Simultaneous monitoring of maternal and fetal heart rate variability during labor in relation with fetal gender

Abstract

Male gender is considered a risk factor for several adverse perinatal outcomes. Fetal gender effect on fetal heart rate (FHR) has been subject of several studies with contradictory results. The importance of maternal heart rate (MHR) monitoring during labor has also been investigated, but less is known about the effect of fetal gender on MHR. The aim of this study is to simultaneously assess maternal and FHR variability during labor in relation with fetal gender. Simultaneous MHR and FHR recordings were obtained from 44 singleton term pregnancies during the last 2 hr of labor (H H ). Heart rate tracings were analyzed using linear (time- and frequency-domain) and nonlinear indices. Both linear and nonlinear components were considered in assessing FHR and MHR interaction, including cross-sample entropy (cross-SampEn). Mothers carrying male fetuses (n = 22) had significantly higher values for linear indices related with MHR average and variability and sympatho-vagal balance, while the opposite occurred in the high-frequency component and most nonlinear indices. Significant differences in FHR were only observed in H with higher entropy values in female fetuses. Assessing the differences between FHR and MHR, statistically significant differences were obtained in most nonlinear indices between genders. A significantly higher cross-SampEn was observed in mothers carrying female fetuses (n = 22), denoting lower synchrony or similarity between MHR and FHR. The variability of MHR and the synchrony/similarity between MHR and FHR vary with respect to fetal gender during labor. These findings suggest that fetal gender needs to be taken into account when simultaneously monitoring MHR and FHR.

Systematic Review of Intrapartum Fetal Heart Rate Spectral Analysis and an Application in the Detection of Fetal Acidemia

“…The low frequency was addressed in all the 24 articles, where the most common band was within the interval 0.04–0.15 Hz, used in 12 studies, followed by 0.03–0.15 Hz, addressed by 8 articles. Regarding the power in the LF band, most articles attribute it to the activity of the sympathetic system ( 3 , 28 , 31 , 32 , 34 , 49 , 59 , 60 , 62 ), while others link it to the combined activity of sympathetic and parasympathetic activity ( 11 , 13 , 20 , 21 , 44 , 48 , 57 , 61 ). This different interpretation cannot, in some cases at least, be attributed to the different frequency limits of the bands used for the LF computation (check Table 1 ), and is probably inherited by the same controversial interpretation of the LF component in adults' heart rate analysis ( 29 ).…”

“…For cutoff 7.05, although the acidemic group had only 7 subjects, significant differences were found for VLF and LF spectral bands ( Supplementary Table 4 ), and their AUROC were computed ( Table 5 ). Overall, the best AUROC values were: 0.770 for LF 0.03–0.07 Hz ( 49 ); 0.763 for LF 0.02–0.14 Hz ( 62 ) and 0.762 for LF 0.03–0.15 Hz ( 3 , 31 – 35 , 60 ) (see Table 5 ).…”

Non-linear Methods Predominant in Fetal Heart Rate Analysis: A Systematic Review

“…Besides these factors, Gonçalves et al ( 131 ) and Spyridou et al ( 182 ) noted that gender also has an effect on fHR analysis and should be considered, while Tagliaferri et al ( 183 ) found differences on both linear and non-linear indices between different ethnic groups. Gender was also shown to influence maternal heart rate (MHR) ( 52 ). Even when twins are considered, sex differences were found both by linear and non-linear indices ( 184 ).…”

“…In the literature, we found other entropy measures that appeared in less than 15 articles, such as, permutation entropy ( 41 – 45 ), Rnyi entropy ( 46 – 48 ), Kullback-Leibler entropy ( 41 , 42 , 49 , 50 ), Kolmogorov-Sinai entropy ( 30 ), cross-sample entropy ( 51 , 52 ), tone-entropy ( 53 ), bubble entropy ( 47 ), and compression entropy ( 46 ).…”

Comparison of Computerized Cardiotocography Parameters between Male and Female Fetuses

“…Therefore, findings of these studies cannot be generalized to the whole antepartum period. Moreover, previous studies often examined indices of the FHR that are difficult to reproduce, such as power spectral density (PSD) and approximate entropy (ApEn) [6,7,10,11].…”