ABSTRACT & COMMENTARY
Reduced Fetal Movement, Uterine Arteries, and Stillbirth
By John C. Hobbins, MD
Professor, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora
Dr. Hobbins reports no financial relationships relevant to this field of study.
A recent study has shown a link between abnormal uterine artery waveforms in the second trimester and reduced fetal movements later in pregnancy, as well as with stillbirth and small for gestational age.
Pagani G, et al. Association between reduced fetal movements at term and abnormal uterine artery Doppler indices. Ultrasound Obstet Gynecol 2014;43:548-552.
Guidelines abound for screening and management of almost all of the common complications of pregnancy. These guidelines are published by various medical organizations and are based on expert opinion as well as evidence-based information. Often the same topics are taken on by separate official groups and sometimes the recommendations within these guidelines do not match.
One of the more controversial concepts involves the use of uterine artery Doppler wave form analysis to screen for preeclampsia. This month I will focus on a recent study correlating the results of uterine artery Dopplers and decreased fetal movement with late stillbirth (SB) and the presence of small for gestational age (SGA) babies.1 This paper then will be used to segue into a broader discussion of the role of maternal fetal movement perception in the assessment of fetal condition.
A team from the United Kingdom reviewed patients’ perinatal records between 2008 and 2012, during which time it was common to screen patients between 19 and 23 weeks for later development of preeclampsia with uterine artery Doppler waveform analysis. These patients also had been counseled to report any perceived reduced fetal movements (RFM) to their providers. Since almost all patients were delivered at the same hospital (St. Georges in London), the authors were able to capture essential birth data on 17,649 patients of the original 19,030 who had care during the study period. Seven hundred forty-two (4.2%) women reported RFM, 1494 (8.5%) delivered SGA babies (birth weight less than the 10th percentile), and 53 (0.3%) had a SB after 36 weeks.
Patients with abnormal uterine artery waveforms (pulsatility indices > the 95th percentile) were far more likely to have RFM (odds ratio [OR], 5.3; 95% confidence interval [CI], 4.21-6.01), SGA (OR, 2.41; 95% CI, 2.09-2.79), and were significantly more likely to have a SB (OR, 1.50; 95% CI, 1.21-1.98). The combination of abnormal uterine artery waveform and RFM gave a four times greater chance of SGA and a five times greater chance of SB than if neither was found.
COMMENTARY
The results of the study were difficult to sort out regarding SB because of the relatively small number of late SBs in the study (53 of 17,649), but the data linking uterine artery waveforms with SGA and RFM suggest a placental cause for both — the former being a well-accepted fact, but not the latter.
The greatest thrust for using uterine artery waveforms in the second trimester has been to screen for preeclampsia. Although it is not standard practice in the United States, it is commonly employed in Europe, as documented by its incorporation into practice guidelines.2,3 The major criticism of this screening tool, which has been shown in other studies to have value in predicting SB4,5 and SGA,6 involves the dilemma of what to do with this information. Some studies7 do show benefit in using low-dose aspirin, especially if given early, to prevent severe preeclampsia in women with abnormal uterine artery waveforms — which is the reason for the positive spin employed in the European guidelines.
The featured study now provides a possible reason for starting third trimester fetal movement counts in those patients with abnormal second trimester uterine artery waveforms, and even, perhaps, in some patients who have not had this type of testing. Hot off the press is ACOG’s opinion on the subject of fetal movement assessment, a subject that is covered briefly in the newest guidelines for antenatal fetal surveillance in the July issue of Obstetrics and Gynecology.8 In the 10-page document, one paragraph (20 lines worth) was devoted to fetal movement assessment and its association with SB only. The authors stated that there is no evidence that a formal assessment of RFM has reduced the fetal death rate. They also pointed out that it does increase slightly the number of antepartum visits and fetal evaluations (but without an increase in interventions). The authors said that "although not all women need to perform a daily fetal movement assessment, if a woman notices a decrease in fetal activity, she should be encouraged to contact her health care provider and further assessment should be performed."
I agree that it would be unproductive to use formal kick counts in everyone, but it would make sense for all patients at their first visit to be encouraged to pay attention to their fetuses’ general activity level. In high-risk patients (hypertension, history of previous SB or SGA, inadequate fetal growth in the current pregnancy, oligohydramnios, and with various fetal anomalies), we recommend that patients do daily fetal movement counts in the third trimester. We use this method in SGA pregnancies, in particular, as an adjunctive method of surveillance between visits for non-stress tests, Dopplers, and ultrasound assessments of fetal growth. Our protocol is for the patient to choose the same time each day, usually after a meal, to get in a comfortable position — but not on her back. Then she determines how long it takes to discern 10 separate fetal movements. If that time exceeds 2 hours, she is instructed to give us a call. In the vast majority of cases, this goal is attained well before the first hour has elapsed.
This method gives the patient a chance to participate in her own care and, while it has not yet been proven to prevent SB (a difficult study to take on), unlike just about anything in health care today, it does not cost a dime. In the featured study, 48 patients with SB did not report a "subjective" decrease in fetal movement. It is unclear how many of these patients might have been in a higher risk category to warrant a more formal approach to tracking fetal movement — one that might have detected a bona fide drop in fetal movement before demise.
References
- Pagani G, et al. Association between reduced fetal movements at term and abnormal uterine artery Doppler indices. Ultrasound Obstet Gynecol 2014;43:548-552.
- Bhide A, et al. ISUOG Practice Guidelines: Use of Doppler ultrasonography in obstetrics. Ultrasound Obstet Gynecol 2013;41:233-239.
- Royal College of Obstetricians & Gynaecologists. Small-for-gestational-age fetus, investigation and management. Green-top Guideline no 31. RCOG Press: London UK; 2013. Available at: http://www.rcog.org.uk/womens-health/investigation-and-management-small-gestational-age-fetus-green-top-31. Accessed July 28, 2014.
- Singh T, et al. Role of second-trimester uterine artery Doppler in assessing stillbirth risk. Obstet Gynecol 2012;119:256-261.
- Poon LC, et al. Second-trimester uterine artery Doppler in prediction of stillbirths. Fetal Diagn Ther 2013;33:28-35.
- Vergani P, et al. Prognostic value of uterine artery Doppler velocimetry in growth-restricted fetuses delivered near term. Am J Obstet Gynecol 2002;187:932-936.
- Bujold E, et al. Acetylsalicylic acid for the prevention of preeclampsia and intra-uterine growth restriction in women with abnormal uterine artery doppler: A systematic review and meta-analysis. J Obstet Gynaecol Can 2009;31:818-826.
- Practice bulletin no. 145: Antepartum fetal surveillance. Obstet Gynecol 2014;124:182-192.
