Impact of Room Light on Uterine Contractions and Labor Progression in Pregnancy

Today it remains a challenge to successfully both halt and induce labor progression. Induction of labor is a common obstetric intervention that 1 in 4 women will experience. The goal of induction of labor is to achieve a vaginal birth, however in almost 40% of first-time mothers it fails. Failed labor inductions require a caesarean delivery, which is associated with a vast range of adverse effects for both the mother and her baby. In this application we propose that a simple manipulation of room light will increase the success of vaginal birth through the use of optimal room light settings (halting labor=lights ON, promoting labor=reduced room light/red room light). A sparse literature has shown that the hormone melatonin might be an important hormone to consider during late pregnancy and labor. Pineal melatonin release is only released in darkness at night, where nocturnal light such as room light, suppress pineal melatonin release, reducing uterine contractions (Olcese et al 2013, https://pubmed.ncbi.nlm.nih.gov/22556015/, Rahman et al 2019, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6453747/). Melatonin receptor become upregulated in the pregnant myometrium (uterine smooth muscle), and a small study in women having preterm birth, showed a high expression of melatonin receptor, at a gestational week where women not having preterm uterine contractions, had low levels of melatonin receptor, suggesting that premature increase in myometrium melatonin receptor might in some women be associated with preterm labor and birth (Olcese et al 2013, https://pubmed.ncbi.nlm.nih.gov/22556015/). This study will address how room light impacts melatonin release and uterine contractions in healthy pregnant women.