April 2009 · Vol. 58, No. 4: 220a-220c
CLINICAL INQUIRIES: ONLINE EXCLUSIVE
Evidence Based Answers from the Family Physicians Inquiries Network
Do abnormal fetal kick counts predict intrauterine death in average-risk pregnancies?Carmen Strickland, MD
Department of Family Medicine, Mayo Clinic in Arizona, Scottsdale/Phoenix
Medical College of Wisconsin, Milwaukee
No. Structured daily monitoring of fetal movement doesn’t decrease the rate of all-cause antenatal death in average-risk pregnancies (strength of recommendation [SOR]: B, single good-quality, randomized controlled trial [RCT]). Although maternal perception of decreased fetal movement may herald fetal death, it isn’t specific for poor neonatal outcome (SOR: B, single good-quality, diagnostic cohort study). Monitoring fetal movement increases the frequency of non-stress-test monitoring (SOR: B, single good-quality RCT).
A rare tragedy that monitoring can’t prevent
Fetal movement is a marker of well-being. We draw on our experience with fetal monitoring to know that in healthy fetuses, movement increases sympathetic response and accelerates heart rate. Fetuses with severe acid-base disorders can’t oxygenate their muscles adequately and don’t move. Fetal movement, therefore, is a relatively simple indirect means of fetal assessment that indicates a lack of significant acidosis.
Intrauterine fetal demise (IUFD) is a rare but devastating event in an uncomplicated term pregnancy; it occurs in about 5000 of nearly 4 million us births each year (0.125). As the authors of this Clinical Inquiry state, nearly half of term IUFDs are unexpected and unexplained. Although it may be a logical extension to apply our knowledge of fetal physiology in an attempt to prevent IUFD, no conclusive evidence suggests that daily monitoring of fetal movement improves fetal or neonatal outcomes. We can hope that, with more accurate dating methods and more aggressive control of hypertension, diabetes, and anemia in pregnancy, the number of term IUFDs will continue to fall.
Nearly 50% of late-pregnancy IUFDs have no associated risk factors. Fetal demise, however, may be heralded by decreased fetal movement followed by cessation of movement at least 12 hours before death.1 Maternal monitoring of fetal movement by kick counts has been proposed as a method to verify fetal well-being and decrease the rate of IUFD in the general obstetric population.
Structured daily monitoring of fetal movement doesn’t decrease the rate of all-cause antenatal death in average-risk pregnancies.
Counting doesn’t reduce antenatal death, large study shows
A well-done RCT randomized 68,654 women to either usual care or structured, daily monitoring of fetal movement using the count-to-10 method—daily maternal documentation of the amount of time it takes to perceive 10 fetal movements. Usual care was comprised of a query about fetal movement at antenatal visits and instruction to perform fetal movement monitoring at the provider’s discretion. Mothers were told to visit their health-care provider for evaluation if they felt no movement in 24 hours or fewer than 10 movements in 10 hours during a 48-hour period. The trial showed no benefit from monitoring in reducing the rate of antenatal death from all causes.
The rate of all fetal deaths in the counting group was 2.9 per 1000 normally formed, live, singleton births; the rate in the control group was 2.67 (absolute risk reduction=0.24; 95% confidence interval [CI], –0.5 to 0.98). Women in the counting group spent an average of 160 hours counting during pregnancy and had a statistically significant increase in fetal non-stress-test (NST) monitoring (odds ratio [OR]=1.39; 95% CI, 1.31-1.49; number needed to harm [NNH]=50 to cause 1 additional NST). A statistically insignificant trend toward increased antepartum admissions was also noted in the counting group.2
Maternal perception of less movement not linked to fetal outcome
A retrospective cohort study of 6793 patients compared pregnancy outcomes of 463 women who presented for evaluation of decreased fetal movement with outcomes among the general obstetric population. The study excluded women who reported complete cessation of fetal movement.
Almost 50% of late-pregnancy fetal deaths have no associated risk factors.
Pregnancies evaluated for decreased fetal movement were less likely to have an Apgar score <7 at 5 minutes (relative risk [RR]=0.56; 95% CI, 0.29-0.96; P=.05) and less likely to be preterm (RR=0.68; 95% CI, 0.48-0.94; P=.02). No significant difference in cesarean section for fetal distress or admission to the neonatal intensive care unit was noted between the study and control groups. The study suggests that maternal perception of decreased fetal movement is not associated with poor fetal outcome.3
A recent rigorous systematic review yielded no significant outcome effect related to fetal kick counts.4 A prospective cohort study of 4383 births in California, using historical controls, found a drop in fetal mortality from 8.7 to 2.1 deaths/1000. The historical control rate was higher than statewide data from the same time period, however. The overall weaker design of the study and probable effect of regression to the mean significantly limit the interpretation of outcomes.5
The American College of Obstetrics and Gynecology (ACOG) makes no recommendation for or against assessing daily fetal movement in routine pregnancies. ACOG notes that no consistent evidence suggests that formal assessment of fetal movement decreases IUFD.6
The Institute for Clinical Systems Improvement recommends instructing patients on “daily identification of fetal movement at the 28-week visit.” The institute doesn’t recommend specific criteria for evaluating fetal movements or offer recommendations for follow-up of a maternal report of decreased fetal movement.1 The National Institute for Clinical Excellence in Great Britain recommends against routine formal fetal-movement counting.7
- Institute for Clinical systems Improvement. Routine Prenatal Care. 12th ed. August 2008. Available at: http://www.icsi.org/prenatal_care_4/prenatal_care__routine__full_version__2.html. Accessed november 7, 2008.
- Grant A,
Valentin L, et al. Routine formal fetal movement counting and risk of antepartum late death in normally formed singletons. Lancet. 1989;2:345–349.
- Harrington K,
Jordan L, et al. Obstetric outcome in women who present with a reduction in fetal movements in the third trimester of pregnancy. J Perinat Med. 1998;26:77–82.
- Mangesi L,
Fetal movement counting for assessment of fetal wellbeing. Cochrane Database Syst Rev. 2007;(1):CD004909.
- Moore TR,
A prospective evaluation of fetal movement screening to reduce the incidence of antepartum fetal death. Am J Obstet Gynecol. 1989;160:1075–1080.
- ACOG. Antepartum Fetal Surveillance. ACOG Practice Bulletin, Number 9. Washington, DC: American College of Obstetrics and Gynecology; October 1999.
- National Institute for Clinical Excellence. Antenatal Care: Routine Care for the Healthy Pregnant Woman. Clinical Guideline 62. London: National Institute for Health and Clinical Excellence; March 2008.
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