Objective: To investigate the diurnal rhythms of fetal heart rate in third trimester of pregnancy. Methods: From June 2014 and October 2017, 97 cases of low-risk pregnancy women who received antenatal care and deliveried in Peking University Third Hospital were collected. Totally 130 cases of fetal heart rate and maternal holter monitoring data were analyzed. All cases were singleton pregnancy, cephalic position and had normal perinatal outcome. They were divided into three groups based on gestational age, 29 cases (22.3%,29/130) in pregnancy 28-33(+6) weeks, 37 cases (28.5%,37/130) in 34-36(+6) weeks, and 64 cases (49.2%, 64/130) in 37-40(+6) weeks. Fetal heart baseline (FHB) , fetal heart baseline variation (FHBV) , fetal heart rate acceleration area and maternal heart rate were acquired by computer, their diurnal rhythms and the differences among three groups were analyzed. Results: FHB、FHBV、fetal heart rate acceleration area and maternal heart rate all presented diurnal rhythms. (1) FHB rose in daytime and decreased at night with the minimum value at 2:00-5:00, and didn't decline further at night with the advancing of gestational age (P=0.548). (2) FHBV was similar to FHB, which rose in daytime and decreased at night, but declined smaller at night with the advancing of gestational age, especially after 37 weeks (P<0.01). (3) Fetal heart rate acceleration area reduced in daytime and enlarged at night, and enlarged more with the advancing of gestational age. (4) The diurnal rhythm of maternal heart rate was consistent with fetal heart rate. FHB lagged behind maternal heart rate for 1-2 hours when declining to the nocturnal nadir but been basically in sync with maternal heart rate when recovered. Conclusion: The basic characteristics of fetal heart rate in normal pregnancy exist obviously diurnal rhythms, and change in different trends with the advancing of gestational age.
目的: 探讨妊娠晚期不同孕周胎儿心率(胎心)昼夜节律的变化规律。 方法: 收集2014年6月至2017年10月于北京大学第三医院进行规律产前检查并分娩的无妊娠合并症及并发症、或为低危妊娠,且为单胎、头位、新生儿结局正常的97例孕妇的临床资料,以及在妊娠晚期不同孕周分别采集的130例次母胎动态心电图数据。妊娠28~33周(+6)组29例次(22.3%,29/130),34~36周(+6)组37例次(28.5%,37/130)和37~40周(+6)组64例次(49.2%,64/130)。分析胎心基线、胎心基线变异、胎心加速面积在妊娠晚期不同阶段的昼夜节律变化,以及胎心基线与母体心率的昼夜节律的关系。 结果: (1)妊娠晚期,胎心基线呈现夜间降低、白天升高的昼夜节律,其中夜间2:00~5:00为胎心基线的低值;随孕周增加,胎心基线夜间下降幅度无明显差异(P=0.548)。(2)胎心基线变异与胎心基线的昼夜节律类似,基线变异夜间降低、白天升高,随着孕周增加,尤其是≥妊娠37周,胎心基线变异的夜间下降程度明显减小(P<0.01)。(3)胎心加速面积的昼夜节律呈现夜间升高、白天降低的趋势;随孕周增加,其夜间升高的幅度逐渐增加。(4)胎心基线与母体心率之间的昼夜节律关系表现为胎心基线在夜间最低点的出现落后于母体心率最低点1~2 h,与母体心率的恢复基本同步。 结论: 妊娠晚期胎心存在明显的昼夜节律,且随孕周增加呈现一定的变化趋势。.
Keywords: Circadian rhythm; Heart rate, fetal; Pregnancy trimester, third.