Maternal and Child Health Library

MCH Alert: Focus on Infant Mortality is developed by the Maternal and Child Health Library in collaboration with the National Sudden Infant Death Resource Center. This and past issues are available online at http://www.mchlibrary.info/alert/archives.html and http://www.sidscenter.org/alert/archives.html.

November 30, 2007

1. CAMPAIGN PROMOTES SAFER INFANT SLEEP ENVIRONMENT THROUGH CRIB GIVEAWAYS AND EDUCATION

Bedtime Basics for Babies is a national campaign designed to give families both the equipment and the information they need to ensure a safe sleep environment for infants. The Bedtime Basics campaign, initially launched by First Candle in April 2007, builds on the success of the national Back to Sleep campaign in reducing the risk of sudden infant death, while also emphasizing other aspects of infant sleep surroundings. In response to growing national concern about the number of infants dying in unsafe sleep conditions, the Bill and Melinda Gates Foundation recently awarded First Candle a multimillion-dollar grant to combine two components: (1) a crib-distribution component for families in need and at risk and (2) a public- and professional-education component. During the 7-year initiative, First Candle will work with public and private groups already involved with new parents and infant-mortality prevention in the target states of Indiana and Washington, as well as in the District of Columbia. A research team will track families who receive cribs, information, and support on safe sleep practices starting before their infant is born through the first year. The team will also follow infant death patterns in the targeted states. More information is available at http://www.firstcandle.org/bedtimebasics.

• Factors associated with pregnancy loss include, but are not limited to, chromosomal abnormalities, congenital abnormalities, various maternal factors (e.g., anatomic factors, endocrinopathy, immunologic factors, infection, severe acute illness, thrombophilia, uncontrolled chronic illness), fetal growth restriction, drug use, ectopic pregnancy, smoking, and trauma. Causation is well established for only chromosomal and fetal structural problems. The cause of pregnancy loss remains unexplained in up to 50% of cases.

• Chromosomal abnormalities. In addition to their role in first trimester pregnancy loss, chromosomal abnormalities also cause pregnancy loss in the second trimester.
• Fetal and maternal anatomic factors. Pregnancy loss can be caused by structural abnormalities resulting from uncontrolled maternal diabetes at conception, neural tube defects, amniotic band syndrome, or maternal exposure to teratogens. Major uterine anomalies have traditionally been associated with second trimester pregnancy loss. Cervical insufficiency or incompetence is classically associated with second trimester pregnancy loss, as well.
• Thrombophilia. A meta-analysis of 31 studies of the effect of thrombophilic disorders in pregnancy loss showed that a nonrecurrent pregnancy loss after 20 to 24 weeks' gestation is associated with factor V Leiden, protein S deficiency, and the prothrombin G20210A mutation.
• Infection. Infection has been implicated in 10% to 25% of second trimester pregnancy losses.

• History and physical examination. After a second trimester pregnancy loss, a thorough workup should be done, ideally during preconception counseling.
• Disease management and counseling. Detailed workup and management of many of the maternal factors associated with second trimester pregnancy loss often require referral to an obstetrician or perinatologist; however, the family physician can still play an important role.
• Psychological factors. The family physician is in an ideal position to address the psychological factors in women who have had a second trimester pregnancy loss.

• Research to identify the pathophysiology and genetics of SIDS must be supported and expanded to include larger sample sizes of both affected and control infants, and infants from the highest risk groups.
• Surveillance of trends in rates of SIDS and other sudden unexpected infant deaths is crucial.
• Monitoring is needed of the adoption patterns of risk-reduction recommendations among parents and health professionals and the effect of these recommendations on SIDS rates and on other important outcomes, such as breastfeeding. Established and proven measures, such as supine sleeping for all infants (including those born preterm) and avoidance of smoke exposure in utero, should continually be reinforced to new generations of health professionals, parents, and others who care for young children.
• Standardization of autopsy and scene-investigation protocols and classification of deaths are essential pieces of the SIDS puzzle.

• Overall mortality rates for both late-preterm and term infants declined significantly from 1995 to 2002. Throughout the study period, overall infant mortality rates were approximately three times higher among late-preterm infants than among term infants.
• During infancy, late-preterm infants were approximately four times more likely than term infants to die of newborn bacterial sepsis; congenital malformations; and complications of placenta, cord, and membranes.
• Between 1995 and 2002, rates of overall early neonatal mortality declined significantly among both late-preterm infants and term infants. Despite this decline, in 2002, late-preterm infants were still nearly 6 times more likely than term infants to die during their first week of life.
• In the age-at-death periods of interest, the early-neonatal period had the most disparate cause-specific mortality rates. Late-preterm infants were nearly 19 times more likely than term infants to die of atelectasis (collapse of part or all of the lung), 10 times more likely to die of maternal pregnancy complications, and 6 times more likely to die of congenital malformations.