Risk Of Spontaneous Preterm Delivery Research Articles

High MME use by mother linked to increase in preterm births

Women who use prescription opioids for pain during pregnancy are more likely to deliver their babies prematurely, a study by Sarah S. Osmundson, M.D., and colleagues at Vanderbilt University has found. The study, “Prescription Opioid Exposure During Pregnancy and Risk of Spontaneous Preterm Delivery,” was published Feb. 5 in JAMA Network Open.

Prescription Opioid Exposure During Pregnancy and Risk of Spontaneous Preterm Delivery

Opioid exposure during pregnancy has been associated with preterm birth, but prior studies have not differentiated between spontaneous and indicated preterm birth or fully investigated these associations as functions of opioid dose. To determine whether prescription opioid use during pregnancy is associated with spontaneous preterm birth and whether the association is dose-dependent. This case-control study examined a retrospective cohort of pregnant patients enrolled in Tennessee Medicaid. Enrollment files were linked to health care encounters, hospital discharge information, birth certificate data, and prescription fills. Eligible participants were pregnant people ages 15 to 44 years without opioid use disorder who experienced birth of a single fetus at 24 weeks gestation or greater between 2007 and 2019 with linked birth certificate data. Cases of spontaneous preterm birth were matched with up to 10 controls based on pregnancy start date, race, ethnicity, age at delivery within 2 years, and history of prior preterm birth. Cases and matched controls were continuously enrolled in TennCare for at least 90 days prior to the index date (case delivery date). Total opioid MME filled during the 60 days prior to the index date. The primary outcome was spontaneous preterm birth determined by a validated algorithm using birth certificate data. Conditional logistic regression was used to estimate the association between spontaneous preterm birth and total opioid morphine milligram equivalents (MME) dispensed, adjusting for parity, prepregnancy body mass index, education level, tobacco use, hepatitis infections, and pain indications. A total of 25 391 cases (median [IQR] age, 23 [20-28] years; 127 Asian [0.5%], 9820 Black [38.7%], 664 Hispanic [2.6%]; 14 748 non-Hispanic White [58.1%]) with spontaneous preterm birth were identified and matched with 225 696 controls (median [IQR] age, 23 [20-27] years; 229 Asian [0.1%], 89 819 Black [39.8%], 3590 Hispanic [1.6%]; 132 002 non-Hispanic White [58.5%]) (251 087 patients total), with 18 702 patients (7.4%) filling an opioid prescription in the 60 days prior to the index date. Each doubling of nonzero opioid MME was associated with a 4% increase in the odds of spontaneous preterm birth compared with no opioid exposure (adjusted odds ratio, 1.04; 95% CI, 1.01-1.08). In this case-control study, a positive association was found between total prescription opioid dose dispensed and the odds of spontaneous preterm birth. These findings support guidance to minimize opioid exposure during pregnancy and prescribe the lowest dose necessary.

124 Prescription opioid exposure and risk of spontaneous preterm delivery

124 Prescription opioid exposure and risk of spontaneous preterm delivery

Low-dose aspirin and racial disparities in spontaneous preterm delivery in low-risk individuals

Preterm birth is a leading cause of perinatal morbidity and mortality. There are significant racial disparities in the rates of preterm delivery in the United States, with Black individuals at disproportionately higher risk than their White counterparts. Although low-dose aspirin is currently under investigation for reducing the rates of preterm delivery, limited data are available on how the use of low-dose aspirin might affect racial and ethnic disparities in the rates of preterm delivery. Our group and others have shown that low-dose aspirin decreases spontaneous preterm delivery in low-risk parturients. This study aimed to examine whether the relationship between low-dose aspirin and the risk of spontaneous preterm delivery is modified by race and ethnicity. This was a secondary analysis of a randomized clinical trial examining low-dose aspirin for preeclampsia prevention in low-risk nulliparous individuals. The parent trial defined low risk as the absence of preexisting hypertension or other medical comorbidities. Participants received 60-mg aspirin or placebo between 13 and 25 weeks of gestation. Here, multiple pregnancies, fetal anomalies, terminations or abortions at <20 weeks of gestation, and participants with previous miscarriages were excluded. Our exposure, race and ethnicity, was self-reported in the parent trial and categorized as non-Hispanic White, Hispanic, non-Hispanic Black, and other. The primary outcome was spontaneous preterm delivery at <34 weeks of gestation; the secondary outcomes included spontaneous preterm delivery at <37 weeks of gestation and all preterm deliveries at <34 and <37 weeks of gestation. Fit logistic regression models were used to examine how the use of low-dose aspirin modified the relationship between race and ethnicity and preterm delivery, adjusting for confounders. Furthermore, sensitivity analyses were performed to compare the rates of preterm delivery by race and ethnicity. Of note, 2528 of 3171 parent study participants were included in this analysis. Of the participants, 425 (16.8%) were White, 819 (32.4%) were Hispanic, 1265 (50%) were Black, and 19 (0.8%) were other. The baseline characteristics differed among racial and ethnic groups, including maternal age, body mass index, education level, marital status, tobacco and alcohol use, and pregnancy loss. The rate of spontaneous preterm delivery at <34 weeks of gestation was significantly higher in Black participants (2.8%) than in White (1.2%) and Hispanic (1.2%) participants (P=.04). Logistical regression analysis showed that Black race was no longer an independent risk factor for spontaneous preterm delivery at <34 weeks of gestation when controlling for low-dose aspirin (adjusted odds ratio, 1.71; 95% confidence interval, 0.67-4.40). A similar pattern was found for spontaneous preterm delivery at <37 weeks of gestation and preterm delivery at <34 and <37 weeks of gestation. In our sensitivity analyses, spontaneous preterm delivery at <34 weeks of gestation differed by race and ethnicity in the placebo group (P=.01) but did not differ in the low-dose aspirin group (P=.90). The use of low-dose aspirin mitigated racial disparities in spontaneous preterm delivery at <34 weeks of gestation. Additional investigation is warranted to assess the reproducibility of our findings.

THE ROLE OF UTEROCERVICAL ANGLE IN DETERMINING THE THREAT OF PRETERM BIRTH

Europäische Wissenschaftliche Gesellschaft Home About the Journal Peer Review Editorial Board For Authors Reviewer Recognition Archive Contact Impressum EWG e.V. Crossref Member Badge Erfolgreich durch internationale Zusammenarbeit OBSTETRICS DOI 10.35630/2023/13/4.817 Received 11 July 2023; Accepted 19 July 2023, Published 15 August 2023 THE ROLE OF UTEROCERVICAL ANGLE IN DETERMINING THE THREAT OF PRETERM BIRTH Ufuk Atlıhan orcid id logo , Umit Derundere orcid id logo Private Karatas Hospital, Izmir, Turkey download article (pdf) cfl.ufuk@gmail.com ABSTRACT Preterm labor is one of the leading causes of perinatal morbidity and mortality and is thought to complicate approximately 10-12% of pregnancies. Defined as birth before 37 weeks of gestation, preterm labor is one of the most common obstetric complications worldwide. Although the pathogenesis of preterm labor is not fully understood, intraamniotic infection or hemorrhage, uteroplacental ischemia, uterine overstretching and immunologic processes have been proposed in its etiology. However, there is still no definitive prediction tool. Sonographic assessment of the cervical structure by measuring cervical length (CL) has been used as a popular prediction tool to predict preterm labor. The uterocervical angle (UCA) is defined as the angle between the lower anterior uterine segment and the endocervical canal. Recently, UCA has been proposed as an alternative to CL for predicting preterm labor. In recent years, several studies have investigated the potential impact of UCA for preterm labor prediction. Our study aimed to determine whether the uterocervical angle, a new ultrasonographic marker for predicting preterm labor, is associated with the risk of spontaneous preterm delivery. The present study included 186 singleton pregnant women who gave birth in our hospital between January 2018 and December 2022. The data of the included patients were retrospectively evaluated from the hospital database and patient files. Regarding the primary outcome of our study, we found that there was a statistically significant difference in UCA and cervical length between women who delivered spontaneously preterm and women who delivered at term (p&lt;0.05). In the second trimester ultrasonography evaluation, the mean UCA was wider and the mean cervical length was shorter in the preterm group. Contrary to other studies in the literature, smoking and history of preterm delivery as risk factors were not included in our study. The exact reasons for some of the differences between our findings and the studies reported in the literature are not clear, but may be attributed to several factors. First, the patient type was heterogeneously selected in the cited studies. There are large differences in terms of sample size and studies that may be attributed to such heterogeneity. In conclusion, wider UCA and shorter cervical length in the second trimester are associated with spontaneous preterm delivery. Measurement of UCA is a reproducible technique and the UCA value was found to increase from the first trimester to the second trimester. We recommend the inclusion of UCA in current clinical practice in addition to cervical length measurement as a predictive factor that can be used in decision-making regarding the management of women at risk of preterm delivery. However, future studies are needed to assess the diagnostic accuracy of this index and should specifically consider the use of thresholds and related outcomes (preterm birth rates based on specific gestational weeks).

The role of family history of preterm delivery in the individual risk of spontaneous preterm delivery: a case-control study.

To investigate the role of family history of preterm delivery (PTD) in the individual risk of spontaneous preterm delivery. A retrospective case-control study was conducted on 354 patients who delivered between 2018 and 2020. 177 women who delivered preterm were matched with 177 controls who had full-term delivery. A questionnaire was administered to investigate the family history of PTD of both the patient and her partner. Cases and controls were matched for the anamnestic risk factors for PTD. Seventeen of 173 women (9.8%) in the PTD group reported being born preterm, compared to five of 169 women (2.9%) in the control group (p = 0.01), with an odds ratio (OR) of 3.57 (95% confidence interval, CI 1.29-9.92). Women who delivered preterm also reported more frequently having a sibling who was born preterm (12.4% vs. 4.2%, p = 0.01), with an OR of 3.18 (95% CI 1.31-7.7). No association was found between the partner's family history of premature delivery and the patient's risk of preterm delivery in the present pregnancy. Pregnant patients who were born prematurely or who have siblings born preterm have an increased risk of preterm delivery in their own pregnancies. Assessment of female personal and family history of PTD should be used to identify women at risk of having a PTD in the present pregnancy.

Body Mass Index Categories Among Pregnant Women Attending Primary Health Care Centers / Baghdad 2022

Background: Recommended weight gain to support a healthy pregnancy vary by prepregnant body mass index. Insufficient weight gain especially associated with prepregnant underweight is associated with increased risk of spontaneous preterm delivery, small for gestational age. Extensive weight gain often results in large for gestational age babies also may increase risk during delivery. Good nutrition and a healthy diet during pregnancy are critical for a mother’s health, as well as that of her child. A healthy diet contains adequate energy, protein, vitamins and mineral obtained from a variety of foods including green and orange vegetables, meat, fish, beans, nuts, whole grains, and fruit. Many studies have suggested that weight gain during pregnancy is affected by prepregnancy BMI. This study is conducted to determine maternal weight gain, pattern and associated of some selected socio-demographic factors.  Method: A cross-sectional analytic study wholly  done from July 4th to December 20th; the sample size was 114 pregnant antenatal care files archived selected from primary health care centers. It searched for the full previous pregnancy files and with frequent visits from the beginning of pregnancy to birth. The data and information were collected from antenatal care files from six primary health care centers of As-Salam, AL-A’dil, AL-Mansour, AL-A’dhamiya 3rd, AL-Baladiyaat, AL-Mustansiriya. The exclusion criteria exclude all incomplete files, pregnant women less than 18 years, and pregnant with chronic disease multiple pregnancy. Frequencies and percentage were calculated; Chi square test were used; and the statistical probability were consider significant if P value &lt; 0.05. Results: The current study was conducted through 114 pregnant care files or antenatal care in 6 primary health care centers.  73%  of them gained excessive weight during pregnancy; 11% of them gained insufficient weight gain during pregnancy; and 17% of pregnant women had adequate weight gain during pregnancy. There was a statistically significant association between weight gain during pregnancy and primary health care centers, as representing social factor, and also significant association between pre pregnancy BMI and gestational weight gain.  Conclusion: Gestational weight gain was significantly affected by pre pregnancy body mass index. Prevalence of excessive weight gain increases with the increase of the pre-pregnancy body mass index and with the increase of age in pregnant women. Weight gain during pregnancy should be monitored and intervention should be developed.

Effect of Suture Material in History-Indicated Cerclage on Spontaneous Preterm Delivery Risk [ID: 1370506]

INTRODUCTION: This study aimed to determine whether suture material in history-indicated cerclage is associated with spontaneous preterm delivery (sPTD). METHODS: We conducted a retrospective cohort study of patients with singleton pregnancies who underwent history-indicated transvaginal cerclage at a tertiary care center from June 2015 to January 2022. The primary outcome was sPTD before 24 weeks of gestation. Secondary outcomes included sPTD at less than 26, 28, 32, and 34 weeks of gestation, chorioamnionitis, days in neonatal intensive care unit, and various adverse neonatal outcomes. Baseline characteristics and outcomes were compared using chi-square and Fisher’s exact tests according to type of suture material: 5-mm braided polyester fiber (Mersilene tape) versus monofilament suture (Prolene). Odds ratios (ORs) for sPTD were estimated using multivariable logistic regression. RESULTS: A total of 64 patients were included in the study, with 50 (78%) patients receiving Mersilene and 14 (22%) receiving Prolene. Mersilene, compared to Prolene, was associated with significantly lower rates of sPTD at less than 24 weeks (6% versus 29%, P=.02) and less than 26 weeks (8% versus 29%, P=.04). At more advanced gestational ages, Mersilene still resulted in lower rates of sPTD compared to Prolene, but statistical significance was lost. After adjusting for race and ethnicity, body mass index, use of postoperative progesterone, and gestational age at cerclage placement, patients with Prolene had increased odds of delivery less than 24 weeks (OR 7.69, 95% CI 1.04–56.6). Secondary outcomes were similar between the two groups. CONCLUSION: In patients undergoing history-indicated cerclage, Mersilene compared to Prolene was associated with a significantly lower risk of previable pregnancy loss.

Rate of Spontaneous Preterm Delivery Between Pregnant Women With and Without Gestational Diabetes.

Objective The aim of this study is to compare the rate of spontaneous preterm delivery between gestational diabetes mellitus (GDM) and normal pregnancy. Pregnancy outcomes and associated risk factors for spontaneous preterm delivery were evaluated. Methods A retrospective cohort study was conducted on 120 GDM and 480 normal pregnant women. All women received GDM screening with 50-g glucose challenge test and 100-g oral glucose tolerance test at the first visit and repeated at 24-28 weeks. Data were retrieved from medical records and included baseline and obstetric characteristics, preterm risks, GDM risks, and pregnancy outcomes. Spontaneous preterm birth was defined as delivery before 37 completed weeks of gestation that had been preceded by spontaneous labor. Results GDM women were more likely to be ≥30 years (p=0.032) and have previous GDM (p=0.013). Incidence of overall preterm delivery was significantly higher in GDM women (17.5% vs. 8.5%, p=0.004), as well as the incidence of spontaneous preterm delivery (15.8% vs. 7.1%, p=0.004). GDM women had less gestational weight gain (p<0.001) and were less likely to have excessive weight gain (p=0.002). GDM women were more likely to deliver large for gestational age (LGA) (p=0.02) and macrosomic infants (p=0.027). Neonatal hypoglycemia was significantly more common among GDM women (p=0.013). Multivariate analysis showed that previous preterm birth and GDM independently increased the risk of spontaneous preterm delivery (adjusted OR: 2.56, 95% CI: 1.13-5.79, p=0.024, and adjusted OR: 2.15, 95% CI: 1.2-3.84, p = 0.010, respectively). Conclusion GDM and previous preterm birth significantly increased the risk of spontaneous preterm delivery. GDM also increased the risk of LGA, macrosomia, and neonatal hypoglycemia.

Screening for spontaneous preterm birth by cervical length and shear-wave elastography in the first trimester of pregnancy

First-trimester cervical length for the prediction of spontaneous preterm delivery remains controversial. A better method for the measurement of the first-trimester cervical length and additional cervical ultrasound parameters for the identification of women at high risk for spontaneous preterm delivery are needed. This study aimed to compare the predictive value of cervical length measured by 2 different methods in the first trimester of pregnancy to predict spontaneous preterm delivery and to explore the potential value of first-trimester cervical shear-wave elastography for the prediction of spontaneous preterm delivery. This was a prospective study in unselected singleton pregnancies at 11+0 to 13+6 weeks' gestation. Cervical length was measured by the following 2 methods in the base-cohort population: (1) a linear distance between the 2 ends of the glandular area around the endocervical canal (single-line method: cervical length-s) and (2) a sum of the linear distance from the internal os to the greatest cervical curvature and the linear distance from this point to the external os (2-line method: cervical length-t). In a substudy, cervical shear-wave elastography scores for 9 regions of interest (inner, middle, and external parts of anterior lip, endocervical canal, and posterior lip) in midsagittal plane were also obtained by transvaginal ultrasonography. The screening performance of the first-trimester cervical length measured by the 2 different methods for the prediction of spontaneous preterm delivery was assessed by receiver operating characteristics curve analysis. The areas under the curves were compared using a DeLong test. The predictive performance of a soft cervix (mean elastography scores with multiple of median <5th, 10th, 15th, 20th, and 25th percentile) for spontaneous preterm delivery was also determined. Among a total of 2316 included pregnancies, spontaneous delivery at <37 and <34 weeks' gestation occurred in 111 cases (4.8%) and 20 cases (0.9%), respectively. In the total study population, when compared with the term delivery group, the median cervical length-t was shorter in women with spontaneous delivery at <34 weeks' gestation (36.9 mm vs 35.1 mm; P=.015), but there was no clear correlation for cervical length-s. Receiver operating characteristics curves demonstrated that cervical length-t achieved better performance in predicting spontaneous delivery at <34 weeks' gestation (area under the curve, 0.658 vs 0.573; P<.01) than cervical length-s. The best combined model to predict spontaneous delivery at <34 weeks' gestation was provided by cervical length-t and history of preterm delivery (area under the curve, 0.692). In the substudy, a soft cervix with a mean elastography scores multiple of median <10th percentile had a relative risk of 7.8 (95% confidence interval, 2.1-28.6) for spontaneous delivery at <34 weeks' gestation; the detection rate was 44.4% at a false-positive rate of 9.0%. The 2-line approach provides a better estimate of the actual first-trimester cervical length and achieves better performance as a screening tool for spontaneous preterm delivery at <34 weeks' gestation than the conventional measurement. A soft cervix as determined by shear-wave elastograpthy in the first trimester is associated with an increased risk for subsequent spontaneous preterm delivery.

Effect of second‐trimester sonographic cervical length on the risk of spontaneous preterm delivery in different risk groups: A prospective observational multicenter study

The aim of the study is to compare the effect of cervical length measured with transvaginal ultrasound in the second trimester on the risk of spontaneous preterm delivery (PTD) between different risk groups of asymptomatic women with a singleton pregnancy. This is a pre-planned exploratory analysis of the CERVIX study, a prospective blinded multicenter diagnostic accuracy study. Asymptomatic women with a singleton pregnancy were consecutively recruited at their second-trimester routine ultrasound examination at seven Swedish ultrasound centers. Cervical length was measured with transvaginal ultrasound at 18-20weeks (Cx1; n=11072) and 21-23weeks (Cx2, optional; n=6288). The effect of cervical length on the risk of spontaneous PTD and its discriminative ability was compared between women with: (i) previous spontaneous PTD, late miscarriage or cervical conization (high-risk group; n=1045); (ii) nulliparae without risk factors (n=5173); (iii) parae without risk factors (n=4740). Women with previous indicated PTD were excluded (n=114). Main outcome measures were: effect of cervical length on the risk of spontaneous PTD expressed as odds ratio per 5-mm decrease in cervical length with interaction analysis using logistic regression to test whether the effect differed between groups, area under the receiver operating characteristic curve (AUC), sensitivity, specificity, number needed to screen to detect one spontaneous PTD. The effect of cervical length at Cx2 on the risk of spontaneous PTD <33weeks was similar in all groups (odds ratios 2.26-2.58, interaction p value 0.91). The discriminative ability at Cx2 was superior to that at Cx1 and was similar in all groups (AUC 0.69-0.76). Cervical length ≤25mm at Cx2 identified 57% of spontaneous preterm deliveries <33weeks in the high-risk group with number needed to screen 161. The number needed to screen for groups (ii) and (iii) were 1018 and 843. The effect of cervical length at 21-23weeks on the risk of spontaneous PTD <33 weeks is similar in high- and low-risk pregnancies. The differences in number needed to screen should be considered before implementing a screening program.

The Feasibility of Cervical Elastography in Predicting Preterm Delivery in Singleton Pregnancy with Short Cervix Following Progesterone Treatment.

Previous studies demonstrated an association between cervical strain and risk of spontaneous preterm delivery (sPTD). The present study aimed to assess the efficacy of elastography in predicting sPTD at <32 weeks of gestation in women with singleton pregnancies receiving progesterone for short cervix (≤2.5 cm) diagnosed between 16 and 28 weeks of gestation Among 115 participants eligible for analysis, nine had sPTD at <32 weeks. Preprogesterone (PP0) mean internal os strain (IOS), elasticity contrast index (ECI), hardness ratio (HR), one-week postprogesterone (PP1) IOS, mean external os strain (EOS), ECI, and HR were significantly different between groups. Higher PP0 IOS, PP1 IOS, and PP1 EOS were associated with a 2.92, 4.39 and 3.65-fold increase in the risk of sPTD at <32 weeks, respectively (adjusted for cervical length (CL) at diagnosis; p = 0.04, 0.012 and 0.026, respectively). A combination of CL at diagnosis, PP0 IOS and PP1 EOS showed a significantly higher area under the receiver operating characteristic curve (0.858) than that of CL alone (p = 0.041). In women with singleton pregnancies receiving progesterone for short cervix, cervical elastography performed before and one week after progesterone treatment may be useful in predicting sPTD at <32 weeks of gestation.

Do patients with a short cervix, with or without an ultrasound-indicated cerclage, have an increased risk for a small for gestational age newborn?

Introduction Mothers with a short cervix have been shown to have increased risk of spontaneous preterm delivery (PTD) and newborn morbidity. Those who require an ultrasound-indicated cerclage experience the highest rates of morbidity. Inflammation has been linked to a short cervix, and it has been linked to pregnancies affected by small for gestational age (SGA) newborns. To date, there are no studies that have investigated an association between a short cervix, with or without an ultrasound-indicated cerclage, and a SGA newborn. Methods This was a case-control study examining all pregnancies with a transvaginal cervical length <25 mm found at their second trimester anatomy scan. Cases were subdivided into those who received an ultrasound-indicated cerclage (Group 1, n = 52) and those who did not (Group 2, n = 139). Controls were defined as pregnancies with a transvaginal cervical length >25 mm with no cerclage (Group 3, n = 186) whose due date was within 2 months of the case pregnancy. Each short cervix case was matched with a control from group 3 in a 1:1 ratio. The primary outcome was birthweight <10% (SGA). Unadjusted data was analyzed with simple odds ratios. A logistic regression was used to control for confounding variables and provide an adjusted odds ratios (aOR). Results The incidence of SGA among cases overall (group 1 + group 2) was 13.6% (26/191). In group 3, the SGA incidence was 4.3% (8/186). The adjusted odds ratio (aOR) for a SGA infant was significant, 2.8 (95% CI 1.2, 6.6). Subgroup analysis showed that Group 1 had an increased risk for an SGA infant [aOR 4.9 (95% CI 1.8, 13.7)], but Group 2 did not show a significant finding [aOR 2.3 (95% CI 0.9, 5.7)]. Conclusion Pregnancies complicated by a short cervical length <25mm, with or without a cerclage, were associated with an increased risk for a SGA newborn. Most of this significance was due to the pregnancies which received an ultrasound-indicated cerclage for a mid-trimester short cervix.

Comparison of Effects of Vaginal Progesterone and Intramuscular Progesterone on Prevention of Labor in Woman with a High Risk of Spontaneous Preterm Delivery

Comparison of Effects of Vaginal Progesterone and Intramuscular Progesterone on Prevention of Labor in Woman with a High Risk of Spontaneous Preterm Delivery

Effect of hysteroscopic septum resection on preterm delivery rate in singleton pregnancies

Introduction Uterine septum is the most common uterine anomaly and is often found during the work-up in primary infertile women. In this study, we aimed to evaluate the potential effect of hysteroscopic septum resection (HSR) on preterm delivery (PTD) in primary infertile women who had singleton pregnancies. Material and methods We analyzed 420 singleton pregnancies after primary infertility treatment and compared the PTD rates in women who underwent previous HSR (cases) and women who did not undergo previous operative hysteroscopy or cervical dilation (controls), regardless of the modality of conception (spontaneous or by in vitro fertilization). Results We did not find significant differences between cases and controls for the incidence of overall PTD rate (p = .237), PTD before 32 gestational weeks (p = .848), and between 32 and 37 gestational weeks (p = .324), premature rupture of membranes (p = .419), and neonatal birth weight (p = .129). Overall, the risk of spontaneous PTD <37 gestational weeks after HSR was not found to be significantly higher compared to controls (RR 1.29, 0.61–2.73 95% CI; p = .561). Conclusion According to our results, previous HSR could be not considered a risk factor for PTD in singleton pregnancies, regardless of the modality of conception (spontaneous or by in vitro fertilization).

Brief Report: Markers of Spontaneous Preterm Delivery in Women Living With HIV: Relationship With Protease Inhibitors and Vitamin D.

Women living with HIV (WLHIV) have increased risk of spontaneous preterm delivery (SPTD). We sought to identify plasma predictors of SPTD and their correlations with factors that increase the risk of SPTD, such as vitamin D deficiency and use of protease inhibitors. Plasma was obtained from 103 WLHIV with SPTD (≤35 weeks gestation) and 205 controls with term deliveries (TDs; ≥37 weeds) matched to cases 2:1 by race and gestational age at blood draw. TNFα, IFNγ, IL6, IL8, IL1β, IL18, IL17, granulocyte colony stimulating factor (GCSF), MCP1, IP10, sIL2Rα, sCD14, vascular endothelial factor a, monocyte colony stimulation factor, GROα, MMP9, IL10, TGFβ, sCTLA4, and eicosanoids were compared between cases adjusting for known SPTD risk factors. Participants had similar demographic characteristics, but cases had higher plasma HIV RNA, lower CD4 cells, and more advanced HIV disease compared with controls. High sIL2Rα was associated with increased risk of SPTD. High sCD14, GCSF, PGF2α, and 5-HEPE were marginally associated with increased risk of SPTD. Women who initiated protease inhibitors-containing antiretroviral treatment before or during the first trimester had higher levels of GCSF and 5-HEPE compared with women without such exposure before plasma collection. Vitamin D insufficiency was associated with higher inflammatory sCD14 and PGF2α, and lower anti-inflammatory 5-HEPE. The best plasma predictor of SPTD in WLHIV was sIL2Rα, a marker of T-cell activation. Markers of monocyte activation and eicosanoids were marginally increased in WLHIV and SPTD, suggesting that they may also play a role in the pathogenesis of this disorder.

EP03.05: Transvaginal sonographic cervical length in 11–14 weeks of gestation in a low‐risk population and risk of spontaneous preterm delivery

EP03.05: Transvaginal sonographic cervical length in 11–14 weeks of gestation in a low‐risk population and risk of spontaneous preterm delivery

Change in cervical length and spontaneous preterm birth in nulliparous women with a history of loop electrosurgical excision procedure

Background Prior studies have shown an association between history of loop electrode procedures (LEEP) and spontaneous preterm delivery (SPTD) independent of mid-trimester cervical length. These studies suggest that there may be other factors beyond an individual cervical length, which contribute to identifying at-risk pregnancies. Objective The objective of this study is to determine the association between change in cervical length and SPTD in women with a history of LEEP. Study design This is a retrospective cohort study of singleton nulliparous women with a history of LEEP who received serial cervical length measurements at a single institution between 2012 and 2016. Women with serial cervical lengths and available outcome data were included. The cervical length at different gestational ages and the rate of change in length were compared with the risk for SPTD <37 weeks using Student’s t-test. Results One-hundred-thirty subjects met the inclusion criteria for the study. The mean cervical length (35.3 versus 39.8 mm, p = .042 at 16 weeks; 32.2 versus 37.8 mm, p < .01 at 20 weeks; 29.9 versus 35.6 mm, p = .027 at 24 weeks; 21.6 versus 33.4 mm, p < .01 at 28 weeks) was significantly different between women who had an SPTD <37 weeks compared to women who did not. The average rate of change in transvaginal cervical length between 16 to 28 weeks was significantly different between women who had an SPTD <37 weeks compared to women who did not (−1.4 versus 0.4 mm/week, p < .01). Conclusion Women with a history of LEEP who had an SPTD <37 weeks had a shorter cervical length at 16, 20, 24, and 28 weeks’ gestation and a higher rate of change in cervical length between 16 and 28 weeks than women without a history of SPTD. Our findings support the concept of the preterm birth syndrome as an evolving biophysical process rather than a distinct event, suggesting improved prediction in the setting of prior history of a LEEP with serial imaging.

Defining microbial biomarkers for risk of preterm labor

Preterm birth remains the main contributor to early childhood mortality. The vaginal environment, including microbiota composition, might contribute to the risk of preterm delivery. Alterations in the vaginal microbial community structure might represent a risk factor for preterm birth. Here, we aimed to (a) investigate the association between preterm birth and the vaginal microbial community and (b) identify microbial biomarkers for risk of preterm birth. Microbial DNA was isolated from vaginal swabs in a cohort of 69 women enrolled at hospital admission for their delivery. Microbiota was analyzed by high-throughput 16S rRNA sequencing. While no differences in microbial diversity measures appeared associated with the spontaneous preterm and full-term outcomes, the microbial composition was distinct for these groups. Differential abundance analysis showed Lactobacillus species to be associated with full-term birth whereas an unknown Prevotella species was more abundant in the spontaneous preterm group. Although we studied a very miscegenated population from Brazil, our findings were similar to evidence pointed by other studies in different countries. The role of Lactobacillus species as a protector in the vaginal microbiome is demonstrated to be also a protector of spontaneous preterm outcome whereas the presence of pathogenic species, such as Prevotella spp., is endorsed as a factor of risk for spontaneous preterm delivery.

Large-for-gestational-age fetuses have an increased risk for spontaneous preterm birth.

Our aim was to investigate the association between large-for-gestational-age and the risk of spontaneous preterm birth. We studied nulliparous women with a singleton gestation using data from the Dutch perinatal registry from 1999 to 2010. Neonates were categorized according to the Hadlock fetal weight standard, into 10th to 90th percentile, 90th to 97th percentile, or above 97th percentile. Outcomes were preterm birth <37+0 weeks and preterm birth between 25+0-27+6 weeks, 28+0-30+6 weeks, 31+0-33+6 weeks, and 34+0-36+6 weeks. We included 547,418 women. The number of spontaneous preterm births <37 weeks was significantly increased in the large-for-gestational-age group ( > p97) compared with fetuses with a normal growth (p10-p90) (11.3% vs. 7.3%, odds ratio (OR) 1.8; 95% CI 1.7-1.9). The same results were found when limiting analyses to women with certain pregnancy duration (after in vitro fertilization). Large-for-gestational-age increases the risk of spontaneous preterm delivery from 25 weeks of gestation onwards.