Low Birth Weight and Prevention of Preterm

Prevention of Preterm Low Birth Weight

Prevention of Preterm and Low Birth Weight Births,Causes of Low Birth Weight or Preterm Birth,Descriptive Research Related on Low Birth Weight and Prevention of Preterm,Role  of  Prenatal Care to Reduce Low Birth Weight,Effectiveness Breast Feeding as Preventive Interventions,Cessation of Smoking and Affects on Low Birth Weight,Conclusion.

Prevention of Preterm and Low Birth Weight Births

    The prevention of preterm and low-birth weight (LBW) births continue to be a major health care challenge in the United States. Preterm or premature births are defined as those occurring before 37 completed weeks of gestation, with very preterm births considered to be those occurring before 32 completed weeks of gestation. 

    Low-birth weight is defined as a weight of less than 2,500 grams (5 lbs 8 oz), while very-low-birthweight (VLBW) indicates a weight of less than 1,500 grams (3 lbs 4 oz). 

    In spite of major advances in prenatal and perinatal health care, the incidence of preterm birth in the United States increased by 27% between 1981 and 2001, now representing 11.9% of all births. 

    In 2001, preterm birth with low-birthweight was the leading cause of death in the 1st first month of life, accounting for 23% of all neonatal deaths, and further, is a leading contributor to infant morbidity including: mental retardation, cerebral palsy, vision and hearing deficits, and chronic lung disease. 

    Demographically, there is an increasing disparity in rates of preterm and low-birthweight births by African-American mothers (17.5% in 2002) and those by white mothers (11.1% in 2002) (Centers for Disease Control and Prevention, National Center for Health Statistics, 2003). This growing disparity is not explained by known risk factors for preterm births.

Causes of Low Birth Weight or Preterm Birth

    The occurrence of preterm births and low-birthweight births are a distinct but highly related phenomenon, with 98% of VLBW births and 66% of LBW births associated with prematurity. Additionally, 20%-30% of low-birthweight births are associated with maternal smoking. 

    The specific causes of pre-term birth remain unclear at this time despite intensive research. However, risk factors as associated with preterm birth include: maternal use of alcohol, tobacco or other drugs during pregnancy; low maternal weight pre-pregnancy or low weight-gain during pregnancy; short interpregnancy interval; maternal infections including periodontal disease; social stress; maternal age; and domestic violence. 

    Reflecting the continuing concern regarding preterm and LBW births in the United States, two of the objectives of Healthy People 2010 are the reduction in the incidence of low-birthweight and very-low-birthweight births, and the reduction of preterm births.

Descriptive Research Related on Low Birth Weight and Prevention of Preterm 

    Research related to preterm and LBW births includes descriptive, correlational, and historical studies exploring the relationships among possible risk factors and birth outcomes; the evaluation of common interventions (traditionally designated prenatal care and bed rest for prevention of preterm labor) designed to reduce the incidence of preterm and low-birth weight births; and testing interventions directed at modifiable risk factors.

Role  of  Prenatal Care to Reduce Low Birth Weight

    One of the areas intensively studied is the role of prenatal care in reducing the incidence of LBW births. In 1985 the Institute of Medicine (IOM) published a report concluding that, based on available research, early and comprehensive prenatal care was effective in reducing the incidence of LBW (Institute of Medicine, 1985). 

    This conclusion promoted a national policy advocating universal and Carly prenatal care. However, in a recent meta-analysis of original research, systematic reviews, other meta analyses, and comments evaluating the content, timing, and context of prenatal care, Lu, Tache, Alexander, Kotelchuk, and Halton ( 2003 ) conclude that there is little evidence that prenatal care as currently practiced is effective in preventing preterm or LBW births. 

    In a critical review of current science related to preterm and LBW births, Lu and colleagues propose that the content of prenatal care be redesigned to include risk assessments for neuro endocrine, immune-inflammatory, and vascular mechanisms now thought to have a causative role in preterm and LBW births. 

    Furthermore, they challenge the timing of prenatal care, suggesting that many of the antecedents to preterm and LBW births occur early in the life of the mother, before the initiation of prenatal care or pregnancy. 

    Factors including maternal nutritional status, early exposure to infectious or inflammatory disease, and early chronic maternal stress may be related to later negative birth outcomes. Thus, the timing of “prenatal care” needs to be reconceptualized to include early and comprehensive health care rather than limited to the period of the pregnancy. 

    Finally, they propose that prenatal care that does not address the social and environmental context of the mother is likely to be ineffective. The experience of racial discrimination, air and water pollution, neighborhood safety concerns, and the lack of a socially supportive environment have all been linked to an increased incidence of preterm and LBW births.

Effectiveness Breast Feeding as Preventive Interventions

    The effectiveness of a second common intervention, prolonged bedrest to prevent preterm labor, has been challenged by nurse researchers. Maloni (1996) describes the common side effects of prolonged bedrest during pregnancy, including depression, anxiety, and muscle weakness. 

    In a sample of 141 women treated with prolonged antepartum bedrest, maternal weekly weight-gain was lower than the IOM recommendations (p < 0.001) and infant birthweights were lower than the national mean when matched with the national average for each infant's race, gender, and gestational age (p < 0.001) (Maloni , Alexander, Schluchter , Shah, & Park, 2004). 

    In addition, while the prescription of bedrest continues to be a common intervention to prevent preterm labor, no controlled studies have been reported to support its effectiveness.

Cessation of Smoking and Affects on Low Birth Weight 

    Two interventions evaluated in controlled studies are the effectiveness of smoking cessation programs and community based nursing telephone follow up. Maternal smoking during pregnancy accounts for 20%-30% of all LBW births in the United States (Healthy People 2010, 2000) and is one of the most important modifiable causes of poor pregnancy outcomes. 

    Smoking cessation programs as part of prenatal care have been studied to determine their impact on maternal smoking behaviors. A nurse-managed smoking cessation program consisting of a 15-minute individualized intervention combined with telephone follow-up after 7-10 days was evaluated with 178 pregnant women ( Gebauer , Kwo , Haynes, &Wewers , 1998). 

    At 6-12 weeks after the intervention, the intervention group had a 19% self-reported abstinence and a 15.5% abstinence confirmed by saliva cotinine, compared with 0% in the control group. 

    In related work, the 6th Research Based Practice program developed by the Association of Women's Health, Obstetrical and Neonatal Nurses (AWHONN) focused on the development of an evidence-based protocol to address smoking in pregnancy ( Maloni , Albrecht, Thomas , Halleran , & Jones, 2003). 

    The AWHONN program uses translational research to create protocols for integration directly into clinical practice. The protocol to address smoking cessation during pregnancy includes screening strategies and counseling during prenatal care.

    In a prospective, randomized trial with a sample of 1,554 women receiving prenatal care, the effectiveness of a nursing telephone intervention was tested. Women in the intervention group received telephone calls from a registered nurse one-two times per week during the 3rd trimester of their pregnancies. 

    In a cohort of African-American women 19 years of age or older, the incidence of LBW births was reduced from 15.3% in the control group to 11.3% in the intervention group ( Muender , Moore, Chen, &Sevick , 2000).

Conclusion

    In summary, the mechanisms leading to preterm and LBW births are not clearly understood. Therefore, much of current research is focused on the elucidation of causation and on the evaluation of interventions to reduce known risk factors. 

    Interventions reported to be effective include smoking cessation classes and telephone follow-up and support by nurse clinical specialists. Controversies continue regarding the effectiveness of prenatal care as it is commonly provided and the use of bedrest for the prevention of pre term labor.