Genetic influence on prolonged gestation: a population-based Danish twin study

Area of Science:

• Reproductive biology
• Genetics
• Obstetrics

Background:

• Prolonged gestation, defined as a pregnancy lasting longer than 42 weeks, can lead to adverse maternal and neonatal outcomes.
• The etiology of prolonged gestation is not fully understood, with potential contributions from genetic and environmental factors.

Purpose of the Study:

• To investigate the potential genetic heritability of prolonged gestation.
• To differentiate between maternal and fetal genetic influences on pregnancy duration.

Main Methods:

• Utilized data from the Danish Twin Registry, Danish Civil Registration System, and Danish Medical Birth Register.
• Analyzed gestational duration in 2588 same-sex twin pairs where both twins had their first child between 1978 and 1996.
• Employed biometric modeling to estimate the heritability of prolonged gestation.

Main Results:

• Higher concordance rates for prolonged gestation (>41 and >42 weeks) were observed between monozygotic female twins compared to dizygotic female twins, indicating maternal genetic effects.
• Biometric modeling estimated that maternal genetic factors account for 23% to 30% of the liability to prolonged gestation.
• No significant genetic influence on prolonged gestation was detected in male twin pairs, suggesting a lack of paternal genetic effect through the fetus.

Conclusions:

• Maternal genes play a significant role in determining pregnancy duration and influencing prolonged gestation.
• Paternal genetic contributions to prolonged gestation, mediated via the fetus, were not supported by the study findings.
• Further research may explore other genetic or environmental factors contributing to prolonged gestation.