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Facts of Life

Facts of Life:
Issue Briefings for Health Reporters
Vol. 10, No. 4
April 2005

Prenatal Care: Proven Practices or Old Wives’ Tales?

The Issue

The Facts

Leaving Well Enough Alone

Expert Sources

References

The Issue:

The nine months of pregnancy come complete with a rich folklore, from guessing at a baby’s sex by the expectant mother’s shape to home remedies for morning sickness. Along with these ageless stories and advice, women also face a variety of recommendations from the modern world of medicine on how best to take care of themselves during pregnancy. Yet new systematic reviews suggest that in some cases, the evidence supporting a link between prenatal care and specific outcomes may be as scarce as the data behind the “old wives’ tales.”.

Healthy Moms, Healthy Babies

Recently, physicians have shifted the focus of prenatal care further back into time, recommending healthy changes long before women consider having children. The success story of folic acid is part of this trend. In 1996, the Food and Drug Administration asked manufacturers to add folic acid to grain products like cereals and breads, and neural tube birth defects dropped by 19 percent in 2001 as a result. Exercise and diet counseling and domestic abuse screening are now part of the preconception care guidelines recommended by the U.S. Preventive Services Task Force and others. 1

Taking Stock

The new antidepressants are a success story, an effective treatment for millions and a market winner for many drug companies. But researchers are just beginning to examine the 20 years’ worth of data available for the drugs to answer some pressing questions about their use. Are all second-generation antidepressants equally effective? How often do serious side effects like suicide occur? And should the medications be used sparingly in certain groups, like children and pregnant women?. A review of the cost effectiveness of depression treatment concluded that there are few studies that compare the cost-effectiveness of behavioral and drug-based therapies for depression.1

The Facts:

  • A systematic review of studies of communication between pregnant women and their physicians suggests that women are less anxious about prenatal testing if the test information is provided in a variety of formats. 3
  • About 2 percent of women, according to a 2001 Cochrane Collaboration systematic review of more than 2,500 patients, may prefer their pregnancy care to be led by a general practitioner or midwife as opposed to an obstetrician or gynecologist. 4
  • A literature review of 296 studies found that abused pregnant women are more likely to have kidney infections, gain less weight and have cesarean deliveries. 5
  • A 2005 meta-analysis concluded that progesterone drugs given to pregnant women at risk for premature deliveries could reduce rates of premature birth and low birth weight. 6
  • Calcium supplements may reduce the risk of high blood pressure in pregnant women at high risk for gestational diabetes and those who have calcium-poor diets. 7
  • Vitamin B6 may help prevent nausea and vomiting in early pregnancy, according to a 2003 Cochrane Collaboration systematic review. 8
  • Group breastfeeding education classes can prolong the time that a mother nurses her children, according to a 2001 systematic review. 9
  • The opinion of prominent physicians in a community can strongly influence rates of vaginal birth after cesarean section, a 2004 review found. 10
  • Education programs to increase rates of vaginal birth after a previous cesarean section have no effect, according to a 2000 Cochrane Collaboration systematic review. 11
  • The evidence that bed rest, special diets and birth education prevent low birth weight is inconclusive, according to a 2003 systematic review. 12
  • The impact of gestational diabetes screening on the health of mothers and newborns is uncertain because there are no well-conducted, randomized controlled trials of such screening, according to the U.S. Preventive Services Task Force. 13
  • A 2003 review found no suitable prenatal screening tests to predict postnatal depression in a general population of pregnant women. 14

 

Leaving Well Enough Alone:

In developed countries like the United States, pregnant women usually visit their obstetrician at least monthly over the course of a healthy and problem-free pregnancy. During these visits, women receive numerous blood and urine tests to detect high blood pressure, anemia, diabetes and birth defects in the fetus. At some stage in the pregnancy, women may undergo an ultrasound or some other form of fetal monitoring. At the very least, expectant mothers are handed a prescription for prenatal vitamins and a list of foods to eat and avoid.

The evidence that multiple visits, constant monitoring and special diets lead to better outcomes for baby and mother, however, is being questioned by new systematic reviews and large-scale analyses of available studies. For instance, a major review by the World Health Organization in 2001 found that women who visited their doctors only four times during their pregnancy were comparable to those who had 12 or more visits in rates of pre-eclampsia (a dangerous form of very high blood pressure among pregnant women), postpartum anemia, low birth weights and infant and mother deaths. 15

“ Traditionally, low-risk pregnant women in the United States who participate in prenatal care have been scheduled for about 14 to 16 prenatal visits, which is the schedule recommended by the American College of Obstetricians and Gynecologists,” says Deborah Walker, a clinical nursing professor at Wayne State University.

Walker says the available evidence from the WHO report and a similar study in 1989 by the U.S. Department of Health and Human Services16 suggests most women will do fine with fewer visits. But women who have been used to a certain level of care may have trouble getting used to that idea, according to the WHO report, which found that expectant mothers in developed countries like the United States were more dissatisfied with the reduced visit schedule.

Low birth weight and early delivery are among the most common pregnancy complications, and women at risk for those complications are treated with a variety of preventive measures. But according to Dr. Michael Lu of the University of California, Los Angeles School of Medicine, there is little evidence to support most of these treatments, including bed rest, childbirth education and antibiotic and hormonal treatments. Preterm births and low birth weights are not “effectively prevented by prenatal care in its present form,” Lu and colleagues concluded in a 2003 systematic review. 12

Among the other interventions offered routinely to pregnant women are ultrasound readings and nutritional advice. Yet there is scarce evidence to support either recommendation, according to recent reviews by the Cochrane Collaboration. In 2000, reviewers concluded that late term ultrasound in low-risk pregnancies does not benefit either mother or baby.17 A 2003 review found that there was no “consistent benefit” to mother or child when women ate more daily calories and grams of protein during their pregnancies. 18

 

Expert Sources:

Michael C. Lu
UCLA Schools of Medicine & Public Health
(310) 825-5297
mclu@ucla.edu

Seth Brody
University of North Carolina at Chapel Hill and Wake Medical Center
(919) 350-8535
sbrody@med.unc.edu

Deborah S. Walker
Wayne State University
(313) 577-1798
dswalker@wayne.edu

Lelia Duley
University of Oxford
+44 1865 226642
lelia.duley@ndm.ox.ac.uk

References

1. M.A. Honein et al. (2001) Impact of folic acid fortification of the US food supply on the occurrence of neural tube defects. Journal of the American Medical Association, 285, 2981-2986.

2. N. Pattison et al. (1999) Cardiotocography for antepartum fetal assessment. The Cochrane Database of Systematic Reviews 1999, Issue 1.

3. R.E. Rowe et al. (2002) Improving communication between health professionals and women in maternity care: a structured review. Health Expectations, 5, 63-83.

4. J. Villar et al. (2001) Patterns of routine antenatal care for low-risk pregnancy (Cochrane Review). The Cochrane Library, 4, 2001.

5. A. Boy and H.M. Salihu (2004) Intimate partner violence and birth outcomes: a systematic review. International Journal of Fertility and Women’s Medicine, 49, 159-164.

6. L. Sanchez-Ramos et al. (2005) Progestational agents to prevent preterm birth: a meta-analysis of randomized controlled trials. Obstetrics and Gynecology, 105, 273-279.

7. A.N. Atallah et al. (2002) Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems. The Cochrane Database of Systematic Reviews 2002, Issue 1.

8. D. Jewell and G. Young (2003) Interventions for nausea and vomiting in early pregnancy. The Cochrane Database of Systematic Reviews 2003, Issue 4.

9. M.I. de Oliveira et al. (2001) Extending breastfeeding duration through primary care: a systematic review of prenatal and postnatal interventions. Journal of Human Lactation, 17, 326-343.

10. D.F. Kraemer et al. (2004) The relationship of health care delivery system characteristics and legal factors to mode of delivery in women with prior cesarean section: a systematic review. Women's Health Issues, 14. 94-103.

11. A.J. Gagnon (2000) Individual or group antenatal education for childbirth/parenthood. The Cochrane Database of Systematic Reviews 2000, Issue 4.

12. M.C. Lu et al. (2003) Preventing low birth weight: is prenatal care the answer? Journal of Maternal, Fetal and Neonatal Medicine, 13, 362-380.

13. S.C. Brody et al. (2003) Screening for gestational diabetes: a summary of the evidence for the U.S. Preventive Services Task Force. Obstetrics and Gynecology, 101, 380-392.

14. M.P. Austin and J. Lumley (2003) Antenatal screening for postnatal depression: a systematic review. Acta Psychiatrica Scandinavica, 107, 10-17.

15. G. Carroli et al. (2001) WHO systematic review of randomised controlled trials of routine antenatal care. The Lancet, 357, 1565-1570.

16. D.S. Walker et al. (2001) Evidence-based prenatal care visits: when less is more. Journal of Midwifery and Women’s Health, 46, 146-151.

17. L. Bricker and J.P. Neilson (2000) Routine ultrasound in late pregnancy (after 24 weeks gestation). The Cochrane Database of Systematic Reviews 2000, Issue 1.

18. M.S. Kramer and R. Kakuma (2003) Energy and protein intake in pregnancy. The Cochrane Database of Systematic Reviews 2003, Issue 4.

The Center for the Advancement of Health is an independent nonprofit organization that promotes greater recognition of how psychological, social, behavioral, economic and environmental factors influence health and illness. The Center advocates the highest quality research and communicates it to the medical community and the public. The fundamental aim of the Center is to translate into policy and practice the growing body of evidence that can lead to the improvement and maintenance of the health of individuals and the public. The Center was founded by the John D. and Catherine T. MacArthur Foundation and the Nathan Cummings Foundation, which continue to provide core funding. Funding for this series was provided by the Robert Wood Johnson Foundation.

For Information Contact:
Lisa Esposito
Editor, Health Behavior News Service
Center for the Advancement of Health
2000 Florida Ave., NW, Suite 210
Washington, DC 20009
p. 202.387.2829 / f. 202.387-2857
press@cfah.org
http://www.cfah.org

© Copyright 2005, Center for the Advancement of Health

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