Risk factors of early spontaneous preterm birth despite carrying a cervical pessary in singleton pregnancies with a short cervix: Development of a risk prediction model

Introduction

We aimed to identify the incidence and risk factors of spontaneous preterm birth in pessary carriers with singleton pregnancies and a short cervix in the mid-trimester of pregnancy.

Material and Methods

Patient data were obtained from the PECEP Trial. We analyzed singleton pregnancies in pessary carriers with a short cervix (≤25 mm) between 18 and 22 gestational weeks. Demographics and obstetric history were compared to identify risk factors for spontaneous preterm birth < 34 gestational weeks. Each demographic and obstetric variable was compared between spontaneous preterm birth < 34 and ≥ 34 weeks of gestation.Regression analysis was used to identify risk factors. A risk score model was generated using the odds ratio for significant factors. The risk score model and spontaneous preterm birth risk were assessed using the receiver operating characteristic curve. Perinatal outcomes were compared by risk score.

Results

Among 190 pregnant individuals, 12 (6.3%) had spontaneous preterm birth < 34 gestational weeks. In the bivariate analysis, statistically significant differences between those with and without spontaneous preterm birth were only observed for mean cervical length at diagnosis and mean cervical length after pessary placement. By multiple logistic regression analysis, maternal age (OR 0.818; 95% CI 0.69-0.97; P 0.020), cervical length at diagnosis (OR 0.560; 95% CI 0.43-0.73; P < 0.001) and smoking status (OR 7.276; 95% CI 1.02-51.80; P 0.048) remained significantly associated with spontaneous preterm birth.The ROC curve from the multiple logistic regression analysis, including cervical length, maternal age and smoking status, had an area under the curve (AUC) of 0.952 (P < 0.001). The ROC curve for the risk score model incorporating all three variables had an AUC of 0.864 (95% CI 0.77-0.96; P < 0.001). A high-risk score was predictive of spontaneous preterm birth with a sensitivity of 75%, specificity of 84%, positive predictive value of 24%, and negative predictive value of 98%.Women with a high-risk score had a significantly reduced latency to delivery and poorer neonatal outcomes than those with a low-risk score.

Conclusions

Patients at a high risk for spontaneous preterm birth despite pessary therapy may be identified using cervical length at diagnosis added to maternal age and smoking status.

A pragmatic evaluation of the implementation and acceptance of a universal second trimester cervical length screening program in an un-selected population

PURPOSE

To evaluate patients' acceptance of a universal transvaginal ultrasound cervical length (CL) screening program and the feasibility of initiating treatment with progesterone in a clinical setting in women found to have a short cervix.

METHODS

An observational, pragmatic cohort study was conducted at one tertiary care facility from 2012-2015, involving eligible women with singleton pregnancies who accepted and underwent second-trimester CL screening. The primary outcomes were the percentage of women who were eligible and accepting of screening, compliance with progesterone treatment, and the screening value of TVCL in predicting SPTB. Secondary outcomes were the number of women who received progesterone treatment and the rates of SPTB.

RESULTS

Overall cervical length screening acceptance rate was found to be 82.5%. Of the 797 women that underwent screening, 21 women (2.6%) had a TVCL < 25 mm, of whom nine had a TVCL < 20.0 mm. Nineteen of the 21 women with a TVCL < 25 mm were treated with progesterone, with a 94.7% compliance rate. Delivery outcomes were obtained for 767 women. Of those with a TVCL < 25 mm, there was a 35% rate of SPTB as opposed to a 6.3% SPTB rate in those with TVCL > 25 mm. The negative predictive value for SPTB with a TVCL 25 mm or greater was 94.0%.

CONCLUSION

Universal cervical length screening was successfully implemented in 82.5% of the patient population with a high compliance rate with progesterone treatment. Furthermore, there was a higher rate of SPTB in those with a shorter cervix. Based on our outcomes obtained in an observational and pragmatic manner, we showed that incorporating second trimester transvaginal cervical length screening into routine clinical practice is readily accepted and, with the addition of vaginal progesterone treatment, may reduce the rate of prematurity.

Identifying the barriers to universal cervical length screening for preterm birth prevention at a tertiary hospital in Thailand (patient's perspectives): implementation research

PURPOSE

To identify patient perspectives of barriers to cervical length screening to prevent preterm births.

METHODS

In Phase I of this prospective descriptive implementation study, 40 pregnant women of up to 24 week gestation were interviewed. Phase II comprised questionnaire development and data validation. The questionnaire was subsequently administered to 400 participants in Phase III.

RESULTS

Most participants (74.3%) realised preterm babies have complications and high care costs (53%). They recognised that premature-birth risk identification enables appropriate pregnancy care (93.8%), but they were unaware that cervical length measurements indicate the risk (59.5%). The participants who were aware wanted to be examined (63.5%) because of concern about preterm birth (95.8%). Husbands were reported to influence decision-making about screening (81.3%) and subsequent treatment (42.5%). If the associated costs were subsidised, the majority of participants (67.3%) would undergo screening.

CONCLUSION

Physicians do not explain ways to prevent preterm births. Government policy on preventing preterm births is not well established. Screening and treatment costs are major barriers.

TRIAL REGISTRATION

Thai Clinical Trials Registry (TCTR) number: TCTR20190813003.

Prevention of Prematurity: Advances and Opportunities

Preterm birth (PTB) rate varies widely and has significant racial and ethnic disparities. Although causal mechanisms are ill understood, socioenvironment, phenotype, and genotype provide insight into pathways for preventing PTB. Data suggest varied response to current medical interventions is explicable Approved by underlying pharmacogenomics. Currently, prevention focuses on minimizing iatrogenic PTB and risk reduction especially in those with prior PTB using proven medical and public health strategies. In the future, preventive approaches will be based on better understanding of sociodemography, nutrition, lifestyles, and underlying individual genetic and epigenetic variation. Statistical approaches and "big-data" models are critical in future study.

Pregnant women's preferences for and concerns about preterm birth prevention: a cross-sectional survey

BACKGROUND

Although there is a call for patient-centred prenatal care, women's preferences for and concerns about preterm birth (PTB) prevention have not been well-studied. Therefore, we conducted a cross-sectional survey to determine women's preferences for PTB prevention and their likelihood of following their healthcare provider's recommendations for PTB prevention, as well as factors associated with these responses.

METHODS

A piloted self-administered questionnaire was completed by pregnant women who could read English. Data were collected about their preferences for and concerns about PTB prevention, and the likelihood of following their healthcare provider's recommendations, using multivariable logistic regression to control for other factors.

RESULTS

Three hundred and eleven women at a median of 32-weeks of gestation completed the survey, a response rate of 85.2%. Most women reported that if they were told they were at increased risk for PTB, they preferred not to use PTB prevention (65.8%), of whom almost all (93.4%) reported they preferred close-monitoring and 6.6% preferred neither monitoring nor prevention. A much smaller proportion of women reported that they would not follow their healthcare provider's recommendation for progesterone (10.9%) compared to pessary (28.7%) or cerclage (50.2%). Women who were neither married nor in a common-law relationship were more likely to report that they would not follow recommendations for progesterone (aOR = 5.88 [95% CI: 1.72, 20.00]). Most women (84.5%) reported they would use other sources of information other than their main healthcare provider to learn more about PTB prevention, with the most popular source being the internet.

CONCLUSIONS

Most women reported that if they were told they were at increased risk of PTB, they preferred close-monitoring over using PTB prevention. Their reported likelihood of not following their healthcare provider's recommendations for PTB prevention varied from 10.9% for progesterone to 50.2% for cerclage. These findings suggest that more education about the risk of PTB, PTB preventions, as well as compliance with progesterone is needed and that the internet would be an important source of information. However as our study was completed by women at a median of 32 weeks of gestation, future surveys targeted at women earlier in their pregnancy are needed.

Prevention of preterm birth in modern obstetrics

Spontaneous preterm labor is a complex process characterized by the interplay of multiple different pathways. Prevention of preterm labor and delivery is also complicated. The most effective interventions for prevention of preterm birth (PTB) are progestin prophylaxis and lifestyle modifications, with cerclage placement also playing a role in selected populations. Interventions such as activity modification, home tocometry, and routine antibiotic use have fallen out of favor because of lack of effectiveness and possibility of harm. The solution to the problem of PTB remains elusive, and researchers and clinicians must collaborate to find a cure for preterm labor.