Correction: Riyadh Mother and Baby Multicenter Cohort Study: The Cohort Profile.

[This corrects the article DOI: 10.1371/journal.pone.

Riyadh Mother and Baby Multicenter Cohort Study: The Cohort Profile.

Objectives: To assess the effects of non-communicable diseases, such as diabetes, hypertension and obesity, on the mother and the infant.

Methods: A multicentre cohort study was conducted in three hospitals in the city of Riyadh in Saudi Arabia. All Saudi women and their babies who delivered in participating hospitals were eligible for recruitment.

Polymorphism in the ADRB2 gene explains a small portion of intersubject variability in pain relative to cervical dilation in the first stage of labor.

Background: Variability in labor pain has been associated with demographic, clinical, and psychological factors. Polymorphisms of the β2-adrenergic receptor gene (ADRB2) influence sensitivity to experimental pain in humans and are a risk factor for chronic pain. The authors hypothesized that polymorphisms in ADRB2 may influence labor pain.

Oxytocin and catechol-O-methyltransferase receptor genotype predict the length of the first stage of labor.

Objective: We aimed to identify genetic factors that influence the rate of the first stage of labor.

Study Design: We prospectively enrolled 233 laboring nulliparous parturients. Demographic, clinical, and genetic data were collected.