Craniofacial anomalies amongst births at two hospitals in Nairobi, Kenya


The pattern of congenital oral and craniofacial anomalies (CFAs) in the Kenyan population remains unknown. The objective of this study was to describe the pattern of occurrence of CFAs at two hospitals in Nairobi. A descriptive cross-sectional study at the Kenyatta National Hospital and Pumwani Maternity Hospital was carried out from November 2006 to March 2007. Mothers who delivered at the hospitals consented to an interview and physical examination of their babies within 48 h of delivery. The anomalies were classified for type and magnitude. Data were analysed to determine the association of these anomalies with ages of the mothers, gender, weight, birth order, mode of delivery and birth status of the babies. During the study period, 7989 babies were born. The CFAs manifested in 1.8% of the total births and were more common in female (1.4%) than in male (1.0%) live births. 12.8% of stillbirths had CFAs, with lesions manifesting more in males (16.7%) than in females (6.9%). The commonest CFA was preauricular sinus (4.3/1000) followed by hydrocephalus (1.9/1000) then preauricular tags and cleft lip and palate (1.5/1000 and 1.3/1000 total births, respectively).

Congenital craniofacial anomalies (CFAs) are rare. Cleft lip and or palate are the most common, occurring in 0.06–2.13/1000 live births. The highest incidence of cleft lip and palate has been reported in the Indian tribe of Montana (1:276), followed by oriental groups (1:500); the least affected are the negroid population (1:2000). Single minor anomalies occur in 14% of newborns whilst major congenital malformations are found in 2% of live births and 22% of stillbirths. The maternal age most involved in anomalies is 20–35 years and the pregnancies affected are mostly breech presentations and often the first born. A higher frequency of major anomalies occurs in multiple births than in single births and males have more malformations than females.

Major congenital anomalies are amongst the leading causes of neonatal mortality, they contribute substantially to chronic disease morbidity, profoundly affect families and their management is expensive and long term. Minor anomalies may be unwanted, cosmetically disfiguring and may be a sign of internal anomalies; hence the need to know their pattern of occurrence in any population. Classification of CFAs is usually based on new theories but it always remains controversial. Anatomical classification includes oral, nasal, aural, orbital, cranial and other organ/structural anomalies. A review of the published literature ( Table 1 ) reveals a paucity of information on the pattern of occurrence of CFAs in most African populations including those in Kenya. The purpose of the present study was to document the pattern of occurrence of CFAs in two hospitals in Nairobi over a 4.5 month period.

Table 1
An overview of studies that show incidence of CFAs.
Author and year Anatomical classification of the anomalies Specific anomalies
Al-Omari et al. (2004), Cawson (1991), Dilley et al. (1991), Day (1984), Fasana (1980), Jain and Krogan (1983), Gorlin et al. (2000), Hunter and Roberts (1988), Iregbulem (1982), Kalter and Warkany (1983), Khan and Ivanov (1977), Moore and Persand (2003), Murray et al. (1997), O’Doherty (1975), Persaud (1979), Russell et al. (2004), Scheinfeld et al. (2004), Screan and Connor (1996), Stricker et al. (1990), Tomizawa et al. (1999), Wilson and Clarke (1977), Yadav (2001) Oral anomalies Clefts, micrognathia, aglosia, agnathia, leukoedema, mucocoeles, cysts, pits/fistulae, epulides, lymphangioma, notch, natal/neonatal teeth, aglosia, ankyloglosia, macroglosia
Chung and Myrianthopoulos (1975), Moore and Persand (2003), Fasana (1980), Kalter and Warkany (1983), Stricker et al. (1990) Ocular anomalies Cyclopia, ethmocephaly, synophthalmia, microphthalmia, anophthalmia, cryptophthalmia microblepharon, microorbitism, euryblepharon, coloboma, blue sclera
Fasana (1980), Gorlin et al. (2001), Kohelet and Arbel (2002) Nasal anomalies Nasal aplasia with proboscis, choanal atresia, nasoschisis, nasal duplication
Durakbasa et al. (2004), Fasana (1980), Moore and Persand (2003), Scheinfeld et al. (2004), Stricker et al. (1990), Wang (2001) Aural anomalies Microtia, preauricular sinus, tags, fistulae, duplication of external auditory meatus, atresia, auricular hypoplasia
Day (1984), Kalter and Warkany (1983), Mcintosh et al. (1954), Scheinfeld et al. (2004) Cranial anomalies Acrania, microcephaly, macrocephaly, hydrocephalus, cranium bifidum
Chung and Myrianthopoulos (1975), Fasana (1980), Moore and Persand (2003), Scheinfeld et al. (2004) Cutaneous anomalies Congenital alopecia, random patches of white hair, absence of skin

Most of these anomalies appear only as case reports in the literature.

Material and methods

This survey was executed at the two largest government delivery centres in Nairobi, Kenya, after approval by the institutional review boards. The study population included all mothers who delivered and their babies. It was a descriptive cross-sectional study of incidence of clinically manifest CFAs at birth with the dependant variable being the presence of an anomaly. The demographic data documented included age of mother, birth status, mode of birth presentation, gender, birth weight, birth order and mode of delivery of each participating subject. The inclusion criteria entailed all births at 20 weeks or more of gestation and/or at least a 500 g birth weight. Only mothers with Kenyan citizenry were included in the study. Sample size was calculated using the Fisher et al. formula for population studies using the prevalence of single minor anomalies (14%) since these anomalies are the ones which have been widely reported on.

All women admitted for delivery were requested to agree to an interview and examination of their babies within 48 h of admission. An interview and examination form was used to document the demographic data and record findings from systematic examination of all births by midwives who had been trained by the principal investigator (PI) on how to complete the forms and how to perform a head to toe examination of the infants to elicit anomalies. The anomalies were classified by the structures involved, whether they were major or minor and whether single or multiple. Each centre was manned day and night. The PI visited the study sites daily and during each visit randomly picked the completed interview schedules at each centre and re-interviewed the mothers. The babies present were then re-examined. Informed consent was obtained from the mothers and confidentiality was ensured by use of in-patient numbers only.

Whenever a case was delivered, the PI was alerted by mobile phone. Any infant with an anomaly transferred to the newborn unit before examination was examined whilst any stillbirth transferred to the mortuary before examination was followed by the investigator for examination and photography where indicated. Each malformation was counted once, such that if an infant had both cleft lip and encephalocoele, it entered both classes for the tabulation of the number of infants with each anomaly born in the population. Parents with questions on malformations were counselled and educated by the investigators. Referrals for further management were made according to the rules of each hospital. Data analysis was done according to the statistical package for social sciences (SPSS) software version 12.0 and Epi Info packages.


During the study period there were 7989 new births: 4264 (53.4%) male, 3721 (46.6%) female and 4 (0.05%) with ambiguous external genitalia. 146 CFAs occurred in 1.8% of the total births. There were 7623 live births with CFAs in 1.3%. There were 366 (4.6%) stillbirths in the two hospitals, with 12.8% CFAs: 174 males, 188 females. Of these, 29 (16.7%) male and 13 (6.9%) female stillbirths had CFAs. Although there were more female stillbirths, the male babies had more anomalies than the females. The four babies with ambiguous external genitalia were all stillbirths and had major multiple CFAs ( Table 2 ). The youngest mother was a 12-year-old primigravida whilst the oldest was 47 years. The mean age of the mothers was 25.2 years (mode 24 years); the median age was 25 years. Most anomalies occurred during the peak reproductive age of 20–24 years, producing 88 (34.4%) of the total anomalies. Extremes of ages (<15 and >35 years) were not significantly associated with anomalies.

Table 2
Distribution of births by hospital, gender and birth status.
Centre Total births Gender Frequency of anomalies Live births Stillbirths
PMH 5579 M – 3002
F – 2575
AEG – 3
141( * 85) 5395( * 44) 184( * 41)
KNH 2410 M – 1262
F – 1145
AEG – 1
115( * 61) 2228( * 55) 182( * 6)
Total 7989 M – 4264
F – 3721
AEG – 4
256( * 146) 7623( * 99) 366( * 47)

* CFAs. M – males, F – females, AEG – ambiguous external genitalia. Outside the bracket in anomalies column is whole body anomalies.

The peak birth weight was 3.0–3.9 kg. Peak anomalies were noted in the 2.0–2.9 kg birth weight group. The smallest baby weighed 0.5 kg and the heaviest 5.4 kg. CFAs were common at birth weights above 2.5 kg (60.2%), whilst weight below 2.5 kg was significantly associated with whole body anomalies ( Tables 3 and 4 ). Figure 1 shows the proportion of anomalies according to birth weight to rule out the idea that there were more anomalies in a certain weight group because more babies belonged to that group.

Table 3
Tests of significance for birth weight, ages of mothers and birth order in association with anomalies.
Variable n per group Odds ratio 95% confidence p value
Normal Anomalous
Birth weight
<2.5 kg 1399 113
>2.5 kg 5931 134 3.58 2.74–4.66 * 0.000 ( p < 0.01)
Birth order
First borns 3195 139
Others 4423 106 1.82 1.40–2.37 * 0.000 ( p < 0.01)
Mothers’ age
<35 years 6661 208 1.07 0.59–1.90 0.05 (0.912)
>35 years 418 14

* Significantly associated with occurrence of anomalies. Not recorded (NR) values reduced the n per a class.

Table 4
Distribution of anomalies according to birth weight of babies.
Baby Centre Birth weight of babies (kg)
NR 0.1–0.9 1.0–1.9 2.0–2.9 3.0–3.9 4.0 and above Mean weight (±SD) Statistical tests
Normal KNH 204 71 196 663 1086 100 2.7 (±0.81) χ 2 = 207.09; 4df * p < 0.01 (0.000)
PMH 217 23 210 1586 3200 178 3.04 (±0.548)
Abnormal KNH-WB 8 0 31 41 30 4 2.53(±0.82) χ 2 = 25.09; 4df * p < 0.01 (0.000)
PMH-WB 0 18 17 58 36 12 2.52 (±0.98)
CFAs KNH + PMH 5 22 25 58 25 11
Total 429 112 454 2348 4352 294 7989

* p significant differences at α = 0.01. WB – whole body anomalies include CFAs. KNH, Kenyatta National Hospital; PMH, Pumwani Maternity Hospital.

Fig. 1
Proportions of anomalies according to birth weight ( n = 7989).

73.8% of the babies born with anomalies were between the first and the second birth order. There were no anomalies beyond sixth borns. To rule out the idea that the first borns seemed heavily laden with anomalies just because there were more first borns in this study, a proportionality test was done which showed that the sixth borns had the highest proportion of anomalies. Fisher exact test (Fisher exact test χ 2 = 0.27: 1df p > 0.05) was carried out to determine whether the first or sixth borns were the most predisposed to anomalies. It confirmed that first borns were significantly associated with anomalies ( Fig. 2 ).

Fig. 2
Proportions of anomalous babies by birth orders ( n = 7989).

The 146 CFAs were broadly classified into aural (65), orbital (15), cranial (35), oral (26) and isolated nasal anomalies (5). Aural anomalies ( Table 5 ) formed 44.5% of the CFAs and occurred at a rate of 8.1/1000 of the total births, of which the preauricular sinus was the most common minor anomaly. Microtia ( Fig. 3 A and B ) occurred in a spurt within 1 week, ranging from the most severe (type III) to the least severe (type I). It was common in males and the right ear was the most involved. The syndromic low-set ear was noticed in 2 infants who had Down’s syndrome (0.3/1000 births): this occurred in conjunction with posteriorly oriented ears, webbed neck and mongoloid slanting palpebral fissures. Imperforate external auditory meatus, preauricular cyst and atretic ears had the least incidence. Preauricular sinus was common on the right, was single in all instances except in one case whereby two sinuses occurred with one superior to the other, both along the preauricular crease above the tragus. It occurred 1.5 times more in females than in males. Preauricular tags showed a preponderance for the right side with no gender predilection and both the sinuses and tags were observed more in live births. Preauricular tags were mostly single and ranged from negligible skin elevations to large ones interfering with cosmesis. Some were the same colour as the surrounding skin whilst others were darker or lighter: they coexisted with normal and abnormal helices in equal proportions. In one instance, three preauricular tags of different colours and sizes were observed anterior to the auricle ( Fig. 3 D).

Table 5
Distribution of aural anomalies by type.
Aural anomalies Frequency % of anomaly % in total births Incidence/1000
Preauricular sinus 34 54.8 0.43 4.3
Preauricular tag 12 19.4 0.15 1.5
Microtia 6 9.7 0.08 0.8
Low-set ears 6 9.7 0.08 0.8
Imperforate Ex. auditory meatus 3 1.6 0.04 0.4
Atretic ears 2 1.6 0.03 0.3
Posteriorly oriented ears 1 1.6 0.01 0.1
Preauricular cyst 1 1.6 0.01 0.1
Total 65 100 0.81 8.1

Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Craniofacial anomalies amongst births at two hospitals in Nairobi, Kenya
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