Amniotic fluid is formed by the mother and the baby when it passes urine and also from the baby’s lungs moreover, it surrounds the baby within the uterus and allows it to grow. It is almost like a swimming pool in which the baby can move about easily, extend its limbs and therefore grow adequately while also helping as a safety barrier for the baby with regard to buffering it from any kind of knocks from the outside.
In an interview with HT Lifestyle, Dr Anitha Manoj, Fertility Specialist at GarbhaGudi IVF, shared, “Amniotic fluid is nothing but the water level around the baby. It is very important because it acts like a cushion and gives nutrition support for the baby. Therefore, the levels of amniotic fluid should be normal. It should be at least more than 8 cm and less than 25 cm which is the upper limit. When amniotic fluid is adequate, there will be enough space for the baby to move around and for the growth of the baby. Amniotic fluid will have enough nutrients which can help with the growth of the baby.”
She added, “Amniotic fluid is mainly formed by the secretion of the urine by the baby and from secretions through the skin. If Amniotic fluid is adequate, it shows that the baby is healthy and that the renal systems of the baby are functioning normally. When amniotic fluid is excessive, it shows that there is excessive urine production and excessive excretion from the skin. It can be from the mother’s high sugar levels or some other problems with the baby.”
Causes for low amniotic fluid in pregnancy
Dr Prathima Reddy, Director and Lead Consultant at SPARSH Hospital for Women and Children, explained, “It can be divided into the first two trimesters, that is up to about 24 weeks, and then the last couple of trimesters i.e. up to 40 weeks. The only obvious cause of reduced fluid or oligohydramnios or low amniotic fluid is leaking of membranes or rupture of membranes. This means that the waters have broken and the mother is physically leaking water from the uterus. It is an easy diagnosis because the mother may tell us that she’s leaking fluid and her underclothes are wet constantly. After a couple of examinations and a scan, it will reveal that she’s actually leaking. This means the membranes which are a barrier between the outside world and the uterus have gone. This is one of the reasons for reduced fluid or oligohydramnios both in the first six months and in the latter half of the pregnancy.”
She elaborated, “In the first 24 weeks, if there is a low amniotic fluid or oligohydramnios, one will have to think about any kind of congenital defects, and if it is an early onset of blood pressure, or fetal growth restriction, that must be considered. Post the first 24 weeks, we may have to consider high blood pressure which can set in later. In the beginning it may not show up as high blood pressure but may show up as reduced fluid or reduced growth of the baby. Diabetes on the other hand gives rise to increased fluid with the baby. Mainly there are two conditions. One, breaking of water which is a physical thing that happens for which there is no real reason, two, there could be medical reasons such as birth, congenital problems with the baby, early onset of blood pressure, fetal growth restriction or growth problems with the baby. If the mother goes beyond her due date, it’s a natural progression of the placenta aging, the fluid coming down, and the baby maturing. All this happens when it’s time for delivery. Sometimes, the condition is unknown. It is not always known why mothers can have low amniotic fluid.”
Bringing her expertise to the same, Dr Anitha Manoj said, “Any problems in pregnancy can be attributed to three causes- maternal, fetal and placental causes. In case of low amniotic fluid, maternal causes can be something on the lines of lack of blood supply to the placenta for the growth of the baby. When there is pregnancy-induced hypertension for the mother, uncontrolled diabetes, malnutrition, and dehydration, can be some of the maternal causes for low amniotic fluid. In terms of fetal reasons, it can be renal pathology i.e. some problems with the kidneys of the baby where urine production is not happening or urine excretion is not happening or obstruction for urine excretion.”
Pointing out that it can also be due to some other anomalies where the urine production is not happening or where the skin is not contributing enough, Dr Anitha Manoj said, “Placental causes can include hypoperfusion i.e not enough blood supply to the placenta because of the mother, microthrombosis i.e. small placenta, abnormal placentation or low lying placenta can also cause low amniotic fluid. Amniotic fluid mainly comprises fetal urine, debris, protein content and vernix caseosa (shedding of skin cells). Whatever skin gets shed from the baby that will be in the amniotic fluid, it has the cushioning effect for the baby.”
Symptoms
Dr Anitha Manoj emphasised, “The fluid has to be enough for the baby to move. When the fluid decreases, the mother might feel that the baby is not growing. If the stomach size is less i.e inadequate uterine height or subnormal uterine height, the mother might feel the movements of the baby are a little less. The mother might have experienced some amount of leaking of fluid like urine. Urine is voluntary, mothers can control it but the amniotic fluid cannot be controlled. For example, her inner or her clothes might get wet. The mother can notice fluid leaking from her vagina. When this happens, she has to consult the doctor immediately.”
Treatment
According Dr Prathima Reddy, there is no real treatment that can help this. She said, “When the membranes have broken, or they have ruptured the membranes, and they’re leaking, the final treatment will be the delivery at some point in time. There is a risk of infection because the barrier between the outside world and the inside world is gone; therefore, infection may track up into the uterus, affecting the baby and the mother. So the treatment for that will be delivery, but then that delivery will be decided on by the obstetrician depending on the condition of the mother and the condition of the baby. If there are no signs of infection, doctors tend to push the pregnancy as far as possible.”
Dr Prathima Reddy added, “The one entity is where the physical barrier of the membranes has gone, therefore, there is active leaking, and the other entity encompasses all the medical problems. The others are all medical problems like chronic blood pressure, hypertension, or pre-eclampsia, controlling your blood pressure may help reduce the incidence of reduced fluid or oligohydramnios. One of the things proposed is drinking 2.5 liters of water per day which may improve the amniotic fluid. This is for the medical problem that causes it, not for the leaking. If it is leaking, nothing can stop it. It will continue to leak. It’s like a balloon that has got a hole, and it’s leaking. The delivery is done only if the water is not broken, not if the fluid is low. At some point, doctors have to think about delivering even if the fluid is low. So these are the main options and there is no medication specifically.”
She pointed out –
- Regular checkups: There will be regular checkups by an obstetrician to check if the mother and the baby’s health is good.
- Regular scans: Scans need to be done weekly or in two-week intervals, and early delivery may need to be planned for the baby’s safety.
Dr Anitha Manoj concluded, “When the amniotic fluid level is dropping, the gestational age matters a lot. It is a bad sign if it happens before 28 weeks i,e before the baby attains proper viability. The prognosis is poor if the amniotic fluid drops before 28 weeks. Increasing hydration of the mother is advised. Mothers must drink more fluids such as IV fluids, increased protein content, protein infusions and protein supplements. If it is after 28 weeks and between 34 weeks then these other measures can help along with treatment for the lung maturity of the baby and then the delivery of the baby can happen. Post 34 weeks, there is no need to wait, the level of amniotic fluid can affect the baby’s growth which can result in an Intrauterine death of the baby.”
