Some pregnant women describe a burst of energy during pregnancy, usually during the third trimester, according to online blogs such as Mothering. This infusion of energy is thought to part of a primitive nesting instinct to prepare for the birth of a baby, according to the Mayo Clinic. Experiencing a burst of energy before labor happens to some women, but not all.
Nesting Instinct and Behavior
Pregnant women who describe an energy boost during the weeks or days before labor say they are driven to organize and reorganize to prepare for their baby. Although there is not enough proof, some experts say that this burst of energy and call to action is a woman's response to an evolutionary nesting instinct and behavior that is found in many species.
There is little information on nesting instinct and behavior in pregnant women. Some evidence for this behavior comes from two studies reported in 2013 in the Journal of Evolution and Human Behavior by researchers at McMaster University in Canada:
- One study was an online questionnaire of women after pregnancy compared to answers from non-pregnant women.
- Using a similar questionnaire, the second study followed women during pregnancy and the postpartum period.
The authors concluded that pregnant women, compared to non-pregnant women, exhibited nesting behaviors similar to other non-human species. The activities included "space preparation and social selectivity (who the women chose to associate with)" to prepare a safe, organized space for their baby.
According to the authors, these behaviors "peaked in the third trimester," but women may get this drive as early as five months of pregnancy. Not all women appear to experience this burst of energy and compulsive drive, and there is no data to suggest that this boost signals impending labor.
Human Evolutionary Adaptation
A modern woman's energy infusion and her preparations before childbirth are said to be adaptative to modern life. While ancient women prepared "nests" of straw and animal skins, modern women's nesting behavior is to cook, clean, and reorganize the house and the baby's room and clothes.
The theory of human nesting behavior comes from observations and studies of several non-human species, such as birds, mice, rats, rabbits, and sheep. The nesting instinct and compulsive, organizing behavior is seen in many species as they prepare to nurture and protect their baby by building birth nests and sanctuaries before giving birth. According to a study in rabbits published in 2006 in the Journal of Endocrinology, the onset of the behavior is related to changes in the hormones estradiol, progesterone, and prolactin.
Manage Your Energy Boost
If you find yourself with a new boost of energy that drives you to compulsive preparation for your baby's arrival, be sure to not wear yourself out in the process, especially close to your due date. Ask for help to manage your preparations safely and find time to relax before labor begins.