Evidence map›Paper›PMID 10102850›Full record

ArticleBMJ (Clinical research ed.)1999

Twins and maternal smoking: ordeals for the fetal origins hypothesis? A cohort study.

S Williams, R Poulton

Abstract readTwin Study
In one paragraph

Article in BMJ (Clinical research ed.), 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

23 citing papers in PubMed, 2 syntheses or guidelines pooled it.

  1. Pooled it
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  7. Parental smoking during pregnancy and offspring bone mass at age 10 years: findings from a prospective birth cohort.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2011
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  14. Birthweight, rapid growth, cancer, and longevity: a review.Journal of the National Medical Association · 2003
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

2 authors.

S WilliamsUniversity of Otago, Box 913, Dunedin, New Zealand. sheila.williams@stonebow.otaga.ac.nz
R Poulton

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo assess the direct and indirect effects of being a twin, maternal smoking, birth weight, and mother's height on blood pressure at ages 9 and 18 years.

designLongitudinal study. SUBJECTS: Cohort born in 1972-3.

settingDunedin, New Zealand.

main outcome measureBlood pressure at ages 9 and 18 years.

resultsCompared with singletons, twins had a systolic blood pressure 4.55 (95% confidence interval 1.57 to 7.52) mm Hg lower at age 9 after adjustment for direct and indirect effects of sex, maternal smoking, mother's height, socioeconomic status, and birth weight, as well as concurrent height and body mass index. Blood pressure in children whose mothers had smoked during pregnancy was 1.54 (0.46 to 2.62) mm Hg higher than in those whose mothers did not. The total effect of birth weight on systolic blood pressure at age 9 was -0.78 (-1.76 to 0.20) mm Hg and that for mother's height was 0.10 (0.06 to 0.14) mm Hg. Similar results were obtained for systolic blood pressure at age 18. The total effect of twins, maternal smoking, and birth weight on diastolic blood pressure was not significant at either age.

conclusionsTwins had lower birth weight and lower systolic blood pressure at ages 9 and 18 than singletons. This finding challenges the fetal origins hypothesis. The effect of maternal smoking was consistent with the fetal origin hypothesis in that the infants of smokers were smaller and had higher blood pressure at both ages. This may be explained by pharmacological rather than nutritional effects. The total effect of birth weight on systolic blood pressure, after its indirect effect working through concurrent measures of height and body mass index was taken into account, was small.

Indexed as

Prenatal Exposure Delayed EffectsSmokingAdolescentBirth WeightBlood PressureBody HeightChildCohort StudiesFemaleHumansLongitudinal StudiesMaleMaternal ExposureNew ZealandPregnancy

Identifiers

PMID10102850
PMCPMC27807

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.