DOI: http://dx.doi.org/10.18203/2320-1770.ijrcog20210746

Evaluation of categories of intrapartum fetal heart rate tracings in pregnancies complicated with fetal growth restriction and its relation to perinatal outcome

Bhavya H. U.

Abstract


Background: Intrapartum FHR monitoring is widely used during labour as changes in FHR precede brain injury, so timely response to abnormal FHR patterns might be effective in preventing it. There is a strong association between stillbirth and FGR which warrants intensive intrapartum fetal surveillance for optimal perinatal outcome. In this study we aimed to classify intrapartum FHR tracings into different categories in FGR pregnancies and correlate with perinatal outcome.

Methods: A total 100 singleton pregnant women >34 weeks gestation with FGR were included in study. FHR tracings were followed throughout first and second stage of labour. FHR tracing were categorized into NICHD 3-tier classification as category I, II and III. Maternal and neonatal outome in each category were analysed.

Results: Mean duration of category I tracings was 9.05 hours, category II was 7.66 hours and that of category III was 0.49 hours. During late active phase 25/95 patients with category I FHR tracings had vaginal delivery, 62/95 had category II FHR tracings, of which 95.1% had vaginal delivery and 4.9% had instrumental. 8/95 with category III FHR tracings required caesarean section. All patients with category I tracings had normal neonatal outcome, among patients with category II FHR tracings, 74.6% had normal whereas 25.4% had adverse outcome, all with category III FHR tracings had adverse outcome.

Conclusions: Categorizing FHR tracings is helpful to distinguish neonates who are likely to have normal outcome from those who are at risk for fetal hypoxia. When the category II tracings are present, it requires more vigilant monitoring and decision taking.


Keywords


Categorization, Fetal growth restriction, Fetal heart rate, National Institute of Child Health and Human Development, Perinatal outcome

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References


Beard RW, Filshie GM, Knight CA, Robert GM. Intensive care of high risk fetus in labour. J Obstet Gynecol Br Commonw. 1971;78:865-70.

Gabert HA, Stenchever MA. Continuous electronic monitoring of fetal heart rate during labour. Am J Obstet Gynecol. 1973;115:919-24.

Paul RH, Hon EH. Clinical fetal monitoring. Am J Obstet Gynecol. 1974;118:529-33.

Liston R, Sawchuk D, Young D. Society of Obstetrics and Gynecologists of Canada, British Columbia Perinatal Health Program. Fetal health surveillance: antepartum and intrapartum consensus guideline. J Obstet Gynaecol Can. 2007;29(Suppl):3-56.

Winkler CI, Hauth JC, Tucker JM, Owen J, Brumfield CG. Neonatal complications at term as related to the degree of umbilical artery academia. Am J Obstet Gynecol. 1991;164(2):637-41.

Royal College of Obstetricians and Gynecologists. The use of electronic fetal monitoring: The use and interpretation of cardiotocography in intrapartum fetal surveillance. Evidence-based clinical guideline No.8 London, UK: RCOG Press; 2001.

Macones GA, Hankins GD, Spong CY, Hauth J, Moore T. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring. Update on definition, interpretation, and research guideline. Obstet Gynecol. 2008;112:661-6.

Okai T, Ikeda T, Kawarabayash T, Kozuma S, Sugawara J, Chisaka H, et al. Intrapartum management guidelines based on fetal heart rate pattern classification. J Obstet Gynaecol Res. 2010;36(5):925-8.

Mandruzzato G, Antsaklis A, Botet F, Chervenak FA, Figueras F, Grunebaum A, et al. Intrauterine restriction (IUGR). J Perinat Med. 2008;36(4):277-81.

Bukowski R. Stillbirth and fetal growth restriction. Clin Obstet Gynecol. 2010;53(3):673-80.

De Onis M, Blossner M, Villar J. Levels and patterns of intrauterine growth retardation in developing countries. Eur J Clin Nutr. 1998;52(1):5-15.

American College of Obstetricians and Gynecologists 2009. ACOG practice bulletin no. 106: Intrapartum fetal heart rate monitoring: nomenclature, interpretation, and general management principles. Obstet Gynecol. 114(1):192-202.

International Federation of Gynecology and Obstetrics Workshop on the Guidelines for the use of fetal heart rate monitoring. Int J Gynaecol Obstet. 1987;25:159-67.

Blackwell SC, Grobman WA, Antoniewicz L, Hutchinson M, Bannerman CG. Interobserver and intraobserver reliability of the NICHD 3-tier FHR Interpretation System. Am J Obstet Gynecol. 2011;205:378.e1-5.

Dellinger EH, Boehm FH, Crane MM. Electronic FHR monitoring: Early neonatal outcomes associated with normal rate, fetal stress and fetal distress. Am J Obstet Gynecol. 2000;182:214-20.