Risk factors for birth defects in Singapore: a case control study.

To explore possible risk factors for birth defects, a matched case-control study was carried out at Kandang Kerbau Hospital in Singapore from January 1986 to December 1988. Cases and controls were selected from livebirths born in that hospital during that period. Cases were babies who were clinically detected as having defects at birth and the diagnosis reconfirmed at 6 weeks post partum. Each case was matched to a control by maternal age, ethnic background of mother, the same class of maternity ward and time of delivery. Five hundred and seventy-two matched pairs were accrued for the study. The parents of both cases and controls were interviewed at 6 weeks post partum. Information on the medical and birth history of both mother and baby was obtained from medical records. Using conditional logistic regression analysis to adjust for potential confounders, the strongest risk factors for birth defects were family history of birth defects (OR 3.3; 95% CI 1.8-6.4) and parents having a previous abnormal baby (OR 2.4; 95% CI 1.1-5.3). Other notable risk factors included drug history during pregnancy (OR 1.2; 95% CI 0.8-2.0), the ingestion of traditional medicine during pregnancy (OR 1.4; 95% CI 1.0-2.0), injuries or accidents during pregnancy (OR 2.2; 95% CI 1.5-3.2) and maternal diabetes mellitus (OR 1.3, 95% CI 0.3-7.1). Mothers in professional occupations (OR 1.4, 95% CI 0.7-2.6) and those in production occupation (OR 1.2, 95% CI 0.9-1.7) had an increased risk for birth defects compared to housewives.(ABSTRACT TRUNCATED AT 250 WORDS)

Descriptive profile of birth defects among livebirths in Singapore.

A case-control study of birth defects was carried out in Kandang Kerbau Hospital in Singapore for a three-year period from January 1986 until December 1988. This paper presents the descriptive profile of birth defects among livebirths seen in that hospital. Out of 44,842 livebirths, 678 babies were found to have birth defects, giving a prevalence of 15.13 per 1000 livebirths (95% CI 14.0-16.2). The musculoskeletal system was the most frequently affected system accounting for 161 cases with a prevalence of 3.59 per 1,000 livebirths (95% CI 3.06-4.19), followed by 111 cases with defects of the gastrointestinal system (2.47 per 1,000 livebirths 95% CI 2.04-2.98), 88 cases of chromosomal disorders (prevalence of 1.96 per 1,000 livebirths 95% CI 1.57-2.42), 78 cases with defects of the cardiovascular system (1.74 per 1,000 livebirths 95% CI 1.38-2.17), 73 cases with defects of the urogenital system (1.63 per 1,000 livebirths 95% CI 1.28-2.05), and 52 cases with defects of the central nervous system (1.16 per 1,000 livebirths 95% CI 0.87-1.52). The prevalence of cleft lip, cleft palate in isolation, and cleft lip and palate combined was 1.72 per 1,000 livebirths and the occurrence of Down's syndrome was 1 in 700 livebirths. When reviewed 6 weeks postpartum, the rate of false positives at birth was 4%. In a control group of 709 "normal" cases at birth, the rate of cases not detected at birth but detected at 6 week follow-up, false negatives was 0.84%.

PIP: A case-control study of birth defects was carried out in Kerdang Kerbau Hospital in Singapore over a 3-year period from January 1986 to December 1988. This paper presents the descriptive profile of birth defects among live births seen in that hospital. Of 44,842 live births, 678 babies were found to have birth defects, which gives a prevalence of 15.13/1000 live births (95% CI 14.0-16.2). The musculoskeletal system was the most frequently affected system, accounting for 161 cases with a prevalence of 3.59/1000 live births (95% CI 3.06-4.19), followed by 111 cases with gastrointestinal system defects (2.47/1000 live births, 95% CI 2.04-2.98), 88 cases of chromosomal disorders 1.96/1000 live births, 96% CI 1.57-2.42), 78 cases with cardiovascular system defects (1.74/1000 live births, 95% CI 1.38-2.17), 73 cases with urogenital system defects (1.63/1000 live births, 95% CI 1.28-2.05), and 52 cases with central nervous system defects (1.16/1000 live births, 95% CI 0.87-1.52). The prevalence of cleft lip, cleft palate in isolation, and cleft lip an palate combined was 1.72/1000 live births and the occurrence of Down's syndrome was 1 in 700 live births. When reviewed 6 weeks postpartum, the rate of false positives at birth was 4%. Among a control group of 709 normal cases at birth, the rate of cases not detected at birth but at the 6-week followup showed a rate of 0.84% false negatives.

Concentrations of lead in maternal blood, cord blood, and breast milk.

Lead concentrations in maternal blood, umbilical cord blood, and breast milk from 114 women who were not occupationally exposed to lead were determined by graphite atomic absorption spectrophotometry. The mean concentrations of lead in maternal blood, umbilical cord blood and breast milk were 0.7, 0.55, and 0.23 mumol/l, respectively. A significant correlation was observed between maternal and umbilical cord blood (r = 0.63). A lower correlation was noted between maternal blood and breast milk (r = 0.29). These results suggest that lead freely crosses the placental barrier from mother to fetus and the transfer of this heavy metal from maternal tissues to breast milk is possible, but the metabolic mechanisms are more complicated. In addition, a longitudinal study was conducted of concentrations of lead in breast milk in nine lactating women. Results suggested no significant change in the content of lead in breast milk during early lactation.

Histopathology of nasopharyngeal carcinoma: correlations with epidemiology, survival rates and other biological characteristics.

A total of 363 cases of nasopharyngeal carcinoma (NPC) in Singapore were classified into squamous cell carcinoma (SCC; 73 cases), non-keratinizing carcinoma (NKC; 178 cases) and undifferentiated carcinoma (UC; 172 cases). Possible biological differences between these histologic types and between tumors with and without lymphocytic infiltration were investigated by correlations with survival rates and with selected epidemiologic, immunovirologic, and immunogenetic data on the disease. The 5-year survival rates following radiotherapy were 25.3% for all cases and 58.8% for tumors restricted to the nasopharynx. The 5-year survival rate for SCC was poorer than for the combined NKC and UC groups (p less than 0.05). The 3-year survival rate was better for tumors with lymphocytic infiltration (p less than 0.05), but there were no differences in the 5-year survivals. The survival rates were better in females (p less than 0.01) and in the younger age groups (p less than 0.01). There were no significant correlations between histopathology of NPC and the distributions of cases by age, sex, HLA antigen profiles, or cell-mediated immune status. Squamous cell carcinoma was associated with lower levels of antibodies to the Epstein-Barr nuclear antigen (p less than 0.05), but there were no differences with respect to antibodies against other EBV related antigens. These findings support the view that SCC, NKC, and UC of the nasopharynx, as defined in the WHO classification, are variants of a fairly homogeneous group of neoplasms in the Singapore population.

Effects of etomidate given in repeated doses.

Fifty fit, female patients were given four consecutive intravenous doses of etomidate 10 mg, so as to maintain sleep, after establishment of epidural block for postpartum sterilization. A matched group was given four doses of thiopentone 125 mg. Cumulative hypnotic effect, as judged by increasing sleep duration with second and subsequent doses, was much less with etomidate than with thiopentone. Etomidate did not depress blood pressure, whereas it fell progressively with successive doses of thiopentone. Injection pain was reported in 68% of patients receiving etomidate, and this tended to increase with successive doses; 12% also showed local inflammation at the injection site. Tremor, due to etomidate, was common, but did not increase with successive doses. Feelings of sleepiness, lasting several hours after waking, were more common after thiopentone than after etomidate.

Etiological factors in nasopharyngeal carcinoma: a hospital-based, retrospective, case-control, questionnaire study.

A total of 379 Singapore Chinese patients with NPC were interviewed by use of a questionnaire covering the following items: occupation, level of education, language medium of education, personal and family history of nasal illnesses, types of medicines used, use of Chinese medicines for the nose and throat, use of soya sauce, Chinese tea, cooling drinks and alcohol, cigarette smoking (number and duration), cooking fuels and use of incense (frequency and duration) and of anti-mosquito coils. The same questionnaire was given to two groups of controls: 595 patients with diseases of the ear, nose and throat other than NPC and 1 044 patients with diseases other than cancer or otorhinolaryngeal disease. NPC patients differed significantly from both groups of controls in that they showed stronger associations with personal history of nasal illnesses, family history of nasal illnesses, use of Chinese medicines for the nose and throat and exposure to smoke from anti-mosquito coils.

Serum gastrin in patients with various types of chronic gastritis.

Fasting serum gastrin was determined in 35 Chinese patients with various types of chronic gastritis and in 23 Chinese control subjects. The mean (+/- S.D.) fasting serum gastrin levels for 13 patients with chronic atrophic gastritis, 16 patients with chronic gastritis and six patients with acute-on-chronic gastritis were 32.1 (+/- 38.9) pg./ml., 36.1 (+/- 23.2) pg./ml. and 33.7 (+/- 19.4) pg./ml., respectively. The mean (+/- S.D.) fasting serum gastrin levels for the whole gastritis group (35 patients) and the control group were 34.2 (+/- 28.8) pg./ml. and 24.6 (+/- 13.7) pg./ml., respectively. Statistical analysis showed that the mean basal serum gastrin levels of the three gastritis groups did not differ significantly from control subjects and with each other.

Detection of nasopharyngeal carcinoma from measurements made on the lateral neck radiograph.

Tables of normal values are available for the measurement of four sagittal diameters (Roof, FM, C1 and C2) and areas of the soft tissue of the nasopharynx as seen in the lateral neck radiograph. The lateral neck radiographs of 100 nasopharyngeal carcinoma (NPC) cases as well as 100 normal controls of corresponding sex and age distribution are measured to ascertain the usefulness of the above measurement in the detection of NPC. Depending on the method of calculation, figures for positive results (sensitivity) may rise to as high as 85% but the specificity (i.e. probability of a correct diagnosis in a person without NPC) is at the same time lowered to 92%. The detection of NPC from any lateral neck radiograph, however, presents a different problem compared to the situation when a person clinically suspected of having NPC is referred for radiography. Many factors are involved in the former situation and it is to this situation that the predictive value (PV) of the scores has to be employed.

Clinical evaluation of etidocaine in continuous caudal analgesia for pelvic floor repair and post-operative pain relief.

A randomized double-blind trial compared 1-0% etidocaine and 1-5% lignocaine (both with 1/200,000 adrenaline), for caudal anaesthesia for pelvic floor repair. Etidocaine was highly effective for the surgical procedure, with rapid onset of action, adequate muscle relaxation and longer duration of action. Its use for post-operative analgesia may be hindered by the concomitant immobilization of the legs. The problem of tachyphylaxis with etidocaine needs further investigation.

A preliminary study of the health of a populaltion staying in apartments of varying sizes in Singapore.

A study was made of the health of 438 households living in high-rise flats in three public housing estates in Singapore. These households were selected by serial sampling from a total sample of 594 households; 156 (26%) were non-respondents. The study used personal interviews to collect data. Respondents questioned directly indicated a low but positive effect of high-rise living conditions on their physical health. The perceived health status of most of these flat dwellers remained unchanged after moving into their present accomodation. The major findings with regard to mental health were: (a) worry and anxiety were associated with the socio-economic status of the respondents; (b) the recreational activities of the respondents were related to their socio-economic status, although the majority spent most of their spare time at home; (c) living conditions in flats tended to affect the patterns of social contacts of the residents with their extended families and primary groups. Three factors (income, education and ethnic group) affected the social behaviour of the respondents with regard to health: (a) the preference for, and selection of, the first source of medical treatment varied for the different soci-economic and ethnic groups; (b) self-medication was associated with ethnic group; (c) the level of education affected the decision on when to receive antenatal care.

Serum gestrin in Chinese patients with peptic ulcer.

Fasting serum gastrin was determined in 30 Chinese patients with duodenal ulcer, 43 Chinese patients with gastric ulcer, 23 Chinese control subjects, 14 European control subjects and ten Indian control subjects. Basal and pentagastrin-stimulated peak acid outputs were also determined in the Chinses patients with duodenal or gastric ulceration. The mean (+/- SD) basal serum gastric level for Chinese controls and Chinese patients with duodenal and gastric ulcer were 24-6 pg/ml (+/- 13.7 pg/ml), 18-5 pg/ml (+/- 8-9 pg/ml), and 33-9 pg/ml (+/- 27-7 pg/ml), respectively. Statistical analysis showed no significant difference between the Chinese control subjects and the Chinese patients with duodenal or gastric ulcer, but the mean fasting serum gastrin level of Chinese gastric ulcer patients was significantly higher than that of Chinese duodenal ulcer patients. Comparison of the mean fasting serum gastrin level of the Chinese, European, and Indian control subjects showed no significant difference. Statistical analysis also showed no significant correlation between fasting serum gastrin level and both basal and peak acid outputs, in Chinese patients with duodenal or gastric ulcer.

Pentagastrin-stimulated gastric acid secretion in acute and chronic gastritis. Histological and secretory correlations.

Basal and pentagastrin-stimulated gastric acid secretion were determined in 122 patients with various types of gastritis and in 20 control subjects. All the gastritis patients and the control subjects were adult Chinese. The histological diagnosis was based on gastric biopsy specimens obtained through a fibergastroscope. Statistical analysis of the results in the various histological groups of gastritis and controls indicated that chronic superficial gastritis and chronic atrophic gastritis are not associated with reduced gastric acid secretion in Chinese subjects. In addition, analysis of combinations of the groups of patients with various types of gastritis showed no significant difference in the mean basal acid output but the mean peak acid output of patients with chronic gastritis was significantly higher than that of patients with chronic atrophic gastritis.

The prevalence of chronic gastritis in patients with gastric ulcer.

Multiple gastric biopsies were performed with a duodenofiberscope in 58 Chinese subjects. All 58 cases had a gastric ulcer crater, demonstrated by endoscopy, or barium meal, or both. Histological sections of the gastric biopsies showed chronic atrophic gastritis in 12 (20.6%), chronic gastritis in 31 (53.4%), and acute-on-chronic gastritis in 11 (19%). Only two cases or 3.4% had normal gastric mucosa, while 54 cases or 93% had some form of chronic gastritis, on the gastric biopsy. The gastritis was associated with intestinal metaplasia in 16 cases (27.6%), while two cases had histological evidence of gastric atypia. No significant difference was found in the mean basal and peak acid outputs among the three groups of gastric ulcer cases with chronic atrophic gastritis, chronic gastritis, and acute-on-chronic gastritis. The high frequency of chronic gastritis (93%) occurring in patients with gastric ulcer in the present series suggests that chronic gastritis may be an important aetiological factor in the pathogenesis of gastric ulceration.