Preterm Delivery In Women Research Articles

Prediction of impending preterm delivery based on sonographic cervical length and different cytokine levels in cervicovaginal fluid in preterm labor.

The aim of this study was to determine whether cervicovaginal interleukin (IL)-1β, IL-6 and IL-8 levels, and cervical length, alone or in combination, could predict impending preterm delivery in women with preterm labor and intact membranes. Cervicovaginal swab samples for IL-1β, IL-6, and IL-8 assays were taken from 136 consecutive women with preterm labor (23-34 weeks) before the transvaginal ultrasonography examination to measure cervical length. The primary outcome measurement was spontaneous preterm delivery within 7 days of sampling. Spontaneous preterm delivery within 7 days occurred in 28.6% (39/136) of patients. Receiver-operator characteristic (ROC) curves indicated that cervical length (P < 0.001), cervicovaginal IL-6 (P < 0.001) and IL-8 (P = 0.014), but not IL-1β, could predict delivery within 7 days. According to the logistic regression analysis, high cervicovaginal IL-8 (P = 0.008) and IL-6 (P = 0.038) levels and short cervical length (P < 0.001) were significantly associated with delivery within 7 days, even after controlling for baseline variables. A combination of cervix length and cervicovaginal IL-8 increased the specificity of detecting delivery within 7 days to 92.8%, which was superior to either test alone (P < 0.001), but the sensitivity was only 56.4%. In women with preterm labor, among the parameters assessed, cervicovaginal IL-6 and IL-8 and cervical length are the most important parameters in predicting impending preterm delivery. A combination of cervix length and cervicovaginal IL-8 appeared to be the best for predicting impending preterm delivery, but the relatively low sensitivity of this test may limit its clinical usefulness.

HCV-HIV coinfected pregnant women: data from a multicentre study in Italy.

To provide information about main pregnancy outcomes in HIV-HCV coinfected women and about the possible interactions between HIV and HCV in this particular population. Data from a multicenter observational study of pregnant women with HIV, conducted in Italian University and Hospital Clinics between 2001 and 2015, were used. Eligibility criteria for analysis were HCV coinfection and at least one detectable plasma HCV-RNA viral load measured during pregnancy. Qualitative variables were compared using the Chi-square or the Fisher test and quantitative variables using the Mann-Whitney U test. The Spearman's coefficient was used to evaluate correlations between quantitative variables. Among 105 women with positive HCV-RNA, median HCV viral load was substantially identical at the three trimesters (5.68, 5.45, and 5.86 log IU/ml, respectively), and 85.7 % of the women had at least one HCV-RNA value >5 log IU/ml. Rate of preterm delivery was 28.6 % with HCV-RNA <5 log IU/ml and 43.2 % with HCV-RNA >5log (p = 0.309). Compared to women with term delivery, women with preterm delivery had higher median HCV-RNA levels (third trimester: 6.00 vs. 5.62 log IU/ml, p = 0.037). Third trimester HIV-RNA levels were below 50 copies/ml in 47.7 % of the cases. No cases of vertical HIV transmission occurred. Rate of HCV transmission was 9.0 % and occurred only with HCV-RNA levels >5 log IU/ml. Coinfection with HIV and HCV has relevant consequences in pregnancy: HIV coinfection is associated with high HCV-RNA levels that might favour HCV transmission, and HCV infection might further increase the risk of preterm delivery in women with HIV. HCV/HIV coinfected women should be considered a population at high risk of adverse outcomes.

Prophylaxis of preterm delivery in women with pulmonary tuberculosis

The organizational and treatment activities aimed on prophylaxis of preterm delivery in pregnant women with pulmonary tuberculosis are presented in the article. Dominating factors provoking preterm delivery in this contingent of patients are analyzed. It is established that premature delivery in case of tuberculosis arises at every second patient.

Predictive value of cervical length in women with twin pregnancy presenting with threatened preterm labor.

To assess the accuracy and determine the optimal threshold of sonographic cervical length (CL) for the prediction of preterm delivery (PTD) in women with twin pregnancies presenting with threatened preterm labor (PTL). This was a retrospective study of women with twin pregnancies who presented with threatened PTL and underwent sonographic measurement of CL in a tertiary center. The accuracy of CL in predicting PTD in women with twin pregnancies was compared with that in a control group of women with singleton pregnancies. Overall, 218 women with a twin pregnancy and 1077 women with a singleton pregnancy, who presented with PTL, were included in the study. The performance of CL as a predictive test for PTD was similar in twins and singletons, as reflected by the similar correlation between CL and the examination-to-delivery interval (r, 0.30 vs 0.29; P = 0.9), the similar association of CL with risk of PTD, and the similar areas under the receiver-operating characteristics curves for differing delivery outcomes (range, 0.653-0.724 vs 0.620-0.682, respectively; P = 0.3). The optimal threshold of CL for any given target sensitivity or specificity was lower in twin than in singleton pregnancies. However, in order to achieve a negative predictive value of 95%, a higher threshold (28-30 mm) should be used in twin pregnancies. Using this twin-specific CL threshold, women with twins who present with PTL are more likely to have a positive CL test, and therefore to require subsequent interventions, than are women with singleton pregnancies with PTL (55% vs 4.2%, respectively). In women with PTL, the performance of CL as a test for the prediction of PTD is similar in twin and singleton pregnancies. However, the optimal threshold of CL for the prediction of PTD appears to be higher in twin pregnancies, mainly owing to the higher baseline risk for PTD in these pregnancies.

Inflammatory Bowel Disease and Risk of Adverse Pregnancy Outcomes.

Background and ObjectivesExisting data on pregnancy complications in inflammatory bowel disease (IBD) are inconsistent. To address these inconsistencies, we investigated potential associations between IBD, IBD-related medication use during pregnancy, and pregnancy loss, pre-eclampsia, preterm delivery, Apgar score, and congenital abnormalities.MethodsWe conducted a cohort study in >85,000 Danish National Birth Cohort women who were pregnant in the period 1996-2002 and had information on IBD, IBD-related medication use (systemic or local corticosteroids, 5-aminosalicylates), pregnancy outcomes and potential confounders. We evaluated associations between IBD and adverse pregnancy/birth outcomes using Cox regression and log-linear binomial regression.ResultsIBD was strongly and significantly associated with severe pre-eclampsia, preterm premature rupture of membranes and medically indicated preterm delivery in women using systemic corticosteroids during pregnancy (hazard ratios [HRs] >7). IBD was also associated with premature preterm rupture of membranes in women using local corticosteroid medications (HR 3.30, 95% confidence interval [CI] 1.33-8.20) and with medically indicated preterm delivery (HR 1.91, 95% CI 0.99-3.68) in non-medicated women. Furthermore, IBD was associated with low 5-minute Apgar score in term infants (risk ratio [RR] 2.19, 95% CI 1.03-4.66). Finally, Crohn’s disease (but not ulcerative colitis) was associated with major congenital abnormalities in the offspring (RR 1.85, 95% CI 1.06-3.21). No child with a congenital abnormality born to a woman with IBD was exposed to systemic corticosteroids in utero.ConclusionWomen with IBD are at increased risk of severe pre-eclampsia, medically indicated preterm delivery, preterm premature rupture of membranes, and delivering infants with low Apgar score and major congenital malformations. These associations are only partly explained by severe disease as reflected by systemic corticosteroid use.

Predictive biomarkers of preterm delivery in women with ongoing IVF pregnancies

In vitro fertilization (IVF) pregnancies potentially have a higher rate of preterm delivery (PTD) than do spontaneously conceived gestations, and differences persist following adjustment for multiple gestation, maternal age, and parity. The reasons for this increased susceptibility to PTD remain incompletely elucidated. To identify potential biomarkers predictive of PTD in IVF subjects, we performed a retrospective analysis of multiple markers in sera obtained during early gestation that have been suggested to be associated with peri-implantation events. Sera from 35 women with a preterm birth and 68 women with a term delivery, obtained between 9 and 11 days after embryo transfer, were tested blindly for concentrations of interleukin (IL)-1β, IL-6, IL-13, IL-17, human epididymal protein 4 (HE4), secretory leukocyte protease inhibitor (SLPI), insulin-like growth factor (IGF)-I, IGF-II, IGF binding protein (BP)-1, and interferon-γ. Concentrations of HE4 (p=0.001) and IL-13 (p=0.029) were reduced, and levels of IGF-II (p=0.023) and SLPI (p=0.043) were increased, in women who subsequently delivered preterm. By receiver operator curve analysis, the combination of HE4 and IL-13 levels best predicted the outcome preterm birth. The association between deficiencies in circulating HE4 and IL-13 levels during early pregnancy and subsequent PTD suggest that factors contributing to sub-optimal embryo implantation influence length of gestation in women undergoing IVF.

The risk of preterm delivery in women with a history of laparoscopic adjustable gastric banding compared to roux en Y gastric bypass: a systematic review protocol.

REVIEW QUESTION / OBJECTIVE The quantitative objective is to compare the risk of preterm delivery in women with a history of laparoscopic adjustable gastric banding or roux en Y gastric bypass More specifically, the objective is to compare: The risk of preterm delivery in women with a history of laparoscopic adjustable gastric banding or roux en Y gastric bypass and a subsequent preterm delivery. INCLUSION CRITERIA Types of participants This review will consider studies that include women with a history of laparoscopic adjustable gastric banding or roux en Y gastric bypass. To include as many studies as possible, no limits were placed on surgery to conception interval, number of pregnancies, body mass index limits, and age. Types of Exposure This review will consider studies that evaluate women who have undergone laparoscopic adjustable gastric banding or roux en Y gastric bypass prior to conception. Studies including a single bariatric surgical technique or a group of surgical methods of which the exposure types are a part will be included regardless of technique, type of surgical unit, or specialty of performing surgeon. Types of outcomes This review will consider studies that include the following outcome measures: preterm delivery as defined by live birth prior to 37 completed weeks of gestation. Premature rupture of membranes is a condition in which the amniotic sac ruptures prior to the completion of 37 weeks gestation. Delivery, vaginal or operative, occurs within 24 hours and is used as a surrogate measure for preterm delivery. As authors do not uniformly include the same types of pregnancy and neonatal outcomes in their research, studies addressing preterm delivery as an individual outcome measure or as part of a group of outcome measures will be included.

The risk of preterm delivery in women with a history of laparoscopic adjustable gastric banding compared to roux en Y gastric bypass: a systematic review protocol

The risk of preterm delivery in women with a history of laparoscopic adjustable gastric banding compared to roux en Y gastric bypass: a systematic review protocol

Mental health in early pregnancy is associated with pregnancy outcome in women with pregestational diabetes.

To explore the role of early pregnancy health-related quality of life, anxiety, depression and locus of control for pregnancy outcome in women with pregestational diabetes. This was a cohort study of 148 pregnant women with pregestational diabetes (118 with Type 1 diabetes and 30 with Type 2 diabetes), who completed three internationally validated questionnaires: the 36-item Short-Form Health Survey, the Hospital Anxiety and Depression Scale and the Multidimensional Health Locus of Control survey at 8 weeks. Selected pregnancy outcomes were preterm delivery (< 37 weeks) and large for gestational age infants (birth weight > 90(th) percentile). Differences between groups in the questionnaires were analysed using an unpaired t-test. Women with preterm deliveries (n = 28) had lower (i.e. worse) mean (sd) quality-of-life scores for the two 36-item Short-Form Health Survey scales, Role-Emotional [58.3 (38.1) vs. 82.9 (31.3); P = 0.0005] and Mental Health [67.7 (20.4) vs. 75.2 (15.8), P = 0.04], and a lower score for the 36-item Short-Form Health Survey scale Mental Component Summary (42.8 (13.1) vs. 48.8 (9.7), P = 0.03) in early pregnancy, compared with women with term deliveries. Depression symptoms (Hospital Anxiety and Depression Scale depression score ≥ 8) were more frequent in women with preterm vs. term deliveries (seven (25%) vs. six women (5%); P = 0.003), while levels of anxiety and locus of control were similar in these two groups. No difference in early pregnancy scores for health-related quality of life, anxiety, depression and locus of control were seen in women delivering large or appropriate for gestational age infants. Poor mental quality of life and the presence of depressive symptoms in early pregnancy were associated with preterm delivery in women with pregestational diabetes.

Transvaginal sonographic evaluation of cervical length in the second trimester of asymptomatic singleton pregnancies, and the risk of preterm delivery.

To evaluate cervical length in asymptomatic women with singleton pregnancies in the second trimester by means of transvaginal ultrasonography, and to examine the relation between cervical length and spontaneous preterm delivery. Observational, prospective study. A university hospital and a county hospital in Western Sweden. A total of 2122 asymptomatic women with live singleton pregnancies without fetal anomalies. Cervical length was measured at between 16 and 23 weeks of gestation by means of transvaginal ultrasonography. Data were analysed using logistic regression analysis. Cervical length in relation to spontaneous preterm delivery <34 weeks (primary outcome) and <37 weeks of gestation (secondary outcome). Eleven women had a cervical length of ≤25 mm (0.5%) and 73 women had a cervical length of ≤30 mm (3.4%). Spontaneous preterm delivery at <34 weeks occurred in 22/2061 women (1.1%) and at <37 weeks in 87/2061 women (4.2%). There was a significant association between cervical length and spontaneous preterm delivery at <34 weeks (odds ratio 1.78; 95% confidence interval 1.19-2.65 for a decrease of cervical length by 5 mm) but no significant association at <37 weeks. The rate of short cervical length of ≤25 mm was lower than expected. The study confirmed the increased risk of spontaneous preterm delivery in women with a short cervix, although the analysis was based on only a few cases. In Sweden, a larger study is needed to evaluate the prevalence of short cervical length and the possible association with preterm delivery before universal screening can be recommended.

Risk factors for spontaneous preterm delivery after arrested episode of preterm labor

Introduction: We aimed to identify specific risk factors for spontaneous preterm delivery (PTD) among women with arrested preterm labor (PTL).Method: A retrospective study of women admitted due to imminent PTL and intact membranes, which did not progress to PTD within 24 h from admission. Eligibility was limited to singleton gestations at 24 + 0/7–33 + 6/7 weeks of gestations with no known chromosomal or structural anomalies. All women were treated with corticosteroids and tocolysis. Comparison was made between those who delivered at <37 + 0/7 weeks of gestation (study group) to women who delivered at ≥37 + 0/7 weeks of gestation (controls).Results: Overall, 301 women were recruited, of which 85 (28.2%) delivered before 37 + 0/7 weeks and 216 (71.8%) delivered at term. Advanced cervical dilatation was found to be an independent risk factor for PTD [for women with no past PTD: adjusted odds ratio (aOR) 1.66, 95% CI: 1.06–2.61 for each 1 cm dilatation; for women with past PTD: aOR 2.81, 95% CI: 1.02–7.73 for each 1 cm dilatation]. Among women without past PTD, additional independent risk factors for PTD were earlier gestational week at admission (OR: 1.20, 95% CI: 1.09–1.32 for each earlier week) and short cervical length (OR: 1.04, 95% CI: 1.01–1.08 for each decrease of 1 mm in cervical length).Conclusion: Advanced cervical dilatation, earlier gestational age at the episode of arrested PTL, and short cervical length are specific risk factors for PTD in women with arrested PTL. These findings may assist in counseling women and direct further investigation.

Can plateletcrit, an underestimated platelet parameter, be related with preterm labour?

Objective: Noninvasive and simple markers are needed for the prediction of preterm delivery in women at risk for preterm labour. The aim of this study was to determine the value of platelet indices in the prediction of preterm delivery. Design: A retrospective study. Setting: Routine antenatal care in Zonguldak Bülent Ecevit University between 2008 and 2011. Sample: Ninety patients who delivered between 28 and 37 weeks of gestational age and 128 patients who delivered at term. Methods: Plateletcrit and other haematological markers, cervical dilatation and effacement, and the neutrophil-to-lymphocyte ratio as an inflammation marker. Main outcome measure: The role of platelet indices in predicting the preterm delivery. Results: The platelet count, plateletcrit, white blood cell count, red cell distribution width, and neutrophil count were significantly higher in the preterm delivery group. Receiver operating characteristic curve analysis showed that the plateletcrit cut-off value for predicting spontaneous preterm labour was 0.201%, with a sensitivity of 95.6% and specificity of 87.5%; the cut-off value for the platelet count was 234 ? 103/mm3 with a sensitivity of 81.0% and specificity of 71.0%. Conclusion: Plateletcrit is a low-cost, widely available, and noninvasive marker that might be used for the prediction of preterm delivery in patients with a history of preterm labour.

Economic analysis of use of pessary to prevent preterm birth in women with multiple pregnancy (ProTWIN trial).

To assess the cost-effectiveness of a cervical pessary to prevent preterm delivery in women with a multiple pregnancy. The study design comprised an economic analysis of data from a randomized clinical trial evaluating cervical pessaries (ProTWIN). Women with a multiple pregnancy were included and an economic evaluation was performed from a societal perspective. Costs were estimated between the time of randomization and 6 weeks postpartum. The prespecified subgroup of women with a cervical length (CL) < 25(th) centile (< 38 mm) was analyzed separately. The primary endpoint was poor perinatal outcome occurring up to 6 weeks postpartum. Direct medical costs and health outcomes were estimated and incremental cost-effectiveness ratios for costs to prevent one poor outcome were calculated. Mean costs in the pessary group (n = 401) were € 21,783 vs € 21,877 in the group in which no pessary was used (n = 407) (difference, -€ 94; 95% CI, -€ 5975 to € 5609). In the prespecified subgroup of women with a CL < 38 mm we demonstrated a significant reduction in poor perinatal outcome (12% vs 29%; RR, 0.40; 95% CI, 0.19-0.83). Mean costs in the pessary group (n = 78) were € 25,141 vs € 30,577 in the no-pessary group (n = 55) (difference, -€ 5436 (95% CI, -€ 11,001 to € 1456). In women with a CL < 38 mm, pessary treatment was the dominant strategy (more effective and less costly) with a probability of 94%. Cervical pessaries in women with a multiple pregnancy involve costs comparable to those in women without pessary treatment. However, in women with a CL < 38 mm, treatment with a cervical pessary appears to be highly cost-effective.

Prophylactic oral nifedipine to reduce preterm delivery: a randomized controlled trial in women at high risk.

To establish the efficacy of prophylactic nifedipine vs. placebo in reducing spontaneous preterm delivery in asymptomatic women at high risk for preterm delivery. Prospective multicentric randomized double-blind study. Tertiary care centre, University Hospitals of Brescia and Torino, Italy. Eighty-seven singleton pregnancies without uterine contractions and ultrasonographic cervical length of ≤25mm at 24-32weeks, at risk for preterm delivery, with longitudinal follow up in our Preterm Prevention Clinic. Selection was done on the basis of ultrasonographic cervical length; 43 women were randomized to receive placebo and 44 to receive nifedipine. Primary end point: spontaneous preterm delivery <37weeks in nifedipine vs. placebo. delivery <32weeks, maternal side effects, neonatal complications, admissions to the Neonatal Intensive Care Unit and randomization/delivery time in nifedipine vs. placebo. There was no trend towards a lower risk of spontaneous preterm delivery, neither at <37weeks of nifedipine vs. placebo (11.4% vs. 19.0%; p=0.320), or <32weeks (2.3% vs. 2.4%; p=0.973). Nifedipine reduced spontaneous preterm delivery <37weeks (p=0.015) in the multiparous women by stratified analysis for parity. SECONDARY OUTCOMES between the groups did not differ except for a higher percentage of maternal side-effects in the nifedipine group (31.8%) vs. placebo (11.9%) (p<0.05). Subgroup analysis showed a borderline (p=0.047) lower percentage of spontaneous preterm delivery in women with a ultrasonographic cervical length of <20mm in the nifedipine group. Prophylactic nifedipine in asymptomatic women at high risk for preterm delivery had a positive effect on the rate of spontaneous preterm delivery <37weeks in multiparous women.

Abnormal Cervical Cancer Screening in Pregnancy and Preterm Delivery

Preterm delivery is a major cause of neonatal morbidity and mortality. Human papillomavirus (HPV) infection is common in reproductive-aged women. We hypothesised that abnormal cervical cancer screening tests, as a proxy for HPV infection, would be associated with preterm delivery. We conducted a retrospective cohort study of women delivering liveborn singletons beyond 20 weeks gestation, who had a Papanicolaou (Pap) test within 1 year prior to delivery. Women with abnormal Pap or positive high-risk HPV tests, classified as having 'abnormal screening', were compared with women classified as having 'normal screening' in bivariate analysis for overall preterm delivery at less than 37 weeks gestation. Using Poisson regression, we report unadjusted (RR) and adjusted (aRR) risk ratios for spontaneous preterm delivery due to preterm labour and preterm premature rupture of membranes. Among 2686 women meeting criteria for analysis, 213 (8%) had abnormal screening. Women with abnormal screening, compared with normal screening, were not more likely to deliver preterm (12.2% vs. 9.8%, RR 1.3 [95% confidence interval (CI) 0.9, 1.8], aRR 1.2 [95% CI 0.8, 1.7]). Women with abnormal screening, however, were at greater risk for spontaneous preterm delivery in unadjusted and adjusted analysis (8.9% vs. 4.5%; RR 2.0 [95% CI 1.2, 3.2], aRR 1.8 [95% CI 1.1, 2.9]). There was no difference in risk of overall preterm delivery in women with abnormal compared with normal cervical cancer screening tests. Our data suggest, however, that abnormal screening in pregnancy may be associated with spontaneous preterm delivery.

Associations between 25-hydroxyvitamin D levels and pregnancy outcomes: a prospective observational study in southern China.

Observational studies relating 25-hydroxyvitamin D (25(OH)D) and pregnancy outcomes have reported conflicting results. The aim was to assess maternal 25(OH)D status and its association with pregnancy outcomes. A prospective observational study was carried out in Guangzhou city (23 ºN), China. Pregnant women (n=2960) and healthy controls (n=100) were recruited at a teaching hospital. Maternal 25(OH)D levels were measured at 16-20-week gestation. The pregnant women, if met inclusion and exclusion criteria, were enrolled in further analysis for pregnancy outcomes (n=1953). Mean serum 25(OH)D in pregnant women was 27.03±7.92 ng/ml. In total, 18.9 and 48.6% of pregnant women had low (25(OH)D less than or equal to 20 ng/ml) and medium level (25(OH)D 21-29 ng/ml) of vitamin D, respectively. 25(OH)D was highest in summer and lowest in winter, which showed a positive correlation with temperature (R=0.942) and calcium (R=0.074). Most maternal outcomes (premature rupture of membranes break, polyhydramnios, oligohydramnios, pre-eclampsia, cesarean section), fetal outcomes (spontaneous abortions, medically induced labor, fetal death, fetal distress, fetal growth restriction) and neonatal outcomes (malformations, birth weight and height, low birth weight, macrosomia, small-for-gestational age, score of Apgar 1',5', asphyxia of newborn) were not significantly different between groups, but prevalence of gestational diabetes (adjusted odds ratio (OR) 1.017; 95% confidence interval (CI) 1.002-1.033) and preterm delivery (adjusted OR 1.038; 95% CI 1.018-1.059) in high level group (25(OH)D ⩾30 ng/ml) was higher than that in low and medium level groups. The prevalence of low level of vitamin D (serum 25OHD ⩽20 ng/ml) was 18.9% among pregnant women in southern China. There were no significant differences in most adverse pregnancy outcomes among pregnant women with different levels of vitamin D at 16-20-week gestation except for higher prevalence of gestational diabetes and preterm delivery in women with high level of vitamin D, possibly related to the older age and higher body mass index of this group.

Effect of cigarette smoking on mRNA and protein levels of oxytocin receptor and on contractile sensitivity of uterine myometrium to oxytocin in pregnant women

ObjectivesAlthough smoking is the most important modifiable risk factor associated with preterm delivery, the underlying mechanism by which smoking stimulates premature uterine contractions is still poorly understood. In the present study, we investigated whether cigarette smoking affects the contractile sensitivity of uterine myometrium to oxytocin in pregnant women. Study designCigarette smoking habits of pregnant women were evaluated by direct interviews and by measuring exhaled carbon monoxide (CO). We isolated myometrial strips from pregnant smokers and non-smokers and evaluated uterine contractile sensitivity to oxytocin. Gene expression levels of oxytocin receptors (OTR) were compared between myometrial strips obtained from smokers and non-smokers by real-time PCR. OTR protein levels in the myometrium were evaluated by Western blotting. ResultsThe reported number of cigarettes smoked per day by the interviewee significantly correlated with the concentration of exhaled CO. Oxytocin sensitivity increased significantly in smokers (n=6) compared with non-smokers (n=11). Real-time PCR analysis did not reveal any significant difference in OTR mRNA expression between smokers and non-smokers. Western blotting revealed that OTR level was significantly increased in smokers compared with non-smokers. Both number of cigarettes smoked per day and the concentration of exhaled CO correlated with oxytocin sensitivity. ConclusionOur findings suggest that smoking increases oxytocin sensitivity of pregnant myometrium by increasing OTR levels even though OTR mRNA expression remains unaltered, thereby increasing the risk of preterm delivery in women who smoke during pregnancy. The sensitivity is dependent on number of cigarettes smoked per day.

Prediction of Preterm Birth in Multiple Pregnancies: Development of a Multivariable Model Including Cervical Length Measurement at 16 to 21 Weeks’ Gestation

ObjectiveTo develop a multivariable prognostic model for the risk of preterm delivery in women with multiple pregnancy that includes cervical length measurement at 16 to 21 weeks’ gestation and other variables. MethodsWe used data from a previous randomized trial. We assessed the association between maternal and pregnancy characteristics including cervical length measurement at 16 to 21 weeks’ gestation and time to delivery using multivariable Cox regression modelling. Performance of the final model was assessed for the outcomes of preterm and very preterm delivery using calibration and discrimination measures. ResultsWe studied 507 women, of whom 270 (53%) delivered<37 weeks (preterm) and 66 (13%)<32 weeks (very preterm). Women with cervical length<30mm delivered more often preterm (hazard ratio 1.9; 95% CI 0.7 to 4.8). Other independently contributing predictors were previous preterm delivery, monochorionicity, smoking, educational level, and triplet pregnancy. Prediction models for preterm and very preterm delivery had a c-index of 0.68 (95% CI 0.63 to 0.72) and 0.68 (95% CI 0.62 to 0.75), respectively, and showed good calibration. ConclusionIn women with a multiple pregnancy, the risk of preterm delivery can be assessed with a multivariable model incorporating cervical length and other predictors.

The use of 17-hydroxy progesterone in women with arrested preterm labor: a randomized clinical trial

Background: The use of 17-alpha-hydroxyprogesterone caproate (17 P) has been shown to reduce preterm delivery in women who have had a prior preterm birth. The role of 17 P in women with arrested preterm labor is less certain.Aims: To compare the preterm birth rate and neonatal outcome in women with arrested preterm labor randomized to receive 17 P or placebo.Materials and methods: Women with arrested preterm labor were randomized to weekly injections of either 17 P (250 mg) or placebo. Maternal and neonatal outcome were evaluated.Results: Forty-five singleton pregnancies were randomized after successful tocolysis; 22 received 17 P while 23 got placebo. Gestational age at delivery (p = 0.067) and the interval from treatment to delivery (p = 0.233) were not affected by 17 P. Significantly less women in the 17 P group delivered at <34 weeks (14 versus 21, p = 0.035). There was also a significant reduction in the risk of neonatal sepsis (p = 0.047) and gr III/IV intraventricular hemorrhage (IVH) (p = 0.022) in the 17 P group.Conclusion: In this study, 17 P did not delay the interval to delivery after successful preterm labor, but births <34 weeks as well as neonatal sepsis and IVH were reduced by 17 P treatment.

What is the value of measuring cervical length in pregnant patients with prior preterm labor?

Evidence-Based Answer Cervical length is a good predictor of preterm delivery in women with a singleton gestation who have a history of preterm delivery (SOR: B, retrospective cohort trial). Early cervical length measurements potentially identify women who may benefit from cerclage placement, which has been shown to reduce previable birth (SOR: B, single RCT).