CLINICAL BRIEFS
Indian J Pediatr 1990; 57 : 581-590
Lethal Congenital Malformations-Role in Perinatal Deaths N.S. Suguna Bal, Elizabeth Mathews, P.M.C. Nail', K. Sabarinathan
Department of Pediatrics, S.A.T. Hospital, Ttivandrum LetLal congential malformation is an important cause of perinatal deaths in developed countries. In developing countries, it is yet to become an important cause of death. The present communication is an attempt to study the incidence and pattern of lethal congential malformations and their contribution to perinatal deaths. Fifty lethal congenital malformations comprised 0.36% of 13964 consecutive births during a period of one year and caused 9.38% of still births, 7.03% of early neonatal deaths and 8.4% of perinatal deaths. Eighteen (36%) CNS lethal malformations (CNSLM) and seventeen maltisystern lethal malformations (34%) together comprised 70% of all lethal malformations. Among the CNSLM, 12 were anencephalies, and all these were still births. Fifty percent of early neonatal deaths occurred within one hour and 88.89% within 24 hours. Necropsy was performed in 18
obtained from inpatient records and for still births from maternal case record. Necropsy was carried out whenever the consent was available. Chromosomal karyotyping was done whenever possible. CASE REPORT Of the 13964 consecutive births there were 597 perinatal deaths. There were 50 lethal congenital malformations constituting an incidence of 8.38% of perinatal deaths and 0.36% of total births. Out of the 50 lethally malformed babies 32 were still born and 18 five born, giving a percentage of 64% for still births and 36% for early neonatal deaths. They caused 9.38% of still births and 7.03% of first week neonatal deaths. T~LE 1. Distribution of Lethal Congenital Malformations According to Birth Weight Birth weight (gm)
cases,
All lethal congenital malformations noted among 13964 consecutive births in S~A.T. Hospital, Trivandrum, during a period of one year formed the study material. Any anatomical defect present at birth and recognised with naked eye, radiograph, ultrasound or necropsy was considered as lethal congenital malformation if incompatible with fife, resulting in still birth or early neonatal death. The data for the live born infants were
500-999
3
1
4
1000-1499
4
2
6
1500-1999
6
3
9
2000-2499
6
6
12
2500-2999
10
4
14
3000-3499
1
1
2
> 3500
2
1
3
32
18
50
Total
581
Still Neonatal Total birth death
582
VoL 57, No. 4
THE INDIANJOURNALOF PEDIATRICS
Of the 50 infants 31 (62%) weighed below 2500 gins, 9 (18%) between 1500-1999 gins, 6 (12%) between 1000-1499 gins and 4 (8%) weighed below 1000 gms (Table 1). Twentysix babies were preterm and 5 small for gestational age. Of these 4 (8%) were less than 28 weeks gestation, 8 (16%) between 28-31 weeks, 15 (30%) between 3236 weeks and 23 (46%) between 37-41 weeks gestation. A study of the pattern of lethal malformations revealed that 70% involved mainly two systems CNS (36%) and multisystem (34%) (Table 2).
In still births central nervous system malformation dominated (46.9%) while in early neonatal deaths, multisystem and chromosomal anomalies together accounted for 55.5%. Among the central nervous system malformations anencephaly was the commonest (66%) (Table 3). Among neonates with congenital malformation, 50% died within one hour and 88.89% within 24 hours. Necropsy was done in 18 cases. The various malformations noted at necropsy are shown in Table 4.
TAeUg2. Pattern of Lethal Congenital Malformations System
Stillbirth
%
Early neonatal birth
%
Central nervous system
15
46.9
3
16.7
Multisystem
12
37.5
5
27.8
Skeletal
2
6.3
1
5.6
Gastrointestinal
2
6.3
Skin
1
3.1
Chromosomal
5
27.8
Cardio vascular
4
22.2
T~ta 3. CNS Malformations in Perinatal Deaths .
Still birth
Type
Early neonatal death
Total
% of total CNS malformations
lethal congenital malformations
Anencephaly
11
11
61.12
22
Anencephaly with meningomyelocele
1
1
5.55
2
Hydrocephalus
3
2
5
27.78
10
1
1
5.55
2
3
18
100
36
Hydranencephaly i
Total
15/32
f:
% of total
CLINICALBRIEFS : LL:rrHALCONGENITALMALFORMATIONS T~
4. Distribution of Congenital Malformations in Necropsy Cases
Anomaly
1. 2.
3. 4.
5. 6. 7. 8. 9.
583
Multisystemmalformation Down's syndrome Trisomy 13-15 Trisomy 18 Hydranencephaly CNS malformation (cystic malformation of cerebellum with hypoplasia) Acephalus acardia Diaphragmatic hernia Exomphalos CVS malformation (TGA, AV canal defect) Epidermolysisbullosa Total
Still birth
Early Neonatal Death
Total No.
%
1
5 1 1
6
33.33
3
3
1
1
5.55
1 1 1 1
5.55 5.55 5.55 5.55
1 1
1 1
5.55 5.55
15
18
,100%
1 1
3
1 t
1
9
'
27.77
i
TGA-Transposition of Great Arteries, AV canal-Atrio-Ventricular Canal. Chromosomal analysis were done in 12 cases, including all the multisystem malformations. DISCUSSION The present study has shown that among 13964 births at S.A.T. Hospital, Trivandrum during a period of one year, the incidence of lethal congenital malformation was 3.6/1000 births and 8.38% of perinatal deaths. The 50 lethal congenital malformations constituted 9.38% of still births and 7.03% of early neonatal deaths. The incidence of lethal congenital malformatious vary widely in literature from 0.3% to 7.4%. In the Avon studyt where
36180 blrt~ were prospectlvely ~tudied during 1976-1979, the incidence of lethal
malformation was 5 per 1000 births but accounted for 34.1% of perinatal deaths. In a similar study from Vellore 2 the incidence of lethal malformation was 6 per 1000, accounting for 15% of perinatal deaths-13% of still births and 18% of early neonatal deaths. This fmding may be predictive that consequent to improved standard of perinatal care, lethal congenital malformations will increasingly emerge as a major cause of perinatal deaths in developing countries also. Regarding the pattern of lethal congenital malformation& the Central Nervous
system malformation (36%) was slightly more than the multisystem malformation (34%), In the Vellore itudy~ Central Nervot~ System (C3~I$) malformation formed
584
THE INDIAN JOURNAL OF PEDIATRICS
40% and Multisystem (MS) 30%. Predilection for CNS malformation was noted by Chopra et aP also. Central Nervous System malformation dominated in still births (46.9%), where the CNS : MS ratio was 5 : 4 while in early neonatal deaths, multisystem and chromosomal anomalies together accounted for 55.53%, the MS : CNS ratio being 3 : 1. Similar findings have been reported by other workers also.z'*7 Autopsy studies are helpful in bringing to light occult congenital malformations,s In developed countries, though the perinatal mortality has fallen to less than 10/1000 births, the contribution of lethal malformation to perinatal mortality has almost doubled over the past 10 years despite improvements in obstetric and paediatric services and advances in perinatal diagnosis? This is to be expected as with improved obstetric and neonatal care, other causes of perinatal deaths which are to a large extent preventable like birth asphyxia, birth trauma and infection will naturally decrease in number so that lethal congenital malformations which are unavoidable, will make up a greater proportion of perinatal deaths. ACKNOWLEDGEMENT
Authors are grateful the Superintendent, S.A.T. Hospital for pert0 Ision to conduct the StUdy.
Vol. 57, No. 4 REFERENCES
1. Mutch LMM, Brown NJ, Speidel BD, Dun PM. Perinatal mortality and neonatal survival in Avon, 1976-1979. Br Med Y 1981; 282 : 119-122. 2. Jadhav M, Lelama CG. Perinatal mortality in Vellore part II : Lethal malformations. Indian l Pediatr 1986; 53 : 353-357. 3. Chopra J, Rao M. Role of congenital anomalies in perinatal mortality. Y Obstet Gynaecol India 1982; 32 : 27-29. 4. Athavale VB, Wagle CS, Kandoth WK, Radha RA. Autopsy studies in 1050 cases in relation to age and duration of illness. Indian Pediatr 1969; 6 : 398-415. 5. Tibrewala NS, Bhat S, Pal PM. Autopsies in newborn study of 356 cases. Indian Pediaw 1975; 12 : 365-369. 6. Young ID, Clarke M. Lethal malformations and perinatal mortality. A 10 year review with comparison of ethnic differences, BrMed J 1987; 295 : 89-91. 7. Maheswari HB, Teja K, Rani S. Causes of late fetal and neonatal deaths. Indian Pediatr 1971 : 417-420. 8. Bhakoo ON, Narang A, Kulkami KN et al. Neonatal mortality and morbidity in hospital born babies. Indian Pediatr 1975; 12 : 443-450. 9. Misra PK, Bajpai PC, Tripathi TK et al. Perinatal mortality-a hospital study. Indian Pediatr 1973; 10 : 545-550. 10. Srivastava JR, Saluja KK, Bai S, Samuel KC. Studies on perinatal mortality in Medical College Hospitals, Kanpur. Indian Pediatr 1969; 6 : 374-382.
