Among 246 stillborn babies, five cases were excluded as the body structures were not identifiable due to extreme prematurity and maceration. Therefore, for data analyzing purposes 241 cases were included.
The number of stillbirths with obvious structural congenital anomalies either malformations, deformations, or chromosomal abnormalities were detected among 36 (14.9%) fetuses out of 241 of the whole stillbirth sample. Of them, 34 (14.1%) fetuses were recognized with observable structural congenital malformations and deformations while chromosomal abnormalities were found in 2 (0.8%) stillbirths. Female, male and unidentified fetal sex stillbirths frequencies were 23 (9.5%), 12 (5.0%) and 1 (0.4%) respectively. The mean POG of all stillbirths with congenital malformations and chromosomal abnormalities was 217 days (31 weeks) and SD ± 36.975. For stillbirths that did not show congenital anomalies, mean POG was 228.19 and SD ± 39.156.
One sample t test was done to see whether there is a significance difference between the mean POGs of stillbirths with and without congenital anomalies. Mean difference was − 10.246 and Significance (2-tailed) was 0.105. The 95% CI of the difference ranged between − 22.76 and 2.26. Thus the values revealed that there is no statistically significance between those two means of POGs.
Further, box and whisker plot illustrated the comparison between the distribution of POGs among male and female stillbirths with congenital anomalies.
According to the Fig. 1, POG was distributed within a vast difference of days among female babies with congenital anomalies than male stillborn infants, and the mean POG of them was higher than of males and the whole stillborn babies with congenital anomalies. The mean POG for male stillbirths with congenital anomalies was 213.42 (± 36.736) days and for females it was 223.09 (± 35.715).
The presence of congenital anomalies according to the fetal sex was calculated. The results are presented in the table I.
Table 1
Presence of congenital anomalies according to the fetal sex
Sex of the stillborn baby
|
Congenital anomalies
|
Total
|
Present
|
Absent
|
Female
|
23 (18.0%)
|
105 (82.0%)
|
128 (100.0%)
|
Male
|
12 (10.7%)
|
100 (89.3%)
|
112 (100.0%)
|
Total
|
35 (14.6%)
|
205 (85.4%)
|
240 (100.0%)
|
Female stillborn babies suffered from congenital anomalies than males (Table I).
Risk estimate was calculated between the presence or absence of congenital anomalies and the fetal sex being male or female (Table II).
Table 2
Risk estimate for fetal sex and presence of congenital anomalies
|
Value
|
Odds Ratio for fetal sex (Female / Male)
|
1.825
|
For cohort congenital anomaly = Present
|
1.682
|
For cohort congenital anomaly = Absent
|
0.918
|
N of Valid Cases
|
240
|
The odds of having of congenital anomalies 1.825 times greater for female stillbirths compared to male stillborn babies (Table II). Relative risk for outcome as congenital anomalies present among stillbirths is 1.682 while relative risk for outcome as absent congenital anomalies was 0.918.
Stillborn fetuses with congenital malformations, deformations, and chromosomal abnormalities were categorized according to their POG at death (Table III).
Table 3
Frequency of stillbirths with congenital anomalies in relation to POG at death and fetal sex
POG (weeks)
|
Sex of the fetus
|
Total number of stillbirths (%)
|
Male –n (%)
|
Female–n (%)
|
Unidentified – n (%)
|
Preterm
|
< 28
|
6 (2.4)
|
5 (2.0)
|
-
|
11 (4.5)
|
28 to < 32
|
3 (1.2)
|
6 (2.4)
|
-
|
9 (3.7)
|
32 to < 37
|
1 (0.4)
|
8 (3.3)
|
1 (0.4)
|
10 (4.1)
|
Term
|
≥ 37
|
2 (0.8)
|
4 (1.6)
|
-
|
6 (2.4)
|
Total
|
12 (4.9)
|
23 (9.4)
|
-
|
36 (14.6)
|
The least number was reported from gestational age is 37 weeks or greater where the stillborn fetuses reached the term pregnancy (Table III). The highest proportion of the stillbirths fell into the preterm category (N = 30, 12.1%).
To describe this distribution further, OR was calculated between the POG (preterm and term) and the presence of congenital anomalies (present or absent) (Table IV).
Table 4
Risk Estimate between the presence of congenital anomalies and the POG
Presence of congenital anomalies
|
POG (weeks)
|
OR
|
95% CI
|
< 37 (Preterm)
|
≥ 37 (Term)
|
Lower
|
Upper
|
Present
|
30 (18.1%)
|
6 (8.0%)
|
2.537
|
1.008
|
6.386
|
Absent
|
136 (81.9%)
|
69 (92.0%)
|
The risk to be preterm stillbirth for the fetuses with visible structural congenital anomalies was 2.537 times greater than the stillbirths which did not have obvious structural congenital anomalies (Table IV).
The recorded visible structural congenital anomalies were classified according to the blocks of ICD 10 (Q00-Q99). The blocks found in the study were congenital malformations of the nervous system (Q00-Q07); eye, ear, face, and neck (Q10-Q18); the circulatory system (Q20-Q28); cleft lip and cleft palate (Q35-Q37); other congenital malformations of the digestive system (Q38-Q45); congenital malformations of the genital organs (Q50-Q56); congenital malformations and deformations of the musculoskeletal system (Q65-Q79); other congenital malformations (Q80-Q89); and chromosomal abnormalities, not elsewhere classified (Q90-Q99).
The various congenital anomalies that belonged to the above blocks of ICD 10and their frequencies, were presented in Table V.
Table 5
Frequencies of reported visible structural congenital anomalies and their distribution according to the ICD 10 blocks and the sex of the fetus
Block (N, %)
|
Congenital malformation, deformation, and chromosomal abnormality
|
ICD
Code (Q)
|
Number (%)
|
Total Number (%)
|
Male
|
Female
|
The nervous system (n = 19, 7.7%)
|
Anencephaly
|
00.0
|
1
|
8
|
9 (3.7)
|
Craniorachischisis
|
00.1
|
-
|
1
|
1 (0.4)
|
Occipital encephalocele
|
01.2
|
-
|
1
|
1 (0.4)
|
Congenital hydrocephalus
|
03.8
|
-
|
2
|
2 (0.8)
|
Spina bifida
|
05
|
-
|
6
|
6 (2.4)
|
Eye, ear, face and neck (n = 2, 0.8%)
|
Anophthalmos
|
11.0
|
1
|
-
|
1 (0.4)
|
Macrophthalmos
|
11.3
|
1
|
-
|
1 (0.4)
|
The circulatory system (n = 1, 0.4%)
|
Ectopia cordis
|
24.8
|
-
|
1
|
1 (0.4)
|
Cleft lip and cleft palate (n = 4, 1.6%)
|
Cleft soft palate
|
35.3
|
1
|
-
|
1 (0.4)
|
Cleft lip, bilateral
|
36.0
|
-
|
1
|
1 (0.4)
|
Cleft lip, unilateral
|
36.9
|
1
|
-
|
1 (0.4)
|
Cleft hard palate with
unilateral cleft lip
|
37.1
|
1
|
-
|
1 0.4)
|
Other congenital malformations of the digestive system (n = 1, 0.4%)
|
Unspecified malformation of the anus (relatively large anal diameter)
|
45.9
|
1
|
-
|
1 (0.4)
|
Genital organs (n = 5, 2.0%)
|
Hypoplasia of penis
|
55.6
|
2
|
-
|
2 (0.8)
|
Malformations of vulva
|
52.7
|
-
|
1
|
1 (0.4)
|
Undescended testicle, bilateral
|
53.2
|
1
|
-
|
1 (0.4)
|
Indeterminate sex, unspecified
|
56.4
|
1
|
-
|
1 (0.4)
|
Congenital malformations and deformations of the musculoskeletal system (n = 26, 10.6%)
|
Facial asymmetry
|
67.0
|
2
|
-
|
2 (0.8)
|
Congenital Clubhand
|
71.4
|
-
|
1
|
1 (0.4)
|
Phocomilia, upper limb
|
73.1
|
-
|
1
|
1 (0.4)
|
Congenital shortening of upper limbs
|
71.4
|
-
|
3
|
3 (1.2)
|
Congenital scoliosis
|
67.5
|
-
|
2
|
2 (0.8)
|
Congenital malformation of the bony thorax (very narrow rib cage)
|
76.8
|
1
|
-
|
1 (0.4)
|
Omphalocele
|
79.2
|
1
|
3
|
4 (1.6)
|
Congenital shortening of lower limbs
|
72.8
|
-
|
3
|
3 (1.2)
|
Congenital talipes equinovarus (CTEV)
|
66.8
|
2
|
4
|
6 (2.4)
|
Achondroplasia
|
77.4
|
1
|
1
|
2 (0.8)
|
Treacher-Collins syndrome
|
75.4
|
-
|
1
|
1 (0.4)
|
Other congenital malformations (n = 1, 0.4%)
|
Micrognathia
|
87.0
|
-
|
1
|
1 (0.4)
|
Chromosomal abnormalities, not elsewhere classified (n = 3, 1.2%)
|
Down syndrome
|
90
|
2
|
1
|
3 (1.2)
|
The most frequently affected body system was the musculoskeletal system (n = 26, 10.6%) (Table V). However, the most frequent type of anomaly was anencephaly which represented 3.7% of the stillbirth sample followed by spina bifida and CTEV (each n = 6, 2.4%). The only chromosomal abnormality that displayed identifiable structural anomalies was Down syndrome (n = 3, 1.2%). Majority of the congenital malformations and deformations affected female stillbirths. Three types of chromosomal abnormalities were observed (Achondroplasia, Down, and Treacher-Collin syndromes).