Polyhydramnios PDF

Polyhydraminos Course outline Amniotic fluid -introduction Complication Definition of polyhydraminos Management Incidence References Etiology Types Signs and symptoms AMNIOTIC FLUID Amniotic fluid is a clear, slightly yellowish liquid that surround...

Polyhydraminos Course outline Amniotic fluid -introduction Complication Definition of polyhydraminos Management Incidence References Etiology Types Signs and symptoms AMNIOTIC FLUID Amniotic fluid is a clear, slightly yellowish liquid that surrounds the unborn baby (fetus) during pregnancy. Origin: It is probably of mixed maternal and fetal origin. Circulation: The water in the amniotic fluid is completely changed and replaced in every 3 hours. AMNIOTIC FLUID... Volume: Amniotic fluid volume is related to gestational age. It measures about 50 mL at 12 weeks, 400 mL at 20 weeks and reaches its peak of 1 liter at 36–38 weeks. Thereafter the amount diminishes, till at term it measures about 600–800 mL. As the pregnancy continues post term, further reduction occurs to the extent of about 200 mL at 43 weeks. AMNIOTIC FLUID... Physical Features: The fluid is faintly alkaline with low specific gravity of 1.010. It becomes highly hypotonic to maternal serum at term pregnancy. An osmolarity of 250 mOsmol/L is suggestive of fetal maturity. The amniotic fluid’s osmolality falls with advancing gestation. AMNIOTIC FLUID... Color: In early pregnancy it is colorless, but near term it becomes pale straw colored due to the presence of exfoliated lanugo and epidermal cells from the fetal skin. It may look turbid due to the presence of vernix caseosa. AMNIOTIC FLUID... Composition: In the first half of pregnancy, the composition of the fluid is almost identical to a transudate of plasma. But in late pregnancy, the composition is very much altered mainly due to contamination of fetal urinary metabolites. The composition includes—(1) water 98–99% and (2) solid (1–2%). AMNIOTIC FLUID... The solid constituents are: (a) Organic: Protein–0.3 mg% NPN (non protein nitrogen)–30 mg% Total lipids–50 mg% Glucose–20 mg% Uric acid–4 mg% Hormones (prolactin, insulin and renin) Urea–30 mg% Creatinine–2 mg%. AMNIOTIC FLUID... (b) Inorganic — The concentration of the sodium, chloride and potassium is almost the same as that found in maternal blood. As pregnancy advances, there may be slight fall in the sodium and chloride concentration probably due to dilution by hypotonic fetal urine, whereas the potassium concentration remains unaltered. AMNIOTIC FLUID... (c) Suspended particles include—Lanugo, exfoliated squamous epithelial cells from the fetal skin, vernix caseosa, cast off amniotic cells and cells from the respiratory tract, urinary bladder and vagina of the fetus. AMNIOTIC FLUID... Function: Its main function is to protect the fetus by providing nutrition, acting as shock absorber, allowing free movement of the fetus, maintaining an even temperature, dilating cervix at the time labour, guards infection to fetus by flushing the birth canal. POLYHYDRAMNIOS (Syn: Hydramnios) POLYHYDRAMNIOS... Definition: Anatomically, polyhydramnios is defined as a state where liquor amnii exceeds 2,000 mL. Clinical definition The excessive accumulation of liquor amnii causing discomfort to the patient and/or when an imaging help is needed to substantiate the clinical diagnosis of the lie and presentation of the fetus. Sonographic diagnosis is made when amniotic fluid index (AFI) is more than 25 cm (more than 95th centile for gestational age) and a deepest vertical pocket (DVP) is more than 8 cm. Incidence Excessive amniotic fluid is identified in approximately 1 percent of pregnancies. It is more common in multiparae than primigravidae. While minor degrees of hydramnios are fairly common, hydramnios sufficient to produce clinical symptoms probably occursin 1 in 1,000 pregnancies. Etiology The exact cause of excess accumulation of the liquor is still speculative. It may be the result of deficient absorption as well as excessive production of liquor amnii, which may be temporary or permanent. Certain maternal or fetal factors are found to be associated with hydramnios, yet the cause remains unknown in about 60%. The composition of the liquor amnii, however, remains normal.  Etiology... 1. Fetal Anomalies: Congenital fetal malformations (structural and chromosomal) are associated with polyhydramnios in about 20% cases. a. Anencephaly—Hydramnios is found in association with anencephaly in about 50% cases. The causes of excessive production of liquor amnii may be due to: transudation from the exposed meninges, absence of fetal swallowing reflex and, possible suppression of fetal antidiuretic hormone leading to excessive urination. Etiology... b. Open spina bifida—increased transudation from the meninges. c. Esophageal or duodenal atresia—preventing swallowing of the liquor. However, hydramnios is associated only in about 15% cases of esophageal atresia. d. Facial clefts and neck masses—by interfering normal swallowing. Etiology... e. Hydrops fetalis due to Rhesus isoimmunization, nonimmune hydrops, cardiothoracic anomalies, fetal cirrhosis and fetal infections with TORCH and parvovirus B19 infection are often associated with hydramnios. f. Aneuploidy and genetic syndromes. Etiology... 2. Placenta: Chorioangioma of the placenta: Tumor growing from a single villus consisting of hyperplasia of blood vessels and connective tissue results in increased transudation..  Etiology... 3. Multiple Pregnancy: Multiple pregnancy is about 10 times more common than its overall incidence. Hydramnios is more common in monozygotic twins, usually affecting the second sac. In TTTS the recipient twin develops polydramnios Etiology... 4. Maternal: a. Diabetes: Hydramnios is associated with diabetes in about 30% cases. It is presumed that a raised maternal blood sugar → raised fetal blood sugar → fetal diuresis → hydramnios. b. Cardiac or renal disease—may lead to edema of the placenta leading to increase in transudation. 5. Idiopathic: 50–60% Clinical Types : Depending on the rapidity of onset, hydramnios may be: Chronic (most common): onset is insidious taking few weeks. The chronic variety is 10 times more common than the acute one. Acute (extremely rare):onset is sudden, within few days or may appear acutely on pre-existing chronic variety. Often early as 16 to 20 weeks and leads to labor before 28 weeks. Clinical Types Polyhydramnios may be: Mild: DVP more than 8–11 cm Moderate: DVP: 12–15 cm and Severe: DVP more than or equal to 16 cm. Chronic Polyhydramnios In the majority of cases, the accumulation of liquor is gradual and as such, the patient is not very much inconvenienced. Chronic Polyhydramnios... Symptoms: The symptoms are mainly from mechanical causes. Respiratory—The patient may suffer from dyspnea or even remain in the sitting position for easier breathing. Palpitation Edema of the legs, varicosities in the legs or vulva and hemorrhoids. Chronic Polyhydramnios... Signs: The patient may be in a dyspneic state in the lying down position. Evidence of preeclampsia (edema, hypertension and proteinuria) may be present. Chronic Polyhydramnios... Abdominal Examination Inspection: Abdomen is markedly enlarged, looks globular with fullness at the flanks. The skin is tense, shiny with large striae. Chronic Polyhydramnios... Palpation: Height of the uterus is more than the period of amenorrhea. Girth of the abdomen round the umbilicus is more than normal. Fluid thrill can be elicited in all directions over the uterus. Fetal parts cannot be well-defined; so also the presentation or the position. Chronic Polyhydramnios... Auscultation: Fetal heart sound is not heard distinctly, although its presence can be picked up by Doppler ultrasound. Internal Examination: The cervix is pulled up, may be partially taken up or at times, dilated, to admit a fingertip through which tense bulged membranes can be felt. Investigations Sonography: Sonography is helpful : 1. To detect abnormally large echo-free space between the fetus and the uterine wall (largest vertical pocket more than 8 cm). Amniotic fluid index (AFI) is more than 25 cm. 2. To exclude multiple fetuses, 3. To note the lie and presentation of the fetus, 4. To diagnose any fetal congenital malformation. Investigations... Blood: 1. ABO and Rh grouping: Rhesus isoimmunization may cause hydrops fetalis and fetal ascites. 2. Postprandial sugar and if necessary glucose tolerance test. Amniotic fluid: Estimation of alpha fetoprotein which is markedly elevated in the presence of a fetus with an open neural tube defect. Differential Diagnosis Polyhydramnios may get confused with: Twins Pregnancy with huge ovarian cyst Maternal ascites. Differential Diagnosis... 1. Twins: The diagnosis is often confused and difficult because of its association with hydramnios. Abdomen is markedly enlarged, too many fetal parts, fluid thrill absent, straight X-ray or sonography confirms the diagnosis Differential Diagnosis... 2. Pregnancy with huge ovarian cyst: the gravid uterus can be felt separate from the cyst, internal examination shows the cervix to be pushed down into the pelvis. In hydramnios, the lower segment has to ride above the pelvic brim, so that the cervix is drawn up, X-ray of the abdomen or sonography is helpful. Differential Diagnosis... 3. Maternal ascites: Presence of shifting dullness, Resonance on the midline due to floating gut whereas in hydramnios, it becomes dull, Internal examination and palpation of the normal size uterus, if possible, can give the clue, Sonography helps to exclude pregnancy. Complications The complications of hydramnios are grouped into: A. Maternal B. Fetal Complications... A. Maternal: During pregnancy: There is increased incidence of: Preeclampsia (25%) Malpresentation and persistence of floating head Premature rupture of the membranes Preterm labor either spontaneous or induced Accidental hemorrhage due to decrease in the surface area of the emptying uterus beneath the placenta, following sudden escape of liquor amnii. Complications... During labor Early rupture of the membranes Cord prolapse Uterine inertia Increased operative delivery due to malpresentation Retained placenta, postpartum hemorrhage and shock. The postpartum hemorrhage is due to uterine atony. Complications... Puerperium: Subinvolution Increased puerperal morbidity due to infection resulting from increased operative interference and blood loss. Complications... B. Fetal: There is increased perinatal mortality to the extent of about 50%. The deaths are mostly due to prematurity and congenital abnormality (40%). Other contributing factors are cord prolapse, hydrops fetalis, effects of increased operative delivery and accidental hemorrhage. Management Recently there has been a falling trend in the incidence of hydramnios of severe magnitude. The reasons are: Early detection and control of diabetes. Rhesus isoimmunization is now preventable. Genetic counseling in early months and detection of fetal congenital abnormalities with ultrasound and their termination, reduce their number in late pregnancy. Management... Treatment of polyhydramnios is usually tailored according to the underlying cause. Mild Polyhydramnios (DVP: 8–11 cm): It is commonly found in midtrimester and usually requires no treatment, except extra bed rest for a few days. The excess liquor is expected to be diminished as pregnancy advances (transient). Management Severe Polyhydramnios (DVP: ≥16 cm): In view of the risks involved and the high perinatal mortality rate, the patient should be shifted in a hospital equipped to deal with “high-risk” patients. Principles: To relieve the symptoms To find out the cause To avoid and to deal with the complication. Management Polyhydramnios may be: transient where returned to normal with progress of pregnancy or persistent cases with persistent polyhydramnios need investigations for congenital fetal anomalies, genetic syndromes and also need close monitoring. Management... Supportive therapy includes bed rest, if necessary, with a back rest and treatment of the associated conditions like preeclampsia or diabetes on the usual line. Indomethacin therapy: Maternal dose: 1.5 mg to 3mg/kg/day (25mg tds) Indomethacin impairs fetal lung liquid production or enhances absorption, decreases fetal urine production and increase fluid movement across fetal memebranes. Management... Investigations are done to exclude congenital fetal malformations with the available gadgets and also to detect such complications like diabetes or Rhesus isoimmunization. Further management depends on: Response to treatment Period of gestation Presence of fetal malformation Associated complicating factors. Management... Uncomplicated cases: (No demonstrable fetal malformation) I. Response to treatment is good: The pregnancy is to be continued awaiting spontaneous delivery at term. II. Unresponsive: (with maternal distress). Management... II. Unresponsive... a. Pregnancy less than 37 weeks: An attempt is made to relieve the distress with a hope of continuation of pregnancy by amniocentesis (amnio reduction). Slow decompression is done at the rate of about 500 mL per hour and the amount of fluid to be removed should be sufficient enough to relieve the mechanical distress. Management... a. Pregnancy less than 37 weeks... Normally amniodrainage is stopped when the AFI is less than 25 cm. Because of slow decompression, chance of accidental hemorrhage is less but liquor amnii may again accumulate, for which the procedure may have to be repeated. Amniotic fluid can be tested for fetal lung maturity. Management... b. Pregnancy more than 37 weeks: Induction of labor is done. The following procedures may be helpful. Amniocentesis → principal purpose of amniocentesis is to relieve maternal distress, To check the favorable lie and presentation of the fetus → a stabilizing oxytocin infusion is started. Management... Low rupture of the membranes is done when the lie becomes stable and the presenting part gets fixed to the pelvis. This will minimize sudden decompression with separation of the placenta, change in the lie of the fetus and cord prolapse. Management... With congenital fetal abnormality (complicated): Referral to a maternal fetal medicine unit should ideally be done. When decision for termination is made, it is to be done irrespective of duration of pregnancy. Amniocentesis is done to drain good amount of liquor. Thereafter induction by vaginal PGE2 gel insertion followed by low rupture of membranes is done. Management... With congenital fetal abnormality... If, accidentally, low rupture of the membranes occurs, escape of gush of liquor should be immediately controlled by placing the palm over the introitus to avoid accidental hemorrhage. The lie should be checked and if found longitudinal, oxytocin infusion may be started. Management... During Labor: Internal examination should be done soon after the rupture of the membranes to exclude cord prolapse. If the uterine contraction becomes sluggish, oxytocin infusion may be started, if not contraindicated. Management... During Labor... To prevent postpartum hemorrhage, intravenous methergine 0.2 mg should be given with the delivery of the anterior shoulder. One must remain vigilant following the birth of the baby for retained placenta, postpartum hemorrhage and shock. Baby should be thoroughly examined for any congenital anomaly. Acute Polyhydramnios Acute hydramnios is extremely rare. The onset is acute and the fluid accumulates within a few days. It usually occurs before 20 weeks of pregnancy. It is usually associated with monozygotic twins with TTTS or chorioangioma of the placenta. Acute Polyhydramnios... Symptoms: Features of acute abdomen predominate, such as abdominal pain, nausea and vomiting. Signs: The patient looks ill Absence of features of shock Edema of the legs or presence of other associated features of preeclampsia Abdomen is hugely enlarged more than the period of amenorrhea; the wall is tense with shiny skin Acute Polyhydramnios... Signs... Fluid thrill is present Fetal parts cannot be felt nor is the fetal heart sound audible Internal examination reveals taking up of the cervix or even dilatation of the os through which the bulged membranes are felt Sonography shows multiple fetuses or at times fetal abnormalities. Acute Polyhydramnios... Treatment: Most often, spontaneous abortion occurs. In case with severe TTTS, repetitive amnioreduction until the AFI is normal, may improve the perinatal outcome. Laser ablation may cure the cause of TTTS whereas amnioreduction only treats the symptoms. Summary of nursing process Assessment Assess for the following: Ballottement results in fluid waves Fundal height excessive for gestation Fetus difficult to outline with palpation Fetalabnormalities of CNS or GI tract Easy fatigability Summary of... Diagnosis Risk for fetal injury Impaired physical mobility Actual/Risk for fluid volume deficit Anxiety Anticipatory grieving Altered family process Actual/ Risk for altered parenting. Health seeking behaviors. Summary of... Planning Promote maternal comfort Promote maternal –fetal well-being Provide opportunities for counseling and support. Provide education for self- care measures in increasing comfort  Summary of... Implementation Facilitate testing: Aminocentesis, sonogram. Assess FHR Anticipate premature labour and postpartum hemorrhage caused by over distention of the uterine muscles. Instruct and explain the nature of problem: Need to obtain immediate medical attention for problems. Need to observe for preeclampsia Summary of... Evaluation Ensure that the expected mother: Verbalizes increased comfort Progresses to uneventful birth, as does herbaby Verbalizes support Verbalizes self-care measures. References Dutta DC;Textbook of Obstetrics,9th edition, new delhi, India,jaypee Brothers Medical Publishers(P) Ltd., 2018, page no.200-203. Marshall J, Raynor M; Myles Textbook for Midwives, 7th edition, Edinburg, New york, Oxford Philadelphia, Churchill living stone Elsevier, 2014, pageno.236-238. Annamma Jacob; Textbook of Midwifery and Gynecological Nursing, 4th edition, New Delhi, India, Jaypee Brothers Medical Publishers(p)Ltd ,2015, pageno.333-336. WHO, department of reproductive health and research, IMPAC, Geneva, JHPIEGO, 2003,Page no.S-88