Document Type : Original Article
Authors
1 obstetrics and gyecology department ,faculty of medicine,AL-Azhar university
2 obstetrics and gynecology department,faculty of medicine,AL-Azhar university.
3 obstetrics and gynecology department ,faculty of medicine ,Al-Azhar university
Abstract
Keywords
INTRODUCTION
The liquid that surrounds a developing foetus in the amniotic sac, amniotic fluid (AF), is normally clear to pale yellow in colour. The makeup of AF is diverse, containing a variety of maternal and foetal components. The AF's composition varies with gestational age, with an average pH of 7.2 and specific gravity of 1.2. 1.0069–1.008. 13
In preterm and early term infants, lung immaturity is still the leading cause of morbidity and mortality. Although gestational age (GA) is the strongest predictor of lung maturity, respiratory distress syndrome and transitory tachypnea in the newborn are not limited to premature births (34 weeks). These problems are substantially more common in late preterm (34–36 weeks' gestation) and early term (37–38 weeks' gestation) newborns than in neonates delivered at or after 39 weeks' gestation.11
Because lung immaturity is linked to insufficient pulmonary surfactant production, respiratory distress syndrome (RDS), formerly known as hyaline membrane disease, is the most prevalent cause of respiratory distress in premature newborns. With the use of prenatal steroid medication, early provision of
positive airway pressure, and, in some circumstances, exogenous surfactant therapy, RDS can be avoided or its severity reduced.3
For nearly a quarter-century, Gray-level measurements, lung tissue mobility, and relative characteristics of lung-to-placenta or -liver imaging, among other things, have been utilised to attempt foetal lung ultrasound images without being invasive. These studies discovered a strong relationship between respiratory illness and death, but the diagnostic accuracy was insufficient to be useful for therapeutic purposes.4
The use of foetal ultrasonography to predict foetal lung maturity has long been suggested as a non-invasive alternative to amniocentesis. Gray-scale measurements, lung tissue motility, and the link between imaging features of foetal lung vs. placental or hepatic tissue have all been attempted utilising computer analysis of foetal lung ultrasound pictures over the last 25 years. 20
PATIENTS AND METHODS
Study design and setting: This was a prospective cohort study that was completed on 300 women coming for labour at El Hussein University and Shibin Elqantar public hospital in obstetrics and gynecology department from December 2019 to August 2021.
Criteria for inclusion: All women who are pregnant with a viable foetus and have an uncomplicated singleton pregnancy are eligible. Women have to be certain of their last menstrual cycle date and have it confirmed by ultrasound during the first trimester of pregnancy.
Criteria for exclusion: Multiple pregnancies, Malformations of the foetus ,complications (hypertension, diabetes, etc.) Macrosomic foetuses or intrauterine growth restriction Presence of meconium-stained fluid or antepartum haemorrhage.
Ethical considerations: Approval of ethical committee was obtained from Al-Azhar university faculty of medicine, Egypt. Verbal consent was taken from all cases before participation in this study. The nature and aims of this work were fully discussed to all women who were included in this study. No funding sources.
Methods:
All patients were subjected to the following:
Detailed personal, obstetric and medical history including: Personal history including age, smoking and level of education. Obstetric history including gravidity, parity, number of abortions, modes of delivery in previous pregnancies, first day of the last normal menstrual period and the gestational age, onset, duration. Medical history including Present or Past history
Examination: Vitalsigns are all important factors to consider. Abdominalexaminationforassessmentoffundallevelandfetalheartsounds. Palpation of the belly to detect foetal size and presentation, as well as uterine activity.
Lab assessment: Allinvestigationsobtainedaccordingtostandardprotocoloflabour inourhospitalincludingcompletebloodcount,CRPandgrouping,liverenzymes,kidneyfunctions,randombloodsugar,andurineanalysis.
Ultrasound evaluation: Allmotherswereexaminedbyultrasoundprenatallyforassessment of amniotic fluid index, umbilical artery Doppler, assessment of estimated fetal weight&fetalmaturitysign.The existence and size of epiphyseal ossification centres, placental grading (classification based on chorionic convolutions and calcifications), and other imaging measurements have all been used to determine maturity (19-21).Some mature fetuses may not have these findings at term, and some fetuses having these traits may be immature (e.g., maternal diabetes complicated by macrosomia). In general, ultrasonography assessment of gestational age in the third trimester (indirectly evaluating for maturity) is inferior to other approaches.
Technique: Abdominal ultrasound was done using mindray DP20 with center frequency 3.5MHZ. ultrasoundexaminationwasdoneOn the same day after their delivery, they went to the radiology department for an obstetric ultrasound scan. The same ultrasonographer performed the ultrasound examinationtodecreasetheintraobserver variability.
Ultrasound Findings: The placenta was graded according to Grannum's categorization. Biparietal diameter (BPD): The axial section of the foetal skull was measured with callipers from the outer table to the inner table of the skull, where a clear midline echo of the thalamus and septum pellucidum could be seen. Epiphyseal centres: The foetus' lower limbs were inspected, and callipers were used to measure the distal femoral epiphysis and proximal tibial epiphysis. Amniotic fluid linear densities: Linear densities in the amniotic fluid were observed.
Postoperative management: Each neonate was examined by the paediatrician for the following foetal outcomes: foetal sex, weight, APGAR score at one and five minutes, signs of a respiratory problem, admission to the neonatal intensive care unit (NICU) and follow-up by the paediatrician for the duration of the hospitalisation, and any adverse neonatal morbidity or mortality up to discharge.
Sample size calculation: Based on previous studies who found that the adjusted the mean significant difference in the Mean FL between the RDS and the non-RDS, were in -RDS (1.27 ± 0.07) and non -RDS (1.47 ± 0.11) (Laban et al., 2015). Based on this assumption, the sample size was determined according to the using the formula:
Where
n is the sample size and Z/2 is 1.96. (The key number that separates the 95 percent of the Z distribution in the middle from the 5% in the tail.)
0.84 (Z) (The critical value that separates the lower 20 percent of the Z distribution from the upper 80 percent )
= the standard deviation of the mean MCA's estimate RI equals 0.07.µ1 = mean in FL in -RDS. (1.27).
µ2 = mean in FL in non-RDS. (1.47).
The sample size was calculated to be 300 patients in total.
Statistical analysis and data management
Data was collected, coded, updated, and entered into IBM SPSS version 20 (Statistical Package for Social Science). The qualitative data were given as numbers and percentages, the quantitative data with parametric distribution as mean, standard deviations, and ranges, and the quantitative data with non-parametric distribution as median with inter quartile range (IQR). When comparing two groups with qualitative data, the Chi-square test was utilised, but the Fisher exact test was used instead when the predicted count in any cell was less than 5. In the comparison of two groups with quantitative data and parametric distribution, the independent t-test was employed, while the Mann-Whitney test was used in the comparison of two groups with quantitative data and non-parametric distribution. The confidence interval was set at 95%, while the acceptable margin of error was set at 5%. As a result, the following p-value was declared significant: Non-significant if the P value is greater than 0.05. (NS). Significant if the P value is less than 0.05. (S). Highly significant if the P value is less than 0.01. (HS).
RESULTS
|
Neonatal respiratory distress syndrome (RDS) |
||||||
Positive (No.=47) |
Negative (No.=253) |
Chi square test |
|||||
No |
% |
No |
% |
x2 |
p value |
||
Maternalage |
Mean±SD |
29.62 |
4.96 |
31.55 |
4.97 |
2.454 |
0.015 |
Gestationalage |
Mean±SD |
35.68 |
0.76 |
36.04 |
0.81 |
2.829 |
0.005 |
Residence |
Rural |
25 |
53.2% |
128 |
50.6% |
0.107 |
0.743 |
Urban |
22 |
46.8% |
125 |
49.4% |
|||
Gravidity |
Once upon a time |
4 |
8.5% |
38 |
15.0% |
5.403 |
0.611 |
At least twice |
8 |
17.0% |
31 |
12.3% |
|||
At least three times |
4 |
8.5% |
34 |
13.4% |
|||
At least four times |
6 |
12.8% |
35 |
13.8% |
|||
At least five times |
10 |
21.3% |
30 |
11.9% |
|||
At least six occasions |
5 |
10.6% |
27 |
10.7% |
|||
a total of seven |
6 |
12.8% |
33 |
13.0% |
|||
a total of eight |
4 |
8.5% |
25 |
9.9% |
|||
Parity |
zero times |
1 |
2.1% |
18 |
7.1% |
6.630 |
0.577 |
Once upon a time |
5 |
10.6% |
44 |
17.4% |
|||
At least twice |
11 |
23.4% |
42 |
16.6% |
|||
At least three times |
7 |
14.9% |
32 |
12.6% |
|||
At least four times |
4 |
8.5% |
30 |
11.9% |
|||
At least five times |
7 |
14.9% |
26 |
10.3% |
|||
At least six occasions |
4 |
8.5% |
30 |
11.9% |
|||
a total of seven |
5 |
10.6% |
23 |
9.1% |
|||
a total of eight |
3 |
6.4% |
8 |
3.2% |
|||
Abortion
|
Zerotimes |
28 |
59.6% |
97 |
38.3% |
8.656 |
0.013 |
Onetime |
10 |
21.3% |
106 |
41.9% |
|||
Twotimes |
9 |
19.1% |
50 |
19.8% |
Table 1: Contrast between neonatal respiratory distress syndrome (RDS) and non RDS groups as regards demographic data
|
Neonatal respiratory distress syndrome (RDS) |
|||||
RDS (No.=47) |
NON-RDS (No.=253) |
Independent t test |
||||
Mean |
SD |
Mean |
SD |
T |
p value |
|
BPD |
82.09 |
2.59 |
88.24 |
3.14 |
12.665 |
<0.001 |
FL |
60.67 |
3.51 |
67.86 |
2.86 |
15.215 |
<0.001 |
AC |
278.72 |
13.92 |
307.96 |
8.67 |
19.037 |
<0.001 |
Table 2: Comparison between neonatal respiratory distress syndrome (RDS) and the non RDS as regards BPD, FL and AC.
|
Neonatal respiratory distress syndrome (RDS) |
||||||
RDS (No.=47) |
NON-RDS (No.=253) |
Chi square test |
|||||
No |
% |
No |
% |
x2 |
p value |
||
PlacentalGrading |
0-I |
34 |
72.3% |
46 |
18.2% |
59.482 |
<0.001 |
II |
8 |
17.0% |
135 |
53.4% |
|||
III |
5 |
10.6% |
72 |
28.5% |
Table 3: Comparison between neonatal respiratory distress syndrome (RDS) and non RDS as regards placental grading.
|
Neonatal respiratory distress syndrome (RDS) |
||||||
Positive (No.=47) |
Negative (No.=253) |
Chi square test |
|||||
No |
% |
No |
% |
x2 |
p value |
||
COLON |
I |
5 |
10.6% |
19 |
7.5% |
11.466 |
0.003 |
II |
28 |
59.6% |
91 |
36.0% |
|||
III |
14 |
29.8% |
143 |
56.5% |
|||
Thalamicechogenicity |
Echogenic |
13 |
27.7% |
194 |
76.7% |
44.528 |
<0.001 |
Echolucent |
34 |
72.3% |
59 |
23.3% |
|||
Lung/liverechogenicity
|
Hyper-echoic |
13 |
27.7% |
70 |
27.7% |
1.648 |
0.439 |
Hypo-echoic |
17 |
36.2% |
70 |
27.7% |
|||
Iso-echoic |
17 |
36.2% |
113 |
44.7% |
Table 4: Comparison between neonatal respiratory distress syndrome (RDS) according thalamic echogenicity, lung/liver echogenicity and colonic grading.
|
Neonatal respiratory distress syndrome (RDS) |
|||||
Positive (No.=47) |
Negative (No.=253) |
Independent t test |
||||
Mean |
SD |
Mean |
SD |
T |
p value |
|
APGAR1min |
2.98 |
0.82 |
5.26 |
0.79 |
18.062 |
0.001 |
APGAR5min |
5.91 |
0.83 |
7.8 |
1.14 |
10.838 |
0.012 |
Table 5: Comparison between neonatal respiratory distress syndrome (RDS) according Apgar score.
|
Neonatal respiratory distress syndrome (RDS) |
||||||
Positive (No.=47) |
Negative (No.=253) |
Chi square test |
|||||
No |
% |
No |
% |
x2 |
p value |
||
NICUadmission |
No |
21 |
44.7% |
221 |
87.4% |
46.276 |
<0.001 |
Yes |
26 |
55.3% |
32 |
12.6% |
|||
Mortality |
No |
45 |
95.7% |
252 |
99.6% |
5.966 |
0.015 |
Yes |
2 |
4.3% |
1 |
0.4% |
Table 6: Comparison between neonatal respiratory distress syndrome (RDS) according NICU admission and mortality.
Item |
AUC |
Sensitivity |
Specificity |
-PV |
+PV |
P value |
FFP |
0.726 |
61.70 |
83.40 |
92.1 |
40.8 |
0.001 |
DFE |
0.874 |
85.11 |
89.72 |
97.0 |
60.6 |
0.001 |
PTE |
0.925 |
93.62 |
91.30 |
98.7 |
66.7 |
0.001 |
Table 7: Cut of point, sensitivity and specificity of FFP, DFE and PTE among RDS.
This table shows that in FFP, DFE and PTE:
Its sensitivity is 61.7%, 85.11% and 93.62%
Its specificity is 83.4%, 89.72% and 91.30%
The positive predictive value is 40.8%. 60.6% and 66.7%
The negative predictive value is 92.1%, 97% and 98.7%
DISCUSSION
The pulmonary system is one of the last foetal organ systems to mature in terms of both function and structure. Preterm delivery can result in substantial newborn morbidity or mortality due to the immature pulmonary system's inability to sufficiently oxygenate the preterm neonate.6
Respiratory distress syndrome in newborns(RDS)isconsideredastheir lungs are immature, it is a primary cause of mortality and morbidity in newborns. It is more common in neonates that are born prematurely, and it is linked to inverselywithgestationalageatbirth.18
Thedecisiontocontinueordelaydeliverydependsusuallyontheabilitytoefficientlyassessfetallungmaturityforensuringtheprotectionofthefetusfromriskssuchassequelaeofrespiratorydistresssyndrome(RDS),necrotizingenterocolitis,intraventricularhemorrhage,patentductusarteriosusandneonatalsepsisasmuchaspossible.16, 11
Fetallungmaturitycanbeassessedbybiochemicaltestssuchaslecithin/sphingomyelinratio,absenceorpresenceofphosphatidylglycerolandamnioticliquid,fluorescentpolarization,foamstabilityorshaketestlamellarbodythatallrelyonamniocentesis,whichisaninvasivemethodtodeterminefetallungmaturitythatcouldcausecomplications.13
Ultrasoundbeingtheeasiest,for routine obstetric scanning, a simple, common, non-invasive, and cost-effective equipment is available. Ultrasound measures include bi-parietal diameter, femur length, epiphyseal centres of the lower limb, placental grading, colon grading, and free-floating particles in the amniotic fluid for assessing foetal lung maturity.withcontroversialdiagnosticaccuracy.4, 20
Therefore, the goal of our research was to assess thevalueofassessmentofamnioticfluidusingultrasonographyinpredictingfetallungmaturityanditsimpactonfetaloutcome.
Thisprospectivecohortstudyincludedthreehundredpregnantwomen.Theywerelaterdividedintotwogroups;RDSgroupandnon-RDSgroup.
Regardingthedemographiccharacteristicsofthestudiedcases,ourresultsrevealedthepresenceofa significant distinction betweenRDSgroupas well as non -RDSgroupregardinggestationalage(Pvalue=0.0005).Therewasnostatisticallysignificantdifferenceasregardsmaternalage,gravidity,parityandabortionamongRDS&non-RDSfetusesasillustratedinTable(1).
SuchfindingswereinagreementwithstudiesbyWang 28 et al. thatindicatedthatwith increasing gestational age, the risk of RDS reduced andShapiro-Mendoza and Lackritz25 studythatIn comparison to babies born at term, babies born between the 34th and 37th week of pregnancy had a higher risk of RDS. Additionally,Abdulla et al.3 study indicatedthatIncidence of RDSwasInfants born before 40 weeks gestation have a 12 percent chance of dying, whereas those born after 40 weeks have a 0% chance. ApreviousstudybyMehrabadi et al.19indicatedthatearly gestation RDS was substantially linked with maternal age (35 years) butprotectiveforlategestationRDS.
OurresultsindicatedastatisticallysignificantdecreaseinthevaluesoffetalbiometricmeasurementsincludingBPD,FLandACamongRDSgroupincomparisonwiththenon-RDSgroup(Pvalue<0.001)asillustratedinTable(2).
SuchfindingswereinagreementwithastudybyKandil et al.15 indicatedthedecreasedBPD,FL,andACamongRDSgroupandthatbyusingthefetalbiometryvaluesinthepredictionoffetalpulmonarymaturity,aBPDbetween8.28and9.35 cm,ACbetween29.5and32.2 cm,andFLbetween6.27and7.21 cmcorrelatedwithmaturefetallungs.
ItwasindicatedthatBPDcanbeusedforthe timetableinBPD bigger than 9.2 cm and elective caesarean section showed90% of foetuses have reached lung maturity.withhighspecificityandsensitivity(92%and87%respectively)andIn 80% of the cases, BPD 8.7 cm revealed RDS.19
Pallavi et al.21indicatedthatBPDisanaccuratefoetal lung maturity marker becausetheBPD and Correlation> 9.0 cm.The predictability of a positive shake test (in amniocentesis) was 100 percent. OurresultsindicatedastatisticallysignificantdifferencebetweenRDSgroupandnon-RDSgroupregardingplacentalgrading(Pvalue<0.001)asillustratedinTable(3).
SuchfindingswereinagreementwithDas et al.7thatindicatedthattherespiratorydistresssyndromewasfoundtobeassociatedwithgrade0andgradeIplacentaandnocasesweredetectedingradeIIorgradeIIIplacenta.
Previousstudiesby Keikhaie et al. and Sharma et al.14, 26indicatedthatgradeIIIplacentawasassociatedwithgoodfetalpulmonarymaturityandtheabsenceofrespiratorydistresssyndrome.
Ourresultsindicatedastatisticallysignificantdecreaseinfree-floatingparticles(FFP),distalfemoralepiphysis(DFE)andproximaltibialepiphysis(PTE)valuesamongRDSgroupincomparisonwiththenon-RDSgroup(Pvalue<0.001)asillustratedinTable(4).
SuchfindingsareinagreementwithAbdou et al.3thatindicatedthatthemeanepiphysealossificationcentersweresignificantlylowinneonatalwithrespiratorydistresssyndrome.ApreviousstudybyElsaeed et al.9indicatedthatAs long as the diameter is at least 1 mm.
ultrasonography may identify each epiphyses ossification centre at a much earlier stage.However,Kandil et al.15indicatedthateven though thedetectionofossificationAlthough the presence of centres indicates foetal lung maturity, their absence does not rule out lung maturity. Furthermore, to prevent being confused with other neighbouring cartilaginous structures, these epiphyseal foci must be recognised with extreme caution. In difficult pregnancies, DFE detection of any size may not be related with foetal lung maturity.
Ourresultsindicatedadifference that is statistically significant betweenRDSgroupas well as non -RDSgroupregardingcolon(pvalue=0.003)andthalamicechogenicity(Pvalue<0.001),however,non-statisticallysignificantbetweenbothgroupsregardingLung/liverechogenicityasillustratedinTable(5).
SuchfindingswereinagreementwithstudiesbyKandil et al.15 thatThere was no evidence of a link between prenatal lung echogenicity and liver maturity or newborn RDS..Thesameresearchindicatedthalamic echogenicity was found to be a reliable predictor of foetal lung maturity witha77%and79%forsensitivityandspecificity,respectivelyandKeikhaie et al. 14 studythatthe foetal intestine was divided into four phases.AndGrade 4 foetal intestine was found to be a predictor of foetal lung maturitywith a good specificity and a low sensitivity (62.5%) (98.9 percent).
ApreviousstudybyRasheed et al.24 indicatedthatthe examination of the echogenic thalamus is advantageous and can be used as a foetal lung maturity measure.
OurresultsindicatedastatisticallysignificantdifferencebetweenRDSgroupandnon-RDSgroupregardingbirthweight(Pvalue<0.001)andnosignificantdifferencebetweenbirthgroupsregardingfetalsex(Pvalue>0.05)asillustratedinTable(6).
SuchfindingswereinagreementwithastudybyFehlmann et al.10thatindicatedthatRDShadahighincidenceinverylowbirthweightinfants,despitethefrequentuseofantenatalsteroids.
Condò et al.6studythatindicatedthatthe biggest risk factor for RDS is a low birth weight,butcontrarilywithourresults,thesamestudyindicatedthattheriskofRDSwashighwhenfetalsexismale.
OurfindingswereindisagreementwithapreviousstudybyPeacock et al.23thatindicatedthatMale preterm newborns are more likely than girls of the same gestational age to develop RDS and require more immediate respiratory and circulatory care. Furthermore, men have been linked to a higher risk of neonatal mortality and respiratory disease.
SuchhighriskwasexplainedascausedbyDuring the foetal phase, oestrogen regulates surfactant protein synthesis and promotes certain growth factors.12
OurresultsindicatedthepresenceofsignificantdecreaseinAPGARscoreatoneminuteandfiveminutespostbirthamongRDSgroupincomparisonwiththenon-RDSgroup(Pvalue<0.001)asillustratedinTable(7).
SuchresultsareinagreementwithWang et al.28thatindicatedthatanAt 5 minutes after birth, the Apgar score was 7.revealednegativeroleonthedevelopmentofRDSandindicatedpoorconditionsafterdeliveryduetotheimpairmentoftherespiratoryfunctionthatexacerbateshypoxia
Thavarajah et al.27studyindicatedthatBoth low and intermediate Apgar scores were substantially related with infant issues such as respiratory distress, feeding difficulty, hypothermia, and convulsions.
AretrospectivecohortstudybyChen et al.5indicatedMale infants with low gestational ages and low Apgar scores died at a higher rate than female neonates duetoRDSsyndrome.
OurresultsindicatedastatisticallysignificantincreaseinNICUadmission,mortalityrateandhospitalstayamongRDSgroupincomparisonwiththenon-RDSgroup.
SuchfindingswereinagreementwithEdwards et al.8thatindicatedthatneonatalrespiratorydistressisamajorreasonforincreasedmorbidityandmortalityamongnewborn,causingincreasedinfantsbeingadmittedtoneonatalunitssoearlyrecognitionofsignsandsymptomsofneonatalrespiratorydistressandpropermanagementcouldimprovetheprognosisofthesebabies.
OurresultsindicatedthatultrasoundparametersareprecisepredictorsintheassessmentofRDSincludingproximaltibialepiphysis(PTE)followedbydistalfemoralepiphysis(DFE)thenamnioticfluidfreefloatingparticles(FFP)thatshowedsensitivityvalues(93.62%,85.11%,and61.7%)respectivelyandspecificityvalues(91.30%,89.72%and83.4%)respectively.
SuchfindingswereinagreementwitharecentstudybyKandil et al.15thatindicatedthatultrasoundparametersaregoodpredictorsintheassessmentofRDSincludingepiphyses of the proximal tibiathatthe distal femoral epiphyses had the highest sensitivity (91%) and specificity (95%) after the proximal femoral epiphyses.showedThe sensitivity is 90% and the specificity is 84 percent.
ApreviousstudybyPatil et al.22indicatedthatThe foetal tibial epiphysis exhibited the best sensitivity (98.7%), specificity (88.8%), and accuracy of any of the tests (97.7 percent )followedbyfetalfemoralepiphysisthatshowedhighsensitivity(92.8%), whereaslowspecificity(60%) and a high level of precision (91.0 percent )intheevaluation ofRDS.
CONCLUSION
Ultrasound parameters including proximal tibial epiphysis (PTE) followed by distal femoral epiphysis (DFE) then amniotic fluid free floating particles (FFP) are precise predictors in the assessment of RDS with varying degrees of performance.