Progestogen maintenance therapy for prolongation of pregnancy after an episode of preterm labour: A systematic review and meta-analysis.

BACKGROUND: Evidence for progestogen maintenance therapy after an episode of preterm labour (PTL) is contradictory. OBJECTIVES: To assess effectiveness of progestogen maintenance therapy after an episode of PTL. SEARCH STRATEGY: An electronic search in Central Cochrane, Ovid Embase, Ovid Medline and clinical trial databases was performed. SELECTION CRITERIA: Randomised controlled trials (RCT) investigating women between 16+0 and 37+0 weeks of gestation with an episode of PTL who were treated with progestogen maintenance therapy compared with a control group. DATA COLLECTION AND ANALYSIS: Systematic review and meta-analysis were conducted. The primary outcome was latency time in days. Secondary neonatal and maternal outcomes are consistent with the core outcome set for preterm birth studies. Studies were extensively assessed for data trustworthiness (integrity) and risk of bias. MAIN RESULTS: Thirteen RCT (1722 women) were included. Progestogen maintenance therapy demonstrated a longer latency time of 4.32 days compared with controls (mean difference [MD] 4.32, 95% CI 0.40-8.24) and neonates were born with a higher birthweight (MD 124.25 g, 95% CI 8.99-239.51). No differences were found for other perinatal outcomes. However, when analysing studies with low risk of bias only (five RCT, 591 women), a significantly longer latency time could not be shown (MD 2.44 days; 95% CI -4.55 to 9.42). CONCLUSIONS: Progestogen maintenance therapy after PTL might have a modest effect on prolongation of latency time. When analysing low risk of bias studies only, this effect was not demonstrated. Validation through further research, preferably by an individual patient data meta-analysis is highly recommended.

Severe metabolic ketoacidosis as a primary manifestation of SARS-CoV-2 infection in non-diabetic pregnancy.

We present a case of a metabolic acidosis in a term-pregnant woman with SARS-CoV-2 infection.Our patient presented with dyspnoea, tachypnoea, thoracic pain and a 2-day history of vomiting, initially attributed to COVID-19 pneumonia. Differential diagnosis was expanded when arterial blood gas showed a high anion gap metabolic non-lactate acidosis without hypoxaemia. Most likely, the hypermetabolic state of pregnancy, in combination with maternal starvation and increased metabolic demand due to infection, had resulted in metabolic ketoacidosis. Despite supportive treatment and rapid induction of labour, maternal deterioration and fetal distress during labour necessitated an emergency caesarean section. The patient delivered a healthy neonate. Postpartum, after initial improvement in metabolic acidosis, viral and bacterial pneumonia with subsequent significant respiratory compromise were successfully managed with oxygen supplementation and corticosteroids. This case illustrates how the metabolic demands of pregnancy can result in an uncommon presentation of COVID-19.

Cervical Pessary After Arrested Preterm Labor: A Randomized Controlled Trial.

OBJECTIVE: To assess the effectiveness of cervical pessary in reducing the rate of preterm birth in women at high risk for preterm birth who did not deliver after an episode of threatened preterm labor. METHODS: In a multicenter open-label randomized controlled trial, a cervical pessary was compared with no intervention (control group) (one-to-one ratio). Women between 24 and 34 weeks of gestation at high risk for preterm birth based on a short cervical length (less than 15 mm) or an intermediate cervical length (between 15 and 30 mm) with a positive fetal fibronectin test who did not deliver after an episode of threatened preterm labor were eligible. The primary outcome was birth before 37 weeks of gestation. Secondary outcomes were a composite adverse neonatal outcome, preterm birth before 34 and 32 weeks of gestation, and side effects. A total sample size of 200 women carrying singletons was planned so as to have adequate statistical power to detect a reduction in the rate of preterm birth from 40% to 20%. Women with twin gestations were also enrolled but were considered only in secondary analyses. After a planned interim analysis, the trial was stopped for futility. RESULTS: From November 2013 through September 2016, 130 women with a singleton pregnancy (65 pessary, 65 no treatment) were recruited. The groups had comparable baseline characteristics. In the cervical pessary group, 31 (48%) women delivered before 37 weeks of gestation compared with 25 (39%) in the no-treatment group (relative risk 1.2, 95% CI 0.83-1.8). Nine (15%) children in the cervical pessary group had the composite adverse perinatal outcome compared with eight (13%) in the control group (relative risk 1.2, 95% CI 0.49-2.9). CONCLUSION: In women at high risk for preterm birth who did not deliver after an episode of threatened preterm labor, treatment with a cervical pessary is not effective. CLINICAL TRIAL REGISTRATION: Netherlands Trial Register, NTR4210.

Repeated cervical length measurements for the verification of short cervical length.

OBJECTIVE: To determine if the verification of short cervical length with a repeated measurement improved the identification of patients with short cervical length at increased risk of preterm delivery. METHODS: The present secondary analysis analyzed prospective cohort study data from patients with singleton pregnancies without a history of preterm delivery who presented for obstetric care in the Netherlands and delivered between November 18, 2009, and January 1, 2013. Cervical length was measured during standard anomaly scan and a second measurement was performed if the cervical length was 30 mm of shorter. Logistic regression and Cox proportional hazards modeling were used to evaluate associations between cervical length measurements and spontaneous preterm delivery before 37 weeks of pregnancy. RESULTS: Cervical length measurements from 12 358 patients were included; 221 (1.8%) had an initial cervical length measurement of 30 mm or shorter. A second cervical length measurement was performed for 167 (75.6%) patients; no differences were identified in the odds of spontaneous preterm delivery when evaluated using the first, second, or a mean of both measurements, regardless of whether cervical length was analyzed as a continuous or dichotomous variable. CONCLUSION: Among patients with singleton pregnancies, verification of short cervical length did not improve the identification of short cervical length.

Which Factors Contribute to False-Positive, False-Negative, and Invalid Results in Fetal Fibronectin Testing in Women with Symptoms of Preterm Labor?

Objective We assessed the influence of external factors on false-positive, false-negative, and invalid fibronectin results in the prediction of spontaneous delivery within 7 days. Methods We studied symptomatic women between 24 and 34 weeks' gestational age. We performed uni- and multivariable logistic regression to estimate the effect of external factors (vaginal soap, digital examination, transvaginal sonography, sexual intercourse, vaginal bleeding) on the risk of false-positive, false-negative, and invalid results, using spontaneous delivery within 7 days as the outcome. Results Out of 708 women, 237 (33%) had a false-positive result; none of the factors showed a significant association. Vaginal bleeding increased the proportion of positive fetal fibronectin (fFN) results, but was significantly associated with a lower risk of false-positive test results (odds ratio [OR], 0.22; 95% confidence intervals [CI], 0.12-0.39). Ten women (1%) had a false-negative result. None of the investigated factors was significantly associated with a significantly higher risk of false-negative results. Twenty-one tests (3%) were invalid; only vaginal bleeding showed a significant association (OR, 4.5; 95% CI, 1.7-12). Conclusion The effect of external factors on the performance of qualitative fFN testing is limited, with vaginal bleeding as the only factor that reduces its validity.

Effectiveness of a cervical pessary for women who did not deliver 48 h after threatened preterm labor (Assessment of perinatal outcome after specific treatment in early labor: Apostel VI trial).

BACKGROUND: Preterm birth is a major cause of neonatal mortality and morbidity. As preventive strategies are largely ineffective, threatened preterm labor is a frequent problem that affects approximately 10 % of pregnancies. In recent years, risk assessment in these women has incorporated cervical length measurement and fetal fibronectin testing, and this has improved the capacity to identify women at increased risk for delivery within 14 days. Despite these improvements, risk for preterm birth continues to be increased in women who did not deliver after an episode of threatened preterm labor, as indicated by a preterm birth rate between 30 to 60 % in this group of women. Currently no effective treatment is available. Studies on maintenance tocolysis and progesterone have shown ambiguous results. The pessary has not been evaluated in women with threatened preterm labor, however studies in asymptomatic women with a short cervix show reduced rates of preterm birth rates as well as perinatal complications. The APOSTEL VI trial aims to assess the effectiveness of a cervical pessary in women who did not deliver within 48 h after an episode of threatened preterm labor. METHODS/DESIGN: This is a nationwide multicenter open-label randomized clinical trial. Women with a singleton or twin gestation with intact membranes, who were admitted for threatened preterm labor, at a gestational age between 24 and 34 weeks, a cervical length between 15 and 30 mm and a positive fibronectin test or a cervical length below 15 mm, who did not deliver after 48 h will be eligible for inclusion. Women will be allocated to a pessary or no intervention (usual care). Primary outcome is preterm delivery < 37 weeks. Secondary outcomes are amongst others a composite of perinatal morbidity and mortality. Sample size is based on an expected 50 % reduction of preterm birth before 37 weeks (two-sided test, α 0.05 and ß 0.2). Two hundred women with a singleton pregnancy need to be randomized. Analysis will be done by intention to treat. DISCUSSION: The APOSTEL VI trial will provide evidence whether a pessary is effective in preventing preterm birth in women who did not deliver 48 h after admission for threatened preterm labor and who remain at high risk for preterm birth. TRIAL REGISTRATION: Trial is registered at the Dutch Trial Register: http://www.trialregister.nl , NTR4210, date of registration: October 16th 2013.

Indicators for Cervical Length in Twin Pregnancies.

OBJECTIVE: Cervical length (CL) is associated with the risk of preterm birth (PTB) in multiple pregnancies. However, the position of CL within the pathophysiological pathway of PTB is unclear, and it is unknown which factors are predictive for CL. This study aims to investigate whether in twin pregnancies baseline maternal and obstetrical characteristics are potential indicators for CL, to improve insight in the pathophysiological pathway of PTB. STUDY DESIGN: Secondary analysis of data on twin pregnancies and CL measurement between 16 and 22 weeks. A set of 10 potential indicators, known to be associated with an increased risk of PTB and/or which have a plausible mechanism resulting in a change of CL were selected. We used multivariable linear regression with backward selection to identify independent indicators for CL. RESULTS: A total of 1,447 women with twin pregnancies were included. Mean CL was 43.7 (±8.9) mm. In multivariable analysis, age (0.27 mm/y; 95% confidence interval [CI] 0.16 to 0.39), use of assisted reproductive technologies (ART) (-1.42 mm, 95% CI -2.6 to -0.25), and having delivered at term in a previous pregnancy (1.32 mm, 95% CI 0.25 to 2.39) were significantly associated with CL. CONCLUSION: This study shows that in twin pregnancies, age, use of ART and having delivered term in a previous pregnancy has an association with CL.

Risk stratification with cervical length and fetal fibronectin in women with threatened preterm labor before 34 weeks and not delivering within 7 days.

OBJECTIVE: To stratify the risk of spontaneous preterm delivery using cervical length (CL) and fetal fibronectin (fFN) in women with threatened preterm labor who remained pregnant after 7 days. DESIGN: Prospective observational study. SETTING: Nationwide cohort of women with threatened preterm labor from the Netherlands. POPULATION: Women with threatened preterm labor between 24 and 34 weeks with a valid CL and fFN measurement and remaining pregnant 7 days after admission. METHODS: Kaplan-Meier and Cox proportional hazards models were used to estimate cumulative percentages and hazard ratios (HR) for spontaneous delivery. MAIN OUTCOME MEASURES: Spontaneous delivery between 7 and 14 days after initial presentation and spontaneous preterm delivery before 34 weeks. RESULTS: The risk of delivery between 7 and 14 days was significantly increased for women with a CL < 15 mm or a CL ≥15 to <30 mm and a positive fFN, compared with women with a CL ≥30 mm: HR 22.3 [95% confidence interval (CI) 2.6-191] and 14 (95% CI 1.8-118), respectively. For spontaneous preterm delivery before 34 weeks the risk was increased for women with a CL < 15 mm [HR 6.3 (95% CI 2.6-15)] or with a CL ≥15 to <30 mm with either positive fFN [HR 3.6 (95% CI 1.5-8.7)] or negative fFN [HR 3.0 (95% CI 1.2-7.1)] compared with women with a CL ≥ 30 mm. CONCLUSIONS: In women remaining pregnant 7 days after threatened preterm labor, CL and fFN results can be used in risk stratification for spontaneous delivery.

Folate related gene polymorphisms and susceptibility to develop childhood acute lymphoblastic leukaemia.

Acute lymphoblastic leukaemia (ALL) is the most common paediatric cancer, accounting for nearly 30% of all paediatric cancers and 80% of childhood leukaemias. Polymorphisms in folate-related genes may influence the susceptibility to childhood ALL. This review summarizes the results of 14 studies that focussed on the relationship between folate-related gene polymorphisms and the susceptibility to ALL and that fulfilled certain quality criteria. The total group consisted of 729 children and 1821 adults or non age-defined patients. The results of different studies sometimes contradict each other, for which there are several possible explanations. This includes an influence of the type of population studied, because there was a difference between Asian and European study results. Based on several studies, it is plausible that polymorphisms in the MTHFR gene, 677C>T and 1298A>C, are associated with a decreased susceptibility to childhood ALL in non-Asian populations. Polymorphisms in other folate related genes (MTRR, MTR [MS], TYMS [TS], SLC19A1 [RFC1], NNMT, and SHMT1) are less clearly associated with susceptibility to ALL, and the number of included studies on this subject in this review is limited. Further investigations on the relevance of these polymorphisms need to be performed. In general, it is clear that susceptibility to (childhood) ALL is partly related to constitutional differences in folate gene polymorphisms.