^[i] Am J Obstet Gynecol 2000 Dec;183(6):1544-8 A randomized controlled trial of the effect of increased intravenous hydration on the course of labor in nulliparous women. Garite TJ, Weeks J, Peters-Phair K, Pattillo C, Brewster WR This study presents the novel finding that increasing fluid administration for nulliparous women in labor above rates commonly used is associated with a lower frequency of prolonged labor and possibly less need for oxytocin. Thus inadequate hydration in labor may be a factor contributing to dysfunctional labor and possibly cesarean delivery. PMID: 11120525

^[ii]  Obstet Gynecol 1996 Nov;88(5):797-800 Maternal position during labor: effects on fetal oxygen saturation measured by pulse oximetry. Carbonne B, Benachi A, Leveque ML, Cabrol D, Papiernik E.

OBJECTIVE: To determine the effects of maternal left lateral, right lateral, and supine positions during labor on fetal oxygen saturation measured by pulse oximetry. METHODS: Fetal oxygen saturation measured by pulse oximetry was obtained in 15 laboring women randomly and successively adopting left lateral, supine, and right lateral positions for 10 minutes each. Repeated measures analysis of variance was used for statistical analysis. RESULTS: Changes in fetal oxygen saturation were observed in different maternal positions. The supine position was associated with a lower fetal oxygen saturation than the left lateral position. One supine hypotensive syndrome occurred and was associated with a drop in fetal oxygen saturation. CONCLUSION: Maternal supine position during labor is associated with a lower fetal oxygen saturation than the left lateral position. PMID: 8885916

Zhonghua Fu Chan Ke Za Zhi 1993 Sep;28(9):517-9, 567
[Changing fetal position through maternal posture]Zhao XB, Shan JZ.
The fetal position of 249 cases in their late pregnancy was detected by ultrasound. The results showed that the position of fetal spine tended to lie on the same side as mother's posture during bedrest just before examination. Fetal posterior or transverse spinal position was prone to occur when mother was on her supine position. The fetal cephalic presentation did not correspond entirely with the fetal spinal position. Eighty of the 249 cases presenting fetal spinal posterior or transverse position were chosen at random and corrected by Sims' or hand-knee posture. The better results were obtained especially by the latter. The success rate of correction by maternal posture was affected by the engagement of fetal head and the volume of amniotic fluid. The mechanism of hand-knee posture was discussed. The result indicated that maternal posturing is a clinically valuable procedure. It may be done during pregnancy or in labor to prevent fetal malpresentation. PMID: 8313740

^[iii]  Zhonghua Fu Chan Ke Za Zhi 2001 Aug;36(8):468-9
[Correction of occipito-posterior by maternal postures during the process of labor]
Wu X, Fan L, Wang Q.
OBJECTIVE: To investigate the effect on correction of occipito-posterior (OP) by changing maternal posture during labor. METHODS: One hundred normal primigravida with head OP position in the latent phase of labor were randomly divided into 2 groups: Group A (n = 50), women were instructed to lay on the same lateral posture with the fetal spine during labor in order to correct the fetal position from OP to occipito anterior (OA); Group B (n = 50) lay on the opposite side to the fetal spine. The OP position was diagnosed by vaginal examination or B ultrasound, and the course of labor and mode of delivery were observed. RESULTS: Thirty-four women delivered vaginally (68%) in group A, with 27 of them turned to OA position (54%); spontaneously while they were 22 (44%) and 12 (24%) in group B respectively, a significant difference was shown (P < 0.005). The average time interval for the 1st stage was (13.5 +/- 6.5) hour and (17.1 +/- 7.2) hour for group A and B respectively, also a significant difference was noted (P < 0.01). CONCLUSION: To instruct women in labor to take the lateral recumbent position with the same side of fetal spine for correcting OP to OA is an effective method. It may increase vaginal deliveries and shorten the first stage of labor, thus reduce dystocia due to OP position. This method is simple and effective, and maybe adopted in most obstetric units.PMID: 11758180 

^[iv] Induction doubles the risk of cesarean for primps nearly triples the risk of shoulder dystocia

Am J Obstet Gynecol. 2000 Oct;183(4):986-94.
Maternal and neonatal outcomes after induction of labor without an identified indication.
Dublin S, Lydon-Rochelle M, Kaplan RC, Watts DH, Critchlow CW.
OBJECTIVE: This study was undertaken to examine associations between induction of labor and maternal and neonatal outcomes among women without an identified indication for induction. STUDY DESIGN: This was a population-based cohort study of 2886 women with induced labor and 9648 women with spontaneous labor who were delivered at 37 to 41 weeks' gestation, all without identified medical and obstetric indications for induction. RESULTS: Among nulliparous women 19% of women with induced labor versus 10% of those with spontaneous labor underwent cesarean delivery (adjusted relative risk, 1.77; 95% confidence interval, 1.50-2.08). No association was seen in multiparous women (relative risk, 1.07; 95% confidence interval, 0. 81-1.39). Among all women induction was associated with modest increases in instrumental delivery (19% vs 15%; relative risk, 1.20; 95% confidence interval, 1.09-1.32) and shoulder dystocia (3.0% vs 1. 7%; relative risk, 1.32; 95% confidence interval, 1.02-1.69). CONCLUSION: Among women who lacked an identified indication for induction of labor, induction was associated with increased likelihood of cesarean delivery for nulliparous but not multiparous women and with modest increases in the risk of instrumental delivery and shoulder dystocia for all women. PMID: 11035351

^[v] Eur J Obstet Gynecol Reprod Biol 2000 Apr;89(2):153-7

Adverse effects of epidural analgesia in labor.
Zimmer EZ, Jakobi P, Itskovitz-Eldor J, Weizman B, Solt I, Glik A, Weiner Z.
OBJECTIVE: To examine the influence of epidural analgesia on labor and delivery in nulliparous and multiparous women. DESIGN: Data were collected on 847 consecutive parturients with singleton pregnancy and vertex presentation (384 nulliparous and 463 multiparous). The obstetrical and labor characteristics including maternal age, parity, gestational age, previous cesarean section, instrumental delivery, mode and timing of analgesia, mode of delivery, indications for cesarean section or instrumental delivery were analyzed comparing patients who received epidural analgesia with women who received systemic analgesia. RESULTS: Epidural analgesia was administered in 233 nulliparous and 141 multiparous women. A stepwise logistic regression analysis revealed that epidural analgesia independently affected the rate of non-spontaneous delivery and the duration of the second stage of labor in nulliparous (P=0.0017 and P=0.0036, respectively) and multiparous (P=0.001 and P=0.0081, respectively) women. Epidural analgesia independently affected the duration of labor only in nulliparous women (P=0.0001). CONCLUSION: Women should be informed that prolongation of labor and increase in nonspontaneous deliveries should be expected when choosing epidural analgesia in labor. PMID: 10725574 

Am J Perinatol 2002 Apr;19(3):119-26 Effect of maternal epidural analgesia on fetal intrapartum oxygen saturation. East CE, Colditz PB.

The use of maternal epidural analgesia in labor may be associated with nonreassuring fetal heart rate (FHR) patterns. Fetal oxygen saturation (FSpO2) monitoring may improve assessment of fetal well-being during this time. Mean FSpO2 values were compared over seven 5-minute epochs: 5 minutes prior to an epidural event (combined insertion of epidural/top-up epidural analgesia and infusion pump bolus), to 30 minutes following the event, including possible effects of maternal position and FHR pattern on FSpO2 values. Mean FSpO2 values were significantly different between the 5 minutes prior (49.5%) versus 16-20 minutes (44.3%, p <0.05), 21-25 minutes (43%, p <0.01), and 26-30 minutes (43.8%, p <0.05) epochs; and 6-10 minutes (48.3%) versus 21-25 minutes (43%, p <0.05) epochs, but were not influenced by FHR pattern or maternal position. There were no differences in mean FSpO2 values following administration of an epidural infusion bolus. We conclude that fetal oxygenation was affected following initial or top-up epidural analgesia and that fetal intrapartum pulse oximetry may be useful in assessing fetal status following these events.
PMID: 12012286