Premature Amniotic Fluid Discharge (Early Membrane Rupture)
Amniotic fluid in which the baby is protected in the womb; It is trapped by the membranes called amniotic membrane and chorionic membrane. These membranes ensure that the baby is protected against vagina and external infections. The condition of early water coming, called the early membrane rupture, refers to the opening (tearing) of these membranes before the labour begins. In 10% of all pregnancies, water may come first, and 80% of this condition is found in term pregnancies (37 weeks after delivery). In 3.5% of all pregnancies, water may come before 37 weeks, and 30-40% of premature births is due to early water.
As mentioned above, the membranes surrounding the amniotic fluid and surrounding the baby consist of two layers. The inner layer, called the amniotic membrane, is thin, and the outer layer, called the chorion skin, is thick. Amniotic membrane is more suitable for stretching. There is a collagen connective tissue between the two layers. The growth activity in the amniotic and chorion membranes continues until the 28th week. It decreases after 28 weeks and until the 37th week of the baby, the amniotic membranes gradually disappear from the collagen connective tissue and begin to weaken against stretching. The membranes surrounding the baby growing according to the membranes surrounding the premature baby can now respond to the growth of the baby by intrauterine pressure, uterine contractions and tearing of the baby’s movements. The period until the onset of birth after the dice are torn is called the ‘latent period’.
Delivery usually takes place within the first 24 hours after the damage is ruptured and water comes in. This is considered to be the time that minimizes the possibility of the baby being affected by infections. If the time exceeds 24 hours, there will be a ‘prolonged early water arrival’ situation. In the case of premature water, it is also frequently delivered within 24 hours, but it can be waited for a period of time to ensure that there is no infection and for lung maturation under antibiotic protection. However, it is very important to ensure that the situation is safe for the waiting period.
The Related Causes
The most common among the causes is the infection in the amniotic and chorion membranes. Microorganisms reduce the durability of the membranes by secreting a number of enzymes that weaken the integrity of the collagen connective tissue that ensures the integrity of the membranes. The most common microorganisms are:
Group B streptococci
Therefore, vaginal culture in women with suspected early water intake is diagnostic; it will be very useful in follow up and treatment.
It is observed that women who smoke have 3 times more early water than women who do not. There are studies indicating that smoking impairs protein metabolism in the membranes and reduces type 3 collagen.
A number of reasons such as ascorbic acid (vitamin C), low levels of copper and zinc and low levels of prolactin hormone are also suggested in women. However, in addition to a study claiming that the use of vitamin C decreases the possibility of early water intake of women, there are also studies indicating that women who take vitamin C and E come with water more frequently.
The Related Risk Factors
* A history of early water intake (raises the possibility of 32% recurrence in the next pregnancy)
* Recurrent bleeding in the early weeks of pregnancy
* Overstretching of the uterus (multiple pregnancies, excessive water increase)
* Cervical insufficiency
* Cerclage in the cervix with the diagnosis of cervical insufficiency
* Conization story
* Invasive intervention history such as amniocentesis and cordocentesis
* Presence of sexually transmitted diseases
* Low socioeconomic level
* Marginal entry of the cord into the placenta
* Placement of the placenta in the fundus (near the womb) (causing the weakest part of the membranes to remain in the cervix)
Findings and Diagnosis
Continuous or intermittent or more or less fluid is the most common finding. However, taking a history may not always be sufficient for diagnosis. If birth is not considered, vaginal examination should be avoided by hand as much as possible, as this examination may cause the infection by moving the microorganisms in the vagina upwards. This may lead to shortening of the latent period. Therefore, the sterile speculum should be placed in the vagina and this method should be used for diagnosis.
The diagnostic evidence that can be evaluated with a speculum are:
* Amniotic fluid ponding can be seen in the back of the vagina.
* Fluid flow can be monitored directly from the cervix, or the patient can be monitored by straining, coughing, or lightly pressing on the abdomen.
* When speculum is placed, additional conditions such as cervical opening, fetal foot adhesion or amniotic bulging can also be evaluated.
* When nitrazine paper turns from yellow to dark blue, it shows the pH value which is alkaline like amnios fluid and can be used in diagnosis. However, alkaline urine, semen (blood), blood, trichomonas infection and alkaline change can be seen in bacterial vaginosis. This may decrease the diagnostic value (diagnostic value 93%).
* Amniotic membrane can be dried on slide (glass) and evaluation of fern view can be done under microscope. Again semen (cervix) and cervical mucus may mislead the diagnosis (diagnostic value 96%).
* Insulin-like growth factor (diagnostic value is about 95-100%) and placental alpha microglobulin 1 protein (AmniSure diagnostic value is 98.7%) that binds to protein 1 known as immunochromatographic methods are other diagnostic methods. For these tests, amniotic fluid and test kits should be combined. They are not affected by vaginal discharge, small amounts of blood, semen and alkaline urine.
Also, fetal fibronectin determination in cervical secretions is a test that may indicate preterm labour, but not early birth.
Evaluation of amniotic fluid by ultranonography is another diagnostic method if the baby’s kidney-urinary tract development is normal and there is no restriction in the womb. If the amniotic fluid is decreased, this will be accepted in favour of early water arrival.
In the event that the arrival of amniotic fluid cannot be proven, although it is not applied any longer; It is also a diagnostic method to monitor the diluted indigocarmine dye injected into the amniotic fluid from the abdomen in a gauze put into the vagina half an hour later.
Vaginal ultrasonography can be safely applied in premature cases if water comes early and is a valuable treatment method that can be applied without increasing the risk of infection for the evaluation of the cervix.
The Related Maternal Reasons
The “latent period”, expressed as the time between the rupture of the membranes and the onset of labour, is inversely proportional to the gestational week. In other words, while it may be longer in the premature period, it tends to be shortened to term, ie, birth. In the near-birth period, 80-90% probability of birth will begin within 24 hours after water comes. While it is longer than 24 hours in 57-83% of the cases in the premature period, it can be more than 72 hours for 15-26% and 7 days and more in 19-41%.
The probability of extending the duration of the latent period more than 3 days is 33% between 25th-32nd weeks, 16% between 33rd-34th weeks and 4.5% between 35th-36th weeks.
The main problem here is that the mother faces the possibility of infection after the early water comes. The risk of sepsis arises with the infection of the membranes first, then the intrauterine tissue and the infection that passes through this point. Although infection is the biggest cause of early water intake, the possibility of latent infection should always be kept in mind in early unexplained water intake. Not only the process of early water supply and the prolongation of the latent phase, but also the prolongation of labour, which increases the risk of infection.
Sensitivity in the uterus in diagnosis and examination, painful uterus, detection of fever exceeding 38 degrees, foul-smelling discharge and leukocyte count exceeding 20.000 and height of C reactive protein (CRP), pulse rate of the mother over 120 and heart rate of the fetus per minute is over 160 will increase the probability. Having two or more of these findings is diagnostic in terms of infection. Although leukocyte height alone is not significant in terms of diagnosis, the mother’s fever height alone is considered significant.
The Related Fetal Reasons
The most important factor that determines the risk is the gestational week. The earlier water comes in the week, the greater the risks associated with the premature baby.
The second effect is infections that occur during pregnancy, birth or later.
Since the amniotic fluid will decrease in early water supply, umbilical cord pressure and the pressure problems of the baby’s body, which will be caused by long-term water shortage especially in the early weeks, the delay in the development and maturation of the baby with the decreased amniotic fluid and the associated respiratory stress can be counted.
Amniotic fluid is essential for lung development. If early water comes before the 23rd week, the probability of lung development called pulmonary hypoplasia is almost 100%. It is rarely seen if it is later than 24-26 weeks. The probability decreases as the week increases. In case of early water coming below 25 weeks, if there is a severe water shortage exceeding 14 days, it is observed that the lungs do not develop 80% (pulmonary hypoplasia). If there is no severe water shortage after 25 weeks or if the water shortage is less than 5 days, the rate drops to 2%.
New-born complications may occur related to the premature birth of the baby. These; respiratory stress, intracranial hemorrhage (intracranial hemorrhage), intestinal necrosis (NEK; necrotizing enterocolitis), new-born retinopathy, PDA (heart disease called skate ductus arteriosus), and bronchopulmonary dysplasia (lung development disorder). The frequency of these conditions decreases as the gestational week increases.
In recent years, we can talk about better perinatal outcomes by giving glucocorticoids to mothers, increasing lung maturity and improving intensive care technical conditions.
An important point here; It is the correct calculation of the gestational week in the pregnant woman with early water. If the pregnancy week has not been calculated correctly before, amnios fluid will decrease and it will be difficult to decide the net pregnancy week on ultrasonography. As the week grows, the place of ultrasonography in the net determination of pregnancy week decreases and in cases where amniotic fluid decreases, its sensitivity decreases even more. In order to reach the correct week, a good questioning of the last menstrual history and most importantly, an ultrasonography evaluation made in the first 12 weeks are the most appropriate ways. After the gestational week is calculated correctly, it will be possible to decide whether to follow or terminate the pregnancy related to early water in the light of clinical and laboratory evaluations.
In Differential Diagnosis
* Increased colorless, odorless, itching-free physiological discharge due to hormonal changes,
* Discharge due to vaginal infections,
* Urinary incontinence
* Disposal of the mucus plug in the cervix takes place and every situation is evaluated.
The Treatment of Premature Amniotic Fluid Discharge
The first factor that determines the approach to treatment is pregnancy week. Because the most common complications related to the baby depend on the severity of premature. The second factor is to determine the presence of infection regardless of the gestational week.
Culture should be taken for group B streptococcus and antibiotic therapy should be started for the same agent without waiting for the results of the culture. Patients are taken to absolute bed rest and pet tracking is performed to estimate the amount of incoming fluid.
Sedimentation, C reactive protein (CRP) and leukocyte values are frequently monitored in the laboratory.
Uterine tenderness in the mother, foul-smelling discharge, tachycardia (palpitations) and palpitations in the baby may indicate the onset of infection.
* If the presence of infection is determined
* If the cervix opens
* If meconium is detected in the amniotic fluid
* If there is evidence of baby stress in NST
* If there is water in the gestational week under 23 weeks, the follow-up decision is not appropriate and a birth decision must be made.
Especially under 32 weeks, 1500 grams and breech arrivals, it will be appropriate to deliver by cesarean. In other cases, the condition of the cervix, the severity of the infection, the baby’s arrival and physical examination of the mother, additional complications in the mother, whether or not the baby is under stress and the way of birth will be determined according to the presence of meconium. If a vaginal delivery decision is made, the baby will be constantly monitored with the NST device called a non-stress test.
In any case, an effective and multiple antibiotic group will be determined according to culture results or clinical approach.