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Objective: To determine the relationship between intrapartum contraction frequency, rest interval duration, and cervical dilation speed and the risk of neonatal hypoxic-ischemic encephalopathy (HIE).Study Design: This was a retrospective case-control study conducted in a maternity hospital in Dublin, Ireland. Babies born without major congenital anomalies between September 2006 and November 2017 at ≥ 35 + 0 weeks' gestational age were eligible. Cases were diagnosed with moderate-severe HIE. The controls were the first eligible baby born before and after each case with normal Apgar scores and not admitted to the neonatal unit. Intrapartum uterine activity was assessed by automated analysis of external tocography recordings. Cervical dilation was assessed by linear interpolation between vaginal examination measurements. The speed of cervical dilation was expressed as the times from 4 to 6 cm, >6 cm to the start of pushing, and from pushing to delivery.Results: Intrapartum tocographs results were available in 49 of 88 cases and 121 of 176 controls. The median contraction rate in cases was 7.7 (Interquartile range [IQR]: 6.6-9.0) compared to 7.0 in controls (IQR: 6.2-7.9) (p = 0.021). The median rest interval duration was 56 s (IQR: 38-76) in cases and 62 s (IQR: 50-79) in controls (p = 0.058). Cases took longer to progress from > 6 cm to the start of pushing (cases: 02:58 [01:14-04:49], controls: 01:48 [00:51-03:34], p = 0.020) and from pushing to delivery (cases: 00:34 [00:24-01:10], controls: 00:27 [00:13-00:56], p = 0.036).Conclusions: Higher contraction frequencies and slower progress towards the end of labour are both independently associated with the risk of moderate-severe HIE. Inter-contraction rest interval duration as measured by external tocography does not provide additional accuracy. [ABSTRACT FROM AUTHOR]

• Recommendations on optimal contraction frequency are poorly substantiated by literature. • No distinction in recommendations is made based on presence/absence of FHR abnormalities. • In case of FHR abnormalities, >4 contractions are associated with fetal hypoxia. • We suggest to aim for a maximum contractions frequency of 4 in these women. Current guidelines provide little supporting literature for the definition of uterine tachysystole during labour and no distinction is made for optimal contraction frequency depending on the clinical situation. We hypothesize that fetal hypoxia is frequently caused by uterine tachysystole and that high uterine contraction frequencies are especially harmful when fetal heart rate (FHR) abnormalities are present. We studied the association between contraction frequency and fetal scalp pH values in women with an indication for fetal blood sampling (FBS) based on FHR abnormalities. A retrospective study including 762 women was performed in a tertiary teaching hospital in the Netherlands from January 2015 until January 2020. Women with a singleton pregnancy with a gestational age ≥ 34+0 weeks were included when FBS was performed because of suspicious or pathological FHR tracings. Exclusion criteria were maternal age < 18 years, failed fetal scalp pH values, lack of thirty minute registration by tocodynamometry prior to FBS, poor quality of uterine monitoring, intrauterine resuscitation in the thirty minutes prior to FBS, maternal body mass index ≥ 30 kg/m2 and neonatal birth weight < 10th percentile. Uterine contractions in the thirty minutes prior to FBS were manually annotated by a researcher who was blinded to FBS values, FHR and other obstetrical data. Linear and logistic analysis were used to explore the association between uterine contraction frequency and FBS results. Low fetal scalp pH values were significantly associated with contraction frequency prior to FBS. Fetuses of women with four to five contractions per ten minutes prior to FBS were 2.4 times more likely to have hypoxia as compared to fetuses of women with two to three contractions per ten minutes (aOR 2.4, 95% CI 1.1–5.4). With increasing contraction frequency, the risk of fetal hypoxia further increased. Contraction frequency above four per ten minutes prior to FBS is significantly associated with fetal hypoxia in women with FHR abnormalities. We suggest to aim for a maximum contraction frequency of four per ten minutes in these women. [ABSTRACT FROM AUTHOR]

Objective: Current guidelines provide little supporting literature for the definition of uterine tachysystole during labour and no distinction is made for optimal contraction frequency depending on the clinical situation. We hypothesize that fetal hypoxia is frequently caused by uterine tachysystole and that high uterine contraction frequencies are especially harmful when fetal heart rate (FHR) abnormalities are present. We studied the association between contraction frequency and fetal scalp pH values in women with an indication for fetal blood sampling (FBS) based on FHR abnormalities.Study Design: A retrospective study including 762 women was performed in a tertiary teaching hospital in the Netherlands from January 2015 until January 2020. Women with a singleton pregnancy with a gestational age ≥ 34+0 weeks were included when FBS was performed because of suspicious or pathological FHR tracings. Exclusion criteria were maternal age < 18 years, failed fetal scalp pH values, lack of thirty minute registration by tocodynamometry prior to FBS, poor quality of uterine monitoring, intrauterine resuscitation in the thirty minutes prior to FBS, maternal body mass index ≥ 30 kg/m2 and neonatal birth weight < 10th percentile. Uterine contractions in the thirty minutes prior to FBS were manually annotated by a researcher who was blinded to FBS values, FHR and other obstetrical data. Linear and logistic analysis were used to explore the association between uterine contraction frequency and FBS results.Results: Low fetal scalp pH values were significantly associated with contraction frequency prior to FBS. Fetuses of women with four to five contractions per ten minutes prior to FBS were 2.4 times more likely to have hypoxia as compared to fetuses of women with two to three contractions per ten minutes (aOR 2.4, 95% CI 1.1-5.4). With increasing contraction frequency, the risk of fetal hypoxia further increased.Conclusions: Contraction frequency above four per ten minutes prior to FBS is significantly associated with fetal hypoxia in women with FHR abnormalities. We suggest to aim for a maximum contraction frequency of four per ten minutes in these women. [ABSTRACT FROM AUTHOR]

Objective: Electrohysterography is a non-invasive technique to monitor uterine activity and has a significantly higher sensitivity compared to conventional external tocodynamometry. Whether this technique could lead to improved obstetrical outcomes is still unknown. In this propensity score matched study, clinical results of the first pilot implementing electrohysterography during labor were evaluated. The hypothesis tested is that electrohysterography will help to optimize uterine activity and thereby lead to fewer obstetric interventions. Secondary outcomes were Apgar score, arterial umbilical pH values, first stage labor duration, episiotomy rate and postpartum vaginal blood loss.Study Design: From November 2017 until October 2018, electrohysterography was introduced as a standard alternative for monitoring uterine activity in high-risk deliveries. It could be applied in case of induced labor, previous cesarean delivery, body mass index ≥30 kg/m2 or an inadequate external tocodynamometry monitoring. Outcomes were compared to a matched group of women in which external tocodynamometry was applied for uterine activity monitoring during labor. These women were identified using propensity scores.Results: A total of 348 women received electrohysterography as standard method of uterine monitoring during labor. A match (1:1 ratio) was found for 317 women, resulting in a total population of 634 women. No significant differences were seen in obstetric interventions (i.e. cesarean deliveries and assisted vaginal deliveries) between the electrohysterography and tocodynamometry group (P = 0.80). No statistically significant differences were seen regarding the secondary outcomes.Conclusions: This first pilot study implementing electrohysterography as monitoring method during labor in a high-risk population did not result in statistically significant differences regarding obstetric interventions, low Apgar scores or low umbilical artery pH values. Therefore, we suggest that electrohysterography causes no harm and we recommend further implementation and evaluation in clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: To investigate if tachysystole was associated with an increased risk of cesarean section or unfavorable maternal or neonatal outcomes following induction of labor by misoprostol vaginal inserts.Study Design: We conducted a retrospective cohort study of 446 women over 37 weeks of gestation admitted for labor induction by misoprostol vaginal inserts between May 2016 and May 2017. Fetal heart rate and uterine activity tracings were assessed for tachysystole, defined as ≥ 6 contractions per 10 min, averaged over a 30-minute window. Univariate analysis was performed by using t-test and Chi-square, comparing demographics, pregnancy characteristics, intrapartum monitoring, mode of delivery, neonatal outcomes (Apgar score < 7 at 5 min, umbilical cord artery pH < 7.10, neonatal intensive care unit admission) and maternal outcomes, with regard to the presence of tachysystole. The association between tachysystole and cesarean section was evaluated after adjusting for potential confounders by a modified Poisson regression model, expressed as an adjusted risk ratio and 95 % confidence intervals.Results: A total of 140 women (31.4 %) presented with tachysystole. The median duration of tachysystole was 2 h 12 min. The rate of cesarean section was 25.0 % (N = 35) among patients with tachysystole and 19.6 % (N = 60) for those without tachysystole. Presence of tachysystole during induction of labor with misoprostol vaginal inserts was not associated with cesarean section (adjusted risk ratio,1.0; 95 % confidence interval, 0.7-1.4). Neonatal and maternal outcomes were similar between mothers who did and did not experience tachysystole.Conclusions: This study illustrates that tachysystole is not associated with an increased risk of cesarean section after induction of labor by misoprostol vaginal inserts. The impact of excessive uterine activity on the fetal wellbeing defined by the frequency of uterine contraction alone is probably insufficient. Further research on the development of accurate measures of uterine contractility is necessary to better understand its effect on fetal well-being. [ABSTRACT FROM AUTHOR]