Induction of labor versus conservative management of pregnant diabetic women

Reasons for inducing labor at term in pregnancies complicated by diabetes include the avoidance of fetal demise and the prevention of excessive fetal growth and its concomitant conditions, shoulder dystocia and Cesarean delivery. Objectively evaluating the risks and benefits of labor induction is potentially confounded by the status of the cervix at the time of initiation of induction, early determination of an arrest disorder and physician bias toward Cesarean delivery for women who have diabetes. In non-diabetic women, incorporating estimates of fetal weight in deciding the route of delivery has not diminished the incidence of shoulder dystocia, and may have increased the incidence of Cesarean deliveries. Currently available evidence suggests that, while induction of labor for women who have diabetes may not carry much maternal or fetal risk, the benefit of this procedure is unclear.     

Induction of labor in elderly nulliparous women

Purpose: Maternal age is an important consideration for antenatal care, labor and delivery. We aimed to evaluate the induction of labor (IoL) failure rates among elderly nulliparous women.

Materials and methods: We conducted a retrospective analysis of all nulliparous women at 34?+?0 to 41?+?6 weeks, undergoing cervical ripening by prostaglandin E2 (PGE2) vaginal insert. Study group included elderly (≥35 years) nulliparous and control group included non-elderly (<35 years) nulliparous women. Primary outcome was IoL failure rate and secondary outcome was cesarean delivery rate. Outcomes were compared between the groups by univariate analysis followed by regression analysis to adjust results to potential confounders.

Results: Of 537 women undergoing IoL, 69 (12.8%) were elderly. The univariate analysis demonstrated no difference in IoL failure rate (26.5% versus 34.8%, p?=?0.502) between groups. However, elderly nulliparous women had higher rates of cesarean delivery (36.2% versus 21.4%, p?=?0.009). This difference was no longer significant after adjustment for maternal body mass index, indication for delivery, birth weight and gestational age at delivery.

Conclusion: Among nulliparous women, older maternal age is not associated with higher rates of IoL failure or cesarean deliveries.     

Induction of labor or serial antenatal fetal monitoring in postterm pregnancy: a randomized controlled trial

OBJECTIVE: To compare induction of labor at gestational age 41 weeks with expectant management in regard to neonatal morbidity. Secondary aims were to assess the effect of these managements on mode of delivery and maternal complications. METHODS: Between September 2002 and July 2004, postterm women with singleton cephalic presentation and no prelabor rupture of membranes were randomly assigned to induction of labor at 289 days or antenatal fetal surveillance every third day until spontaneous labor. Main outcome measures were neonatal morbidity, operative delivery rates, and maternal complications. RESULTS: Five hundred eight women were randomly assigned, 254 in each group. No differences of clinical importance were observed in women in whom labor was induced compared with women who were expectantly managed with regard to the following outcomes: neonates whose 5-minute Apgar score was less than 7 (three neonates in the induction group compared with four in the monitoring group, P=.72); neonates whose umbilical cord pH was less than 7 (three compared with two, P=.69); prevalence of cesarean delivery (28 compared with 33, P=.50); or prevalence of operative vaginal delivery (32 compared with 27, P=.49). In the induction group more women had precipitate labors (33 compared with 12, P<.01; number needed to treat was 13), and the duration of second stage of labor was more often less than 15 minutes (94 compared with 56, P<.01; number needed to treat was 7). CONCLUSION: No differences were found between the induced and monitored groups regarding neonatal morbidity or mode of delivery, and the outcomes were generally good. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00385229. LEVEL OF EVIDENCE: I.     

Induction of labor in women with a history of fast labor

Objective: History of fast labor is currently subjectively defined and inductions for non-medical indications are becoming restricted. We hypothesized that women induced for a history of fast labor do not have faster previous labors and do not deliver more quickly.

Methods: A retrospective case-control cohort design studied multiparas undergoing elective induction at one high risk center. Outcomes of dyads electively induced for a history of previous fast labor indication (PFast) were compared to controls with a psychosocial indication.

Results: A total of 612 elective inductions with 1074 previous deliveries were evaluated: 81 (13%) PFast and 531 (87%) control. PFast had faster previous labors (median 5.5?h, IQR: 4.5–6) versus. control (10?h, IQR: 9–10.5; p?<?0.001). Subsequent delivery time from start to expulsion was shorter for PFast (median 7?h, IQR: 5–9, p?<?0.001) than controls with and without a previous labor <5.5?h (8.6?h, IQR: 6–14 and 9.5?h, IQR: 7–15, respectively). PFast were less likely to have a serious maternal complication. Neonatal complications were similar.

Conclusions: Patients induced for a history of fast labor do have faster previous labors, suggesting a significant history of fast labor can be defined as <5.5?h. These women deliver more quickly and with lower morbidity than controls when subsequently induced, therefore the benefit may warrant the risk for a select number of women with a history of a prior labor length <5.5?h.     

Induction of labor in women with oligohydramnios.

OBJECTIVE: To prospectively evaluate the outcome of labor induction in women with oligohydramnios at term. METHODS: This was a prospective case-control study which included 120 consecutive patients with Amniotic Fluid Index (AFI) < or =5 undergoing labor induction. One hundred and sixteen patients with normal amniotic fluid matched for gestational age (+/- 3 days) and Bishop-score served as controls. Inclusion criteria were: requirement of labor induction, singleton pregnancy, nulliparity, Bishop score <5, gestational age > or =266. Preinduction treatment included the use of up to 3 successive doses of dinoprostone intracervical gel (0.5 mg). Vaginal dinoprostone (2 mg) and/or oxytocin were then applied to induction labor, if necessary. RESULTS: The rate of cesarean section in AFI < or = 5 group (38.3%) was not significantly different to that in control group (34.2%). The interval from induction to vaginal delivery was not significantly different for AFI < or =5 group (1499 +/- 895 min.) and control group (1398 +/- 852 min.). The changes in Bishop score evaluated at 6th and 12th hour after dinoprostone were not significantly different in control and AFI< or =5 group. More women in the latter group (11.7% vs 3.3%, Chi Square:4.86, p = 0.027) required the use of drugs in order to manage tachysystole/hyperstimulation allowing a OR = 3.83 (95%C.I. = 1.13-14.27). The length of stay at hospital was 4.2 +/- 1.8 days for AFI < or =5 group and 4.3 +/- 1.3 for control group. CONCLUSIONS: Oligohydranmios at term did not influence the outcome of induction of labour in nulliparous women with unfavorable cervix.     

Pharmacodynamics of ritodrine in pregnant women during preterm labor

We evaluated the relationship of ritodrine concentration to several maternal variables and to fetal heart rate in 17 women who received the drug for inhibition of preterm labor. Ritodrine was measured by high-performance liquid chromatography with electrochemical detection. Ritodrine increased maternal and fetal heart rate and decreased serum potassium in a dose-related manner, but wide variability was noted between patients and within individual patients. Tachyphylaxis of the maternal heart rate response to continuing treatment with ritodrine was seen in at least seven women. Maternal blood pressure, serum glucose concentration, and frequency of uterine contractions were changed by ritodrine treatment, but the changes in these variables were not closely correlated to the concentration of ritodrine (r less than or equal to 0.30 in all cases). The maximal infusion rate and the concentration of ritodrine in maternal serum after 4 hours of treatment were significantly (p less than 0.001) correlated with the frequency of uterine contractions prior to treatment. Successful inhibition of labor was achieved with serum concentrations of 15 to 31 ng/ml in 10 of 17 women; in six of the other seven women, labor could not be inhibited in spite of serum concentrations of 90 to 146 ng/ml. Side effects, such as hypotension, vomiting, chest discomfort, and shortness of breath, were most commonly observed when the infusion rate and concentration of ritodrine were increasing.     

Induction of labor in women with a uterine scar

Objective: To evaluate the frequency of uterine rupture following induction of labor in women with a previous cesarean section. Misoprostol was compared to other methods of induction.

Methods: A retrospective cohort study of 208 women attempting induction of labor after one previous cesarean section. Delivery data were collected retrospectively and compared. Group 1(2009–2010) was compared with Group 2 (2012–2013). In Group 1, the main method of induction was vaginal PGE₂ (prostaglandin-E₂), amniotomy, oxytocin or a balloon catheter. In Group 2, the dominant method of induction was an oral solution of misoprostol. Main outcome measures: frequency of uterine rupture in the two groups.

Results: Nine cases (4.3%) of uterine rupture occurred. There was no significant difference in the frequency of uterine rupture following the change of method of induction from PGE₂, amniotomy, oxytocin or mechanical dilatation with a balloon catheter to orally administered misoprostol (4.1 versus 4.6%, p?=?0.9). All ruptures occurred in women with no prior vaginal delivery.

Conclusion: The shift to oral misoprostol as the primary method of induction in women with a previous cesarean section did not increase the frequency of uterine rupture in the cohort studied.     

Cervical nitric oxide release in women postterm

OBJECTIVE: Nitric oxide may be a factor in cervical ripening. We compared the nitric oxide metabolite levels in cervical fluid in women going beyond term and in women delivering spontaneously at term. METHODS: We studied a total of 208 women with singleton pregnancies: 108 women who went beyond term (294 days or longer), and 100 women who went spontaneously into labor at term. Cervical fluid samples, collected well before the initiation of labor, were assessed for nitric oxide metabolites using an assay with a detection limit of 3.8 micromol/L. RESULTS: Women going beyond term had detectable levels of nitric oxide metabolites in their cervical fluid (60%) less often (P =.001) than women delivering at term (87%). The nitric oxide metabolite concentration in cervical fluid in women going beyond term (median 23.5 micromol/L; 95% confidence interval less than 3.8, 31.8) was 4.5 times lower (P <.001) than that in women delivering at term (median 106.0 micromol/L; 95% confidence interval 81.8, 135.0). Such a difference (14.0 versus 106.0 micromol/L) also existed when only the 66 women going into spontaneous postterm labor were included in the comparison. Both nulliparous (median less than 3.8 micromol/L) and parous (median 31.3 micromol/L) women going beyond term had lower (P <.01) cervical fluid nitric oxide metabolite levels than nulliparous and parous women delivering at term (medians 76.1 and 101.3 micromol/L, respectively). In the postterm group, women with cervical fluid nitric oxide metabolite concentrations at or below the median failed more often (P <.001) to progress in labor and had longer (P =.02) duration of labor than those with cervical fluid nitric oxide metabolite concentrations above the median. CONCLUSION: Reduced cervical nitric oxide release may contribute to prolonged pregnancy. LEVEL OF EVIDENCE: II-2     

Self-efficacy for labor and childbirth fears in nulliparous pregnant women

In this secondary analysis, the relationship between self-efficacy for labor and childbirth fears in healthy nulliparous women was investigated during the third trimester of pregnancy. The sample consisted of 280 predominantly white, well-educated, middle-class nulliparae enrolled in childbirth classes. Consistent with Bandura's self-efficacy theory, outcome expectancies for childbirth were unrelated to childbirth fears while self-efficacy expectancies were significantly correlated with childbirth fears. When the sample was divided into a low-fear and a high-fear group, significant differences were found between groups on a number of psychological variables. The women in the high-fear group were characterized by significantly higher learned helplessness, chance health locus of control and powerful others health locus of control, and significantly lower self-esteem and generalized self-efficacy. The most common fears of the high-fear women were of losing control during delivery, of the birth itself, of something being wrong with the baby and of painful contractions.     

Prevention of respiratory distress syndrome in pregnant diabetic women during labor

In the period between 1973 and 1976, in order to prevent neonatal RDS, 24 insulin-dependent diabetic mothers were given Dexamethason before delivery. The treated group was compared with a control group comprising 26 women of the same gesational age, severity of diabetes and mode of delivery. Neonatal care was similar in both groups. In the group where steroid prophylaxis was applied, decrease of RDS morbidity and mortality was observed. The authors accentuate that Dexamethason given to the mother may have an unfavourable effect on carbohydrate metabolism. Therefore, it is recommended to perform 4-hour determinations of blood sugar, urinary sugar and acetone and accordingly, modification of therapy.     

Selective labor induction in postterm patients. Observations and outcomes.

Six hundred twenty-nine postterm patients with reliable dates were evaluated for expectant management. Patients with medical or obstetric complications, a Bishop score greater than 6 or abnormal antepartum testing were ineligible for such management. The incidences of macrosomia, fetal distress necessitating cesarean section and low five-minute Apgar scores were similar in patients with labor induction as compared to those managed expectantly. The cesarean section rate was significantly lower in patients who underwent induction for a Bishop score greater than 6 as compared to those followed expectantly (15% vs. 28%). The lowest cesarean section rate was seen in patients with Bishop scores greater than 8 (5%) versus 15% in patients with Bishop scores of 6-8.