Factors associated with delayed onset of active labor following vaginal misoprostol administration among women at Mbarara Regional Referral Hospital, Uganda.

OBJECTIVE: To determine the factors associated with delayed onset of active labor following labor induction with vaginal misoprostol. METHODS: We conducted a prospective cohort study over 6 months at a tertiary hospital in Uganda. We enrolled mothers with pregnancies of at least 28 weeks, who were undergoing labor induction with 50 µg of vaginal misoprostol, administered every 6 hours with a maximum of four doses, and followed them up until onset of active labor. Labor onset was considered delayed if it occurred later than 12 hours after the first dose. Bivariate and multivariate analysis was performed to determine factors associated with delayed onset of active labor. RESULTS: Of the 88 mothers enrolled, 22.7% (n=20) had delayed onset of active labor. Nulliparity (adjusted relative risk [aRR] 2.34, 95% confidence interval [CI] 1.17-4.68) and gestational age less than 37 weeks (aRR 3.79, 95% CI 1.40-10.23) were associated with delayed onset of active labor following vaginal misoprostol administration whereas higher body mass index (aRR 0.38, 95% CI 0.18-0.79) decreased the risk. CONCLUSION: Delayed onset of active labor following labor induction remains an important obstetric care challenge. Mothers undergoing labor induction should have their body mass index documented, and nulliparous women and mothers at less than 37 weeks of gestation should have their labor monitored for a longer duration following labor induction.

Oxytocin discontinuation after the active phase of induced labor: A systematic review.

BACKGROUND: Oxytocin is the most widely used drug in the induction of labor, but it could have potential adverse effects that derive from uterine hyperstimulation. AIM: To determine the benefits and drawbacks of oxytocin continuation versus oxytocin discontinuation after the active phase of induced labor. METHODS: We systematically searched Pubmed, EMBASE, Scopus, ClinicalTrials.gov and Cochrane Library Plus until October 2017, for randomized controlled trials comparing oxytocin continuation with oxytocin discontinuation when the active phase of labor is reached were included. Data was collected by three reviewers and quality of the included studies assessed using the methodology recommended in the Cochrane Handbook. StatsDirect software was used to calculate risk ratios for binary variables and weighted mean differences for continuous variables. A fixed-effects or random-effects model was used as appropriate. RESULTS: Nine studies were selected including 1538 women, 774 in the oxytocin continuation group and 764 in the oxytocin discontinuation group. The incidence of cesarean sections (14.3% vs. 8.6%; relative risk, 1.67; 95% confidence interval: 1.25-2.23), uterine hyperstimulation (12.4% vs. 4.7%; relative risk, 2.59; 95% confidence interval: 1.70-3.93) and nonreassuring fetal heart rate (19.2% vs.12.5%; relative risk, 1.55; 95% confidence interval: 1.18-2.02) were significantly higher in the oxytocin continuation group. An increase in the duration of the second stage of labor in the oxytocin discontinuation group was observed (pooled mean difference, -7.03; 95% confidence interval: -9.80 to -4.26). CONCLUSIONS: After the active phase of induced labor, oxytocin continuation increases the risk of cesarean section, uterine hyperstimulation and alterations to the fetal heart rate.

Castor oil for induction of labor in post-date pregnancies: A randomized controlled trial.

BACKGROUND: Castor oil is a substance used for labor induction in an inpatient setting. However, its efficacy as an agent for the induction of labor, for post-date pregnancies in an outpatient setup is unknown. OBJECTIVE: Efficacy of castor oil as an agent for the induction of labor, for post-date pregnancies in outpatient settings. METHODS: Eighty-one women with a low-risk post-date singleton pregnancy with a Bishop score≤7, without effective uterine contractions were randomized to the intervention, 60ml of castor oil, or the control, 60ml of sun-flower oil. The primary outcome was proportion of women entering the active phase of labor 24, 36, 48h after ingestion. Secondary outcomes included meconium stained amniotic fluid, abnormal fetal heart rate tracing, cesarean section rate, instrumental deliveries, birth weight, 5min Apgar score, chorioamnionitis, hypertensive complications, retained placenta, and post-partum hemorrhage. FINDINGS: Intervention and control groups included 38 and 43 women, respectively. No differences in baseline characteristics, except for age were noted. The observed interaction between castor oil and parity was significant (pinteraction=0.02). Multiparous women in the intervention group exhibited a significant beneficial effect on entering active labor within 24, 36 and 48h after castor oil consumption compared with the placebo (Hazard Ratio=2.93, p=0.048; Hazard Ratio=3.29, p=0.026; Hazard Ratio=2.78, p=0.042 respectively). This effect was not noted among primiparous women. No differences in rate of obstetric complications or adverse neonatal outcomes were noted. CONCLUSION: Castor oil is effective for labor induction, in post-date multiparous women in outpatient settings.

Castor oil as a natural alternative to labor induction: A retrospective descriptive study.

AIM: To describe birthing outcomes among women who consumed castor oil cocktail as part of a freestanding birth center labor induction protocol. METHODS: De-identified data from birth logs and electronic medical records were entered into SPSS Statistics 22.0 for analysis for all women who received the castor oil cocktail (n=323) to induce labor between January 2008 and May 2015 at a birth center in the United States. Descriptive statistics were analyzed for trends in safety and birthing outcomes. RESULTS: Of the women who utilized the castor oil cocktail to stimulate labor, 293 (90.7%) birthed vaginally at the birth center or hospital. The incidence of maternal adverse effects (e.g., nausea, vomiting, extreme diarrhea) was less than 7%, and adverse effects of any kind were reported in less than 15% of births. An independent sample t-test revealed that parous women were more likely to birth vaginally at the birth center after using the castor oil cocktail than their nulliparous counterparts (p<.010), while gestational age (p=.26), woman's age (p=.23), and body mass index (p=.28) were not significantly associated. CONCLUSIONS: Nearly 91% of women in the study who consumed the castor oil cocktail to induce labor were able to give birth vaginally with little to no maternal or fetal complications. Findings indicate further research is needed to compare the safety and effectiveness of natural labor induction methodologies, including castor oil, to commonly used labor induction techniques in a prospective study or clinical trial.

Epidurals and the Modern Labor Curve: How Epidural Timing Impacts Fetal Station during Active Labor.

OBJECTIVE: The objective of this study was to estimate epidural timing's impact on fetal station during active labor. STUDY DESIGN: This secondary analysis of a single-institution prospective cohort study included all term singleton pregnancies, stratified by parity. Those with early epidurals (placed at <6 cm) were compared with those with late epidurals (placed at ≥6 cm). The primary outcome was median fetal station from 6 to 10 cm. Secondary outcomes included rate of prolonged first or second stage of labor (>95%). Multivariable logistic regression adjusted for labor type. RESULTS: Among 7,647 women, 3,434 were nulliparous (2,983 with early epidurals and 451 with late epidurals) and 4,213 multiparous (3,141 with early epidurals and 1,072 with late epidurals). Interquartile ranges (IQRs) suggested fetal station at 6 cm was likely lower among those with early epidurals (nulliparous: median head station -1 [IQR: -1 to 0] for early epidural vs. -1 [IQR: -2 to 0] for late epidural, p < 0.01; multiparous: -1 (IQR: -2 to 0] for early epidural vs. -1 [IQR: -3 to -1] for late epidural, p < 0.01). Early epidurals were not associated with increased risk of prolonged first stage, but among nulliparous were associated with decreased risk of prolonged second stage (adjusted odds ratio: 0.66 [95% confidence interval: 0.44-0.99]). CONCLUSION: Early epidurals were associated with lower fetal station in active labor but not prolonged first stage.

Effect of hyoscine butyl-bromide on the duration of active phase of labor: A randomized-controlled trial.

OBJECTIVE: Hyoscine butyl bromide (HBB) is known for its antispasmodic action and has been in use for over five decades, there is however no consensus on its effectiveness in the labor process. The aim of this study was to determine the effect of HBB on the duration of the active phase of labor. MATERIALS AND METHODS: A randomized double-blind placebo-controlled clinical trial involving 160 parturient who received either intravenous Hyoscine butyl-bromide (20 mg in 1 ml; n = 80) or intravenous normal saline (1 ml, n = 80). The mean duration of active phase of labor was compared between the two groups. RESULTS: The observed mean duration of the active phase of labor was significantly shorter (P = 0.001) in the Hyoscine butyl-bromide group (365.11 ± 37.32 min, range = 280-490) than in the Placebo group (388.46 ± 51.65 min, range = 280-525). There was no significant difference between the two groups in the mean duration of the second and third stages of labor (20.46 ± 10.46 vs. 23.38 ± 18.95 min, P = 0.43 and 8.96 ± 4.34 vs. 9.23 ± 5.92 min, P = 0.75, respectively). The mean 1-min APGAR scores were also comparable (8.08 ± 1.54 vs. 7.64 ± 1.60, P = 0.08). The mean postpartum blood loss was significantly less in the Hyoscine butyl-bromide group (303 ± 96.52 vs. 368 ± 264.19 ml, P = 0.04). CONCLUSION: Hyoscine butyl-bromide was effective in shortening the duration of the active phase of labor. It was also associated with significantly less postpartum blood loss.

Analysis of intravaginal misoprostol 0.2 mg versus intracervical dinoprostone 0.5 mg doses for labor induction at term pregnancies.

OBJECTIVES: Labor-induction methods are used in about 23% of labors. Most commonly, pharmacological methods are used to pre-induct the labor with dinoprostone - a PGE2 analog, and misoprostol - a PGE1 analog. The aim of this study was to evaluate two pharmacological methods of labor induction with the use of prostaglandins applied via an intravagi-nal insert containing misoprostol at a dose of 0.2 mg and intracervical gel containing dinoprostone at a dose of 0.5 mg. MATERIAL AND METHODS: This retrospective study was conducted on a group of 50 adult patients qualified for the pre-induction of labor. Following data were recorded: the time from the drug administration to the beginning of regular contractile function, the time from administration to amniotic fluid rupture, the time from medicament administration to the vaginal labor or caesarean section, the duration of I, II and III stages of labor, the delivery method and in the event of caesarean section - the indications for surgery. RESULTS: In comparison to dinoprostone, the misoprostol application was found to shorten the time from drug administration to amniotic fluid rupture by 14.1 hours, the time to the beginning of the first stage of labor by 11.7 hours and from the drug administration to the delivery by 17.3 hours (p-value < 0.05). The duration of the first stage of labor in the misoprostol group was shorter by 1.2 hours than in dinoprostone group (p-value < 0.05). CONCLUSIONS: Application of intravaginal insert with misoprostol at a dose of 0.2 mg appears to be a more effective method of labor induction in comparison to intracervical gel with dinoprostone at a dose of 0.5mg. Thorough analysis of these methods requires further studies.

Continuation versus discontinuation of oxytocin infusion during the active phase of labour: a randomised controlled trial.

OBJECTIVE: To investigate whether discontinuation of oxytocin infusion increases the duration of the active phase of labour and reduces maternal and neonatal complications. DESIGN: Randomised controlled trial. SETTING: Department of Obstetrics and Gynaecology, Regional Hospital of Randers, Denmark. POPULATION: Women with singleton pregnancy in the vertex position undergoing labour induction or augmentation. METHODS: Two hundred women were randomised when cervical dilation was ≤4 cm to either continue or discontinue oxytocin infusion when cervical dilation reached 5 cm. MAIN OUTCOME MEASURES: The primary outcome was duration of the active phase of labour, defined as the time period from 5 cm of cervical dilation until delivery. Secondary outcomes were mode of delivery, uterine tachysystole, hyperstimulation, abnormalities in fetal heart rate, postpartum haemorrhage rate, perineal tears, and neonatal outcomes. RESULTS: The active phase of labour was longer by 41 minutes (95% confidence interval 11-75 minutes) in the discontinued group (median 125 minutes in 85 women who had reached the active phase and delivered vaginally) versus the continued group (median 88 minutes in 78 women). The incidence of fetal heart rate abnormalities (51 versus 20%) and uterine hyperstimulation (12 versus 2%) was significantly greater in the continued than the discontinued oxytocin group. The incidence of tachysystole, caesarean deliveries, postpartum haemorrhage, third degree perineal tears and adverse neonatal outcomes was higher in the continued group, but did not reach significance. CONCLUSIONS: Discontinuation of oxytocin infusion in the active phase of labour may improve some labour outcomes but has the disadvantage of increasing the duration of the active phase of labour. TWEETABLE ABSTRACT: Stopping oxytocin in the active phase seems to make labour less complicated but lengthens duration.

Implementing High-Value Care.

OBJECTIVES: Our objectives were to assess physician knowledge of costs of products, tests, and services commonly used by obstetrician/gynecologists (OB/GYNs) and identify those items that could be eliminated without decreasing quality of care by performing a prospective observational pilot study. METHODS: An anonymous electronic survey was distributed to 70 OB/GYN providers at Greenville Memorial Hospital. Survey items included common laboratory tests, medications, and clinical services. The survey was used to identify items with high cost for which there were less costly but equally efficacious alternatives. As an educational intervention, grand rounds reviewing the survey results, as well as recommendations that would allow for lean healthcare changes, were conducted. Utilization and cost savings were tracked for a 1-year preintervention and a 1-year postintervention. RESULTS: In total, 50 of 70 providers (71%) completed the survey. Hydrocortisone acetate/pramoxine hydrochloride and dinoprostone vaginal inserts were targeted for intervention. Use of the dinoprostone vaginal insert decreased 50.5% with a savings of $66,500 when comparing the preintervention period with the postintervention period. Use of hydrocortisone acetate/pramoxine hydrochloride decreased 90% with a savings of $92,655. Combined, the decreased use of these products led to a $159,155 cost savings in the 1-year postintervention period. CONCLUSIONS: OB/GYN providers at our institution had a poor working knowledge of costs. Through the use of a survey and educational intervention, we demonstrated that simple interventions could lead to high-quality, lean healthcare changes.

Effect of oxytocin discontinuation during the active phase of labor.

OBJECTIVE: To observe the progression of labor when oxytocin use is limited to the onset of the active stage of labor. METHODS: A randomized, prospective controlled study was performed to address the issue of oxytocin infusion after the onset of active labor in 140 patients. In the study group, infusion of oxytocin was discontinued at the onset of the active phase of labor, which was accepted as a cervical dilatation of 5 cm. In the control group, incremental oxytocin infusion was administered until 5 cm cervical dilatation, and then was maintained at the same level until delivery. RESULTS: The primary outcome variable was duration from the beginning of the active phase to delivery. In the study group, the duration of the active phase of labor was about 30 min longer than in the control group and this difference was significant. The secondary outcomes of the study were maternal-fetal complications of oxytocin and in both groups there were no significant differences. CONCLUSION: It is not reasonable to discontinue oxytocin infusion at the beginning of active labor. Nevertheless, for an accurate conclusion expanded investigations are needed.

Herbal therapies in pregnancy: what works?

PURPOSE OF REVIEW: The aim of this article is two-fold: to report the prevalence of herbal products used by pregnant women and to evaluate the evidence of efficacy and safety of the most popular remedies. RECENT FINDINGS: Of the 671 articles identified, 15 randomized controlled trials (RCTs) and 16 non-RCTs were eligible. Ginger was the most investigated remedy and it was consistently reported to ameliorate nausea and vomiting in pregnancy. Although raspberry, blue cohosh, castor oil, and evening primrose oil are believed to facilitate labor in traditional medicine, very few scientific data support such indication. Moreover, they have been associated with severe adverse events. Data on the safety of Hypericum perforatum in pregnancy or lactation are reassuring, whereas efficacy was demonstrated only in nonpregnant individuals. There is still insufficient evidence regarding the efficacy and safety of Echinacea, garlic, and cranberry in pregnancy. SUMMARY: Epidemiological studies reported a wide range of use of herbal remedies in pregnancy. Too few studies have been devoted to the safety and efficacy of singular herbs. With the exception of ginger, there are no consistent data to support the use of any other herbal supplement during pregnancy. Severe adverse events have been reported using blue cohosh and evening primrose oil.

Oxytocin discontinuation during active labor in women who undergo labor induction.

OBJECTIVE: The purpose of this study was to determine whether there is an increase in the cesarean delivery rate in women who undergo induction when oxytocin is discontinued in the active phase of labor. STUDY DESIGN: We conducted a prospective randomized controlled trial of women who underwent induction of labor at term; they were assigned randomly to either routine oxytocin use (routine) or oxytocin discontinuation (DC) once in active labor. Analysis was by intention to treat. RESULTS: Two hundred fifty-two patients were eligible for study analysis: 127 patients were assigned randomly to the routine group and 125 patients were assigned randomly to the DC group. Cesarean delivery rate was similar between the groups (routine, 25.2% [n = 32] vs the DC group, 19.2% [n = 24]; P = .25). There was a higher chorioamnionitis rate and slightly longer active phase in those women who were assigned to the DC group. In adjusted analysis, the rate of chorioamnionitis was not different by randomization group but was explained by the duration of membrane rupture and intrauterine pressure catheter placement. CONCLUSION: Discontinuation of oxytocin in active labor after labor induction does not increase the cesarean delivery rate significantly.

Oxytocin regimen for labor augmentation, labor progression, and perinatal outcomes.

OBJECTIVE: To examine the effects and safety of high-dose (compared with low-dose) oxytocin regimen for labor augmentation on perinatal outcomes. METHODS: Data from the Consortium on Safe Labor were used. A total of 15,054 women from six hospitals were eligible for the analysis. Women were grouped based on their oxytocin starting dose and incremental dosing of 1, 2, and 4 milliunits/min. Duration of labor and a number of maternal and neonatal outcomes were compared among these three groups stratified by parity. Multivariable logistic regression and generalized linear mixed model were used to adjust for potential confounders. RESULTS: Oxytocin regimen did not affect the rate of cesarean delivery or other perinatal outcomes. Compared with 1 milliunit/min, the regimens starting with 2 milliunits/min and 4 milliunits/min reduced the duration of first stage by 0.8 hours (95% confidence interval 0.5-1.1) and 1.3 hours (1.0-1.7), respectively, in nulliparous women. No effect was observed on the second stage of labor. Similar patterns were observed in multiparous women. High-dose regimen was associated with a reduced risk of meconium stain, chorioamnionitis, and newborn fever in multiparous women. CONCLUSION: High-dose oxytocin regimen (starting dose at 4 milliunits/min and increment of 4 millliunits/min) is associated with a shorter duration of first-stage of labor for all parities without increasing the cesarean delivery rate or adversely affecting perinatal outcomes. LEVEL OF EVIDENCE: II.

A randomized clinical trial to compare the efficacy of different doses of intravaginal misoprostol with intracervical dinoprostone for cervical ripening and labor induction.

OBJECTIVES: To compare the efficacy of 25 vs. 50 microg of intravaginal misoprostol vs. intracervical dinoprostone for cervical ripening and labor induction. MATERIALS AND METHODS: 210 women with Bishop's score <6 were randomized into 3 groups of 70 each to receive 6 hourly doses of either 25 or 50 microg of intravaginal misoprostol or 0.5 mg intracervical dinoprostone to maximum of 3 doses and outcome parameters were compared. RESULTS: Induction to vaginal delivery interval was significantly lower (p < 0.05) for 50 microg (13.8 +/- 6.62 hours) as compared to 25 microg misoprostol (16.4 +/- 7.34 hours) or dinoprostone group (16.3 +/- 7.49 hours). Maximum improvement (p < 0.05) in Bishop's score and minimum oxytocin requirement (p < 0.05) was seen with misoprostol 50 microg. No significant difference was observed for women delivering vaginally within 24 hours (93.8 vs. 89.7 vs. 85.4%), patients delivering after one dose (24.3 vs. 21.4 vs. 20%), cesarean deliveries, fetal outcome, complications like hyperstimulation and fetal heart abnormalities for the 50 vs. 25 microg misoprostol vs. dinoprostone group. CONCLUSION: Intravaginal misoprostol 50 microg administered 6 hourly appears to be most effective as it has least induction to delivery time, has maximum improvement in Bishop's score, least oxytocin requirement without any increase in complication rate.

Surfactant protein-A (SP-A) selectively inhibits prostaglandin F2alpha (PGF2alpha) production in term decidua: implications for the onset of labor.

CONTEXT: Labor is characterized by "decidual activation" with production of inflammatory mediators. Recent data suggest that surfactant protein-A (SP-A) may be critical to the onset of labor in mice. Whether this is also true in humans is unclear. OBJECTIVES: The aim was to investigate: 1) the expression of SP-A at the maternal-fetal interface; 2) the effect of SP-A on the production of inflammatory mediators by human decidua; and 3) the association between single nucleotide polymorphisms in maternal SP-A genes and spontaneous preterm birth. RESEARCH DESIGN AND METHODS: In situ expression of SP-A was investigated by immunohistochemistry and quantitative RT-PCR. Term decidual stromal cells were isolated, purified, and treated with/without SP-A (1-100 µg/ml), IL-1ß, and/or thrombin. Levels of inflammatory mediators [IL-6, IL-8, TNFα, matrix metalloproteinase-3, monocyte chemotactic protein-1, IL-1ß, PGE(2), prostaglandin F(2α) (PGF(2α))] and angiogenic factors (soluble fms-like tyrosine kinase-1, vascular endothelial growth factor) were measured in conditioned supernatant by ELISA and corrected for protein content. The effect of SP-A on eicosanoid gene expression was measured by quantitative RT-PCR. RESULTS: SP-A localized to endometrium/decidua. High-dose SP-A (100 µg/ml) inhibited PGF(2α) by term decidual stromal cells without affecting the production of other inflammatory mediators, and this effect occurred at a posttranscriptional level. Decidual SP-A expression decreased significantly with labor. Single nucleotide polymorphisms in the SP-A genes do not appear to be associated with preterm birth. CONCLUSIONS: SP-A is produced by human endometrium/decidua, where it significantly and selectively inhibits PGF(2α) production. Its expression decreases with labor. These novel observations suggest that decidual SP-A likely plays a critical role in regulating prostaglandin production within the uterus, culminating at term in decidual activation and the onset of labor.

The effect of low molecular weight heparin (dalteparin) on duration and initiation of labour.

It has recently been reported that women treated with low molecular weight heparin (LMWH) during pregnancy had 3 h shorter duration of delivery. The aim of the present study was to evaluate whether LMWH (dalteparin) affects labour. From January 1996 to December 2005, 217 consecutive pregnancies, out of 34 216 newborn (prevalence 0.6%) that were given thromboprophylaxis with dalteparin (usually 5,000 IU once daily). These 217 consecutive pregnancies were compared to an unselected control group (n = 1,499) of gravidae. Main outcome was time in first and second stage of labour and gestational age at delivery. Among nulliparous women, there were significantly fewer women with prolonged first stage of labour as compared to controls (4.1% vs. 8.5%, P = 0.047). In addition, the duration of first stage of labour was 1 h shorter among those treated with LMWH (5.2 vs. 6.2 h, P = 0.06). There were no such differences among parous women. The risk of prematurity, profuse blood loss, and postpartum anaemia was almost doubled among those treated with LMWH (11.5% vs. 5.9%, P = 0.002, 10.6% vs. 5.9%, P < 0.001, and 12.9% vs. 8.7%, P = 0.048, respectively). Treatment with a prophylactic dose of LMWH (dalteparin) during pregnancy was related to fewer women with prolonged first stage of labour, but also to an increased risk of prematurity and blood loss complications.

Prenatal di(2-ethylhexyl)phthalate exposure and length of gestation among an inner-city cohort.

OBJECTIVE: Our objective was to assess the relationship between di(2-ethylhexyl)phthalate (DEHP) exposure during pregnancy and gestational age at delivery among 311 African American or Dominican women from New York City. METHODS: Forty-eight-hour personal air and/or spot urine samples were collected during the third trimester. DEHP levels were measured in air samples and 4 DEHP metabolite levels were measured in urine. Specific gravity was used to adjust for urinary dilution. Gestational age was abstracted from newborn medical records (n = 289) or calculated from the expected date of delivery (n = 42). Multivariate linear regression models controlled for potential confounders. RESULTS: DEHP was detected in 100% of personal air samples (geometric mean: 0.20 microg/m(3) [95% confidence interval [CI]: 0.18-0.21 microg/m(3)]); natural logarithms of air concentrations were inversely but not significantly associated with gestational age. Two or more of the DEHP metabolites were detected in 100% of urine samples (geometric mean: 4.8-38.9 ng/mL [95% CI: 4.1-44.3 ng/mL]). Controlling for potential confounders, gestational age was shorter by 1.1 days (95% CI: 0.2-1.8 days) for each 1-logarithmic unit increase in specific gravity-adjusted mono(2-ethylhexyl)phthalate concentrations (P = .01) and averaged 5.0 days (95% CI: 2.1-8.0 days) less among subjects with the highest versus lowest quartile concentrations (P = .001). Results were similar and statistically significant for the other DEHP metabolites. CONCLUSIONS: Prenatal DEHP exposure was associated with shorter gestation but, given inconsistencies with previous findings for other study populations, results should be interpreted with caution, and additional research is warranted.