Oligohydramnios and its perinatal outcome in a tertiary hospital

Abstract

Background: The importance of amniotic fluid volume as an indicator of fetal status is being appreciated relatively recently. Around 3% to 8% of pregnant women are presenting with low amniotic fluid at any point of pregnancy. The present study was undertaken to study the outcome of pregnancies with Oligohydramnios at or beyond 34 weeks. Methods: This study consists of 50 cases of antenatal patients with oligohydramnios at or beyond 34 weeks of gestation compared with age and gestation matched 50 normal liquor. The outcome measures recorded were labor, gestational age at delivery, amniotic fluid index (AFI), mode of delivery, indication for cesarean section or instrumental delivery, APGAR score and birth weight. Results: Variable deceleration was noted in 13 (26%) and late deceleration in 4 (8%) cases. In control group, 2 (4%) had late deceleration. In cases induced labor is in 15 (30%), spontaneous labor 35 (70%). In cases, term normal vaginal delivery was in 14 (28%), PVD in5 (10%), LSCS in 30 (3%) and instrumental vaginal delivery in 1 (2%). Incontrols, full term normal vaginal delivery was in 42 (84%), PVD in 5 (10%), LSCS in 3 (6%). APGAR score <7 at 1 minute was in 19 (38%) and at 5 minutes was in 5 (10%) in cases. Birth weight is reduced in cases. IUGR was reported in 9 (18%) in cases. Conclusions: Pregnancies with Oligohydramnios (AFI≤5) is associated with increased rate of non-reactive NST. Routine induction of labor for Oligohydramnios is not recommended. It is preferable to allow patients to go into spontaneous labor with continuous FHR monitoring. Antepartum diagnosis of Oligohydramnios warrants close fetal surveillance. Introduction Oligohydramnios refers to reduced amniotic fluid expected for that gestational age. Ultrasound examination is diagnostic and may be described qualitatively (eg; normal or reduced) or quantitatively (eg; amniotic fluid index AFI < 5cm). For normal fetal movements and growth and to cushion the fetus and umbilical cord, adequate volume of amniotic fluid is critical. Oligohydramnios may inhibit these processes and can lead to fetal deformation, umbilical cord compression, and death. Oligohydramnios sequence, or Potters syndrome, is a chain of events that results in severe abnormalities of the fetus. Not all fetuses develop abnormalities due to low levels of amniotic fluid. The occurrence of oligohydramnios sequence depends on few factors, the stage of pregnancy and the level of amniotic fluid. The later stages of pregnancy appear to be troublesome. If oligohydramnios sequence occurs at that time, a more serious condition can occur. The importance of amniotic fluid volume as an indicator of fetal status is appreciated all along [1]. Normally during third trimester, around 3% to 8% of pregnant women are with low amniotic fluid at any point of pregnancy. It is normally anticipated as a sign of placental insufficiency [2] , Amniotic fluid has a number of important roles in embryo/fetal development. It cushions that fetus against trauma, has antibacterial property and promotes growth and development of gastrointestinal and musculoskeletal system [2]. It helps to maintain the fetal body temperature and plays a part in homeostasis of fluid, and permits fetal movements [4, 5]. Amniotic fluid volume maintains amniotic fluid pressure thereby reducing the loss of lung fluid-an essential component to pulmonary development. It prevents compression of the umbilical cord [6]. Decreased amniotic fluid volume is frequently one of the first clues to an underlying fetal abnormality or maternal disease state. A significant reduction in the amniotic fluid correlates with an increased rate of both perinatal morbidity and mortality [7] .