Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

The impact of overseas labour migration on rural Thailand: regional, community and individual dimensions.

"This paper provides a case study of the impact at origin of recent labour migration from rural Thailand to East Asian destinations. It does so through survey information on 63 villages and detailed biographic interviews with recently returned workers. It is concluded that work abroad is regarded by migrants as a strategy of life support; it is sometimes life-enhancing, but only rarely life-changing."

The commodification of international migration: findings from Thailand.

"The organisation of international contract-labour migration within Asia has been increasingly dominated by commercial agencies acting as intermediaries between workers and foreign employers. The principles underpinning the gatekeeping role of such agencies in the East Asian migration system are examined. A consideration of the international labour recruitment system in Thailand is based on survey work among agents, community leaders and recently returned migrants."

Prostitution, condom use, and invasive squamous cell cervical cancer in Thailand.

Cervical cancer is probably caused by a sexually transmitted agent. A case-control study was conducted in three hospitals in Thailand to investigate further the role of male sexual behavior, particularly regarding sexual contacts with prostitutes, in the development of this disease. Data were obtained from interviews with 225 married women with invasive squamous cell cervical carcinoma and 791 hospitalized controls, all of whom reported having only one sexual partner, and from interviews with their husbands. Risk of cervical cancer was strongly related to the women's husbands having visited prostitutes without using a condom when the husbands were less than 30 years old. A strong increasing trend in risk in relation to decreasing frequency of the husbands' condom use with prostitutes was observed, and a weaker increasing trend in risk with husbands' estimated lifetime total number of visits to prostitutes was found. The average latent period between the women's likely initial exposure to a sexually transmitted oncogenic agent and her diagnosis of invasive cervical cancer was about a quarter of a century. Regular use of condoms by customers of prostitutes could reduce the number of invasive cervical cancer cases in the general population of Thailand by at least one fourth.

PIP: Researchers compared data on 225 Thai married women with invasive squamous cell cervical cancer admitted to Siriraj and Chulalongkorn hospitals in Bangkok and at Maharaj Nakorn Chiang Mai Hospital during October 1979-September 1998 with data on 791 hospitalized Thai controls to examine the role of male sexual behavior and prostitution in the development of cervical cancer and the likely protective effect of condom use against cervical cancer. All the cases and controls claimed to have had only one sexual partner. Interviews were conducted with the husbands of all the cases and controls. There was a significant trend of increasing risk of cervical cancer as the frequency of husband's condom use with prostitutes declined (p = 0.004) (relative risk [RR] = 2.05 for rarely or never, 1.24 for sometimes, and 0.96 for always or frequently). The increasing risk of cervical cancer associated with little or no condom use with prostitutes was highest when the husbands were less than 30 years old (RR = 2.11 vs. 1.56-1.81 for age 20 or older). There was a weaker trend of increasing risk of cervical cancer with the husband's estimated lifetime total number of visits to prostitutes (p = 0.12). On average, the latent period between the wife's likely first exposure to a sexually transmitted oncogenic agent (i.e., date of their marriage) and her diagnosis of invasive cervical cancer was 24 years. These findings indicate the condom use with prostitutes would reduce the risk of cervical cancer.

[[A critical period in the evolution of the population of Thailand]].

"The paper, based on population projections for Thailand...examines the growth and the structure of the Thai population between 1990 and 2115. The projections are prepared on the basis of the sex and age distribution of the 1990 population.... The study concludes that in order to maintain...economic and social prosperity, security and [prevent] the eradication of the Thai race, the government will have to raise fertility of the population at least up to the replacement level." (SUMMARY IN ENG)

The long-term growth and development of children exposed to Depo-Provera during pregnancy or lactation.

Children exposed to the injectable contraceptive Depo-Provera (DMPA) during pregnancy (N = 1,207), and/or during breastfeeding (N = 1,215) were exposures during pregnancy or breastfeeding. Weights and heights were measured for all children, and information on signs of puberty obtained for children aged ten and over. Cross-sectional weights and heights by age of DMPA-exposed children were similar to those for controls. Children with DMPA exposure during pregnancy and lactation had an increased risk of suboptimal growth in height, defined as less than two Z scores on NCHS standards (RR = 1.4, 95% CI 1.2-1.8). However, after adjustment for socioeconomic factors by multiple logistic regression, there was no increased risk of impaired growth among the DMPA-exposed children (RR = 1.1, 95% CI 0.8 - 1.6). With the exception of a delay in onset of reported pubic hair growth among DMPA-exposed girls, there were no significant effects on attainment of puberty. We conclude that use of DMPA during pregnancy or breastfeeding does not adversely affect the long-term growth and development of children.

PIP: In Chiang Mai, Thailand, community physicians followed 2422 women who used the contraceptive injectable, Depo-Provera (DMPA), either during pregnancy and/or while breast feeding. They compared the longterm growth of the children exposed to DMPA with that of 1167 children who were not exposed to hormones during pregnancy or lactation. Multiple logistic regression revealed that DMPA exposure did not adversely affect mean height and weight by age for either sex. In fact, the height and weight curves of DMPA exposed children paralleled cross-sectional growth charts of the general population of Chiang Mai. DMPA did not significantly alter breast milk volume or composition. WHO has reported that some DMPA does pass into the breast milk (maternal plasma: milk ratios range from 100:60 to 1:1), but, according to these findings, this passively transferred DMPA dose not adversely affect child development. DMPA exposure in utero did not delay puberty among boys. DMPA-exposed girls experienced a slight but insignificant delay in menarche and breast development (20.6 vs. 22.8% and 57.4 vs. 58.3%, respectively). The hormone appeared to significantly delay appearance of pubic hair among DMPA exposed girls (9.3% of cases had pubic hair by 15 vs. 14.4% of controls; p = .05), but the researchers had to depend on reports of the mothers and children, since cultural sensitivities precluded them from directly observing pubic hair development. In addition, the numbers of children older than 10 years were small. The researchers planned to prospectively follow a larger sample of DMPA-exposed children to more precisely determine puberty-related changes. In conclusion, breast-feeding mothers can safely use Depo-Provera.

In utero exposure to steroid contraceptives and survival during infancy.

A cohort study was conducted in Chiang Mai, northern Thailand, in 1,431 children of women who had used the injectable contraceptive Depo-Provera (The Upjohn Company, Kalamazoo, Michigan), 565 children of women who had used oral contraceptives during pregnancy, and a group of 2,307 control infants with no hormonal contraceptive exposures. In follow-up interviews, information was obtained on stillbirths and deaths. Cause of death was ascertained by interview, death certificate, or medical record, and underlying causes of death were ascribed by a panel. The children exposed in utero to Depo-Provera had higher neonatal and infant mortality rates (44.3 and 62.9 per 1,000 live births, respectively) than did the controls (19.8 and 29.1 per 1,000 live births). Mortality in infants exposed in utero to oral contraceptives was intermediate between that in the other two groups. Adjustment by logistic regression showed no significantly increased risk of mortality among infants exposed to oral contraceptives, but the odds ratio for death was significantly increased with Depo-Provera exposures due to accidental pregnancy (odds ratio (OR) = 1.8 (95% confidence interval (Cl) 1.1-3.0) for neonatal deaths; OR = 2.0 (95% Cl 1.3-3.2) for infant deaths). Adjustment for low birth weight reduced the risks, suggesting that low birth weight may act as an intermediate determinant of Depo-Provera-associated mortality. Among the accidental pregnancies with Depo-Provera, there was a relation between shorter injection-to-conception intervals, when maternal blood levels of the drug are high, and an increased risk of mortality. The odds ratios for neonatal mortality were 2.5 (95% Cl 1.1-5.7), 2.1 (95% Cl 1.0-4.6), and 0.9 (95% Cl 0.4-2.4) for injection-to-conception intervals of less than or equal to 4, 5-8, and greater than 9 weeks, respectively. Adjustment for low birth weight reduced these risks. Chi-square tests for trend were highly significant. Similar associations were also observed between Depo-Provera accidental pregnancies and risks of low birth weight. Thus, infants from accidental pregnancies that occur 1-2 months after a 150-mg Depo-Provera injection may be at increased risk for low birth weight and death. However, the attributable risk is low, because such pregnancies are uncommon.

In utero exposure to steroid contraceptives and outcome of pregnancy.

A cohort study of women who used steroid contraceptives during pregnancy was conducted in Chiang Mai, northern Thailand, between 1984 and 1987. There were 1,573 pregnancies in which the fetus was exposed to the injectable contraceptive Depo-Provera (The Upjohn Company, Kalamazoo, Michigan) (830 accidental pregnancies and 743 infants conceived before the mother started use of Depo-Provera), 601 accidental pregnancies in women who were using oral contraceptives, and 2,578 planned pregnancies with no steroid exposures (controls). Subjects were followed up for interview, and medical records were traced for birth weight. Women using Depo-Provera had more risk factors for adverse pregnancy outcomes than did the other groups. The adjusted odds ratios for low birth weight were increased for accidental pregnancies with fetal exposure to Depo-Provera (odds ratio (OR) = 1.5, 95% confidence interval (Cl) 1.2-1.9) or oral contraceptives (OR = 1.5, 95% Cl 1.2-2.0). The higher risk of low birth weight among infants exposed in utero to Depo-Provera or oral contraceptives is due in part to self-selection for adverse outcomes among women with unplanned pregnancies. However, among accidental pregnancies with Depo-Provera, the risk of low birth weight was significantly increased when conception was estimated to have occurred within 4 weeks of injection. The odds ratios were 1.9 (95% Cl 1.4-3.2) for injection-to-conception intervals of less than or equal to 4 weeks, 1.5 (95% Cl 0.9-2.3) for intervals of 5-8 weeks, and 1.2 (95% Cl 0.7-1.9) for intervals of greater than or equal to 9 weeks. This trend was highly significant. Thus, the authors conclude that early, high-dose in utero exposures to Depo-Provera may affect fetal growth.

[[Psychosocial aspects of aging]].

PIP: A rapid fertility decline and a decrease in mortality levels are changing the age structure of Thailand. The author projects age distributions by sex up to the end of the twenty-first century. Psychological aspects of aging based on a U.S. sample are discussed as they contribute to the understanding of Thailand's changing population structure and its needs. (SUMMARY IN ENG)^ieng

Steroid contraceptive use and pregnancy outcome.

Contraceptive use in relation to pregnancy outcome was studied in 8,816 births in Chiang Mai, northern Thailand, by examination of newborn infants and interviews with their mothers. Four thousand twenty-three women used no contraception before the index pregnancy, 1,229 used the injectable contraceptive Depo Provera (DMPA), and 3,038 used oral contraceptives prior to or during pregnancy. No differences were observed between these groups with respect to still births, multiple pregnancies, and birthweight. Women who used oral contraceptives had unexpectedly low rates of major defects and may have been affected by self-selection bias, whereas the noncontraceptors had rates similar to other populations. There was a significantly increased association of polysyndactyly among infants of DMPA users relative to the other groups, which was most pronounced in offspring of women under age 30 years, and persisted after exclusion of subjects with a family history or infants with multiple abnormalities. However, in five out of the ten polysyndactyly cases, the last injection of DMPA occurred more than 9 months before conception, and only three cases had definite gestational exposure. The association of chromosomal anomalies was also significantly increased in infants of mothers who used DMPA. The unrelated nature of these defects, the lack of confirmation from other studies, the distant preconceptional exposure to DMPA in many cases, and chance effects due to multiple statistical comparisons make a causal association unlikely. Other birth defects that had been previously reported in some publications to be associated with progestational steroid exposure, such as neural tube defects, heart malformations, and limb reduction defects, were not found in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Fertility decline and consequences of the National Family Planning Program: an analysis of the achievements of family planning activities in Chiang Mai and Lamphun provinces].

Based on the census data of 1970 and 1980 for each province of Thailand, the present study has revealed that between 1960-1980, a rapid fertility decline took place in 17 northern provinces and 26 central provinces of Thailand. A similar rapid fertility decline also took place starting in 1975 in the 16 northeast provinces and in the 14 southern provinces. Levels and trends of fertility found in this study suggest that most of the districts in the northern and the central regions reached the replacement level or below by 1985, and that similar levels will be attained by 1990 for almost every district in Thailand. This paper also stresses the impact of the rapid fertility decline on development in Thailand during the past 20 years, and its consequences. Lastly, the present study suggests that, for the future, the most important step is to understand well the consequences of this astonishing rapid fertility decline. This knowledge will be vital for the country and its people.

The rapid fertility decline to below the replacement level in the Chiang Mai area of Thailand.

PIP: The 1st part of this paper presents findings on differences in socioeconomic characteristics between the Chiang Mai (Thailand) city population and populations in other study areas based on analysis of data of a demographic sample survey in Chaing Mai. A 2nd section includes a description of findings on attitudes towards "small" and "large" family sizes. A subsequent section describes the detailed patterns of rapid fertility decline from 1954-78 for each study area. The last part of the paper examines nuptiality and family planning factors in accounting for the decline of fertility. Each women interviewed asked 2 questions concerning her attitude towards large and small family sizes. The findings suggest that women in both urban and rural areas of Chiang Mai province prefer a small family size. The ideal family size preferred by 80.5% was 3 or less. 49.7% accepted an ideal family size of only 2 children. Fertility levels of the Chiang Mai city population as compared with rural populations from 1954-78 show a marked fertility decline in every age group starting after 1954-78 for women in Chiang Mai city and after 1959-63 for women in the other study areas. By 1974-78 fertility levels reached levels "lower than replacement" in all study areas. There was a marked fall in fertility in every age group of the currently reproductive age in all of the study areas. Fertility in every age group continues to fall, even though it has already reached very low levels. As a result, the actual fertility in women at high reproductive ages is now very low. The pattern of fertility decline in all study areas in almost universal. Lastly, the start of the fertility decline took place earlier in Chiang Mai city, in the cohort age 40-44 when they were 25-29, but the start of fertility decline also occurred in the remaining 3 study areas in the same cohort (age 40-44), at age 30-34, instead of 25-29 as in the city, suggesting that fertility decline in the Chiang Mai rural areas followed Chiang Mai city by approximately 5 years. The age structure of the Chaing Mai population in 1960 represents the typical high fertility population; whereas the changes observed in the age structure of 1970, in age group 5-90 and 0-4, suggests that some decline of fertility had already occurred during the first half of the decade and became more rapid in the second. In addition, the changes in age struture of the city population in 1980, in age groups 0-4, 5-9, 10-14, and 15-19, demonstrates the continuing rapid fertility decline into the 1970s. Women in the Chiang Mai area accepted many contraceptive methods. The most popular methods were oral contraceptives and injectables. Findings from this demographic sample confirm the impact of family planning programs on the decline of fertility, from a high level to below the replacement level in fewer than 20 years.^ieng

Return of fertility after use of the injectable contraceptive Depo Provera: up-dated data analysis.

PIP: 796 Thai women who stopped using the long-acting injectable contraceptive depot medroxyprogesterone acetate (DMPA, Depo Povera), 437 women who stopped using oral contraceptives and 125 women who had an IUD removed to have a planned pregnancy, were followed up to ascertain the delay to conception after the end of contraception and to determine the proportion of women who did not conceive in the 4 years after discontinuation. The median delay to conception was 5.5 months plus the estimated duration of the effect of the last injection of DMPA, 3 months for oral contraceptives and 4.5 months after discontinuing the IUD. The proportion of women who did not conceive within 9 months after discontinuation of DMPA is similar to that of ex-IUD users, and by 3 years to that of the ex-pill sample. There is no evidence to suggest that prolonged use of DMPA increases the delay to conception. The return of fertility among never pregnant ex-users resembled that of ever pregnant ex-users. There were comparable proportons of live births among ex-DMPA users and ex-pill users and both of these showed higher proportions of live-births than ex-IUD users. There was no evidence to suggest that previous use of DMPA had any significant adverse effect on the outcome of pregnancy of the subsequent births. This study did not show any association between infertility and the previous use of DMPA or other contraceptives.^ieng

The return of fertility following discontinuation of oral contraceptives in Thailand.

The return of fertility following discontinuation of oral contraception was studied in a survey of 437 Thai women who stopped taking the pill to have a planned pregnancy. Conception rates were reduced during the first 2 months after stopping the pill, and the median delay prior to conception was approximately 3 months. This delay was shorter for nulligravid women. Most women (94.3%) became pregnant within 2 years of stopping the pill. There was a cyclic pattern in the monthly pregnancy rates with peak rates around 3 and 6 months after discontinuing contraception. These findings are similar to those reported for Caucasian women.

PIP: The return of fertility following discontinuation of (OCs) oral contraceptives was studied in a survey of 437 Thai women who stopped taking OCs to have a planned pregnancy. Conception rates were reduced during the first 2 months after stopping OCs, and the median delay prior to conception was approximately 3 months. This delay was shorter for nulligravid women. Most women (94.3%) became pregnant within 2 years of stopping OCs. There was a cyclic pattern in the monthly pregnancy rates with peak rates around 3 and 6 months after discontinuing contraception. These findings are similar to those reported for Caucasian women.

Return of fertility after discontinuation of depot medroxyprogesterone acetate and intra-uterine devices in Northern Thailand.

796 Thai women who stopped using the long-acting injectable contraceptive 'Depo-Provera' (medroxyprogesterone acetate) and 125 women who had an intra-uterine device removed to have a planned pregnancy were followed-up to ascertain the delay between conception and the end of contraception, and to determine the proportion of women who did not conceive in the 2 years after discontinuation. The median delay before conception was 5.5 months plus the estimated duration of the effect of the last injection of depo-provera and 4.5 months after discontinuing the IUD. Since depo-provera acts for approximately 15 weeks, women can except a median delay to conception of around 9 months after their last injection. The proportions of women who did not conceive within 1 year and within 2 years of stopping contraception by the two methods were similar. There was no evidence to suggest that prolonged use of depo-provera increases the delay before conception, and the return of fertility among never pregnant ex-users resembled that of ever pregnant ex-users.

PIP: 796 Thai women (from the family planning clinic of the McCormick Hospital in Chiang Mai, Northern Thailand) who discontinued use of DMPA (depot medroxyprogesterone acetate) and 125 women who stopped using IUD to have a planned pregnancy were followed up to determine the proportion of women who did not conceive within 2 years of discontinuation, and to ascertain the delay between conception and end of contraception. The study was divided into 2 groups: retrospective (consisting of women who discontinued contraception before 12/74 to become pregnant) and prospective (those who stopped DMPA for aplanned pregnancy between 1/75 and 12/76. Life-table conception rates and standard errors were estimatedat monthly intervals and cumulatively over time; median delay before conception was calculated from cumulative rates. As both prospective and retrospective groups exhibited similar cumulative proportions conceiving, the 2 groups were combined for simplicity of presentation of data. Median delay before conception was found to be 5.5 months plus the estimated duration of the effect of the last injection of DMPA and 4.5 months after IUD discontinuation. As the effect of DMPA lasts for approximately 15 weeks, a median delay to conception of around 9 months after last injection can be expected. The proportion of women who did not become pregnant within 1 year and within 2 years of discontinuation of contraception was similar for both methods (DMPA: 21.8% at 1 year and 7.9% at 2 years; IUD: 21% at 1 year and 6.7% at 2 years). Prolonged use of DMPA also did not increase delay before conception, and return of fertility among never pregnant ex-users was similar to that of ever pregnant ex-users.

The timing of the first injection of Depo Provera.

PIP: The timing of the 1st injection of the contraceptive Depo Provera was studied by examining the risk of accidental pregnancy during 3 months following the 1st injection in 7930 women. The pregnancy rate was 1.62 pregnancies/1000 women if the injection was given within the 1st 8 days of the cycle and 6.22 pregnancies/100 women if given between cycle day 9 and 28. The difference is statistically significant (p less than .01). It is recommended that women who present later than cycle day 7 for an injection be given additional contraceptive protection for at least 1 month. There is no justification for rejecting a woman if she requests an injection at any time during her menstrual cycle.^ieng

Use-effectiveness of six-month injections of DMPA as a contraceptive.

PIP: The use of depot-type injections of the contraceptive medroxyprogesterone acetate (DMPA) was studied in 1132 women for up to 5 1/2 years. Continuation rates, reasons for discontinuation, method failure rates, and bleeding patterns were considered. The women received a dose of 400 mg DMPA in aqueous suspension (injected into the deltoid muscle) every six months. In addition, each patient received an oral dose of .04 mg ethynl estradiol for 10 days each lunar month. Of the original acceptors, 36.4 percent used the method for the full 5 1/2 years. The major reasons for discontinuation of DMPA injections were bleeding problems (including amenorrhea) and such other medical reasons as palpitation, abdominal pain, headache, weakness, and dizziness. A total of 26 women became accidently pregnant while using DMPA during the 5 1/2 years. Advantages of DMPA injections were the simplicity, safety, and effectiveness of the method, and the psychological appeal of an injectable contraceptive.^ieng

Use of a long-acting injectable contraceptive in a postpartum family planning program.

PIP: A study of intramuscular injections of depo medroxyprogesterone acetate (Depo Provera) as a postpartum contraceptive was undertaken in an attempt to determine the following: 1) the continuation rates for this contraceptive method in a postpartum family planning program; 2) to compare the continuation rates of Depo Provera given as a postpartum contraceptive with other postpartum contraceptive methods, as reported elsewhere; 3) the use-effectiveness of Depo Provera as a postpartum contraceptive method; 4) the side effects of postpartum injections; and 5) the reasons for discontinuation of this method. Between April 1969 and May 31, 1972 there were a total of 325 acceptors at the Family Planning Department of McCormick Hospital in Chiang Mai, Thailand. 217 of the women were acceptors of 3-month injections and 108 women were acceptors of 6-month injections. Of all acceptors, 94.2% received their 1st injection within 5 days of delivery. Cases continuing beyond 12 months were too few in number for significant statistical analysis. There were no known method failure pregnancies. Of the 325 postpartum acceptors of the 3-month and 6-month Depo Provera injections, 152 had discontinued the method by May 31, 1972. Of these, 47 were lost to follow up. The reasons for the discontinuation of the 105 remaining cases were bleeding problems (amenorrhea, prolonged, frequent or heavy bleeding, and irregular periods), other medical reasons (palpitation and dizziness, abdominal pain, pain at injection site, and melasma), and personal reasons.^ieng