Vol. 4, Issue 1, Part A (2022)

Objective: Our study aims to study the maternal risk factors and perinatal outcomes in antenatally diagnosed oligohydramnios”
Study design: Hospital based prospective observational study
Methods and materials: The present study was a prospective observational study conducted at Dr L. H. Hiranandani Hospital from 01/09/16 to 30/03/18.This study was carried out after obtaining clearance from the institutional ethical committee. 
Antenatal women with singleton pregnancy registered / referred to our hospital at or beyond 28 weeks of gestation with clinically suspected oligohydramnios were screened. Thorough history taking, complete examination and baseline investigations were done for all the cases. Ultrasound examination was done for these women and AFI was calculated by four quadrant amniotic fluid volume measurement technique as described by Phelan, et al.1 A curvilinear transducer was used. By marking, the uterus was divided into four quadrants using the maternal sagittal midline vertically and an arbitrary transverse line approximately half way between the symphysis pubis and upper edge of uterine fundus. The transducer was kept parallel to the maternal sagittal plane and perpendicular to the maternal coronal plane throughout. The deepest, unobstructed and clear pocket of amniotic fluid was visualized and the image was frozen. The ultrasound calipers were manipulated in such a way that it measured the pocket in a strictly vertical direction. The process was repeated in each of the four quadrants. AFI was then calculated. Thus, antenatal women with singleton pregnancy at or beyond 28 weeks of gestation with decreased AFI (AFI < / = 8 cm) on ultrasonography were included in the study. Written informed consent was taken after explaining the purpose of the study. The study did not compromise with any treatment/care given routinely to them.
Results: It was observed that a higher incidence of antenatal high risk factors and adverse perinatal outcome was seen in higher percentage of patients having severe oligohydramnios than that of borderline oligohydramnios. We observed that decreased AFI (AFI < / = 5 cm) was associated with increased incidence of induction of labour, atypical / abnormal NST, meconium staining of liquor, incidence of LSCS, low APGAR score at 5 minutes and NICU admissions. Amniotic fluid volume measured in terms of AFI is a good predictor of adverse perinatal outcome. 
Conclusion: Oligohydramnios is as an indicator of the possible presence of maternal factors e.g. gestational hypertension, fetal growth restriction (FGR), abruptio placentae. It is an indicator of poor perinatal outcome. Estimation of amniotic fluid volume should be a part of antenatal fetal surveillance. Amniotic fluid volume measured in terms of amniotic fluid index (AFI) is a helpful tool in determining patients at risk. Severe oligohydramnios, as compared to borderline oligohydramnios is significantly associated with pregnancy complications and perinatal morbidity and mortality such as increased incidence of induction of labour, atypical / abnormal non stress test (NST), Meconium staining of liquor, increased incidence of LSCS, Low APGAR score at 5 minutes, Increased NICU admissions. This highly significant statistical correlation between oligohydramnios and poor perinatal outcome suggests that AFI in adjunct with other methods of fetal surveillance can be used to identify patients at risk. Detailed history taking, experienced clinical judgment, strict antepartum and intrapartum surveillance can reduce perinatal complications.