Racial and ethnic differences in preterm birth: A complex, multifactorial problem

Preterm birth remains the leading cause of morbidity and mortality among nonanomalous neonates, and is a major public health problem. Non-Hispanic black women have a 2-fold greater risk for preterm birth compared with non-Hispanic white race. The reasons for this disparity are poorly understood and cannot be explained solely by sociodemographic factors. Underlying factors including a complex interaction between maternal, paternal, and fetal genetics, epigenetics, the microbiome, and these sociodemographic risk factors likely underlies the differences between racial groups, but these relationships are currently poorly understood. This article reviews the epidemiology of disparities in preterm birth rates and adverse pregnancy outcomes and discuss possible explanations for the racial and ethnic differences, while examining potential solutions to this major public health problem

Refining pharmacologic research to prevent and treat spontaneous preterm birth

Preterm birth (PTB), delivery prior to 37 weeks’ gestation, is the leading cause of mortality among non-anomalous neonates. Survivors carry an increased risk for lifelong intellectual, physical, and social disabilities compared with their term counterparts (Russell et al., 2007; Bodeau-Livinec et al., 2008; Vohr, 2013; Manuck et al., 2014a, 2016b; Natarajan and Shankaran, 2016). In the US alone, more than 450,000 babies are born too soon and �25,000 die as a result (Hamilton et al., 2015). Approximately two-thirds of all PTBs are spontaneous PTB (SPTB), and occur following preterm premature rupture of membranes, cervical insufficiency, and/or uterine contractions leading to cervical dilation. To reduce the burden of SPTB, interventions must target both prematurity prevention prior to the onset of symptoms and acute treatment once the process of acute preterm labor has begun

17-alpha hydroxyprogesterone caproate for preterm birth prevention: Where have we been, how did we get here, and where are we going?

Prematurity is a major public health problem in the United States and worldwide. Women with a history of a previous preterm birth are at high risk for recurrence. Progesterone is a key hormone involved in pregnancy maintenance. In general, progesterone is thought to maintain pregnancy through several closely linked mechanisms: (1) promotion of uterine quiescence, (2) inhibition of pro-inflammatory cells, and (3) immunosuppressive action. 17-Alpha hydroxyprogesterone caproate is currently the only medication approved to prevent recurrent preterm birth. The purpose of this review is to discuss the history of 17-alpha hydroxyprogesterone caproate use for recurrent preterm birth prevention, the rationale behind 17-alpha hydroxyprogesterone caproate administration, and current evidence-based indications for 17-alpha hydroxyprogesterone caproate use

Screening for spontaneous preterm birth and resultant therapies to reduce neonatal morbidity and mortality: A review

Despite considerable effort aimed at decreasing the incidence of spontaneous preterm birth, it remains the leading cause of perinatal morbidity and mortality. Screening strategies are imperfect. Approaches used to identify women considered by historical factors to be low risk for preterm delivery (generally considered to be women with singleton pregnancies without a history of a previous preterm birth) as well as those at high risk for preterm birth (those with a previous preterm birth, short cervix, or multiple gestation) continue to evolve. Herein, we review the current evidence and approaches to screening women for preterm birth, and examine future directions for clinical practice. Further research is necessary to better identify at-risk women and provide evidence-based management

Progesterone has no place in the prevention of preterm delivery: AGAINST: A call for a measured response to the OPPTIMUM trial

With the concluding words of her plenary talk at the 2016 Society for Maternal–Fetal Medi-cine Annual Meeting – ‘I wouldn’t advise my daughter take vaginal progesterone’ – had Jane Norman and the OPPTIMUM team placed a proverbial nail in the coffin of the only class of medication routinely used for the prevention of preterm birth (PTB)? For practitioners in a field with tragically few effective interventions, it is imperative that we cast a critical eye on even the most robust randomized controlled trial (RCT)

Obstetrical and Neonatal Perspectives on Prematurity

Premature birth before 37 weeks of gestation is the most common cause of infant mortality worldwide. Many pre-term infants who survive are impacted by both short- and long-term morbidity. Efforts by obstetricians and neonatologists have led to significant advances in reducing preterm birth and improving outcomes. In 2014, infant mortality in the United States was the lowest on record. However, additional work is still urgently needed to reduce the burden of preterm birth on patients, families, and society. We believe that this work requires strong collaboration between obstetricians and neonatologists. We selected topics for this theme issue with this goal in mind. This issue highlights current evidence as it relates to pressing topics on premature birth in the fields of obstetrics and neonatology

Alcohol in pregnancy: not recommended at any gestational age

Preterm birth remains a multifactorial, worldwide problem. Though there are multiple established risk factors for preterm birth (e.g. previous preterm birth, short cervix), the association between maternal alcohol consump-tion and prematurity is less clear, with risk ratios ranging from 0.66 (95% CI 0.52–0.84) to 1.34 (95% CI 1.28–1.41)(Strandberg-Larsen et al. Eur J Epi-demiol 2017;32:751–64; Aliyu et al. Eur J Public Health 2010;20:582–7)

Reply

We appreciate Ms Cohain’s interest in our manuscript and concerns regarding the association between oxytocin use and uterine rupture. Unfortunately, oxytocin use was only one obstetric covariate and not our main focus. In addition, the facts presented in Ms Cohain’s letter are incorrect; 4 women with primary uterine rupture were neither induced nor received oxytocin augmentation. The claim that “the unscarred uterus that is not artificially forced to contract, will not contract so hard as to explode itself ” should not, as the majority of situations in medicine and in obstetrics, be considered absolute. We speculate that underlying undiagnosed connective tissue aberrations or genetic factors may have influenced the development of uterine rupture in these 4 women. Unfortunately, our study design precludes an investigation of causation

Collaboratively Understanding and Improving Outcomes for the Mother, Fetus, and Infant

Birth is an incredibly exciting and yet potentially dangerous period for a woman and her fetus, who attempts to navigate the complex transition to neonatal life. Many events during this period establish or disrupt long-lasting health for both the mother and her infant. The challenges during this period are too numerous to quantify, but yield oppor-tunities for prevention and treatment strategies to improve perinatal care and neonatal outcomes. In this issue of Clinics of Perinatology, we highlight these opportunities by including articles that span across obstetrics and neonatology

Genomics of Preterm Birth-Evidence of Association and Evolving Investigations

Preterm birth (PTB) is a large public health problem in the United States and worldwide. There is a clear genetic component to the pathogenesis of PTB, as evidenced by twin studies, heritability studies, and investigations from large population databases. Although numerous single nucleotide polymorphisms have been associated with PTB, results have been inconsistent and overall disappointing. With recent advances in genetic technology, investigations are moving beyond simple, more traditional candidate gene studies, and have expanded to encompass more exploratory analyses using high-throughput genetic techniques. Care should be taken to consider the potential impact of fetal genotype, the environment, and gene-drug interactions (pharmacogenomics) in addition to maternal genotype. Future research should capitalize on evolving analytic techniques, including pathway analyses and correlation of genetic and functional data to optimize discovery, increase knowledge regarding prematurity pathogenesis, and begin to develop novel therapeutic strategies