Related Experiment Video

Updated: Sep 23, 2026

Assessment of the Efficacy of An Osteopathic Treatment in Infants with Biomechanical Impairments to Suckling
07:11

Assessment of the Efficacy of An Osteopathic Treatment in Infants with Biomechanical Impairments to Suckling

Published on: February 5, 2019

[Are more girls than boys born in breech presentation compared with head presentation?]

R Schrage

    Zeitschrift Fur Geburtshilfe Und Perinatologie
    |April 1, 1976
    PubMed

    Insights

    Birth presentation and sex ratios differ, with birth weight significantly influencing these differences. Girls are more common in breech presentations within middle weight groups, impacting overall sex distribution.

    Area of Science:

    • Obstetrics and Gynecology
    • Perinatal Epidemiology
    • Fetal Development

    Background:

    • Sex ratios at birth vary between cephalic and breech presentations.
    • Birth weight is a critical factor influencing presentation type and associated sex ratios.

    Purpose of the Study:

    • To investigate the influence of birth weight on sex distribution in cephalic versus breech presentations.
    • To explore the relationship between fetal weight, presentation, and sex.

    Main Methods:

    • Analysis of birth data stratified by presentation type (cephalic, breech) and birth weight categories.
    • Statistical comparison of sex ratios across different weight groups and presentations.

    Main Results:

    • Cephalic presentations show a slight male excess, particularly in higher birth weight groups.
    • Breech presentations exhibit a more complex sex distribution, with a female predominance in middle weight groups and male predominance in extreme weight groups.
    • The higher prevalence of middle-weight fetuses in breech presentations contributes to the overall excess of female births in this group.

    Conclusions:

    • Birth weight is a decisive factor in the observed sex differences between cephalic and breech presentations.
    • Fetal weight and mobility are key determinants in the occurrence of breech presentations.
    • Potential links between sex-specific infant mortality and birth weight distribution in different presentations warrant further investigation.

    More Related Videos

    Methods for In Vivo Biomechanical Testing on Brachial Plexus in Neonatal Piglets06:51

    Methods for In Vivo Biomechanical Testing on Brachial Plexus in Neonatal Piglets

    Published on: December 19, 2019

    External Cephalic Version: Is it an Effective and Safe Procedure?08:49

    External Cephalic Version: Is it an Effective and Safe Procedure?

    Published on: June 6, 2020

    Related Concept Videos

    Pedigree Analysis02:21

    Pedigree Analysis

    A pedigree is a diagram displaying a family’s history of a trait. Analyzing pedigrees can reveal (1) whether a trait is dominant or recessive, (2) the type of chromosome, autosomal or sex, a trait is linked to, (3) genotypes of family members, and (4) probabilities of phenotypes in future generations. For families with a history of autosomal or sex-linked diseases, this information can be crucial to family planning.Pedigrees Display Family HistoriesIn various plant and animal species,...
    Probability Laws01:49

    Probability Laws

    Overview
    X-linked Traits01:19

    X-linked Traits

    In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be masked by the presence of a normal allele on the second X. In contrast, a mutation on the X chromosome in males more often causes observable biological defects, as there is no normal X to compensate. Trait variations arising from mutations on the X chromosome are called “X-linked”.
    Anatomical Positions01:11

    Anatomical Positions

    In anatomy, several standard anatomical positions are used as references for describing the position and orientation of different body parts. These positions help provide a common frame of reference when discussing anatomical structures. The anatomical position is the standard reference point for describing the body's position and orientation. In this position:
    The body is upright, facing forward, and standing erect.
    The feet are parallel and flat on the floor.
    The arms are hanging by the...
    Lateralization01:28

    Lateralization

    Brain lateralization refers to the division of mental processes and functions between the two hemispheres of the brain, a phenomenon that optimizes neural efficiency and underpins complex abilities in humans. This specialization allows each hemisphere to perform tasks where it has a comparative advantage, facilitating more refined cognitive capabilities across different domains.
    Development of the Oral Microbiota01:28

    Development of the Oral Microbiota

    The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...