Clinical aspects of bowel symptoms in Parkinson's disease.

BACKGROUND: The clinical importance of bowel symptoms in Parkinson's disease (PD) remains to be described in detail. METHODS: A 33-item questionnaire including background parameters, the Cleveland Constipation Score (CCS), and items from the Neurogenic Bowel Dysfunction score was sent to 468 PD patients. Results were compared to a control group (CG) (n = 45). A CCS of at least 15 was used to define severe constipation. RESULTS: Four hundred and sixteen subjects (89%) responded. Median CSS was only 4 (range 0-21) in PD and 2 (range 0-13) in the CG (P < 0.05). Severe constipation was found in 7% with PD and 0% in the CG (P < 0.05). Incomplete emptying at defecation, need for assisted defecation and use of oral laxatives was reported more frequently by PD patients than by the CG (all P < 0.05). The severity of PD was associated with assisted defecation (P < 0.001), unsuccessful attempts at defecation (P < 0.001), incomplete emptying at defecation (P < 0.05), and the CCS (P < 0.01). Time since diagnosis was associated with infrequent defecation (P < 0.0001) and the CCS (P < 0.05). The use of levodopa was associated with less unsuccessful attempts at defecation (P < 0.05). CONCLUSION: Most patients with PD only have minor constipation-related symptoms. However, severe constipation is associated with time since diagnosis and severity of disease.

Neurogenic bowel dysfunction score.

STUDY DESIGN: Cross-sectional questionnaire study. OBJECTIVES: To develop and validate a symptom-based score for neurogenic bowel dysfunction (NBD): NBD score. SETTING: University Hospital of Aarhus, Denmark. METHODS: A questionnaire including questions about background parameters (n=8), faecal incontinence (n=10), constipation (n=10), obstructed defecation (n=8), and impact on quality of life (QOL) (n=3) was sent to 589 Danish spinal cord injured (SCI) patients. The reproducibility and validity of each item was tested in 20 and 18 patients, respectively. Associations between items and impact on QOL were determined by logistic regression analysis. The NBD score was constructed from items with acceptable reproducibility and validity that were significantly associated with impact on QOL. Based on odds ratios for associations between items and impact on QOL, each item was given a corresponding number of points in the NBD score. RESULTS: A total of 424 SCI patients responded. The following 10 items met the criteria above: frequency of bowel movements (0-6 points), headache, perspiration or discomfort before or during defecation (0-2 points), tablets and drops against constipation (0-2 points each), time used for each defecation (0-7 points), frequency of digital stimulation or evacuation (0-6 points), frequency of faecal incontinence (0-13 points), medication against faecal incontinence (0-4 points), flatus incontinence (0-2 points) and perianal skin problems (0-3 points). Differences in NBD score among patients reporting no, little, some or major impact on QOL were statistically significant (all P<0.001). CONCLUSION: Based on valid and reproducible questions, we have constructed a score for NBD that is correlated to impact on QOL.

Socio-economic status and adherence to tuberculosis treatment: a case-control study in a district of Nepal.

SETTING: A western hill district in Nepal, where tuberculosis (TB) treatment under DOTS was offered by the regional tuberculosis centre, two primary health centres, eight health posts, three sub-health posts and one ward of sub-metropolitan Pokhara. OBJECTIVE: To analyse the contribution of socioeconomic status to non-adherence to DOTS. DESIGN: Case-control study. Data were collected by questionnaire-based face-to-face interviews. The study sample consisted of 50 cases and 100 controls. The participation rate was 80% for cases (non-adherents) and 95% for controls. RESULTS: Logistic regression analysis showed that the risk of non-adherence to TB treatment was significantly associated with unemployment (odds ratio [OR] 9.2), low status occupation (OR 4.4), low annual income (OR 5.4), and cost of travel to the TB treatment facility (OR 3.0). Factors significant in the bivariate analyses--living conditions, literacy and difficulty in financing treatment--were not found to be significantly associated with non-adherence when adjusted for other risk factors in the multivariate regression model. CONCLUSION: Low socio-economic status and particularly lack of money are important risk factors for non-adherence to TB treatment in a poor country such as Nepal.

Occupational risk factors, ultraviolet radiation, and ocular melanoma: a case-control study in France.

BACKGROUND: Ultraviolet radiation has been suspected as a possible cause of ocular melanoma. Because this association is controversial, we examine the role of occupational exposure to ultraviolet radiation on the occurrence of this rare cancer. MATERIAL AND METHODS: A population-based case-control study was conducted in 10 French administrative areas (départements). Cases were 50 patients with uveal melanoma diagnosed in 1995-1996. Controls were selected at random from electoral rolls, after stratification for age, gender, and area. Among 630 selected persons, 479 (76%) were interviewed. Data on personal characteristics, occupational history, and detailed information on each job held were obtained from face-to-face interviews using a standardized questionnaire. Estimates of occupational exposure to solar and artificial ultraviolet light were made using a job exposure matrix. RESULTS: Results show elevated risks of ocular melanoma for people with light eye color, light skin color, and for subjects with several eye burns. The analysis based on the job exposure matrix showed a significantly increased risk of ocular melanoma in occupational groups exposed to artificial ultraviolet radiation, but not in outdoor occupational groups exposed to sunlight. An elevated risk of ocular melanoma was seen among welders (odds ratio = 7.3; 95% confidence interval = 2.6-20.1 for men), and a dose-response relationship with job duration was observed. The study also showed increased risk of ocular melanoma among male cooks, and among female metal workers and material handling operators. CONCLUSION: Following the present study, the existence of an excess risk of ocular melanoma in welders may now be considered as established. Exposure to ultraviolet light is a likely causal agent, but a possible role of other exposures in the welding processes should not be overlooked.

Medical risk factors for small-bowel adenocarcinoma with focus on Crohn disease: a European population-based case-control study.

BACKGROUND: Crohn disease and biliary diseases have been associated with small-bowel adenocarcinoma (SBA). We examined how medical conditions affect the risk of SBA. METHODS: A population-based European multicentre case-control study during the period 1995-97 including 95 histologically verified cases of SBA along with 3335 population controls; 70 cases (74%) and 2070 (62%) controls were interviewed about previous medical conditions. RESULTS: Crohn disease was identified in two SBA cases (both located in ileum) and two controls; odds ratio (OR) 53.6 (6.0-477) (95% CI in parentheses). Only one case and no controls had had long-standing Crohn disease. Coeliac disease was associated with SBA (2 cases, 0 controls), but one of the cases was diagnosed at the same time as the SBA. Overall, people with a history of gallstones had no increased risk of SBA. The OR was exclusively increased during the 3-year period preceding the SBA diagnosis. Previous gallstone surgery, which may be a sign of severe gallstone disease, was not associated with SBA. Liver cirrhosis, hepatitis or medical treatments with radioactive substances or corticosteroid tablets were not associated with this disease. Cases with SBA had an increased prevalence of anaemia; OR 15.3 (2.5-92.1). An association between low educational level and SBA was found; OR 1.75 (1.0-3.0). CONCLUSION: This study supports Crohn disease and coeliac disease being strong but rare risk factors for SBA. Previous gallstones were unrelated to SBA, and detection bias may account for the findings in earlier studies.

Choice and chance: determinants of short interpregnancy intervals in Denmark.

BACKGROUND: It is still unclear whether short interpregnancy intervals are a marker for women at risk of poor pregnancy outcome or a direct risk factor for poor perinatal outcomes. The study objective was to identify risk factors associated with short interpregnancy intervals in Denmark. METHODS: From a cohort of pregnant women in a geographically defined area in Denmark (n=11,288) and using register linkage, we identified 5756 multiparous mothers who completed a detailed interview on social behavior during pregnancy. We restricted our analysis to 2904 mothers who had an interpregnancy interval of less than 37 months. Multiple logistic regression was used to estimate the Odds Ratio (OR) of having a short interval as a function of a number of determinants. RESULTS: About 4.8% of the mothers had an interpregnancy interval less than 9 months. Short interpregnancy intervals were more likely to occur in an unplanned pregnancy (OR=2.9, 95% CI: 2.2-3.9), to follow irregular menstruation (OR=1.7, 95% CI: 1.1, 2.5) and to occur in older (OR=1.7, 95% CI: 1.1, 2.5) and high parity mothers (OR=1.9, 95% CI: 1.1, 3.1). Poor housing, smoking and low social status were also associated with short interpregnancy interval CONCLUSION: Short interpregnancy intervals may be a marker for women at risk and these risk factors differ among populations. They also appear to be a result of choice (e.g. in older women). Biological factors also play a significant role in determining short interpregnancy intervals.

The association of indicators of fetal growth with visual acuity and hearing among conscripts.

Impaired fetal growth is associated with increased susceptibility to several chronic diseases. We studied the association between birth weight, indicators of disproportional fetal growth, and impaired visual acuity and hearing in 4,300 conscripts from a well-defined region in Denmark from August 1, 1993, to July 31, 1994. From the standard health examination for conscripts, we obtained data on sight based on the Snellen's chart and data on hearing acuity based on audiometry. By means of record linkage, we obtained data on outcomes for the conscripts at birth from the Medical Birth Registry. From this registry, we have data on birth weight, gestational age, and birth length that were recorded from existing computerized registers based on the records of midwives. A birth weight of less than 3,000 gm and a body mass index at birth of less than 3.4 were associated with reduced visual acuity and impaired hearing. The results could be due to fetal brain programming or due to confounding, by early birth trauma or other factors.

Determinants of child mortality in a rural Ugandan community.

OBJECTIVE: To estimate the rate of and risk factors associated with child mortality in rural eastern Uganda. DESIGN: A community based cross-sectional study using the preceding birth technique--a robust method of obtaining information of survival of the previous child. SETTING: A rural district in Eastern Uganda. PARTICIPANTS: In total, 2888 multigravidae were interviewed in April and May 1999. MAIN OUTCOME MEASURE: Number of deaths among children born alive. RESULTS: The under-two child mortality rate was 108 per 1000 livebirths. The annual child mortality was 82 per 1000 child-years of risk. Child mortality was associated with low parental education, being born to adolescent mothers or mothers aged 35 or more. Unconditional logistic regression showed that children born to uneducated parents had a doubled risk of not celebrating their second birthday. It was three times more likely for a child to die in the neonatal period than in the first year of life. Child mortality risk decreased by 4% and 6% for every year of education attained by mothers and fathers, respectively. Parity, residence and marital status were not associated with excess risk of child mortality. Seasonal mortality followed the El Nino rainfall pattern. Finally, there were geographical differences in child mortality although this was not statistically significant. CONCLUSION: Monitoring trends in child mortality at district level can be done using the preceding birth technique in antenatal settings. Maternal education, an important predictor of child survival should be included in routine data collection at clinics.

Episodic heavy drinking in four Nordic countries: a comparative survey.

AIMS: The purpose of this study was to compare the phenomenon of episodic heavy drinking (binge drinking) and its different indicators in the Nordic countries. DESIGN: A comparative survey of four Nordic countries. SETTING: Telephone interviews in Denmark, 1997; Finland, 1996; Norway, 1996; and Sweden 1996-97. PARTICIPANTS: Random samples of men and women aged 19-71 years. MEASUREMENTS: Episodic heavy drinking was measured by the frequency of subjective intoxication, of drinking six or more drinks at a time (6+), and of negative consequences (mainly hangover symptoms). Additionally, annual consumption and measures of intake per occasion were used. FINDINGS: Annual consumption, overall frequency of drinking and frequency of drinking 6+ were highest in Denmark and lowest in Norway. Frequency of subjectively defined intoxication was highest in Finland. There it was clearly higher than the frequency of drinking 6+, whereas in Denmark the contrary was observed. Finnish and Norwegian men and Danish women reported the largest quantities drunk per occasion. Results on 6+ frequency and the prevalence of negative consequences, with annual consumption held constant, suggest that Danes have the least concentrated drinking pattern. With annual consumption held constant, Norwegians report as high a frequency of intoxication, as do Finns. CONCLUSIONS: The relations between subjective and more objective measures of episodic heavy drinking vary considerably between the Nordic countries. The results suggest that the definition, acceptability and experience of intoxication vary even when a set of relatively homogeneous countries are compared.

A comparative analysis of different methods for obtaining estimates of alcohol consumption in a Danish population survey.

AIMS: The aim of the present study was to compare different measures of alcohol consumption used in a Danish survey. METHODS: A stratified random sample was extracted from the Civil Registration System. From January 1997 to January 1998 approximately 8 telephone interviews were conducted every day, including Sundays and holidays, ending with a total of 3,050 interviews after 1 year. Two main approaches to measure alcohol consumption were used: the quantity-frequency and the recent occasion approaches; the latter is subdivided into previous week and previous day approaches. RESULTS: The overall estimated number of units (= 12 g of pure alcohol) per week was 6.8 (95% confidence intervals (CI): 6.5-7.1), 6.7 (95% CI: 6.4-7.1) and 8.5 (95% CI: 7.8-9.1) for the quantity-frequency, previous week and previous day approaches, respectively. A total of 50% of the men and 70% of the women did not drink alcohol the previous day. Among people classified as high consumers in the previous week and previous day approaches, less than 60% and 30%, respectively, were similarly classified in the quantity-frequency approach. CONCLUSION: There was agreement on the level of alcohol consumption between the quantity-frequency and previous week approaches, but higher estimates when using the previous day approach. The previous day approach varied more in relation to the interview day and season compared with the quantity-frequency approach and the previous week approach. The recent occasions approach showed some difficulties in classifying the individuals. If the alcohol consumption is included in a model as a risk indicator or a confounder, the quantity-frequency approach would be more preferable than the recent occasion approach.

Is there an association between alcohol intake or smoking and small bowel adenocarcinoma? Results from a European multi-center case-control study.

OBJECTIVE: To discover whether tobacco smoking and intake of different types of alcoholic drinks are associated with small bowel adenocarcinoma (SBA). METHODS: A population-based European multi-center case-control study was conducted from 1995 to 1997. RESULTS: After a histological review using uniform diagnostic criteria, 47 (33%) of the 142 identified cases of SBA were excluded due to reclassification as either tumors of the papilla of Vater (n = 22), stromal tumors, or metastases; 95 cases were accepted for study. In all, 70 cases of SBA together with 2070 controls matched by age, sex, and region were interviewed. A high intake (more than 24 g alcohol per day) of beer or spirits was associated with SBA, an odds ratio (OR) of 3.5 and 95% confidence intervals (CI) of 1.5-8.0 and 3.4 (95% CI 1.3-9.2), respectively). There was no association with wine intake or total alcohol intake. Tobacco smoking was probably unrelated to SBA. CONCLUSIONS: A high intake of beer or spirits seems to be a risk factor for SBA. Since this association was not seen for wine drinkers, protective components of wine may counterbalance a carcinogenic effect of alcohol on the small bowel. Alternatively, the result may be confounded by other factors, e.g. dietary factors.

Occupation and small bowel adenocarcinoma: a European case-control study.

OBJECTIVES: Because of the rarity of small bowel adenocarcinoma (SBA), little is known about the aetiology of this disease. This study aimed to identify occupational clustering of cases SBA as a systematic approach to new hypotheses on the aetiology of this disease. METHODS: A European multicentre case-control study was conducted in 1995-7, inclusive. Incident cases aged 35-69 years with SBA (n=168) were recruited before acceptance by a pathologist. Altogether 107 cases and 3915 controls were accepted, of which 79 cases, 579 colon cancer controls, and 2070 population controls were interviewed. RESULTS: The strongest industrial risk factors for SBA taking account of 10 years' exposure lag were dry cleaning, manufacture of workwear, mixed farming (women), and manufacture of motor vehicles (men). A significantly increased risk of SBA (odds ratio (OR) and 95% confidence interval (95% CI)) was found among men employed as building caretakers, OR 6.7 (1.7 to 26.0) and women employed as housekeepers, OR 2.2 (1.1 to 4.9); general farm labourers, OR 4.7 (1.8 to 12.2); dockers, OR 2.9 (1.0 to 8.2); dry cleaners or launderers, OR 4.1 (1.2 to 13.6); and textile workers (sewers or embroiderers), OR 2.6 (1.0 to 6.8). For the last four groups, together with welders OR 2.7 (1.1 to 6.6) (men) an exposure-response pattern was found when calculating the ORs for jobs held 1-5 years and >5 years, with never having held the job as reference. The ORs (95% CIs) for 1-5 years and >5 years were 4.3 (0.4 to 44.0) and 3.5 (0.9 to 13.7), 3.0 (0.3 to 26.2) and 4.3 (0.9 to 21.2), 4.6 (0.4 to 48.1) and 11.0 (2.0 to 60.4), 1.3 (0.2 to 11.0) and 5.8 (2.0 to 17.2), and 2.8 (0.3 to 23.8) and 4.6 (1.3 to 16.6), respectively, for each of these occupations. Among welders, people performing semiautomatic arc welding (MIG/MAG) were identified as a high risk group (OR 5.0 (1.3 to 19.6)). CONCLUSIONS: This explorative study suggests an increased occurrence of SBA in certain occupations, which needs further evaluation.

Low birth weight and preterm delivery as risk factors for asthma and atopic dermatitis in young adult males.

Gestational factors have been hypothesized to play a role in the susceptibility to asthma and atopic dermatitis. We examined whether fetal growth was associated with asthma and atopic dermatitis separately in a population of 4,795 male conscripts born between 1973 and 1975 in Denmark. The prevalence of asthma was 4.7%. The prevalence odds ratio of asthma in conscripts with a birth weight below 2,501 g was 1.5 (95% confidence interval = 0.7-3.1) compared with conscripts with a birth weight of 3,001-3,500 g, adjusted for gestational age and potential confounders. The adjusted prevalence odds ratio among conscripts born before 34 gestational weeks was 0.8 (95% confidence interval = 0.3-2.0) compared with conscripts born at term. The prevalence of atopic dermatitis was 1.0%. The prevalence odds ratio of atopic dermatitis among those with a birth weight below 2,501 g was 3.0 (95% confidence interval = 0.8-11.9) compared with those whose birth weight was between 3,001 and 3,500 g. Men whose gestational age had been below 34 weeks had an adjusted prevalence odds ratio of 0.3 (95% confidence interval = 0.0-3.1). These findings indicate that fetal growth retardation rather than preterm delivery of male infants is the main gestational factor underlying the associations but does not explain the apparent increase over time of asthma or atopic diseases.

Effect of home and hospital delivery on long-term cognitive function.

We examined the relation between place of birth and cognitive function in young adult life in a historical cohort study based upon birth data from the computerized Danish Medical Birth Registry and cognitive function as measured at time of drafting for military service in two Danish counties. The cohort included 4,296 Danish conscripts born between 1973 and 1976, 123 born at home and 4,173 born in hospital or at a birth clinic. Cognitive function was measured by the Boerge Prien test in men, 18 to 20 years of age. The highest possible score is 78. The mean Boerge Prien test score was 43.1 for conscripts born in specialized hospital departments, 2.4 higher for conscripts born in a birth clinic (95% confidence interval = 0.9-4.0), and 2.1 lower for conscripts born at home (95% confidence limits = -3.8 to -0.4) after adjusting for birth weight, length at birth, birth order, gestational age, maternal age, and marital and occupational status. Our findings raise the possibility that home birth can lead to lower cognitive function in adulthood; however, from our data we could not distinguish between planned and unplanned births at home.

[Antibiotic pre-hospital treatment and the course of meningococcal disease]. / Antibiotisk behandling før indlaeggelse og forløbet af meningokoksygdom.

The aim of the study was to assess the effect of pre-hospital antibiotic treatment given by general practitioners to patients with meningococcal disease. It was carried out as a 16-year population-based historical follow-up study based on referral letters and hospital records in the County of North Jutland, Denmark, and included 320 patients with meningococcal disease, of whom 302 were examined by a general practitioner before admission to hospital. The main outcome measure was death. We found that 44 patients (14.6%) were given antibiotic treatment by the referring general practitioner. Nine of these (20.5%) died, compared with 16 (6.2%) patients who did not receive pre-hospital antibiotic treatment. The presence of skin bleeding, petechiae and impaired consciousness were strongly associated with case fatality. Even after adjustment for these variables the odds ratio for death in patients treated with antibiotics was high (3.2; 95% CI 0.9-10.6). In the 15 patients with skin bleeding (ecchymoses, suggillations) the case fatality rate was 100% in patients treated with antibiotics, and 50% in patients who did not receive antibiotics before hospitalization. It is concluded that pre-hospital treatment is mainly given to the most severe cases with expected high case fatality, and this confounding by indication was probably not fully adjusted for with the available data. The results contradict previous findings and provide reason to doubt the benefit of pre-hospital antibiotic treatment in patients with meningococcal disease.

Risk of spontaneous abortion following induced abortion is only increased with short interpregnancy interval.

We set out to study the risk of spontaneous abortion following a first trimester induced abortion as a function of the interpregnancy interval between two pregnancies. The cohort study is based on the following databases: Danish national registries: the Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), and the induced Abortion Registry (IAR). All primigravid women in the time period from 1980 to 1982 were identified in the MBR, the HDR and the IAR. A total of 15 727 women who terminated the pregnancy with a first trimester induced abortion were selected as the induced abortion cohort, and 46 026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies which were not terminated by induced abortion were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected. Women whose first pregnancy was terminated following a first trimester induced abortion had a risk of spontaneous abortion of 11.0% vs. 9.4% in the control cohort. This relative difference of 1.17 was not statistically significant in logistic regression analyses. An increased risk was only found for women who had an interpregnancy interval of less than 3 months (OR=4.06, 95% C.I.=1.98-8.31). The abortion method, vacuum aspiration with dilatation or evacuation with dilatation did not modify this elevated risk. Overall the study did not show an increased risk of spontaneous abortion following one or more induced abortions, except for women with a short interpregnancy interval between an induced abortion and a subsequent pregnancy. We recommend women who have a first trimester induced abortion be advised to wait at least 3-6 months before trying to become pregnant again.

Long-term follow-up of cognitive outcome after breech presentation at birth.

Studies of long-term consequences of birth in breech presentation are sparse. Therefore, we conducted a cohort study linking birth registry data with data collected during evaluation for military service in 4,298 conscripts born between 1973 and 1976. The cognitive functions were measured with the Boerge Prien IQ test. A total of 164 conscripts were born in breech presentation and 70 (42.7%) of these were delivered after Caesarean section. The mean Boerge Prien test score was 43.2 among men born in cephalic presentation and 39.9 among those born in breech presentation for a difference of 3.3 (95% confidence interval = 1.8-4.7). The negative association between breech presentation and cognitive outcome persisted after stratifying by Caesarean section and after adjustment for confounders. It also persisted when we restricted the analyses to term singleton pregnancies.

[Duration of maternity leave and sick leave during pregnancy]. / Orlovsvarighed og fravaersmeldinger i graviditeten.

The aim of the project was to describe the reasons for sick leave during pregnancy. This article presents data on a subgroup of women on sick leave. The purpose of this reanalysis was to examine whether women with short maternity leave had longer sick leave during pregnancy. Pregnant women in a Danish County applying for sick leave in a year were consecutively included in the study. Data were obtained by questionnaires during 1991-1992. Women with rights to a longer maternity leave, obtained through collective bargaining, were mainly employed in occupational groups related to the public sector and were on sick leave significantly longer, than women with short maternity leave, obtained only through legislation. The diagnoses differed among the two groups. Data suggest unequal possibilities for obtaining pregnancy related sick leave, as women with longer predelivery leave and a more secure employment situation had significantly longer sick leave than other women.

Birth weight and length as predictors for adult height.

Adult height has been found to be inversely associated with mortality. Recently, it has been suggested that growth in utero is linked with adult risk of several chronic diseases. The authors examined possible associations between birth weight, birth length, and adult height in young Danish men. They conducted the study in the fifth conscription district of Denmark including all the men born after January 1, 1973 who were residents in the study area during the period August 1, 1993 to July 31, 1994. The Danish Medical Birth Register contains information on all births in Denmark since January 1, 1973. Data on height from the Conscription Register were linked to the Danish Medical Birth Register in 4,300 conscripts examined. Nearly all Danish men have to register with the draft board around age 18 years of age where they undergo a physical examination. There was a strong positive association between birth weight and adult height; for subjects with birth weight < or = 2,500 g, mean height was 175.7 cm, while for those with birth weight > or = 4,501 g, mean height was 184.1 cm. A positive association was also found between birth length and adult height. For subjects with birth length < 47 cm, mean adult height was 175.2 cm, increasing to 184.3 cm at birth length > 56 cm. The associations between birth length and adult height persisted after adjustment for birth weight, gestational age, and other confounders, while the associations between birth weight and adult height almost disappeared when adjusting for birth length and the same confounders. Genetic and/or environmental factors operating both during the pre- and postnatal period may be responsible for the association between birth length and adult height.