Dataset Information

Uterine distention as a factor in birth timing: retrospective nationwide cohort study in Sweden.

ABSTRACT:

Objectives

To determine whether uterine distention is associated with human pregnancy duration in a non-invasive observational setting.

Design

Retrospective cohort study modelling uterine distention by interaction between maternal height and uterine load.

Setting

The study is based on the 1990-2013 population data from all delivery units in Sweden.

Participants

Uncomplicated first pregnancies of healthy Nordic-born mothers with spontaneous onset of labour. Pregnancies were classified as twin (n=2846) or singleton (n=527?868). Singleton pregnancies were further classified as carrying a large for gestational age fetus (LGA, n=24?286) or small for gestational age fetus (SGA, n=33?780).

Outcome measures

Statistical interaction between maternal height and uterine load categories (twin vs singleton pregnancies, and LGA vs SGA singleton pregnancies), where the outcome is pregnancy duration.

Results

In all models, statistically significant interaction was found. Mothers carrying twins had 2.9 times larger positive linear effect of maternal height on gestational age than mothers carrying singletons (interaction p=5e-14). Similarly, the effect of maternal height was strongly modulated by the fetal growth rate in singleton pregnancies: the effect size of maternal height on gestational age in LGA pregnancies was 2.1 times larger than that in SGA pregnancies (interaction p<1e-11). Preterm birth OR was 1.4 when the mother was short, and 2.8 when the fetus was extremely large for its gestational age; however, when both risk factors were present together, the OR for preterm birth was larger than expected, 10.2 (interaction p<0.0005).

Conclusions

Across all classes, maternal height was significantly associated with child's gestational age at birth. Interestingly, in short-statured women with large uterine load (twins, LGA), spontaneous delivery occurred much earlier than expected. The interaction between maternal height, uterine load size and gestational age at birth strongly suggests the effect of uterine distention imposed by fetal growth on birth timing.

SUBMITTER: Bacelis J

PROVIDER: S-EPMC6252709 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Uterine distention as a factor in birth timing: retrospective nationwide cohort study in Sweden.

Bacelis Jonas J Juodakis Julius J Adams Waldorf Kristina M KM Sengpiel Verena V Muglia Louis J LJ Zhang Ge G Jacobsson Bo B

BMJ open 20181031 10

<h4>Objectives</h4>To determine whether uterine distention is associated with human pregnancy duration in a non-invasive observational setting.<h4>Design</h4>Retrospective cohort study modelling uterine distention by interaction between maternal height and uterine load.<h4>Setting</h4>The study is based on the 1990-2013 population data from all delivery units in Sweden.<h4>Participants</h4>Uncomplicated first pregnancies of healthy Nordic-born mothers with spontaneous onset of labour. Pregnancie ...[more]

PMID: 30385442

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Dataset Information

Uterine distention as a factor in birth timing: retrospective nationwide cohort study in Sweden.

Objectives

Design

Setting

Participants

Outcome measures

Results

Conclusions

Publications

Uterine distention as a factor in birth timing: retrospective nationwide cohort study in Sweden.

Similar Datasets

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