JSAFOG Study of ‘Non Stress Test at Admission’ and its Corelation10.5005/jp-journals-10006-1581 with Maternal and Fetal Outcome ORIGINAL ARTICLE Study of ‘Nonstress Test at Admission’ and its Corelation with Maternal and Fetal Outcome 1Navneet Kaur, 2Promila Jindal ABSTRACT Outcome. J South Asian Feder Obst Gynae 2018;10(3):161- 166. Introduction: Non stress test (NST) is the most widely used test for assessment of fetal health and reflects oxygenation of Source of support: Nil brain. NST is usually recommended after 30 to 32 weeks of the Conflict of interest: None pregnancy. The false negative rate of NST (reactive NST in a fetus who actually is in distress) is 3.2/1000 which is very low Date of received: 09/24/2016 and thus NST is considered as a good predictor of fetal health. Date of acceptance: 11/06/2016 Objectives: To evaluate the “NST at admission” in all the Date of publication: December 2018 admitted women > 32 weeks of gestation and to correlate it with type of labour and mode of delivery and maternal and neonatal outcome. INTRODUCTION In modern obstetrics antenatal fetal surveillance is becom- Materials and methods: This prospective study was conducted on all the pregnant women only at > 32 weeks of gestation ing increasingly popular field for timely intervention admitted to Dayanand Medical College and Hospital (DMCH), for good fetal outcome. There are various modalities for Ludhiana from 1/1/2011 to 31/12/2011. Non stress test was done antenatal fetal surveillance but NS) has withstood the in all women using TOCODYNAMOMETER for 20 minutes and test of time since its introduction. Non stress test is the was extended to next 20 minutes in case of inconclusive NST. Both the mother and neonate were followed up till discharge most widely used test for assessment of fetal health and 1 from hospital. The data was analysed statistically using T test reflects oxygenation of brain. Fetal movements during for quantitative variables and Chi square/Z test for qualitative testing are identified by maternal perception and are variables. recorded. NST is based on the hypothesis that heart rate of Results: In 228 women, 233 NSTs (5 twins) were done and 24 fetus who is non acidotic, non impaired will temporarily NSTs needed 20 minutes extension to reach to conclusion.179 accelerate in response to fetal movements. The fetal heart (76.82%) NST were reactive while 54 (23.18%) were non rate normally is increased or decreased by autonomic reactive. Women admitted with reactive NST had significantly higher vaginal delivery rates i.e. (39.78% vs 11.54%). Operative influences mediated by sympathetic or parasympathetic delivery in non reactive NST group was significantly higher than impulses from brain stem centres. Beat to Beat variability reactive NST group, i.e., (88.46% vs 60.22%). All 233 babies is under control of autonomic nervous system. Heart rate were born alive irrespective of the NST status and 47.21% (110) reactivity is believed to be a good indicator of normal fetal required NICU admission. autonomic function. Consequently, pathological loss of Conclusion: The ‘NST at admission’ is a simple method and acceleration may be seen in conjunction with significantly is easy to perform for assessing fetal status antenatally and decreased beat to beat variability and fetal heart rate. ‘NST its reactivity assures good maternal and fetal outcome while 2 non reactivity increases the chances of operative delivery and at admission’ at ≥32 weeks of gestation is one such non- NICU admission. invasive technique by which 20 to 40 minutes of external Keywords: Cesarean, Diabetes, Perinatal outcome, Placenta fetal monitoring is used as a screening test to identify the previa, Pregnancy, Primigravida. time and mode of intervention according to its reactivity. This prospective study was undertaken to evaluate How to cite this article: Kaur N, Jindal P. Study of ‘Nonstress Test at Admission’ and its Corelation with Maternal and Fetal and correlate ‘NST at admission’ with mode of delivery and fetal outcome (Birth weight, Apgar score, NICU admission). 1Senior Resident, 2Professor 1Department of Obstetrics and Gynecology, Government Medical MATERIALS AND METHODS College and Rajindra Hospital, Patiala, Punjab, India 228 women admitted to labour room of DMCH Ludhi- 2Department of Obstetrics and Gynecology, Punjab Institute of Medical Sciences, Jalandhar, Punjab, India ana for any reason at ≥32 weeks of gestation irrespective Corresponding Author: Navneet Kaur, Senior Resident, of age, parity, maternal complications (BOH, DM, Fetal Department of Obstetrics and Gynecology, Government Medical growth restriction (FGR), premature rupture of mem- College and Rajindra Hospital, Patiala, Punjab, India, e-mail: branes (PROM), oligohydramnios), already in labor or [email protected] for induction of labor were included in the study. NST Journal of South Asian Federation of Obstetrics and Gynaecology, July-September 2018;10(3):161-166 161 Navneet Kaur, Promila Jindal was conducted on tocodynamometer for 20 minutes. The statistically significant (p = 0.0450). In the unbooked NST was interpreted as reactive when there were two or cases, 39 NSTs were done (one twin pregnancy) of which more accelerations of fetal heart rate that peak at 15 beats/ 25 (64.1%) were reactive and 14 (35.9%) were non reac- minutes or more above baseline lasting for 15 seconds tive (Fig. 1). Women admitted with reactive NST had or more within 20 min and was labeled non-reactive if significantly higher vaginal delivery rates, i.e., (39.78% either Beat to beat variability < 5 beats/minutes and/or vs 11.54%). Operative delivery in non reactive NST group no fetal movements and/or baseline fetal heart rate <120 was significantly higher than reactive NST group i.e. or >160 beats/minutes and/or < 2 accelerations or of <15 (88.46% vs 60.22%) (Table 1). beats/minutes and/or presence of early, late and variable A total of 166 (72.80%) were high risk having preg- decelerations. If it did not fulfill either of above criteria, nancy induced hypertension 65 (28.50%), oligohy- it was extended to 40 minutes to reach to conclusion. All dramnios with fetal growth restriction 55 (24.12%), for women were followed up for mode of delivery, maternal induction of labor 37 (16.22%) while 62 (27.19%) were and fetal outcome. APGAR score, birth weight, admission already in labor had no associated maternal disease to nursery intensive care unit (NICU), duration of stay (Table 2). There was statistically significant rate of cae- in nursery etc were noted for neonate. Both the mother sarean section in women with APH both in reactive and neonate were followed up till the time of discharge and non-reactive group. Similar trend was observed in from hospital. women with oligohydramnios with FGR and PIH. While in low risk group the vaginal delivery rate was statisti- Statistical analysis cally more significant (67.85%vs 30.35%) than caesarean The data was analyzed statistically using T test for section in reactive NST group and caesarean section rate quantitative variables, Chi square/Z test for qualitative was statistically more significant (71.42%vs 28.57%) than variables. vaginal delivery in non reactive NST group. The differ- ence in vaginal and caesarean section rate w as statistically OBSERVATIONS significant in both the groups. (p = 0.0481) The study was conducted on 228 women and 233 NSTs Due to financial constraints 91/228 women had were done (5 twin pregnancies) of which extended NSTs Doppler velocimetry. All 19 women with non-reactive were done in 24 women. Of the total 233 NSTs, 179 NST and abnormal Doppler had caesarean section while (76.2%) were reactive and 54 (23.18%) were non reactive. 20/21 women with reactive NST and abnormal Doppler There were 190 (83.33%) booked cases and 38 (16.67%) had caesarean section but difference is not statistically unbooked cases. In the booked cases, 194 NSTs were done significant (p = 0.1712) (Table 3). Most common type of (4 twin pregnancies) of which 154 (79.38%) were reactive nonreactivity observed in women with non reactive NST, and 40 (20.62%) were non reactive; the difference being was no acceleration. Two women with early decelera- Fig. 1: Schematic representation of study 162 JSAFOG Study of ‘Non Stress Test at Admission’ and its Corelation with Maternal and Fetal Outcome Table 1: Correlation of ‘NST at admission’ with mode of delivery Total number of No. of women with reac- No. of women with non- women studied tive NST (n = 176) reactive NST (n = 52) Mode of delivery No. % No. % No. % p value Total caesarean section 152 66.67 106 60.22 46 88.46 0.00681• Emergency C-Section 89 58.55 54 30.68 35 67.31 0.00542• (50.94) (76.09) Elective C-Section 63 41.45 52 29.55 11 21.15 0.13983 (49.06) (23.91) Vaginal delivery 76 33.33 70 39.78 6 11.54 0.00737• Instrumental delivery 10 4.39 9 5.11 1 1.92 0.16837 Total 228 100 176 77.19 52 22.81 •Statistically significant tion and 12.50% women with no acceleration delivered were born to mothers admitted with non-reactive NST vaginally. Nearly 81.48% of the babies born to mothers at admission (Table 4). Mean Apgar score of reactive with non reactive NST at admission were discharged in NST group was significantly higher than non reactive satisfactory condition. NST group at 1 minute (7.66 ± 1.03 vs 6.87 ±1.75) and at All 233 babies born to 228 women were alive irre- 5 minutes (8.98 ± 0.97 vs 8.48 ± 1.23) respectively (Table spective of their mother’s NST status and 52.79% (123) 4).