Oligohydramnios

Oligohydramnios is the condition of having too little amniotic fluid. About 8 per cent of all pregnant women are found to have low amniotic fluid at some point, usually in their third trimester. Among those still pregnant two weeks past their due date, 12 per cent have this condition. Amniotic fluid provides the fetus with fluid and nutrients, protects the fetus from trauma, has antibacterial properties and is necessary for the development of a healthy fetus. Studies have suggested that dramatic changes in amniotic fluid volumes can be a reflection of abnormalities in maternal or fetal status increasing the risk of perinatal morbidity and mortality.

The volume of amniotic fluid is ultimately determined by the volume of fluid flowing into and out of the amniotic sac. Fetal urination, lung fluid, and swallowing all make important contributions to fluid movement in late gestation, with minimal contributions from other sources. Fetal disorders that affect any of these processes.

What causes oligohydramnios?

Birth defects – Problems with the development of the kidneys or urinary tract which could cause little urine production, leading to low levels of amniotic fluid.

Placental problems – If the placenta is not providing enough blood and nutrients to the baby, then the baby may stop recycling fluid.

Leaking or rupture of membranes – This may be a gush of fluid or a slow constant trickle of fluid. This is due to a tear in the membrane. Premature rupture of membranes (PROM) can also result in low amniotic fluid levels.

Post Date Pregnancy - A post date pregnancy (one that goes over 42 weeks) can have low levels of amniotic fluid, which could be a result of declining placental function.

Maternal Complications - Factors such as maternal dehydration, hypertension, preeclampsia, diabetes, and chronic hypoxia can have an effect on amniotic fluid levels.

Medications - Certain drugs may cause oligohydramnios. Some drugs are used for management of high blood pressure, should be avoided in pregnancy as they affect the baby's kidney function. Certain drugs used to postpone premature labour such as indomethacin or even ibuprofen may also affect the kidney function of the baby. Talk to your doctor if you need to use these medications during your pregnancy.

An unusually large number of diagnoses seem to be made that "there is not enough amniotic fluid." It is important for parents to know that this is likely an inaccurate assessment. The diagnosis is confirmed by ultrasounds. An ultrasound examination during the second and/or third trimester of a pregnancy is a good tool to help detect the presence of oligohydramnios but it should not dictate to mothers that it is the only way. Ultrasound evaluations of amniotic fluid volumes are becoming a standard part of antepartum assessment of fetal well-being with variances in fluid levels leading to interventions that can increase the risk to both mother and baby. So, here's the point. If your doctor says, "Your fluid is low, we need to induce," don't blink blindly and say, "OK." The problem is that it is very often hard to determine "oligo" with certainty.

This measurement is commonly taken by using an ultrasound to determine the Amniotic Fluid Index (AFI). The AFI was introduced in 1987 to replace the 2 cm “pocket technique” of fluid assessment, and studies continue to question to what extent the AFI reflects actual amniotic fluid volume. The most recent studies say that the AFI is not a great predictor of the Amniotic fluid volume (actual amount of fluid. Doctors want to know the results of a Biophysical Profile to see what is going on. A biophysical profile is a simple, painless test that's performed during pregnancy to assess a foetus's well-being – specifically, whether he's getting enough oxygen inside the uterus or not.

The following criteria are assessed during a biophysical profile:

• Amniotic fluid index (AFI) – four pockets of fluid are measured; two pockets must measure 2 cm or more for a score of 2
• Fetal breathing – fetuses "practice breathing" by contracting and relaxing the diaphragm muscle; a score of 2 is assigned for fetal breathing lasting 30 seconds or more
• Fetal tone – the full extension and flexion of a limb such as opening and closing a hand
• Gross body movements – two or three episodes of movement such as squirming or kicking.

Pregnant women should ask questions such as can I get some fluids (IV, etc.) and retest? Here's some additional good info on AFI here esp relevant to "post-dates" pregnancy.

I have been seeing so many women who say their doctor wants to do a repeat ultrasound or just go ahead and induce on a certain day because it looks like the amniotic fluid is  low. These test can be sometimes so innaccurate and midwives should make people aware of this unnecessary intervention. Women should think twice before agreeing to the an induction. They should ask questions and every question posted should be answered by midwives and OB/GYN.


What I have found is most often, a woman will refuse induction on or around her due date. The doctor, for fear of liability, will order her to come in once or twice a week for non-stress tests (NST or CTG), in which they measure her amniotic fluid. These doctors will then tell the pregnant woman her fluid level is low, and they now have a medical reason to induce, and will promptly send her to the hospital. This tactic seems to be a way to convince a woman to do what the doctor tells her to by scaring her with medical jargon.

What treatment options are available for women with oligohydramnios?

A Cochrane systematic review by Hofmeyr and Gulmezoglu concluded that maternal hydration appears to increase amniotic fluid and may be beneficial in management of oligohydramnios. The amount of fluids a woman drinks daily directly influences the amount of fluid in your uterus. A 2009 study in the "Journal of Obstetrics and Gynaecology Research" demonstrated that pregnant women who had low amounts of amniotic fluid were able to increase the amount of amniotic fluid through oral hydration.

Since low amniotic fluid levels are more common during the summer, pregnant women should be advised careful to drink at least 10 cups of fluids daily, according to the Institute of Medicine. The majority of your fluids should be water, although you can also get fluids from decaffeinated tea, soup and fruit juices. Midwives should advise pregnant women to stay hydrated and monitor the baby's movements. Pregant women should take responsibility for the life they're carrying inside of them and should drink more water though I feel it is an effort for most of them.

Also, to improve the Amniotic fluid level Glucose, coconut water, water, fresh juices, etc should be consumed. Drinking tender coconut water in morning and evening will increase weight of baby also. Watermelon is also a good item to consumed during summer time when the water level in pregnant women decreases. Drink 1 glass of water every half an hour and pass urine at least once in a hour. Fluids will help with hydration. The body can't make fluid without it. Water is an important part of pregnancy. The fluid acts as the body's transportation system, and carries nutrients through the blood to the baby. This will help in preventing urinary infection also.

References
Boyd, R.L. & Carter, B.S. (2002). Polyhydramnios and Oligohydramnios. e Medicine.
Retrieved from http://www.emedicine.com/

Hofmeyr, G. J., Gulmezoglu, A. M. (2002). Maternal hydration for increasing amniotic fluid volume in oligohydramnios and normal amniotic fluid volume. In: The Cochrane Library, Issue 1,  Oxford: Updated Software.

Mozurkewich, E., Chilimigras, J., Koepke, E. et al. (2009).  Indications for induction of labour: a best-evidence review. BJOG. 116(5):626-36.

Phelan, J. P., Smith, C. V., Broussard, P., Small, M. (1987). Amniotic fluid volume assessment with the four-quadrant technique at 36–42weeks’ gestation. J Reprod Med. 32:540–542.

Polyhydramnios

Polyhydramnious or hydramnious is as an abnormally large volume of amniotic fluid. There is a range of 'normal' fluid volumes and an abnormally large volume may raise suspicion of a problem with the pregnancy. Greater deviations from the norm are more strongly associated with abnormality. The definition of "too much" is generally considered to be more than 2 liters; the average amount is about 1 liter, see  "Assessment of amniotic fluid volume".). Most cases of polyhydramnios are mild and involve less than 3 liters of amniotic fluid. So, in many cases, a diagnosis of polyhydramnios means that you're on the high side of normal for amount of amniotic fluid and presents only minor secondary concerns.

Polyhydramnios occurs in about 1 pregnancy out of 100; 95% of those are considered mild to moderate. The symptoms of hydramnios can include rapid growth of the uterus, discomfort in the abdomen, and possibly uterine contractions, but more often than not, there are no symptoms at all.

Pathogenesis

Physiologically, the volume of fluid increases with gestation to a maximum of 800-1,000 ml at 36-37 weeks. It has a number of purposes, including protecting the fetus from trauma and infection, allowing lung development and facilitating the development and movement of the limb and other skeletal parts. Fetal swallowing causes a reduction in the volume of fluid and absence of swallowing or a blockage of the fetal gastrointestinal tract may lead to polyhydramnios. Polyhydramnios is therefore linked to fetal abnormality.

Most women diagnosed with the condition deliver healthy babies. Most of the time, a little extra amniotic fluid is nothing to be concerned about. Such extra fluid is likely to be reabsorbed without any treatment. But when fluid accumulation is severe, it may signal a problem with the baby such as a central nervous system or gastrointestinal defect, kidney or bladder malfunction, or a problem with the baby's ability to swallow.

What causes polyhydramnios?

The causes of polyhydramnios are not completely understood. In many cases it's difficult to say what causes polyhydramnios but there are a few circumstances that make the condition more likely:

■Multiple / twin pregnancies - you're more likely to have abnormal amniotic fluid levels if you're carrying twins or other multiples. The cause of this is often twin-to-twin transfusion syndrome, where one twin has too little amniotic fluid and the other has too much.

 ■Gestational diabetes - greatly increases the likelihood of polyhydramnios. Around one in ten pregnant women with diabetes will develop some degree of excess amniotic fluid. If diabetes is uncontrolled or poorly controlled in pregnancy, there is a much higher incidence of polyhydramnios and the excessive amount of amniotic fluid is a direct result of the unstable diabetes.

 ■Infection - certain infections such as rubella, toxoplasmosis and syphilis may lead to polyhydramnios. These can be checked for with blood tests.

 ■Fetal abnormalities - in about a fifth of cases, excess amniotic fluid may build up when the baby has difficulties swallowing or digesting the amniotic fluid, preventing the fluid from being recycled. This could be caused by an obstruction in the baby's throat (such as cleft lip or palate) or gastrointestinal tract, or by a neurological problem. Polyhydramnios is also associated with problems with the baby's heart, kidneys and with chromosomal abnormalities.

Risk factors

In addition, too much amniotic fluid can put your pregnancy at risk for premature rupture of your membranes, premature labour, placental abruption, breech baby presentation, postpartum haemorrhage or umbilical cord prolapse.

Polyhydramnios increases the risk of postpartum haemorrhage simply because the uterus has been distended more than is usual for a singleton pregnancy.

Polyhydramnios increases the risk of placental abruption because of the mechanical forces at work in separating the placenta from the uterus. Polyhydramnios increases the risk of cord prolapse for several reasons. First, because the baby's presentation is unpredictable, the baby may be in an unfavorable position when the membranes rupture, and the presenting part may not fit into the pelvis well enough to keep the cord from falling out below. Second, because there is so much fluid, there is more pressure on the movable umbilical cord to move it out past the presenting part. If your waters do break before the start of labour you will be advised to lie down and stay reasonably still before going to hospital to reduce the likelihood of a prolapsed umbilical cord.

Growth restriction (IUGR) resulting in skeletal malformations

Stillbirth occurs in about 4 in 1000 pregnancies that suffer from polyhydramnios vs. about 2 in1000 pregnancies with normal fluid levels.

Signs and symptoms

Women might complain of abdominal girth, shortness of breath, oedema of ankles, tense abdomen.  The woman might be restless, abdominal skin might look shiny, difficult to palpate, malpresentation and abnormal lie of the foetus

Management

The first step is to identify any underlying cause. Mild polyhydramnios can be simply monitored and treated conservatively. Pre-term labour is common due to overdistension of the uterus, and measures should be taken to minimise this complication. This includes regular antenatal checks and inspection of the uterus, and bed rest towards the latter stages. Polyhydramnios during pregnancy does not have a harmful effect on the development of the baby or on the woman after delivery, and there is no evidence to suggest that it will recur in a subsequent pregnancy. Bedrest is needed.

Mbilu, J. N. K. (2002). Essentials of Obstetrics and Gynaecology for Clinical Officers and Midwives. Volume 1. Writers Club Press. Lincoln. NE.

Beloosesky, R., Ross, M. G. (2010). Polyhydramnios. UpToDate.

Yeast J. (2006). Polyhydramnios: etiology, diagnosis and management. Neoreviews. 7: 6 e300