A new study from the National Institutes of Health (NIH) reveals that twins, on average, begin their pregnancies smaller than singletons, with reduced fat tissue and muscle mass as early as 15 weeks gestation. These findings could reshape how physicians monitor and manage twin pregnancies, provided the results are confirmed by further research.
The study, led by Dr. Jessica Gleason and Dr. Katherine Grantz from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, is published in JAMA Pediatrics. Researchers analyzed 3D ultrasound scans from 2,604 singleton pregnancies and 315 twin pregnancies, focusing on those with individual placentas. Twin pairs sharing a placenta were excluded from the study.
At just 15 weeks, twins were found to have significantly smaller thigh volumes compared to singletons, with less fat and lean muscle mass. Additionally, their fat-to-lean ratio was proportionally lower by 2.7% to 4.2% throughout the pregnancy, from 15 to 37 weeks. This discovery challenges earlier studies that only noted reduced growth for twins during the later stages of pregnancy, primarily from 28 to 40 weeks.
The researchers suggest that the smaller size of twins early in pregnancy is not due to increased competition for nutrients, as the placental development would have provided sufficient resources during this period. Instead, they propose that this early growth pattern may be an adaptive mechanism, preparing twins to meet the increased nutritional demands later in pregnancy.
If these findings are confirmed, they could help improve guidelines for monitoring twin pregnancies and inform strategies for managing their development.
Related topics:
Maternal Inflammation Linked to Delayed Infant Brain Development
Outdoor Play and Multisport Key to Children’s Motor Development
Study Investigates Hormonal Contraception and Postpartum Depression Risk
