Contributions of ischaemic placental disease to preterm birth in twin gestations

Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Objective Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. Methods We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. Results A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Conclusion Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.

Preeclampsia and preterm delivery: A population-based case-control study

OBJECTIVE

To determine the contribution of preeclampsia toward preterm birth in primiparous women.

METHODS

This large population-based case-control study used the Aberdeen Maternity and Neonatal Databank to analyze data on primiparous women with singleton pregnancies, who delivered between 1997 and 2012.

RESULTS

A significant positive association was found between preeclampsia and preterm birth (adjusted odds ratio 4.43; 95% confidence interval 3.80-5.16). Magnitude of association varied according to the onset of delivery and year of delivery.

CONCLUSION

Preeclampsia is an important contributor to preterm delivery in this setting and therefore a potentially useful condition to target in order to reduce preterm rates.

Epidemiology of twinning in developed countries

Twin births contribute disproportionately to the overall burden of perinatal morbidity and mortality in developed countries. Twins constitute 2%-4% of all births, and the rate of twining has increased by 76% between 1980 and 2009. The rate of preterm birth (<37 weeks) among twins is about 60%. Of all twin preterm births in the United States, roughly half are indicated, a third are due to spontaneous onset of labor, and about 10% are due to preterm premature rupture of membranes. Mortality related to preterm birth is influenced by antecedent factors and is highest when preterm delivery is the consequence of preterm premature rupture of membranes, followed by those as a result of spontaneous preterm labor and lowest among indicated preterm births. There also appears to have been a recent decline in serious neonatal morbidity (one or more of 5-minute Apgar score <4, neonatal seizures or assisted ventilation for ≥ 30 minutes) among twin gestations. Compared with twins conceived naturally, those born of assisted reproduction methods are more likely to deliver at <37 weeks. Although perinatal mortality rates have declined among twin births, the effect of preterm delivery on trends in mortality and morbidity and other long-term consequences remain issues for major concern. With the rapid increase in the liberal use of assisted reproduction methods combined with women electing to postpone their pregnancies and increased likelihood of spontaneous twins with advancing maternal age, this review underscores the need to develop priorities to understand the peripartum and long-term consequences facing twin births.

Epidemiology: the changing face of preterm birth

Preterm birth, defined as a pregnancy ending at less than 37 completed weeks of gestation, is the leading cause of infant mortality in the United States. The occurrence of preterm births rose steadily from 9.4% of all pregnancies in the United States in 1981 to 12.8% in 2006, before declining to 12.7% in 2007 and 12.3% in 2008. Most of the increase was attributable to increases in multiple gestations. Recent research has sought to understand this condition by evaluating its familial occurrence and both clinical and pathologic information to derive an etiologically homogeneous categorization.