Early First Stage Of Labor Research Articles

Oxycodone does not affect placental circulatory physiology during the early first stage of labor-A randomized trial.

Opioids are used for pain relief during the first stage of labor. Oxycodone can cause maternal hypotension that may modify utero- and fetoplacental circulatory physiology. We hypothesized that maternal intravenous (i.v.) oxycodone has no detrimental effect on utero- and fetoplacental hemodynamics during the early first stage of labor. Twenty-two parturients requiring pain relief during the first stage of labor were randomized in a double-blinded and placebo-controlled study. By Doppler ultrasonography, both uterine artery (Ut) and umbilical vein (UV) volume blood flows (Q), Ut pulsatility index (PI), and Ut vascular resistance (RUt) were calculated. Blood flow velocity waveforms were obtained between uterine contractions. After baseline measurements, women received oxycodone 0.05 mg/kg or a placebo intravenous. Doppler ultrasonography was repeated up to 120 min after the first drug administration. The second dose of oxycodone 0.05 mg/kg was allowed at 60 min to all parturients with contraction pain ≥5/10. Maternal plasma samples were collected at each study phase and after delivery with umbilical cord plasma samples, to measure oxycodone concentrations. gov identifier (NCT no. NCT02573831). At baseline, mean QUt and QUV did not differ significantly between the placebo-first (478 mL/min and 57 mL/min/kg) and the oxycodone-first (561 mL/min and 71 mL/min/kg) groups. In addition, RUt and Ut PI were comparable between the groups. Following oxycodone at 60 min, mean QUt and QUV (714 mL/min and 52 mL/min/kg) were similar to the placebo-first (520 mL/min and 55 mL/min/kg) group. Furthermore, all the measured parameters were comparable to the baseline values. At 60 min after the first study drug administration, all the parturients in the placebo-first group needed intravenous oxycodone 0.05 mg/kg. At 120 min, we found no statistically significant change in any of the measured parameters. No significant correlation was found between maternal oxycodone concentration and QUt or QUV. Furthermore, newborn oxycodone concentration did not correlate with QUV. Oxycodone did not have any detrimental effect on either utero- or fetoplacental circulatory physiology during the early first stage of labor. Maternal plasma oxycodone did not correlate with utero- and fetoplacental hemodynamics. No correlation was found between newborn oxycodone concentration and fetoplacental hemodynamics.

The 90% Effective Dose of Sufentanil for Epidural Analgesia in the Early First Stage of Labor: A Double-blind, Sequential Dose-Finding Study

PurposeEpidural analgesia in the latent phase of the first stage of labor has been recognized and accepted by anesthesiologists worldwide. However, there is no unified consensus on the exact dosage of sufentanil with the combination of ropivacaine in the induction of epidural analgesia in the early first stage of labor. In this sequential dose-finding study, the 90% effective dose (ED90) of sufentanil for epidural administration in the early first stage of labor was estimated to minimize the adverse effects of using higher doses. MethodsForty parturients with cervical dilatation of 2 to 4 cm who requested epidural analgesia were enrolled in this study. Parturients received 15 mL of a combination of ropivacaine 13 mg and the test dose of sufentanil. The initial dose of sufentanil in epidural administration was 1 μg, and the dose of sufentanil for the next parturient was based on the response of the preceding participant as per a biased coin up-and-down design. The primary outcome was the dose of sufentanil that resulted in successful epidural administration by maintaining the parturients’ visual analog scale scores at ≤30 mm in the first 15, 30, and 45 minutes of induction. The ED90 and 95% CIs were estimated using isotonic regression methods and bootstrapping. FindingsThe estimated ED90 of sufentanil in epidural administration in the early first stage of labor was 1.91 μg (95% CI, 1.82–2.35 μg) in this sequential dose-finding study. ImplicationsSufentanil at a dosage of 2 μg is recommended for the administration of epidural analgesia in parturients in the early first stage of labor. ChiCTR.org.cn identifier: 1900021683.

Advances in labor analgesia.

The pain of childbirth is arguably the most severe pain most women will endure in their lifetimes. The pain of the early first stage of labor arises from dilation of the lower uterine segment and cervix. Pain from the late first stage and second stage of labor arises from descent of the fetus in the birth canal, resulting in distension and tearing of tissues in the vagina and perineum. An array of regional nerve blocks, systemic analgesic, and nonpharmacologic techniques are currently used for labor analgesia. Nonpharmacologic methods are commonly used, but the effectiveness of these techniques generally lacks rigorous scientific study. Continuous labor support has been shown to decrease the use of pharmacologic analgesia and shorten labor. Intradermal water injections decrease back labor pain. Neuraxial labor analgesia (most commonly epidural or combined spinal-epidural) is the most effective method of pain relief during childbirth, and the only method that provides complete analgesia without maternal or fetal sedation. Current techniques commonly combine a low dose of local anesthetic (bupivacaine or ropivacaine) with a lipid soluble opioid (fentanyl or sufentanil). Neuraxial analgesia does not increase the rate of cesarean delivery compared to systemic opioid analgesia; however, dense neuraxial analgesia may increase the risk of instrumental vaginal delivery.

Comparison of three doses of epidural fentanyl followed by bupivacaine and fentanyl for labor analgesia

Epidural fentanyl 100 microg after lidocaine-epinephrine test dose has been shown to provide adequate analgesia in early labor. This investigation determines the effect of three different bolus doses of epidural fentanyl on duration and quality of analgesia during early first stage of labor. In this prospective, double-blind study, 103 laboring nulliparous at cervical dilation <5 cm were enrolled. After an epidural test dose of lidocaine (60 mg) with epinephrine (15 microg), parturients received, randomly, bolus of epidural fentanyl 50, 75, or 100 microg, followed by a continuous infusion of epidural bupivacaine 0.0625% and fentanyl 3 microg/ml at a rate of 10 ml/h. Pain scores and maternal sedation, pruritus, nausea, and vomiting were recorded 10, 20, and 30 min after fentanyl, and every 30 min thereafter until first request for additional analgesia. Adequate analgesia was achieved in 87% (28/32), 94% (35/38), and 94% (31/33) in the fentanyl 50, 75, and 100 microg groups within 20 min. Mean duration of analgesia before re-dosing was significantly longer in fentanyl 100 and 75 microg groups (185.6+/-82.9 and 188.5+/-82.2 min, respectively) as compared with fentanyl 50 microg group (133.6+/-46.2 min, P<0.016). There was no difference in the incidence of maternal side effects or neonatal Apgar scores among the three groups. After a test dose of lidocaine-epinephrine, the three epidural fentanyl doses produced similar effective labor analgesia. However, epidural fentanyl 75 microg followed by epidural infusion of dilute bupivacaine and fentanyl produced longer duration of analgesia than fentanyl 50 microg followed by the same infusion, with no further prolongation when the dose of fentanyl was increased up to 100 microg.

Obstetric gel shortens second stage of labor and prevents perineal trauma in nulliparous women: a randomized controlled trial on labor facilitation

To determine whether the obstetric gel shortens the second stage of labor and exerts a protective effect on the perineum. A total of 251 nulliparous women with singleton low-risk pregnancies in vertex position at term were recruited. A total of 228 eligible women were randomly assigned to Group A, without obstetric gel use, or to Group B, obstetric gel use, i.e., intermittent application into the birth canal during vaginal examinations, starting at the early first stage of labor (prior to 4 cm dilation) and ending with delivery. A total of 183 cases were analyzed. For vaginal deliveries without interventions, such as C-section, vaginal operative procedure or Kristeller maneuver, obstetric gel use significantly shortened the second stage of labor by 26 min (30%) (P=0.026), and significantly reduced perineal tears (P=0.024). First stage of labor and total labor duration were also shortened, but not significantly. Results did not show a significant change in secondary outcome parameters, such as intervention rates or maternal and newborn outcomes. No side effects were observed with obstetric gel use. Systematic vaginal application of obstetric gel showed a significant reduction in the second stage of labor and a significant increase in perineal integrity. Future studies should further investigate the effect on intervention rates and maternal and neonatal outcome parameters.

Experience of pain and analgesia with water and land births

Labor is one of the most painful experiences in a woman's life. Does water birth influence the pain experienced? Data from an ongoing, longitudinal, prospective observational study that spans 9 years and includes questionnaires from 12,040 births were used to evaluate pain perception (visual analogue scale (VAS)) and analgesic use. Three birthing methods were compared: water birth, bed birth and Maia stool birth. Based on the VAS, the data show that the different birthing methods do not influence the intensity of pain throughout the different stages of labor. The only significant difference noted was that bed births are more painful in the early first stage, and less painful at the end of the second stage. This later difference may be due to increased use of epidural anesthesia in women choosing a bed birth. Women who choose bed births are significantly less likely than others to have an analgesic-free birth. For primiparas, there is also a small but significant difference showing that water births are less likely to require analgesics compared to Maia stool births. No such difference is seen in women who have given birth previously. We conclude that women who choose bed births perceive more pain in the early first stage of labor, leading them to be more likely to choose an epidural anesthesia in the late first stage, or to use other types of analgesics. Women who choose water births or Maia stool births are more likely to get through labor without using any analgesics.

F59Fetal venous Doppler in the normal first and second stage of labor

BackgroundThe aim of the study was to evaluate, whether differences in fetal venous flow velocity waveforms can be seen in fetuses during labor compared to fetuses before labor.MethodThe Pulsatility index for veins (PIV) of the ductus venosus was analysed in 127 fetuses (37th to 41th weeks) before labor by color Doppler sonography (control group). Identically 42 fetuses with normal cardiotocogram were analysed during and between contractions consecutively in the early first stage of labor, at 2–4 cm and 6–8 cm and at full dilatation of the cervix (study group).ResultsThe control group showed a normal PIV of 0.59 (SD 0.24). In the study group between contractions the PIV was normal during all stages of labor with average values of 0.55 − 0.68 (SD 0.26 − 0.42). During contraction the average values of the PIV were 1.64 – 2.48 (SD 0.76 – 1.16). These values were significant elevated (P &lt; 0.001) during contraction compared to the values of contraction free episodes as well as to the control group. The increase of the PIV during contractions was not related to any fetal heart rate deceleration.ConclusionDuring contractions the fetal venous pressure is significantly elevated in normal labor. Reference ranges for the ductus venosus should be established and compared to values in compromised fetuses.

The influence of labor on thrombotic and fibrinolytic systems

Plasma fibrinopeptide A, thrombin-antithrombin III complexes, tissue-plasminogen activator and α 2-plasmin inhibitor-plasmin complexes were measured early in the first stage of labor, in the second stage of labor and at 15 min after placental separation. Fibrinopeptide A and thrombin-antithrombin III complex levels did not change from the first to the second stage of labor but increased significantly after placental separation. There was a significant increase of the tissue-plasminogen activator level between the early first stage of labor and the second stage of labor, and it remained high after placental separation. A significant increase in the level of plasma α 2-plasmin inhibitor-plasmin complexes was observed after placental separation. These findings suggest that activation of the thrombotic system occurs at the time of placental separation and that activation of the fibrinolytic system begins during labor before placental separation to compensate for the hypercoagulable state which develops at the time of delivery.

Maternal cardiovascular dynamics: II. Posture and uterine contractions

Maternal hemodynamic changes were evaluated in 23 normal patients undergoing induction of labor at term. It was found that maternal posture exerted a significant influence on cardiodynamics. A change in position from supine to lateral produced an increase in cardiac output of 21.7 per cent, a decrease in heart rate of 5.6 per cent, and an increase in stroke volume of 26.5 per cent. Similar cardiovascular alterations were produced by effective uterine contractions in the supine position during early first stage of labor. The cardiac output increased by 15.3 per cent, the heart rate declined by 7.6 per cent, and the stroke volume increased by 21.5 per cent. Uterine contractions with patients in the lateral position produced only a 7.6 per cent rise in cardiac output and stroke volume. The heart rate remained unchanged. The vascular obstruction produced by the gravid uterus at term must be considered when evaluating maternal hemodynamics.

Effective uterine blood flow during labor

1.1. The effective uterine blood flow has been measured in 20 women during the early first stage of labor and in 26 women during the late first stage.2.2. Blood flow was within normal resting limits in all but 3 instances in the early first stage, but in the late first stage 16, or more than half, showed diminished uterine blood flow.3.3. Fetal distress developed in 3 cases and these all showed great reduction in the effective uterine blood flow.4.4. The significance of these findings in both normal and pre-eclamptic labors is discussed. The consequent hazards to the infant are considered with reference to the etiology of fetal distress in the first stage of labor.