Regimens of ultrasound surveillance for twin pregnancies for improving outcomes

Development and validation of a prediction model on spontaneous preterm birth in twin pregnancy: a retrospective cohort study

BACKGROUND

This study was conducted to develop and validate an individualized prediction model for spontaneous preterm birth (sPTB) in twin pregnancies.

METHODS

This a retrospective cohort study included 3845 patients who gave birth at the Chongqing Maternal and Child Health Hospital from January 2017 to December 2022. Both univariable and multivariable logistic regression analyses were performed to find factors associated with sPTB. The associations were estimated using the odds ratio (OR) and the 95% confidence interval (CI). Model performance was estimated using sensitivity, specificity, accuracy, area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA).

RESULTS

A total of 1313 and 564 cases were included in the training and testing sets, respectively. In the training set, univariate and multivariate logistic regression analysis indicated that age ≥ 35 years (OR, 2.28; 95% CI 1.67-3.13), pre-pregnancy underweight (OR, 2.36; 95% CI 1.60-3.47), pre-pregnancy overweight (OR, 1.67; 95% CI 1.09-2.56), and obesity (OR, 10.45; 95% CI, 3.91-27.87), nulliparity (OR, 0.58; 95% CI 0.41-0.82), pre-pregnancy diabetes (OR, 5.81; 95% CI 3.24-10.39), pre-pregnancy hypertension (OR, 2.79; 95% CI 1.44-5.41), and cervical incompetence (OR, 5.12; 95% CI 3.08-8.48) are independent risk factors for sPTB in twin pregnancies. The AUC of the training and validation set was 0.71 (95% CI 0.68-0.74) and 0.68 (95% CI 0.64-0.73), respectively. And then we integrated those risk factors to construct the nomogram.

CONCLUSIONS

The nomogram developed for predicting the risk of sPTB in pregnant women with twins demonstrated good performance. The prediction nomogram serves as a practical tool by including all necessary predictors that are readily accessible to practitioners.

Quality appraisal of systematic reviews on methods of labour induction: a systematic review

PURPOSE

Induction of labour has become more common over the last decade, together with an increase in the number of systematic reviews of the subject. However, with multiple systematic reviews it is necessary to evaluate the methodological rigor to ensure the reliability of conclusions and recommendations for clinical practice. Therefore, the aim of this study was to appraise the quality of systematic reviews that examined the efficacy and/or safety of labour induction methods.

METHODS

An electronic search of MEDLINE, Embase, and the Cochrane Library from 2000 to 2020 was conducted. Study selection, data extraction and quality assessment were conducted using A Measurement Tool to Assess Systematic Reviews (AMSTAR) by two independent reviewers, in duplicate.

RESULTS

The search identified 387 publications, of which 48 studies (13%) met the a priori inclusion criteria. No significant relationships were found between study quality and number of citations, journal impact factor, or publication year.

CONCLUSION

Methodological quality for systematic reviews on the induction of labour were ranked as moderate with no significant changes in quality over the past 2 decades. Publication characteristics are not significantly associated with methodological quality, indicating that healthcare professionals should critically appraise studies before applying them to practice.

Regimens of ultrasound surveillance for twin pregnancies for improving outcomes

BACKGROUND

Increased ultrasound surveillance of twin pregnancies has become accepted practice due to the higher risk of complications. There is no current consensus however as to the method and frequency of ultrasound monitoring that constitutes optimal care.

OBJECTIVES

To systematically review the effects of different types and frequency of ultrasound surveillance for women with a twin pregnancy on neonatal, fetal and maternal outcomes.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (all searched 11 August 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials (including those published in abstract form) comparing the effects of described antenatal ultrasound surveillance regimens in twin pregnancies. Trials using a cluster-randomised design would have been eligible for inclusion in this review but none were identified. Trials using a cross-over design are not eligible for inclusion in this review.Different types and frequencies of ultrasound testing (for fetal surveillance and detection of specific problems) compared with each other and also compared with no testing. For example, an intervention might comprise a specific approach to ultrasound examination with dedicated components to detect twin-specific pathology. Different interventions could also include a specific type of surveillance at different intervals or different combinations at the same intervals.In this review we only found one study looking at fetal growth (biometry) and Doppler ultrasounds at 25, 30 and 35 weeks' gestation versus fetal growth alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and quality, and extracted data. We checked data for accuracy.

MAIN RESULTS

We included one trial of 526 women with a twin pregnancy of two viable twins, with no known morphological abnormality, in this review. The trial compared women receiving fetal growth and Doppler ultrasounds at 25, 30 and 35 weeks' gestation to fetal growth alone. We judged the included study to be at low risk of bias however the risk of performance and detection bias were unclear.The primary outcome was the perinatal mortality rate (after randomisation), for which there was no evidence of a clear difference between the fetal growth + Doppler and the fetal growth alone groups (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.32 to 2.41, low-quality evidence) with similar rates in both groups (seven events in the Dopper + fetal growth group and eight in the fetal growth alone group). No clear differences were seen between the two regimens for the other outcomes in this review: stillbirth (RR 0.67, 95% CI 0.11 to 3.99), neonatal death (RR 1.01, 95% CI 0.29 to 3.46, low-quality evidence), gestational age at birth (weeks) (mean difference 0.10, 95% CI -0.39 to 0.59, moderate-quality evidence), infant requiring ventilation (RR 0.86, 95% CI 0.59 to 1.25), admission to special care or intensive care units (RR 0.96, 95% CI 0.88 to 1.05), caesarean section (any) (RR 1.00, 95% CI 0.81 to 1.23, high-quality evidence), elective caesarean section (RR 1.06, 95% CI 0.77 to 1.47), emergency caesarean section (RR 0.93, 95% CI 0.66 to 1.32), induction of labour (RR 1.10, 95% CI 0.80 to 1.50, moderate-quality evidence) or antenatal hospital admission (RR 0.96, 95% CI 0.80 to 1.15, high-quality evidence). The number of preterm births before 28 weeks' gestation was not reported in the included study. For the mortality-related outcomes, event numbers were small.The included study did not report the majority of our maternal and infant secondary outcomes. Infant outcomes not reported included fetal acidosis, Apgar scores less than 7 at five minutes and preterm birth before 37 and 34 weeks' gestation. The maternal outcomes; length of antenatal hospital stay, timely diagnosis of significant complications, rate of preterm, prelabour rupture of membranes and women's level of satisfaction with their care were not reported. The study did not classify twin pregnancies according to their chorionicity. An awareness of the chorionicity may have improved applicability of this data set.We downgraded outcomes assessed using GRADE for imprecision of effect estimates.

AUTHORS' CONCLUSIONS

This review is based on one small study which was underpowered for detection of rare outcomes such as perinatal mortality, stillbirth and neonatal death.There is insufficient evidence from randomised controlled trials to inform best practice for fetal ultrasound surveillance regimens when caring for women with a twin pregnancy. More studies are needed to evaluate the effects of currently used ultrasound surveillance regimens in twin pregnancies. Future research could report on the important maternal and infant outcomes as listed in this review.