolapse and neuro-developmental disorders in the new born babies.
Maternal Complications
The common maternal complication is chorioamnionitis. It is a condition where there is infection of the amniotic sac (membranes that cover the fetus) and it occurs in 13% – 60% of pregnant women. Premature membrane rupture also increases the risk of caesarian deliveries and associated complications.
Management of Premature Rupture of Membranes
If you are at 37 weeks or more the doctor will induce labor. However, if your membranes rupture earlier than that your doctor may recommend bed rest and medications to prolong your pregnancy and prevent infections.
The rupture of amniotic membranes usually leads to spontaneous induction of labor. The amniotic sac serves as a barrier preventing microorganism in the vagina from ascending to the uterus. When the amniotic membranes rupture the risk of infection is high and therefore, labor is usually induced within 12 – 24 hours if it does not occur spontaneously.
When you consult your doctor, they will first confirm the diagnosis; age and the health condition of the fetus and then decide on birthing method of the fetus.
After the rupture of membranes most women go into labor spontaneously. However, about 50% of the women remain pregnant for a week and only a small number of women remain pregnant for 3-4 weeks. In less than 10% of pregnant women the ruptured membrane seals spontaneously. The membranes have a higher probability of sealing spontaneously if the rupture is due to amniocentesis.
If your doctor determines that the fetus and mother are stable then they may decide to allow the pregnancy to continue. However, there is a high risk of incidence of infections such as chorioamnionitis, endometritis, sepsis and maternal deaths.
Medications that May Be Used
1. Antibiotics
If your doctor decides that it is safe to let the pregnancy continue after membrane rupture they may administer certain antibiotics which help in prolonging pregnancy. Amoxicillin, erythromycin, ampicillin are some of the antibiotics which are generally administered. It is presently recommended that patients should be treated with antibiotic therapy for 7 days after which it should be stopped to avoid antibiotic resistant strains from developing. Group B Beta-Hemolytic Streptococcus (GBS) chemoprophylaxis is also administered to prevent GBS infection which may lead to sepsis in the fetus, resulting in fetal death.
2. Corticosteroids
Corticosteroids such as betamethasone are administered to hasten the maturity of the lungs of the fetus and decrease the risk of development of conditions such as respiratory distress syndrome, intraventricular hemorrhage (bleeding in the brain of the infant)and necrotizing enterocolitis (intestines of infants are infected with bacteria).
3. Tocolytics
These are drugs used to prevent premature labor. Tocolytics such as magnesium sulfate when administered have been found to reduce neurodevelopmental disorders in the baby. It is recommended that magnesium sulfate should be administered as a 4- 6 g bolus for 12 -24 hours with a maintenance dose of 1-2 g bolus.
Timing for induction of labor
If you suffer from premature rupture your doctor induces your labor when the gestational age of your fetus is more than 34 weeks to prevent infections. Labor is usually induced between 32 – 34 weeks if the fetal lungs have matured. The ideal gestational age for induction of labor depends on the decision of your health care provider.
Can Premature Rupture of Membranes Be Prevented?
Since the cause is not yet known, there is no information about how to prevent it. However, it is recommended that you regularly consult your doctor during your pregnancy and do not miss any appointments. This will help in early diagnosis and treatment of the condition which will ensure safe delivery.