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

[This corrects the article DOI: 10.1371/journal.pone.0150297.].

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. Data on socio-demographic characteristics in addition to the maternal and neonatal outcomes of pregnancy were collected. The cohort demographic profile was recorded and the prevalence of maternal conditions including gestational diabetes, pre-gestational diabetes, hypertensive disorders in pregnancy and obesity were estimated. FINDINGS: The total number of women who delivered in participating hospitals during the study period was 16,012 of which 14,568 women participated in the study. The mean age of the participants was 29 ± 5.9 years and over 40% were university graduates. Most of the participants were housewives, 70% were high or middle income and 22% were exposed to secondhand smoke. Of the total cohort, 24% were married to a first cousin. More than 68% of the participants were either overweight or obese. The preterm delivery rate was 9%, while 1.5% of the deliveries were postdate. The stillbirth rate was 13/1000 live birth. The prevalence of gestational diabetes was 24% and that of pre-gestational diabetes was 4.3%. The preeclampsia prevalence was 1.1%. The labour induction rate was 15.5% and the cesarean section rate was 25%. CONCLUSION: Pregnant women in Saudi Arabia have a unique demographic profile. The prevalence of obesity and diabetes in pregnancy are among the highest in the world.

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 ß2-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. METHODS: After Institutional Review Board approval and written informed consent, the authors prospectively obtained hourly pain reports from 233 nulliparous parturients during the first stage of labor, of which 199 were included in the current analysis. DNA from blood samples was genotyped at polymorphisms in the genes for the ß2-adrenergic receptor, the µ opioid receptor subtype 1, catechol-O-methyltransferase, fatty acid amide hydrolase, and the oxytocin receptor. Labor pain as a function of cervical dilation was modeled with previously described methods. Patient covariates, ADRB2 genotype, and obstetrical and anesthesia treatment were evaluated as covariates in the model. RESULTS: Labor pain more rapidly became severe in parturients heterozygous or homozygous for the G allele at rs1042714 in the ADRB2 gene. Labor pain increased more rapidly after artificial rupture of membranes, augmentation with oxytocin, and in younger women. Inclusion of covariates explained approximately 10% of the variability between subjects. ADRB2 genotype explained less than 1% of the intersubject variability. CONCLUSION: ADRB2 genotype correlates with labor pain but explained less than 1% of the intersubject variance in the model.

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. We evaluated the influence of population and individual variability using a nonlinear mixed effects model. RESULTS: Parturients who were homozygous for "G" at oxytocin receptor gene rs53576 transitioned to active labor later and thus had slower labor. Catechol-O-methyltransferase rs4633 genotype TT was associated with slower latent phase labor. Labor induction with prostaglandin was associated with faster labor, and request for meperidine was associated with slower labor. Birthweight was related inversely to the rate of the active phase. CONCLUSION: There are demographic, clinical, and genetic factors that influence an individual's rate of labor progress. This information could be used in automated form to improve the prediction of the length of the first stage of labor.