Preterm Birth 1: Epidemiology and Causes of Preterm Birth

Abstract

This paper is the fi rst in a three-part series on preterm birth, which is the leading cause of perinatal morbidity and mortality in developed countries. Infants are born preterm at less than 37 weeks' gestational age after: (1) spontaneous labour with intact membranes, (2) preterm premature rupture of the membranes (PPROM), and (3) labour induction or caesarean delivery for maternal or fetal indications. The frequency of preterm births is about 12-13% in the USA and 5-9% in many other developed countries; however, the rate of preterm birth has increased in many locations, predominantly because of increasing indicated preterm births and preterm delivery of artifi cially conceived multiple pregnancies. Common reasons for indicated preterm births include pre-eclampsia or eclampsia, and intrauterine growth restriction. Births that follow spontaneous preterm labour and PPROM-together called spontaneous preterm births-are regarded as a syndrome resulting from multiple causes, including infection or infl ammation, vascular disease, and uterine overdistension. Risk factors for spontaneous preterm births include a previous preterm birth, black race, periodontal disease, and low maternal body-mass index. A short cervical length and a raised cervical-vaginal fetal fi bronectin concentration are the strongest predictors of spontaneous preterm birth.

Maternal Anemia in Benin: Prevalence, Risk Factors, and Association with Low Birth Weight

“…We did not have information available for the following variables known to be associated with LBW: spousal violence, smoking, alcohol intake, anthropometric measures of the father. [24][25][26] However, they should not be associated with maternal anemia and, thus, should not be confounding factors in our study. Infant's sex and adolescent pregnancies are known to be associated with LBW, but not with anemia.…”

Brain functional network connectivity development in very preterm infants: The first six months

“…One out of every eight babies is born premature each year in the United States [1]. Of these, nearly 10% are born very preterm at 32 weeks completed gestational age or less.…”

Matrix metalloproteinases-2, -3 and tissue inhibitors of metalloproteinases-1, -2 in placentas from preterm pregnancies and their association with one-carbon metabolites

“…A number of factors are known to increase the risk of preterm birth, but the mechanisms underlying the initiation of preterm labor are not clear (Goldenberg et al 2008). Matrix metalloproteinases (MMPs) are reported to contribute during pregnancy in extracellular matrix (ECM) remodeling/degradation leading to cervical ripening, fetal membrane rupture, and finally placental separation from maternal uterus (Stygar et al 2002, Goldman et al 2003.…”