Perinatal outcome of term pregnancies with borderline amniotic fluid index: a prospective case control study

Background: It has been since antiquity that the importance of amniotic fluid and fetal growth with perinatal outcome is being documented. But the lacunae lies in studying the relationship between borderline amniotic fluid and perinatal outcome. The following study was undertaken to provide recent data that would help predict perinatal outcome in borderline AFI pregnancies.Methods: About 144 patients were considered in the study OPD/IPD patients in obstetrics and gynecology department in Bhabha Atomic Research Centre and Hospital, with about 72 cases with borderline amniotic fluid index (5-8 cm) and controls with amniotic fluid index ≥9-25 cm. Patients were selected and subjected to history taking, examination, ultrasound test with doppler studies and perinatal outcome documented over a period of one year.Results: The incidence of borderline AFI in my study was 16%. 58% were primigravidas. Meconium stained liquor was found in 18% cases compared to 7% controls. Low birth weight was found in 12.5% cases and 2.7% in controls. On applying statistical test analysis chi square test, it was found that borderline amniotic fluid index in relation to presence of meconium stained amniotic fluid and low birth weight, p value was found to be statistically significant (<0.05).Conclusions: Borderline amniotic fluid and perinatal outcome had significant relationship in terms of meconium stained liquor and birth weight while rest had no significance. Thus, borderline amniotic fluid patients require vigilant fetal surveillance

Obstetric outcome in pregnancies with borderline versus normal amniotic fluid index

Background: Amniotic fluid is an indicator of placental function on the fetal development. It is regulated by several systems, including transmembraneous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal swallowing), and the balance of fluid movement via osmotic gradients. The amniotic fluid index is the most commonly used method of measuring amniotic fluid. An AFI between 5 to 8 cms is borderline oligohydraminos. To compare the fetal and maternal outcome in pregnancies with borderline amniotic fluid index (5 to 8 cms) and normal AFI.Methods: This prospective cohort study was carried out on 94 pregnant patients attending the antenatal clinic of MES Medical College, Perinthalmanna between January 1st and December 31st 2016. Women with a singleton pregnancy in the third trimester were enrolled into the study. Of these 47 cases were in the normal AFI group and 47 cases in the borderline group. Adequate information was obtained from the patient’s medical record and the groups were compared on maternal and fetal complications.Results: The study results showed that more cases with borderline AFI had their non stress test to be nonreactive (59.6% versus 23.4%) and was associated with more fetal heart rate abnormalities (51% versus 17%). The number of meconium stained amniotic fluid (48.9% versus 19.1%) and caesarean deliveries (51.1% versus 21.2%) were also more among the borderline group.Conclusions: Findings indicated that there are more adverse fetal and maternal outcome among the borderline AFI group

Study of amniotic fluid and its co-relation with pregnancy outcome in high risk pregnancies

Background: Amniotic fluid is an important part of pregnancy sac and helps in fetal development. There is a consistent association between low AFI and conditions like pregnancy induced hypertension, postdated pregnancy and IUGR resulting in poor fetal outcome. In fact, high risk patients with low amniotic fluid index need to deliver quickly. So, an assessment of amniotic fluid volume has become an important component of antenatal testing for the high risk pregnancy. The objective was to study the correlation between Amniotic fluid index less than 5 cm (AFI˂5) and adverse perinatal outcome in high risk pregnancies.Methods: It was a hospital based prospective, comparative study. 150 high risk patients were selected from inpatient department of obstetrics and Gynecology Government Medical College Srinagar, Jammu and Kashmir, India over a period of one and half year. High risk pregnancies belonging to study group with AFI˂5 were demographically matched with high risk pregnancies with AFI >5 serving as comparison group. Perinatal outcome, rate of caesarean section and early intervention need were compared between the two groups.Results: 77.3% women in study group underwent caesarean section as compared to 28% in control group to prevent adverse perinatal outcome. 60% babies in study group had APGAR score less than 6 at 1 minute compared to only 8% in control group. 61.4% babies in study group needed NICU admission compared to 10.7% in study group.Conclusions: AFI is predictor of adverse outcome for high risk pregnancies. The early recognition alerts an obstetrician to prevent perinatal catastrophe if timely intervention is done along with antepartum and intrapartum fetal monitoring

Pregnancy outcome after diagnosis of oligohydramnios at term

Background: To study the perinatal outcome in oligohydramnios (AFI < 5) at term & find out incidence of relation of maternal high risk factors.Methods: A Prospective case control study consists of an analysis of pregnancy outcome in 50 cases with diagnosis of oligohydramnios by ultrasound after 37 completed weeks of gestation compared with 50 controls with no oligohydramnios.Results: The selected outcomes showed significant variations in both groups. There were increased chances of FHR decelerations, Thick meconium, low Apgar score at 5 min. ,birth weight <2.5 kg, admission to NICU, congenital anomalies & neonatal mortality(statistically not significant).Conclusions: An amniotic fluid index of < 5 cm detected after 37 completed weeks of gestation is an indicator of poor perinatal outcome. Determination of AFI can be used as an adjunct to other fetal surveillance methods. It helps to identify those infants at risk of poor perinatal outcome

Perinatal outcome associated with oligohydramnios in third trimester

Background: We aimed to evaluate the effect of Oligohydramnios on fetal outcome in terms of fetal distress, Meconium staining of amniotic fluid, birth weight, Apgar score of newborn babies, NICU admission, early neonatal morbidity and mortality.Methods: This was a prospective study of 156 antenatal patients booked at K. J. Somaiya medical college and research centre during the year January 2012 to December 2013 with gestational age between 30-40wks with AFI<5cms with intact membranes were analyzed for perinatal outcome.Results: The Caesarian section rate for fetal distress was 41% in patients with Oligohydramnios. Meconium staining of amniotic fluid was found in 30.7% patients. APGAR score at 5 minutes <7 was found in 6 patients (3.8%).Conclusions: Oligohydramnios has significant correlation with Caesarean section for fetal distress and low birth weight babies. Oligohydramnios is associated with high rate of pregnancy complication and increased perinatal morbidity and mortality. Oligohydramnios is a frequent occurrence demand careful evaluation, intensive parental counseling, fetal surveillance and proper antepartum and intrapartum care

Perinatal outcome in pregnancies complicated with oligohydramnios at term

Background: AFI of less than or equal to five cm is considered oligohydramnios. Various approaches, such as NST, acoustic stimulation, and foetal Doppler velocimetry, are useful in assessing foetal well-being and identifying pregnancies at risk of postnatal complications. The goal of this study was to learn about the negative perinatal outcomes in pregnant women who had oligohydramnios at term and to assess the efficacy of AFI in predicting foetal distress and caesarean delivery.Methods: A retrospective and comparative study of singleton pregnancies outcomes in 60 women diagnosed with oligohydramnios by USG after 37 weeks of pregnancy, compared to 60 women who did not have oligohydramnios and were matched for other factors. Some criteria for inclusion and exclusion were utilised. The data was analysed using statistical criteria such as mean, standard deviation, and chi square test sensitivity, specificity, PPV, and NPV.Results: The occurrence of non-reactive and re-active NST patterns differed significantly between the two groups. In comparison to women with AFI >5 cm, women with AFI 5cm have a higher rate of labour induction. LBW (2.5 kg) was more common in women with oligohydramnios, and LSCS rates were higher in oligohydramnios-complicated pregnancies.Conclusions: After 37 weeks of pregnancy, an AFI of less than 5 cm is a sign of poor perinatal outcome. AFI can be used in conjunction with other foetal monitoring techniques. AFI is a useful screening test for predicting foetal distress during labour that necessitates a caesarean section

Borderline oligohydramnios in term pregnancy and it's relation with pregnancy outcome

Background: Oligohydramnios can lead to contamination of amniotic fluid, fetal distress, neonatal asphyxia, aspiration pneumonia, increased perinatal mortality and adverse pregnancy outcomes. Because of atypical clinical symptoms, the critical point is to treat patients with oligohydramnios in late pregnancy. The objectives of the research were to study the mode of delivery/rate of operative interference/incidence of cesarean section due to fetal distress/non-reassuring fetal heart rate status in cases of term pregnancy with borderline amniotic fluid index (AFI), and to study the perinatal outcome in cases of term pregnancy with borderline AFI.Methods: The study is a prospective comparative study to be conducted in patients attending antenatal clinic at department of obstetrics and gynaecology, Tirunelveli government medical college hospital from from January 2018 till January 2019 (12 months). Data collected with regards to age, demographic characteristics, and socioeconomic status, detailed history including patient’s complaints, duration of complaints, menstrual and obstetric history, significant past, family and personal history. 265 cases of borderline oligohydramnios were detected of which 150 cases were selected for the study after applying exclusion criteria.Results: APGAR scores between the two groups. The mean APGAR scores of the normal group were 8.3±0.7 and the same of the borderline AFI group was 8.0±0.9. The difference between the means was statistically highly significant (p<0.01).Conclusions: Cumulative analysis of various studies, it will be reasonable to conclude that antepartum surveillance for borderline oligohydramnios is indicated in cases associated with fetal growth restriction or suboptimal fetal growth

Biomarkers of intrauterine hypoxia and perinatal asphyxia, and gestational age as predictors of neonatal outcome

Fetal life occurs in a relatively hypoxic environment. During normal pregnancy, several compensatory mechanisms secure fetal oxygenation and wellbeing. In complicated pregnancies, however, intrauterine hypoxia predisposes the fetus to growth restriction, stillbirth, neurodevelopmental sequelae such as cognitive dysfunction and cerebral palsy (CP), and adverse long-term health impacts. Impairment of respiratory gas exchange—during either pregnancy or delivery—leads to tissue hypoxia, and, if prolonged, to metabolic acidosis and asphyxia. Worldwide, such asphyxia, diagnosed at birth, annually accounts for a million neonatal deaths. Furthermore, neonatal hypoxic ischemic encephalopathy (HIE) originating from perinatal asphyxia may lead to a variety of neurodevelopmental impairments. Therapeutic neuroprotective interventions such as hypothermia have significantly improved the prognosis of severe neonatal encephalopathy. Increased risk for intrauterine fetal hypoxia and perinatal asphyxia occur in various circumstances and pregnancy complications—such as intrauterine growth restriction (IUGR), which affects up to 10% of pregnancies. Timing the delivery in preterm pregnancy with severe IUGR is challenging, owing to balancing between risks related to prematurity and to fetal hypoxia. Another obstetric challenge concerns timing of delivery as well: Neonatal outcomes vary by gestational age also among term pregnancies. In pregnancies beyond 41 gestational weeks, the risk for perinatal morbidity and mortality increases, probably due to the relative insufficiency of the aging placenta. Numerous methods such as fetal Doppler assessments and computerized cardiotocography help in monitoring placental function and fetal wellbeing. These methods, however, are not unequivocally efficient in predicting adverse neonatal outcomes in IUGR or in prolonged pregnancies. Furthermore, the time window for neuroprotective treatment in birth asphyxia is narrow, and additional methods for identifying those neonates who would benefit from neuroprotective actions are essential. We thus searched for biomarkers identifying those fetuses at risk for hypoxia-caused complications, and for predicting outcome after birth asphyxia. Erythropoietin (EPO) is a biomarker of chronic hypoxia, with high levels of EPO associating with increased risk for adverse outcome. S100B is a biomarker of brain- cell damage, and its levels rise in early phases of acute asphyxia. Copeptin, a by-product of arginine vasopressin (AVP) production, is a potential biomarker of birth asphyxia and HIE. Additionally, we aimed to evaluate the association of gestational age with perinatal asphyctic complications and long-term neurologic morbidity. The biomarker studies (I-III) were conducted in the University Hospital of Helsinki, Finland. Data on maternal pregnancy and delivery characteristics, and short-term neonatal outcomes such as Apgar score, originated from hospital charts. The study populations comprised 66 pregnancies complicated by preterm IUGR, 93 low-risk term and prolonged pregnancies, and 140 term neonates with birth asphyxia. Amniotic fluid samples for EPO evaluations we obtained by amniocentesis, at cesarean section, or vaginally at amniotomy. Umbilical serum plasma samples for EPO, copeptin, and S100B assessments we collected at birth. Biomarker levels in amniotic fluid and umbilical plasma samples we measured by immunoassays. Normal amniotic fluid EPO levels we defined as < 3 IU/L, with abnormal levels exceeding 27 IU/L. We considered as normal umbilical plasma EPO levels below 40 IU/L. The register-based cohort study on asphyxia and neurologic morbidity (IV) comprised 1 138 109 women with singleton pregnancies and their newborns between 1989 and 2008 in Finland. The Finnish Medical Birth Register (MBR), maintained by the National Institute for Health and Welfare (THL), provided data for this study. Statistical analyses we performed with the Statistical Package for Social Sciences (SPSS, Chicago, IL, USA), GraphPad Prism 6 and SAS version 9.3 (SAS Institute, Inc, Cary, NC, USA). All tests were two-sided, with probability (p) values of < 0.05 as statistically significant. In IUGR pregnancies, abnormal amniotic fluid EPO levels were associated with decreased umbilical artery pH and base excess (BE) values, abnormal biophysical profile, and reversed end-diastolic flow in the umbilical artery. Most importantly, such abnormal EPO levels were associated with composite adverse neonatal outcomes defined as intraventricular hemorrhage, periventricular leukomalacia, cerebral infarction, or necrotizing enterocolitis (p < 0.001). In low-risk term and postterm pregnancies, EPO levels in amniotic fluid and in umbilical serum correlated with gestational age. Furthermore, EPO levels in amniotic fluid correlated with the levels in umbilical serum, even after vaginal delivery. Among low-risk pregnancies, however, EPO levels correlated with neither umbilical artery pH or BE, nor with other adverse pregnancy outcomes. In our study on biomarkers in birth asphyxia, only copeptin correlated with arterial pH. Its correlation with umbilical artery BE was significantly stronger than were the correlations of S100B or of EPO. Copeptin levels, significantly higher among neonates with birth asphyxia, we demonstrated to increase as a function of labor duration. In the cohort study, multivariate analysis demonstrated an increased risk for low (< 4) one- and five-minute Apgar score, CP, intellectual disability, sensorineural defects, and perinatal mortality among early-term births. Postterm birth resulted in increased risk for low one- and five-minute Apgar scores (< 4), low umbilical artery pH ≤ 7.10, and intellectual disability, whereas risks for CP, epilepsy, sensorineural defects, and perinatal mortality showed no increase. In conclusion, among preterm IUGR pregnancies, high amniotic fluid EPO levels were associated with decreased umbilical artery pH and BE, and with adverse neonatal outcomes. In selected risk-pregnancies, determining amniotic fluid EPO may thus be a useful additional tool in fetal surveillance and in optimizing delivery timing. In term pregnancies, EPO levels correlated with gestational age, probably explained by advancing gestation resulting in weakening placental function and relative hypoxemia. Among low-risk populations, however, EPO was not related to adverse delivery outcomes, and thus may not prove clinically useful in such populations. Furthermore, in cases of acute birth asphyxia, S100B and EPO as biomarkers may not prove valid. In contrast, copeptin has potential for routine use as a biomarker for acute birth asphyxia and neonatal distress. Future studies should determine the correlation of biomarker levels at birth with severity of HIE and with long-term neurological outcome following birth asphyxia. Concerning gestational age at birth, we found an increased risk for low Apgar score, increased neurologic morbidity, and perinatal mortality among early-term neonates. Among postterm births, the risk for birth asphyxia was increased. The long-term neurologic health impacts of postterm birth, however, were less important than previously expected, meaning that further studies on the optimal management of pregnancies beyond 41 gestational weeks are essential.Raskauden aikana sikiö elää verrattain vähähappisessa ympäristössä. Normaalin raskauden aikana lukuisat kompensaatiomekanismit varmistavat sikiön riittävän hapensaannin ja hyvinvoinnin. Sen sijaan komplisoituneissa raskauksissa sikiön kroonisen hapenpuutteen riski on suurentunut lisäten sikiökuoleman, kasvuhidastuman, neurologisten kehityshäiriöiden ja pitkäaikaisten terveysongelmien todennäköisyyttä. Näissä raskauksissa optimaalisen synnytysajankohdan määrittely on usein haastavaa, koska tällöin on huomioitava kohdunsisäisen hapenpuutteen, ennenaikaisen synnytyksen, sekä obstetristen toimenpiteiden aiheuttamat mahdolliset haitat. Sikiön hengityskaasujen vaihdon ongelmat raskauden tai synnytyksen aikana johtavat kudosten hapenpuutteeseen ja hiilidioksidin kertymiseen eli asfyksiaan, mikä pitkittyessään väistämättä johtaa aineenvaihdunnalliseen happamuuteen. Maailmanlaajuisesti perinataalinen asfyksia aiheuttaa vuosittain jopa miljoonan vastasyntyneen kuoleman. Asfyksian aiheuttama hypoksis-iskeeminen enkefalopatia voi myös johtaa pysyvään vammautumiseen ja vakaviin neurologisiin kehityshäiriöihin. Keskushermoston suojaamiseen tähtäävät hoitotoimenpiteet - kuten vastasyntyneen viilennyshoito - ovat olennaisesti parantaneet vastasyntyneen vaikean enkefalopatian ennustetta. Sikiön hyvinvoinnin ja istukan toiminnan seurannassa käytetään lukuisia menetelmiä, kuten sikiön sydänäänten monitorointia ja Doppler-ultraäänitutkimuksia. Käytössä olevilla menetelmillä ei kuitenkaan aina pystytä yksiselitteisesti ennustamaan vastasyntyneen epäsuotuisaa lopputulemaa riskiraskauksissa. Vastasyntyneen asfyksiadiagnoosin asetuksen ja keskushermostoa suojaavien hoitojen käynnistämisen aikaikkuna on kapea, eikä kaikkia intensiivistä tehohoitoa tarvitsevia vastasyntyneitä löydetä nykymenetelmien avulla ajoissa. Uusia menetelmiä kaivataan sekä hapenpuutteen riskissä olevien sikiöiden, että intensiivisestä tehohoidosta hyötyvien vastasyntyneiden tunnistamiseen ja ennusteen arviointiin. Erytropoietiini (EPO) on punasolujen muodostumista lisäävä hormoni, jota käytetään myös hapenpuutteen merkkiaineena. Napaplasman ja lapsiveden kohonneet EPO-pitoisuudet liittyvät vastasyntyneen huonoon lopputulemaan. S100B-proteiini on aivokudoksen soluvaurion merkkiaine, jonka pitoisuudet nousevat myös asfyksiaan liittyvien vaurioiden ilmaantuessa. Vasopressiini on elimistön nestetasapainoa ylläpitävä hormoni, jonka eritys lisääntyy monentyyppisissä stressitilanteissa. Kopeptiini on vasopressiini-erityksen sivutuote, jota pidetään potentiaalisena perinataalisen asfyksian ja hypoksis-iskeemisen aivovaurion merkkiaineena. Tutkimuksessamme selvitimme näiden valikoitujen biomerkkiaineiden käyttöä hapenpuutteen riskissä olevien sikiöiden tunnistamisessa, sekä näiden merkkiaineiden käytettävyyttä perinataalisen asfyksian diagnostiikassa ja vastasyntyneen ennusteen arvioinnissa. Lisäksi selvitimme raskauden keston vaikutuksia perinataalisen asfyksian ja pitkäaikaisen neurologisen sairastavuuden esiintyvyyteen täysiaikaisissa ja yliaikaisissa raskauksissa. Sikiön kasvuhidastumaa ennenaikaisissa raskauksissa käsittelevässä tutkimuksessamme (n=66) totesimme kohonneiden lapsiveden EPO-pitoisuuksien liittyvän napavaltimon vakava-asteisiin virtausmuutoksiin, sekä vastasyntyneen alentuneisiin napavaltimon pH- ja BE-arvoihin. Lisäksi kohonneet EPO-pitoisuudet liittyivät vastasyntyneen vakavaan sairastavuuteen, mukaan lukien vaikea-asteiset aivokammioverenvuodot, aivoinfarktit, periventrikulaarinen leukomalasia, sekä nekrotisoiva enterokoliitti (p < 0.001). Matalan riskin täysiaikaisissa ja lasketun ajan ohittaneissa raskauksissa (≥41 raskausviikkoa) (n=93) EPO-pitoisuudet korreloivat raskauden keston kanssa. Näissä raskauksissa emme todenneet yhteyttä lapsiveden EPO-pitoisuuden ja vastasyntyneen huonon lopputuleman välillä. Asfyktisilla vastasyntyneillä (n=140) totesimme selvästi korkeammat kopeptiinipitoisuudet kuin hyväkuntoisilla vastasyntyneillä. Kopeptiinipitoisuudet myös nousivat synnytyksen keston myötä. Rekisteritutkimuksemme asfyksiasta ja neurologisesta sairastavuudesta kattoi 1 138 109 raskautta vuosina 1989 – 2008. Totesimme varhaiseen täysiaikaiseen syntymään (raskausviikoilla 37+0-38+6) liittyvän matalien Apgarin pisteiden, CP-vamman, älyllisen kehitysvammaisuuden, aistitoimintojen vammojen, sekä perinataalikuolleisuuden suurentuneen riskin. Yliaikainen raskaus (≥42 raskausviikkoa) lisäsi matalan syntymä-pH:n, matalien Apgarin pisteiden, sekä älyllisen kehitysvammaisuuden riskiä, mutta ei liittynyt yleiseen neurologiseen sairastavuuteen eikä lisännyt perinataalikuolleisuutta. Johtopäätöksenä totesimme, että tietyissä riskiraskauksissa lapsiveden EPO-pitoisuuden määrittäminen saattaa olla hyödyllinen lisämenetelmä sikiön voinnin ja synnytyksen ajankohdan arvioinnissa. Toisaalta matalan riskin raskauksissa EPO-pitoisuuden määrityksestä ei vaikuttaisi olevan hyötyä edes lasketun ajan ylittämisen jälkeen. Kopeptiini vaikuttaa erittäin lupaavalta vastasyntyneen asfyksian ja hypoksis-iskeemisen enkefalopatian biomerkkiaineelta, joskin kopeptiinin käytettävyys pitkäaikaisennusteen arvioinnissa edellyttää jatkotutkimuksia. Kohorttitutkimuksessamme totesimme varhaiseen täysiaikaisuuteen liittyvän suurentuneen riskin vastasyntyneen sairastavuuteen ja kuolleisuuteen, sekä pitkäaikaiseen neurologiseen sairastavuuteen. Löydös tukee nykyistä hoitosuositusta synnytyksen ajoittamisesta mahdollisuuksien mukaan lasketun ajan tuntumaan. Toisaalta laajassa kotimaisessa kohortissamme yliaikaisuuden vaikutukset lapsen pitkäaikaiseen neurologiseen terveyteen olivat oletettua vähäisemmät

Impact of oligohydramnios on maternal and perinatal outcome: a comparative study

Background: Oligohydramnios has got significant impact on perinatal outcome and maternal morbidity. Therefore, early detection and its management will help in reduction of perinatal morbidity and mortality, decreased operative interventions. Hence, the present study is undertaken to study the impact of oligohydromnios on perinatal-maternal outcome.Methods: The present study was prospective comparative observational study conducted in the Department of Obstetrics and Gynaecology, Mallareddy Narayana Multispecialty Hospital, reputed teaching hospital from January 2015 to August 2017. The women were divided into study and control groups based on AFI, 100 cases were selected in each group.Results: Out of the 200 women, included in the present study, in study group AFI <5 cm was present in 51% of patients and AFI 5-8 cm in 49% of patients. Doppler abnormalities found in study group (n = 33). 32% of the patients in study group had non-reactive NST while in control group 8%. Caesarean section was performed in 70% of cases in study group as compared to 9% in control group. Foetal distress was the most common indication for LSCS. There were no perinatal deaths in this study.Conclusions: In this study amniotic fluid index of ≤5 cm was commonly associated with increased cesarean section rates, intrauterine growth restriction, Non-reactive NST and abnormal umbilical artery Doppler velocimetry studies. Hence, every case of oligohydramnios needs to be evaluated carefully, early detection and initiation of appropriate treatment and treat the cause if possible

Perinatal outcome associated with oligohydramnios at term

Background: Oligohydramnios is a severe and common complication of pregnancy and its incidence is reported to be around 1 to 5% of total pregnancies. The aim of this study was to perinatal outcome of oligohydramnios (AFI <5) at term.Methods: A prospective study was conducted in which 200 patients at term with oligohydramnios AFI <5 cm with intact membranes were analyzed for perinatal outcome.Results: There were increased chances of FHR decelerations, thick meconium, increased LSCS, low Apgar score at 5 minutes, birth weight <2.5 kg, admission to NICU in pregnancy with oligohydramnios.Conclusions: An amniotic fluid index (AFI) of <5 cm detected after 37 completed weeks of gestation is an indicator of poor perinatal outcome. Determination of AFI can be used as an adjunct to other fetal surveillance methods that helps to identify those infants at risk of poor perinatal outcome