Related Experiment Video
Updated: Aug 8, 2026
08:53
Generation of the Early-Gestational Maternal Immune Activation Mouse Model to Assess Prenatal Inflammation on Neurodevelopment
Published on: March 24, 2026
Birth weight discordance in multiple gestations: occurrence and outcomes
1Department of Maternal and Child Health, University of Alabama at Birmingham, Alabama, USA.
Summary
Birth weight discordance is common in multiple pregnancies, significantly increasing fetal and neonatal mortality risks, especially for smaller twins and those small for gestational age.
Area of Science:
- Perinatology
- Obstetrics
- Neonatology
Background:
- Birth weight discordance is a frequent complication in multiple gestations.
- Significant variations in birth weight occur between co-twins and co-triplets.
- This discordance poses risks to fetal and neonatal well-being.
Purpose of the Study:
- To review the occurrence, measurement, and impact of birth weight discordance.
- To analyze the association between birth weight discordance and mortality in twins and triplets.
- To investigate factors influencing discordance and its effect on neonatal outcomes.
Main Methods:
- Review of existing literature on birth weight discordance in multiple pregnancies.
- Analysis of occurrence rates and severity of discordance in twin and triplet gestations.
- Examination of the relationship between discordance and fetal/neonatal mortality.
Main Results:
- Approximately 25% of twin deliveries and a higher proportion of triplet deliveries exhibit birth weight discordance.
- Severe discordance (>35% in twins, >25% in triplets) is observed in a notable percentage of multiple births.
- Birth weight discordance is significantly linked to increased fetal and neonatal mortality, particularly in smaller or growth-restricted infants.
Conclusions:
- Birth weight discordance is a critical factor influencing mortality in multiple pregnancies.
- The risk of neonatal demise is elevated for discordant infants, especially the smaller twin.
- Gestational age and fetal growth status exacerbate the mortality risk associated with birth weight discordance.
Related Concept Videos
01:20Pathophysiology of Diabetes
Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia. The four categories of diabetes are type 1 diabetes, type 2 diabetes, other specific types of diabetes, and gestational diabetes.
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
01:52Regression Toward the Mean
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when researchers try to extrapolate results...
01:17z Scores and Area Under the Curve
z scores are the standardized values obtained after converting a normal distribution into a standard normal distribution. A z score is measured in units of the standard deviation. The z score tells you how many standard deviations the value x is above (to the right of) or below (to the left of) the mean, μ. Values of x that are larger than the mean have positive z scores, and values of x that are smaller than the mean have negative z scores. If x equals the mean, then x has a z score of zero.
01:29Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
01:21Nondisjunction
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold sister...
01:29Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.