Delivery In Twin Gestations Research Articles

Comparison of Short Cervical Lengths in Singleton and Twin Pregnancies

Introduction: Multifetal gestations are six times more likely to give birth preterm and 13 times more likely to give birth before 32 weeks gestation than women with singleton gestation (Martin et al, 2014-2018). Abnormal cervical shortening measured with transvaginal ultrasonography has been associated with an increased risk of preterm birth (Iams et al, 1996). In singleton pregnancies, midtrimester cervical length of less than 2.5 cm measured between 16-24 weeks has been associated with an increased risk of preterm birth in a variety of screened populations (Crane, JM., Hutchens, D., 2008). In twin pregnancies, a shortened cervix in the second trimester is more common than in singleton pregnancies and can be a predictor of early preterm birth (Yang et al, 2000). Current guidelines from ACOG, state that the data is insufficient to recommend for or against routine endovaginal ultrasound screening of cervical length in twin pregnancy. Our aim was to determine if twin gestations have shorter cervical lengths than singletons at the time of midtrimester anatomy scan, and to investigate the correlation of cervical length with the likelihood of spontaneous preterm birth. Methods: Retrospective chart review between January 2016-January 2022 identified patients with cervical shortening (<2.5 cm) at the time of mid-trimester anatomical ultrasound exam. Exams were performed at the Maternal Fetal Medicine Department at Promedica Toledo Hospital between 16 and 24 weeks’ gestation. Cervical lengths and delivery data were collected and analyzed. Results: 122 patients met inclusion criteria, with 95(78%) singleton pregnancies, and 27(22%) twin gestations. Singleton gestations had an average short cervical length of 1.8 ± 0.6cm, whereas twin gestations had an average short cervical length of 1.29 ± 0.55cm (p<0.0001). Twin gestations were more likely than singleton gestations to have a very short cervical length <1.5cm (OR=6.75, 95% CI 2.59-17.58, p =0.0001). Average gestational age of delivery for singleton gestations identified with a short cervix was 35w6d ± 4w4d, whereas the average age at delivery for twin gestations was 31w6d ± 5w6d (p=0.0002). Discussion: Our results are consistent with previous reports that cervical shortening is more common in twin pregnancies than singleton pregnancies. Our results suggest that twins are more likely to have a very short cervical length identified in between 16-24 weeks. In addition, twin gestations with abnormal cervical shortening deliver at earlier gestational ages in comparison to singleton gestations with abnormal cervical shortening. Obtaining transvaginal cervical lengths at 16-24 weeks gestation allows for earlier identification of shortened cervical length. Ongoing research may identify interventions which are consistently effective in preterm birth prevention in twin gestation.

Induction of labor in twin pregnancy in patients with a previous cesarean delivery

BackgroundTrial of labor after cesarean delivery (TOLAC) in twin gestations has been associated with decreased rates of successful vaginal delivery compared to singleton pregnancies, with mixed results regarding maternal and neonatal morbidity. However, induction of labor (IOL) in this unique population has not yet been fully evaluated.ObjectiveTo assess success rates and maternal and neonatal outcomes in women with a twin gestation and a previous cesarean delivery undergoing IOL.MethodsA retrospective cohort study including women with a twin gestation and one previous cesarean delivery undergoing a trial of labor between the years 2009–2020. Patients requiring IOL were compared to those with a spontaneous onset of labor.ResultsThere were 53 patients who met the inclusion criteria: 31 had a spontaneous onset of labor (58%) and 22 required an IOL. Baseline characteristics were comparable between the groups apart from a history of labor arrest which was more common in the IOL group (40.9% vs. 9.6%, P = 0.006). A successful vaginal delivery occurred in all (100%) women with a spontaneous labor compared to 81% in the IOL group (p = 0.02). Secondary outcomes were comparable. A history of no previous vaginal delivery, maternal obesity, and IOL were associated with TOLAC failure.ConclusionsIOL after cesarean delivery in twin gestation is associated with an increased risk of TOLAC failure compared to spontaneous onset of labor. However, no adverse neonatal or maternal outcomes were found. IOL in this high-risk population is feasible but patients should be counseled about the lower rate of success.

Serum hsCRP in early pregnancy and preterm delivery in twin gestations: a prospective cohort study

BackgroundSystemic inflammation during pregnancy may be associated with preterm delivery (PTD), but data for twin gestations are lacking. The aim of this study was to examine the association of serum high-sensitivity C-reactive protein (hsCRP), a marker of inflammation, in early pregnancy of twin gestations with risk of PTD, including spontaneous (sPTD) and medical-induced preterm delivery (mPTD).MethodsA prospective cohort study involved 618 twin gestations was conducted in a tertiary hospital in Beijing, from 2017 to 2020. Serum samples collected in early pregnancy were analyzed for hsCRP using particle-enhanced immunoturbidimetric method. Unadjusted and adjusted geometric means (GM) of hsCRP were estimated using linear regression, and compared between PTD before 37 weeks of gestation and term delivery at 37 or more weeks of gestation using Mann–Whitney rank sum test. The association between hsCRP tertiles and PTDs was estimated using logistic regression, and further converted overestimated odds ratios into relative risks (RR).ResultsA total of 302 (48.87%) women were classified as PTD, with 166 sPTD and 136 mPTD. The adjusted GM of serum hsCRP was higher in PTDs (2.13 mg/L, 95% confidence interval [CI] 2.09 –2.16) compared to term deliveries (1.84 mg/L, 95% CI 1.80 –1.88) (P < 0.001). Compared with the lowest tertile of hsCRP, the highest tertile was associated with increased risk of PTD (adjusted relative risks [ARR] 1.42; 95% CI: 1.08–1.78). Among twin pregnancies, the adjusted association between high values of serum hsCRP in early pregnancy and preterm delivery was only observed in the subgroup of spontaneous preterm deliveries (ARR 1.49, 95%CI:1.08–1.93).ConclusionsElevated hsCRP in early pregnancy was associated with increased risk of PTD, particular the risk of sPTD in twin gestations.

Effects of parity on preterm delivery in twin gestations conceived with in vitro fertilization

To determine the relationship between prior obstetrical history and gestational age at delivery in a twin pregnancy. Retrospective cohort study using theUnited States Society for Assisted Reproductive Technology Clinic Outcomes Reporting System database. Clinic-based data. Patients undergoing invitro fertilization (IVF) in the United States with live delivery of twins. None. The main outcome measures are median gestational age at delivery and rate of preterm delivery (before 37 weeks). The median gestational age at delivery of IVF-conceived twins was 36.3 (interquartile rate 34.4, 37.6) weeks for nulliparous women, 35.9 (34.0, 37.1) weeks for parous women with a prior preterm birth, and 36.7 (35.1, 37.7) weeks for parous women without a prior preterm birth. The rate of preterm delivery was 61% for nulliparous women, 70% for parous women with a prior preterm birth, and 55% for parous women without a prior preterm birth. Parous women without a history of preterm delivery had lower rates of preterm delivery in a subsequent twin pregnancy than nulliparous women. Nulliparous women had lower rates of preterm delivery compared with parous women with a history of preterm delivery.

Twin Deliveries - East Meets West

Abstract Mode of delivery in twin gestation has been a matter of debate for decades. In 2013, the only randomized controlled trial concerning mode of delivery in twin gestations was published, answering some of the most pressing questions in this matter. The Twin Birth Study randomized patients carrying dichorionic-diamniotic or monochorionic-diamniotic twins, with the first twin in cephalic presentation, between 32 and 39 weeks of gestation, to planned vaginal vs. planned cesarean delivery, and found no significant differences in perinatal or maternal outcomes. These clinical findings greatly benefit our clinical practice, but there lacks related study investigating how the practices have changed. In this review, we searched PubMed from 1980 through January 2021 using combinations of the following terms: twin, delivery, vaginal delivery, and cesarean section. We will try to address the known literature before and after the publication of the Twin Birth Study in western countries and compare that to what has been practiced in China.

Maternal Race/Ethnicity and Mode of Delivery in Twin Gestations [A273

INTRODUCTION: Women of color in the United States have an increased risk of maternal morbidity and a higher risk of cesarean delivery (CD) compared to White women. This study aims to determine whether maternal race/ethnicity influenced mode of delivery (MOD) of twin gestations. METHODS: This was an IRB-approved, retrospective cohort study of all twin deliveries at a single institution between 1/1/2001 and 12/31/2018. Pregnancies delivered&lt;24 weeks or with intrauterine fetal demise were excluded. The primary exposure, self-reported race/ethnicity, was categorized into five groups: White, Hispanic, non-Hispanic Black, Asian/Pacific Islander (PI)/Alaska Native (AN), and Other/Mixed. The primary outcome was CD. Statistical analyses included univariate analysis via Chi-square and ANOVA and logistic regression analysis. RESULTS: A total of 796 pregnancies were included; 377 (47.8%) of participants identified as White, 236 (29.9%) as Hispanic, 83 (10.5%) as Asian/PI/AN, 44 (5.6%) as Black, and 50 (6.3%) as Other/Mixed. BMI, maternal age at delivery, chorionicity, and parity were different by race/ethnicity groups, but gestational age at delivery was not. The overall rate of CD was 71.1% and did not vary by race/ethnicity (P=.51). There were no differences by race/ethnicity when analysis was limited to those delivering&gt;34 weeks and birthweights&gt;2,500 g (P=.07) or among only nulliparous women (P=.77). In multivariable analysis, only nulliparity was associated with increased risk of CD (P&lt;.01). CONCLUSION: Rate of CD for twin gestations is high but was not related to maternal race/ethnicity in this cohort. Further study is needed to evaluate the indications for cesarean deliveries across racial/ethnic groups in twin gestations as this was not examined in this cohort.

Cervical expression of elafin and secretory leukocyte peptidase inhibitor does not predict preterm delivery in twin pregnancy – results from a pilot study

Background. Elafin and secretory leukocyte peptidase inhibitor may serve as the predictors of cervical shortening and preterm delivery in twin gestation. Material and Methods. A prospective observational study was conducted between September 2016 and March 2017. Cervicovaginal swabs collected from 40 women with twin gestation were analysed and the mRNA expression of elafin and secretory leukocyte peptidase inhibitor (SLPI) correlated with preterm delivery. Results. The mean gestational age at delivery was 35.6 ± 5.8 weeks, with 23 women delivering before 37 weeks (57.5%), 7 before 34 weeks (17.5%) and 3 before 32 weeks of gestation (7.5%). The mRNA expression of elafin and SLPI was not dependent on chorionicity and did not correlate with gestational age at delivery. Conclusions. Elafin and SLPI are not appropriate predictors of preterm delivery in twins.

Delivery of Twin Gestation (≥ 32.0 Weeks): The Vaginal Route as a Practicable and Safe Alternative to Cesarean Section.

Objective The appropriate delivery mode for twins is discussed controversially in the literature. The aim of this study was to investigate delivery modes and short-term neonatal outcomes of twin pregnancies delivered in University Hospital Leipzig. Material and Methods A total of 274 twin pregnancies (32.0 to 39.4 weeks of gestation) delivered between 2015 and 2017 were analyzed retrospectively with regard to the planned and final delivery mode as well as neonatal outcomes. The inclusion and exclusion criteria for vaginal delivery were comparable to those of the Twin Birth Study. Results The spontaneous birth rate for births planned as vaginal deliveries was 78.5%; the rate of secondary cesarean section was 19.4%. The final total cesarean rate was 58.8%, and the rate of vaginal deliveries was 41.2%. Vertex or non-vertex position of the second twin had no significant effect on neonatal outcome or mean delivery interval between the birth of the first and second twin. Chorionicity, neonatal weight and gender had no significant impact on delivery mode. However, successful vaginal delivery was associated with higher gestational age and both fetuses in vertex position. The combined neonatal outcome for both twins was significantly worse if they were delivered by cesarean section compared to spontaneous birth. In addition, the leading twin in monochorionic/diamniotic (MC/DA) pregnancies was intubated more frequently after cesarean delivery and had significantly lower Apgar scores. Conclusion Vaginal delivery in twin pregnancies is a practicable and safe option in specific defined conditions and when the appropriate infrastructure and clinical experience is available.

Trial of Labor After Cesarean Delivery in Twin Gestations: Systemic Review and Meta-Analysis

(Am J Obst Gynecol. 2019;220:336–347) While twin gestation pregnancy rates have increased, multiple gestation pregnancies are considered a high-risk condition with significant maternal and perinatal risks. For patients with twin pregnancy and history of previous cesarean delivery, adequate data to guide informed decision-making for planned, elective repeat cesarean delivery (RCD) or planned vaginal delivery are lacking. The aim of this study was to assess maternal and neonatal morbidity associated with trial of labor (TOL) after cesarean delivery in twin pregnancy.

Maternal morbidity of induction of labor compared to planned cesarean delivery in twin gestations

Objective To compare maternal morbidity associated with induction of labor (IOL) with planned cesarean delivery (CD) in twin gestations. Methods This was a retrospective cohort study of vertex-presenting twin pregnancies ≥24-week gestation delivering at our institution from 2016 to 2017. We compared patients undergoing IOL with patients undergoing planned CD. Demographic and pregnancy outcome data were abstracted from the medical record. Our primary outcome was composite maternal morbidity including severe postpartum hemorrhage (PPH) (EBL >1500 cc), hysterectomy, transfusion, ICU admission, use of ≥2 uterotonic medications or maternal death. These morbidities were also assessed independently. Secondary analyses of maternal morbidity among unplanned CD versus planned CD and successful IOL versus planned CD was also performed. Chi-square, Mann–Whitney U and multivariate logistic regression were used in statistical analysis. Results Of 211 twin gestations included, 70.6% were nulliparous, the median age was 35.5 years [32–38], and the median gestational age at delivery was 37 weeks [35–38]. One hundred and five underwent IOL and 106 had a planned CD. Composite morbidity was higher in the IOL group versus planned CD group (30.5 versus 11.3%, p = .001). In the IOL group, 64 (61.0%) achieved a vaginal delivery. Patients in the planned CD group were more likely to be >35 years of age (62.3 versus 48.6%, p = .045), nulliparous (80.2 versus 61.0%, p = .002) and deliver preterm (53.8 versus 38.1%, p = .022). Patients with a planned CD had a significantly lower risk of composite morbidity compared to those who had CD after failed IOL (11.3 versus 48.8%, p ≤ .001) and there was no significant difference in composite morbidity in the successful IOL compared to the planned CD group (18.8 versus 11.3%, p = .18). There were four peri-partum hysterectomies, all within the IOL group. Conclusion Labor induction in twins was associated with increased maternal morbidity compared to planned CD. The increase in adverse maternal outcomes was due to those who underwent an IOL and ultimately required CD.

T-cell immunoglobulin mucin-3 and galectin-9 levels in peripheral blood mononuclear cells predict fetal acidemia in twin pregnancies

Purposes: The pH in the umbilical artery at delivery provides information on the fetal environment and is related to postnatal outcomes. The ability to predict fetal acidemia at delivery would improve clinical management and neonatal well-being. We hypothesized that an alteration in maternal immunity would accompany placental changes that precede a decrease in pH in the fetal circulation in twin gestations. Methods: Peripheral blood mononuclear cells (PBMCs), obtained from 86 women with twin pregnancies, were lysed and assayed for concentrations of T-cell immunoglobulin mucin domain 3 (Tim-3) and galectin-9 (gal-9) by ELISA. Tim-3–gal-9 interaction is a primary mechanism promoting immune suppression. At delivery, the pH of arterial cord blood was determined. Results: In eight women (9.3%), the pH in the placental arteries from both twins was <7.15, indicating fetal acidosis. In the remaining 78 women the arterial pH was ≥7.15 in both twins. The median Tim-3 level was 361 pg/ml when arterial pH was <7.15 and 199 pg/ml when pH was ≥7.15 (p = .003). Similarly, gal-9 was 31.2 versus 12.4 ng/ml when pH was <7.15 or ≥7.15, respectively (p = .001). A Tim-3 concentration >260 pg/ml predicted arterial pH <7.15 with a sensitivity of 87.5%, specificity of 79.5% and negative predictive value of 98.4%. A gal-9 level >18.4 predicted arterial pH <7.15 with a sensitivity of 100%, specificity of 73.8% and a negative predictive value of 100%. Conclusion: We conclude that elevations in Tim-3 and gal-9 in PBMCs during gestation predict the subsequent occurrence of a pH <7.15 in the fetal arteries at delivery in twin gestations.

Plasma progesterone, estradiol, and unconjugated estriol concentrations in twin pregnancies: Relation with cervical length and preterm delivery.

The aim of this study was to examine the association between plasma hormone concentrations, cervical length, and preterm delivery in twin pregnancies, including the effect of progesterone treatment. This study included 191 women pregnant with twins from a randomized placebo-controlled trial. A baseline blood sample was collected at 18-24weeks before treatment with vaginal progesterone (n=95) or placebo pessaries (n=96), and 167 (87.4%) women had a second sample collected after 4-8weeks of treatment. At baseline, 155 (81.2%) women had their cervical length measured. Progesterone, estradiol, and unconjugated estriol concentration was measured, and the association between hormone concentrations, cervical length, and gestational age at delivery was examined. Hormone concentrations were compared in the placebo and progesterone group. Statistical analysis included Spearman's rho, Mann-Whitney U test, Cuzick's test for trends, and linear regression analyses. A short cervical length was associated with preterm delivery. Cervical length and hormone concentrations were not associated (Spearman's rho; progesterone -.05, estradiol .04, estriol .08). Decreasing gestational age at delivery was associated with higher progesterone and estradiol concentrations at baseline (P trend; progesterone 0.04, estradiol 0.02) but not in the second sample or in the weekly change between samples. Progesterone treatment did not increase the progesterone concentration. Plasma concentrations of progesterone, estradiol, and unconjugated estriol at 18-24weeks are not associated with cervical length or preterm delivery in twin pregnancies. Vaginal progesterone treatment does not increase the circulating progesterone concentration in twin pregnancies. Cervical length, but not hormone concentration, is predictive of preterm delivery in twin gestations.

The Utility of Transvaginal Cervical Length in Predicting Delivery Interval in Viable Outpatient Twin Pregnancies [27P

INTRODUCTION: Predicting preterm delivery in twin gestations helps identify women who may benefit from interventions such as antenatal corticosteroids within 7 days of delivery. Our aim was to quantify the performance of short cervical length (CL) (&lt;25mm) in outpatient twin gestations to predict delivery within 7 days. METHODS: Outpatient transvaginal ultrasound reports for diamniotic twin gestations of 23w 0d to 28w 6sd were reviewed between January 2010-July 2014. Index CL was defined as the first CL less than 25mm. Primary outcome was the positive predictive value (PPV) of spontaneous delivery within 7 days of index CL. Secondary outcomes included PPV of index CL of 15mm and 10mm. RESULTS: Of the 411 included charts, 52 patients (12.6%) had a short cervix. There were no significant differences in major risk factors for preterm birth. Four women (1% of the total study population) delivered within 7 days of index CL; three of these had a short cervix while one had a normal CL. PPV of 25mm CL was 5.8% (95% CI 1.2-16.0); NPV 99.7% (95% CI 98.5- &gt;99.9). The PPV of 15mm and 10mm CL were 9.1% (95% CI 1.1-29.2) and 20.0% (95% CI 7.5-55.6). CONCLUSION: In this retrospective observational study, CL of less than 25mm had a poor positive predictive value for delivery within 7 days. 25mm CL cutoff may not be useful to time interventions such as betamethasone administration or hospitalization. PPV increases with decreasing CL. Other tools can be considered in addition to CL measurement for intervention.

686: Cervical length surveillance frequency and the association of spontaneous preterm delivery in twin gestation

686: Cervical length surveillance frequency and the association of spontaneous preterm delivery in twin gestation

Exploring Women's Preferences for the Mode of Delivery in Twin Gestations: Results of the Twin Birth Study.

The Twin Birth Study, an international, multi-center randomized controlled trial was conducted to compare the risks of planned cesarean with planned vaginal delivery for twin pregnancies. The aim of this component of the trial was to understand participants' perspectives of study participation and preferences for the mode of delivery. A mixed-methods questionnaire was distributed to study participants 3 months after giving birth. The questionnaire contained Likert scales and open-ended questions about the experience of being enrolled in a clinical trial and of childbirth, including the mode of delivery. Quantitative data were analyzed using SAS to generate descriptive statistics. Qualitative data were analyzed to identify categories and themes. Ninety-one percent of trial participants completed the questionnaire. Across all groups, the majority of women would participate in a study like this one again if given the opportunity. Main benefits of participating were as follows: benefits to one and one's babies, altruism, and receiving quality care. Randomization for the mode of delivery was challenging for women because of the desire to be involved in decision-making. Findings related to childbirth experience and the mode of delivery demonstrated a preference for vaginal birth across all groups. Those who had a vaginal birth were more satisfied with their birth experience. This study provides evidence to inform practitioners about what women who have twin pregnancies like or dislike about birth and their desire for involvement in decision-making. Vaginal birth was preferred across all study groups and was associated with greater satisfaction with childbirth experience.

Improved Perinatal Mortality in Twins--Changing Practice and Technologies.

We set out to examine rates of perinatal mortality in twin pregnancies over a 17-year study period. Changes in mode of delivery were also examined as well as causes of death in twin mortalities. This retrospective cohort study was performed at three large tertiary referral centers from 1996 to 2012. It included all normally formed twin infants with a birth weight more than 500 g. All cases of perinatal mortality in twin pregnancies (infants more than 500 g who suffered an intrauterine or early neonatal (≤ 7 days of age) death were recorded. The changing rate of cesarean delivery as well as varying causes of death in twins over the course of the study were also examined. During the study period, there were 395,830 pregnancies across the three institutions, this included 6,727 twin gestations. The perinatal mortality rate was 21.5/1,000 twin infants. The perinatal mortality rate in twins decreased over the study period (p = 0.0006; R (2) = 0.55; slope = -1.2). Rates of cesarean delivery in twin gestations were found to have increased over the course of the study (p < 0.0001; R (2) = 0.84; slope = 1.7). There were 288 intrauterine and early neonatal deaths in twin infants, 50% (147/288) occurred in twins born extremely premature (< 26 weeks). Prematurity was the leading cause of mortality in twins, followed by twin-to-twin transfusion syndrome (TTTS). TTTS was found to have a decreasing contribution to perinatal mortality during the study (p = 0.008; R (2) = 0.38; slope = -1.5). The perinatal mortality rate in twins improved during the study. The rate of cesarean delivery increased by 1.7% for each year of the study, culminating in a cesarean delivery rate of 62% in 2012. TTTS made a decreasing contribution to the mortality rate in twins during the study.

Tocolytics used as adjunctive therapy at the time of cerclage placement: a systematic review.

To review the published literature on whether the use of empiric perioperative tocolytic medications could provide additional benefit when used in combination with cerclage. Systematic review of published medical literature reporting the efficacy of empiric tocolytics used as a perioperative adjunct to vaginal cerclage in high-risk patients. A PubMed search without date criteria of various tocolytics and cerclage yielded 42 studies. Review articles were excluded, as were reports of abdominal cerclage, emergent cerclage, or cerclage for the purpose of delayed interval delivery in twin gestations. Only five publications on the topic of perioperative tocolytic use at the time of history or ultrasound-indicated vaginal cerclage placement were identified. These included zero clinical trials, three retrospective cohort studies, one case series and one case report. Only one cohort study compared cerclage with indomethacin and cerclage without indomethacin and suggested no difference between the groups. The other two published cohort studies had no referent group who received cerclage without tocolysis. One case series and one case report were also published reporting cerclage with empiric beta-mimetic and progesterone adjunctive therapy. There is a paucity of published data on the topic of adjunctive perioperative tocolytics with cerclage. Adequately powered clinical trials on perioperative use of tocolysis with cerclage compared with a standard cerclage placement alone are needed to establish efficacy. Until adequately studied, this practice should be considered investigational.

The effect of cerclage in twin gestations with short cervix: a Bayesian evaluation

Objective: Bayesian inference allows the revision of prior clinical estimates of treatment effectiveness based on current data. We apply it to a published dataset evaluating the effect of cerclage upon preterm delivery in twin gestations with a short cervix.Study design: Prior probability distributions for delivery <35 weeks gestation for the control group and the treatment (cerclage) group were constructed under assumptions ranging from treatment having no effect (prior A) to halving early deliveries (prior C). Likelihood functions were calculated based on a published meta-analysis. Posterior probability densities were derived from which risk ratios for early delivery were computed, with 95% credible intervals and the probability of cerclage benefit.Results: Median posterior risk ratios (95% credible intervals) for delivery <35 weeks with cerclage are 1.51 (1.02–2.33) for prior A and 1.11 (0.72–1.77) for prior C. The probability of cerclage benefit ranged from 2.1% for prior A to 31.4% for prior C. By comparison, the conventional risk ratio (95% confidence interval) for early delivery, based on the data alone, is 2.08 (1.18–3.69).Conclusions: As might be anticipated, those with low expectation of cerclage benefit remain more convinced of the ineffectiveness (or harm) of the procedure than those with higher expectations.

The relationship between previous treatment for cervical dysplasia and preterm delivery in twin gestations

Objective: To describe the impact of previous cervical surgery on preterm birth prior to 34 weeks in twins.Methods: A retrospective review of twin pregnancies delivered between January 1998 and December 2005 at two institutions was performed. Women with a prior cold knife cone (CKC), loop electrosurgical excision procedure (LEEP), or ablative procedure were compared to a control group of women who had not undergone a previous treatment for cervical dysplasia. The primary outcome was delivery before 34 weeks of gestation.Results: A total of 876 women met inclusion criteria. Of these, 110 (12.6%) had previous surgical procedures for cervical dysplasia, including CKC (n = 10), LEEP (n = 36), cryotherapy (n = 59) and CO2 laser treatment (n = 5). Delivery prior to 34 weeks was more common in women with a previous CKC compared to women with no prior treatment (40% versus 11.3%; odds ratio [OR], 3.6; 95% confidence interval [CI], 1.7–8.0). Delivery prior to 34 weeks was not more common in women with a previous LEEP (8.3%; OR, 0.8; 95% CI, 0.3–2.3) or ablative procedure (9.4%; OR, 0.9; 95% CI, 0.4–1.9) in comparison to the untreated group. Adjusting for the potential confounders of age, tobacco use, infertility treatments and previous preterm birth did not change the results.Conclusions: Previous CKC is associated with delivery prior to 34 weeks while LEEP and ablative procedures are not. CKC should be carefully considered and avoided when possible in reproductive age women.

Relationship between 17-hydroxyprogesterone caproate concentrations and gestational age at delivery in twin gestation

We sought to evaluate in women with twin gestation the relationship between 17-hydroxyprogesterone caproate (17-OHPC) concentration and gestational age at delivery and select biomarkers of potential pathways of drug action. Blood was obtained between 24-28 weeks (epoch 1) and 32-35 weeks (epoch 2) in 217 women with twin gestation receiving 17-OHPC or placebo. Gestational age at delivery and concentrations of 17-OHPC, 17-hydroxyprogesterone, progesterone, C-reactive protein (CRP), and corticotrophin-releasing hormone were assessed. Women with higher concentrations of 17-OHPC delivered at earlier gestational ages than women with lower concentrations (P < .001). Women receiving 17-OHPC demonstrated significantly higher (P = .005) concentrations of CRP in epoch 1 than women receiving placebo but CRP values were similar in epoch 2 in both groups. A highly significant (P < .0001) positive relationship was observed between 17-OHPC concentration and progesterone and 17-hydroxyprogesterone concentrations at both epochs. Corticotropin-releasing hormone concentrations did not differ by treatment group. 17-OHPC may adversely impact gestational age at delivery in women with twin gestation.