Relationship of Amniotic Fluid Index (AFI) Between Maternal and Perinatal in Patients

Background : Alcohol amniotic, a protecting fluid that surround the embryo. It protects from concussion, pressure, desiccation, reminiscent of the aquatic origin of life. Adequate amount of amniotic fluid is essential requirement for the normal development and it acts like a cushion against trauma, agitation and accidental impulsions. It has also bacteriostatic properties and prevents the infection of many bacterial infections. Aim: To assess the maternal and fetal outcome in cases with normal and abnormal Amniotic Fluid Index levels. Results: The mode of delivery was spontaneous vaginal delivery followed by Assisted VD, Elective CS, Emergency CS respectively. It was affected by amount of liquor since, low AFI group 35 (75%) patients ended up in cesarean section for fetal distress. While in control group 63(18.3%) patients had caesarean section. Conclusion: Early neonatal death was seen in 0.2%, 4.5% and 70.5% newborns were born to pregnant women with normal AFI, oligohydramnios respectively. 70.5% neonates born to pregnant women with oligohydramnios had NICU admission. All cases were admitted in NICU because of respiratory distress.


INTRODUCTION
Amniotic fluidis a dynamic fluid that gives a protection during the pregnancy and its composition is similar with the fetal plasma on its first trimester. Due to lacking of keratins, there is a higher possibility for bidirectional diffusion for amniotic fluid between the fetus and skin. The amniotic membrane is more permeable to water and solutes and acts as a physiological buffer by extending its support to extracellular compartment [1]. There is no much more dilution or internal pressure due to the increased fetal urination and its volume until 14 th week of gestation. Its keratization starts with 19 -20 th and completed at 25 th week of conception. There is a number of factors that determine the formation and removal of the fluid from the membrane after the keratization begins [1][2].
Amniotic fluid production is directly correlated with the fetal urination and its lung fluid volume. The fetus breath essentially contributes effusion of lung fluid in to the amniotic region. Though, the lungs act main contributors, oral, nasal, and tracheal secretions also increase the volume [1][2][3][4]. In addition to, the intra-membraneous pathway carries fluid and solutes in to the fetal circulation through the blood network and placental surface. The trans-membraneous transportation directly involve with the gas exchange between the fetal and maternal blood and minimally affect the amniotic volume [2,[4][5][6]. The fluid volume is mainly regulated by the gestational duration and maintained between a fixed ranges. Its volume increases with week by week and attain the peak on 36 -38 weeks [2,7]. A delicate balance is maintained between its inflow and outflow in the amniotic cavity [3,5,[8][9][10]. The studies showed the ratio of fluid removal is much more smaller than the inlet and achieving a fine balanced state for physiological smoothness [2,5,6]. Though, governed by such kind of unequal parameters, its volume remained to be in an equilibrium [3,7]. There is in conclusive results regulating the factors such as fetal urine or lung fluid volume that determine the amniotic fluid volume. Meantime, several studies showed that the intramembranous pathway play a significant role in retrieving the balanced situation [2][3][4][5]7]. Apart from these, few studies also showed that the bacterial biofilms contribute the amniotic equilibrium and acts as an important component for host defense mechanisms [8,[9][10][11][12][13].
Amniotic fluid volume homeostasis is maintained by the delicate balance between inflow (fetal urine and to a lesser extend, lung secretion) and outflow (swallowing and intramembranous absorption) of fluid in the amniotic cavity Several studies demonstrate that the amount of fluid removed by fetal swallowing is significantly smaller than that produced by fetal urination [2,5,6]. Despite these considerably unequal parameters, amniotic fluid volume remains in relative equilibrium [3]. Several studies suggest that neither lung fluid production nor urination serves as a regulatory role in the control of amniotic fluid volume. Whether fetal swallowing serves a regulatory role remains possible but inconclusive [10,11]. Studies suggest that the is responsible for the correction of imbalances and that it appears to play a significant role in establishing of the amniotic fluid volume [2,12]. ]. It is possible also that aggregates of exfoliated cells from the fetal digestive, respiratory and urinary tracts, amniotic membranes, fetal skin and umbilical cord [14,15] may contribute to the presence of amniotic fluid "sludge" and participate in the host response during microbial invasion of amniotic cavity. [16]

MATERIALS AND METHODS
Five hundred (500) participants study antenatal women with low risk at term who got admitted for safe confinement in the Department of Obstetrics and Gynaecology of BIHER were registered for the study.

Inclusion Criteria
Antenatal women at term gestation,Age 25-35 years, Singleton pregnancy, Women are willing to participate in the study.

Exclusion Criteria
High risk pregnancies like preeclampsia, GDM and medical disorders complicating pregnancy, Prolonged pregnancy, Antenatal women with ruptured membrane, Multiple pregnancy, Major fetal anamolies

METHODOLOGY
Gestational age is established by history, clinical examination and dating scan. Obstetric scan, AFI were done by following proper instructions and four quadrant technique. The maternal and perinatal outcome of these patients will be assessed and analysed to see the correlation of varying levels of AFI Then the maternal and fetal product is distinguished prospectively and equated. The statistical analysis was done based on Pearson Chi Square method.
The following are the intrapartum finding in baby born to pregnant women with normal AFI-early deaccelaration (0.5%), late deaccelaration (1.6%) and Variable deaccelaration (3.7%) The following are the intrapartum finding in baby born to pregnant women with oligohydramniosearly deaccelaration (2.3%), late deaccelaration (56.8%) and Variable deaccelaration (34.1%).  The mode of delivery in our study significantly affected by amount of liquor. In low AFI group 35 (75%) patients ended up in cesarean section for fetal distress. While in control group 63 (18.3%) patients had caesarean section. Our study documented higher rates of LSCS compared to study conducted by Sriya R et al. In their study cesarean section for fetal distress was documented in 43.05% cases with AFI<5cm. While in control group with AFI>5cm, 12.5% patients had emergency cesarean section [18].Similarly, In a study conducted by Jabeen S et al has also documented a higher possibility for cesarean emergency during fetal distress, 33.3% patients ended up in cesarean section having AFI<5cm [17]. Locatelli et al had showed that a very low incidence of 8.2% cesarean section rate in patients with, AFI<5cm while in control group with normal amniotic fluid index, 3.9% women ended up in cesarean section for fetal distress Morris JM et al has reported 26% incidence of cesarean with a fetal distress [15] Zhang J et al has reported 10% the relatively higher possibility for emergently cesarean on fetal distress in patients with AFI<5cm while in control group it was only 5 %. Results which are inconsistent with our study because of difference in defining In our study fetal distress was diagnosed by the presence of meconium stain liquor and/or fetal heart rate abnormalities detected on intermittent auscultation. While in the reports diagnosis of fetal distress was based on continuous electronic fetal heart tracing and fetal scalp pH values. As facilities for fetal scalp pH were not available therefore our cesarean during fetal distress might be higher than above mentioned studies.

CONCLUSION
There is a high risk for oligohydramnios patients to give low-birth-weight infants, low Apgar scores at 5 minutes, neonatal intensive care unit admissions, or perinatal death compared to pregnant women with Polyhydramnios.

CONSENT AND ETHICAL APPROVAL
The present prospective study was conducted after getting proper approval from the Institutional Ethics Committee (IEC) and Informed consent from the participants based on ICH/GCP guidelines.  Obstet Gynecol. 1997;89:913-7.