Descriptive profile of birth defects among livebirths in Singapore

Asian Oral-Facial Cleft Birth Prevalence

Objective:

To determine the clefting birth prevalence among Asian populations, specifically Chinese and Japanese, using raw counts from nonoverlapping published studies of Asian populations, and to investigate whether Asian clefting rates have been interpreted accurately as being up to twice the Caucasian rate.

Design:

A literature review of articles giving raw counts of clefting in Asian populations, primarily Japanese and Chinese.

Main Outcome Measures:

Where possible, clefts were identified by the patients’ ethnicity, country of origin, cleft type, syndromic status, and birth status.

Results:

Prevalence rates of cleft lip with or without cleft palate per 1000 live births are reported. Syndromic plus nonsyndromic cleft lip with or without cleft palate: Chinese, 1.30; Japanese, 1.34; Other Asian, 1.47; and total, 1.33. Nonsyndromic cleft lip with or without cleft palate: Chinese, 1.20; Japanese, 1.18; Other Asian, 1.22; and total, 1.19.

Conclusions:

Overall, Chinese and Japanese live birth prevalence rates for nonsyndromic cleft lip with or without cleft palate, based on the published reports of birth prevalence, are significantly lower than the oft-quoted rate of 2 per 1000 for Asians. The apparent reason for the discrepancy is that many published prevalence rates included all pregnancies (live births plus pregnancy losses) and do not distinguish between syndromic and nonsyndromic clefts or between cleft palate alone and cleft lip with or without cleft palate. These results demonstrate that it is extremely important for current population-based studies of clefts to include careful delineation of population groups, syndromes, cleft type, and birth status.

Dental maturation of unilateral cleft lip and palate

Cleft lip and palate (CLP) is the most common craniofacial abnormality and the fourth most common birth defect in Singapore. Many reports suggest that CLP children have delayed dental development and asymmetrical timing of tooth-pair formation. The aim of this study was to investigate the timing of development of permanent teeth in unilateral CLP (UCLP) children and to compare the findings with non-CLP children in Singapore. A total of 60 UCLP children aged between 5 and 9 years (mean 6.64 ± 0.90 years) and a non-CLP control group matched for age, gender, and race were investigated and compared. Dental records and radiographs were studied and the dental maturation was determined using the Demirjian's method (1973). The dental maturation of UCLP children were delayed compared with non-CLP children by a mean of 0.55 ± 0.75 years and the delay was statistically significant (P < 0.001). The UCLP group also had significantly higher risk of asymmetrically developing tooth pairs than the control group (P < 0.001). The most commonly delayed tooth in development was the maxillary cleft-sided lateral incisor. In conclusion, the UCLP children in Singapore demonstrated delayed dental maturation and a higher occurrence of asymmetrical tooth-pair formation than the non-CLP children.

Congenital anomalies in Iran: a cross-sectional study on 1574 cases in the North-West of country

BACKGROUND

At least one congenital anomaly is present in between 1% and 6% of all infants throughout the world. The aim of this study was to document some epidemiological features of congenital anomalies in the North-West of Iran.

METHODS

The study cases (n = 1574) comprised all births registered/notified to three university-hospitals of Tabriz University of Medical Sciences, Iran, from 2000 to 2004.

RESULTS

Total prevalence of congenital anomalies was 165.5 per 10 000 births [95% confidence interval (CI): 157-174]. Genito-urinary tract and kidney defects, anomalies of nervous system and limb anomalies accounted proportionally for more than 65% of anomalies in the region. The total prevalence of congenital anomalies in the study area increased from 104.6 per 10 000 births in 2000 (95% CI: 90-119) to 170.1 per 10 000 births in 2004 (95% CI: 152-189).

CONCLUSIONS

It is concluded that the data from this cross-sectional study of congenital anomalies in the North-West of Iran may be used as the baseline information to establish a population-based registry of birth defects in the area for health care and research purposes.