() III-2 13,985 Aim: to examine data on rates of preterm birth in Indigenous women from Victoria. Methods: 5 years (1st January 2010-31st December 2014) of retrospective data from The Northern Hospital's (Melbourne, Victoria) database were analysed. Mothers and babies were split according to self-reported indigenous status: 13,800 nonindigenous mothers, 185 indigenous mothers, 301 indigenous babies and 13,843 nonindigenous babies. Primary outcomes measured were low birthweight (LBW) and preterm birth. There was a higher incidence of indigenous babies born preterm (8.8% vs 5.9%, P = 0.034), but the adjusted odds ratios for preterm birth were not significant (indigenous babies OR 1.19, 95% CI: 0.77-1.87, indigenous mothers OR 0.97, CI: 0.52-1.80). Heterogeneity of indigenous people and geography means that inferences about indigenous health are difficult to make. It appears that Victorian urban indigenous women have similar rates of preterm birth to nonindigenous women.
() I 107 studies Aim: to assess the published evidence concerning the association between psychosocial stress (PSP) and PTB, highlighting established and hypothesized physiological pathways mediating this association. Method: The PubMed and Web of Science databases were searched using the keywords 'psychosocial stress', 'pregnancy', 'pregnancy stress', 'preterm', 'preterm birth', 'gestational age', 'anxiety', and 'social support'. The association of PSP with PTB varied with the dimensions and timing of PSP. Stronger associations were generally found in early pregnancy, and most studies demonstrating positive results found moderate effect sizes (RR 1.2 to 2.1). Subjective perception of stress and pregnancy-related anxiety appeared to be the stress measures most closely associated with PTB. () I 23 studies 25,663 women Aim: To understand the effect of untreated depression on neonatal outcomes. Methods: Searches of MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health, Cochrane Central Register of Controlled Trials, and Web of Science were conducted. Randomised and non-randomised studies examining neonatal outcomes in women with depression receiving neither pharmacological nor treatment compared with women without depression were included. Data were pooled data using random-effects meta-analyses, heterogeneity quantified using the I2 statistic and explored with subgroup analyses by type of assessment of depression, severity, reported conflicts of interest, and study quality. Untreated depression was associated with significantly increased risks of preterm birth (OR 1.56; 95%CI 1.25 to 1.94; 14 studies), with a trend toward higher risks for exposure to more severe depression. While the odds of preterm birth almost doubled in studies reporting conflicts of interest (ie with pharmaceutical industry support) (OR, 2.50; 95%CI, 1.70-3.67; 5 studies; I2, 0%), studies not reporting such conflicts showed more moderate results (OR, 1.34; 95%CI, 1.08-1.66; 9 studies; I2, 30%).
() I 39 studies Aim: to outline the evidence on the risk of preterm associated with antenatal depression, anxiety, and stress. Methods: Four electronic database searches were conducted to identify quantitative population-based, multi-centre, cohort studies and randomised-controlled trial studies focusing on the association between antenatal depression, anxiety, and stress, and preterm birth published in English between 1980 and 2013. Depression — in studies with a low risk of bias OR ranged from 1.13 to 3.93 with narrow confidence intervals. One study found no clear link between major depressive episode and PTB but a significant increase in risk for PTB with antidepressant use (OR = 2.1 [95%CI 1.0–4.6]). Anxiety — three of four studies found a significant association, with OR ranging from 1.48 to 2.73. Perceived stress — five studies consistently demonstrated a statistically significant relationship. Of the three studies with low risk of bias two demonstrated increased risk from OR 1.14 to RR 1.75. {Ding, 2014 #1375} I 12 studies 17,304 women To investigate the association between maternal anxiety and preterm birth(PTB)and/or low birthweight(LBW). Literature was searched until June 2013. Only prospective cohort studies that reported data on maternal anxiety during pregnancy with PTB and/or LBW were included. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using fixed or random effects models depending on the size of heterogeneity. Maternal anxiety during pregnancy was associated with significant increased risk of PTB (pooled RR 1.50, 95%CI 1.33 to 1.70). () I 25 studies Aim: to provide a summary of the published evidence of the relationship between prenatal maternal anxiety and PTB while examining methodological and statistical sources of heterogeneity. Methods. Published studies from MEDLINE, CINAHL, PsycINFO, and EMBASE, until June 2015, were extracted and reviewed. The odds ratio for prenatal maternal anxiety was 1.70 (95%CI 1.33 to 2.18) for PTB and 1.67 (95%CI 1.35 to 2.07) for spontaneous PTB comparing higher levels of anxiety to lower levels.
() 20 studies Aim: to assess the risk for PTB in women with treated and untreated cervical intraepithelial neoplasia (CIN). Methods: We performed an electronic literature search in MEDLINE, Embase and CENTRAL for studies that reported on pregnancy outcome after treated and untreated CIN. The methodological was scored using the STROBE combined checklist for observational studies. We extracted data on PTB<37 weeks, very PTB<32 weeks, spontaneous PTB<37 weeks, (preterm) premature rupture of membranes ((P)PROM), perinatal mortality and caesarean each before and after treatment for CIN. We used the Mantel-Haenszel method to estimate summarizing odds ratios. Our search identified 620 studies, of which 20 were reporting on pregnancy outcome for a total of 12,159,293 women. There were 20,832 women who gave birth after treatment for CIN before pregnancy, 52 women who gave birth after treatment for CIN during pregnancy, 64,237 women with CIN who gave birth before treatment, and 8,902,865 women who gave birth without CIN. Compared to women with untreated CIN, women treated for CIN before or during pregnancy, had overall a significantly higher risk of PTB<37 weeks (OR 1.7, 95%CI 1.0 to 2.7). Compared to women with untreated CIN, women treated for CIN before pregnancy had an increased risk of preterm birth (OR 1.4, 95%CI 0.85 to 2.3). Women treated during pregnancy had a clearly increased risk for PTB compared to women with untreated CIN (OR 6.5, 95%CI 1.1 to 37). In women with cervical surgery compared to women with untreated CIN, the risks for spontaneous PTB<37 weeks (OR 0.87, 95% CI 0.54 to 1.4) was not increased. The increased risk of PTB in women who underwent cervical surgery for CIN is especially increased when performed during pregnancy. When performed before pregnancy the risk of PTB is increased, although insignificant.
Q5 Should cervical length be routinely measured as part of 17–22 week ultrasound assessment? Study ref Design LoE N Aim/methods Results Comments () SLR I 3 RCTs 287 women Aim: to evaluate the effect of knowledge of the TVS cervical length (CL) in preventing PTB in singleton pregnancies presenting with threatened PTL. Methods: We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register and the Cochrane Complementary Medicine Field’s Trials Register (May 2016) and reference lists of retrieved studies. Selection criteria included RCTs of singleton gestations with threatened PTL randomised to management based mainly on CL screening (intervention group), or CL screening with no knowledge of results or no CL screening (control group). Participants included women with singleton gestations at 23+0 to 36+6weeks with threatened PTL. Three trials including a total of 287 singleton gestations with threatened PTL between 24+0 and 35+6 weeks were included in the meta-analysis, of which 145 were randomized to CL screening with knowledge of results and 142 to no knowledge of CL. Compared with the control group, women who were randomized to the known CL group had a significantly lower rate of PTB <37 weeks (22.1 vs 34.5%; RR 0.64 (95%CI 0.44 to 0.94); 3 trials; n=287) and a later gestational age at delivery (MD 0.64 (95%CI 0.03 to 1.25) weeks; MD, 4.48 (95% CI, days; 3 trials; n=287). All other outcomes for which there were available data were similar in the two groups. There is a significant association between knowledge of TVS CL and lower incidence of PTB and later gestational age at delivery in symptomatic singleton gestations with threatened PTL. Given that in the meta-analysis we found a significant 36% reduction in the primary outcome, but other outcomes were mostly statistically similar, further study needs to be undertaken to understand better whether the predictive characteristics of CL screening by TVS can be translated into better clinical management and therefore better outcomes and under what circumstances.
() Decision analytic model — Aim: to identify whether and under what circumstances transabdominal ultrasound (TAUS) would be Methods: we compared an initial TAUS CL screening approach with universal transvaginal screening in a hypothetical cohort of women with a singleton pregnancy. Cost, probability, and utility estimates were derived from the existing literature. Under baseline assumptions, universal transvaginal was the dominant strategy. In comparison to TAUS, universal transvaginal CL screening reduced preterm birth by 0.03%, reduced costs by $1.2 million and increased quality-adjusted life years by 70 per 100,000 women. Although robust to many changes in many estimates, the model was sensitive to the cost of a transvaginal ultrasound, the prevalence of a short cervix and the test characteristics (ie, sensitivity and specificity) of a TAUS screening examination for short CL. Compared with an initial TAUS screen, universal transvaginal ultrasound was a more cost-effective strategy under most assumptions. Optimizing TAUS testing characteristics or applying a transabdominal screening strategy in lower risk populations may yield an initial TAUS to be effective.
Q6 What holistic preventative strategies including models of maternity care, reduce the incidence and impact of premature labour and birth? Group antenatal care compared to standard care Study ref Design LoE N Aim/methods Results Comments () SLR IV 11 studies Aim: To estimate the effect of group prenatal care on perinatal outcomes compared with traditional prenatal care. Methods: We searched MEDLINE through PubMed, EMBASE, Scopus, Cumulative Index of Nursing and Allied Health literature, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. The rate of preterm birth was not significantly different with group care compared with traditional care (pooled rates 7.9% vs 9.3%, pooled RR 0.87, 95%CI 0.70 to 1.09). Midwifery-led care Study ref Design LoE N Aim/methods Results Comments () SLR I 15 trials 17,674 women Aim: To compare midwife-led continuity models of care with other models of care for childbearing women and their infants. Methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (25 January 2016) and reference lists of retrieved studies. All published and unpublished trials in which pregnant women were randomly allocated to midwife-led continuity models of care or other models of care during pregnancy and birth were included. Women who had midwife-led continuity models of care were less likely to experience preterm birth <37 weeks (average RR 0.76, 95%CI 0.64 to 0.91; n=13,238; 8 studies; high quality) than women who received other models of care.
Specialised antenatal clinics for women at risk Study ref Design LoE N Aim/methods Results Comments () SLR I 15 RCTs Aim: to analyse the of integrative packages of antenatal care or models of care as a means of reducing PTB rates in all pregnant women. Methods: Systematic search of seven electronic databases and reference lists of retrieved studies from 2014. Systematic review and of trials of alternative antenatal care models (specialist PTB programmes and midwife-led continuity models of care) versus standard care. The risk of preterm birth was not significantly reduced in women randomised to specialist preterm birth programmes (RR 0.92, 95%CI 0.76 to 1.12). Reduced visits versus standard care Study ref Design LoE N Aim/methods Results Comments () 7 RCTs Aim: To compare the effects of antenatal care programmes with reduced visits for low-risk women with standard care. Methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 March 2015), reference lists of articles and contacted researchers in the field. Randomised trials comparing a reduced number of antenatal visits, with or without care, versus standard care were included. In high-income countries, the number of visits was reduced to 8; in countries many women in the reduced visits group had fewer than 5 visits but content was altered so as to focus on specific goals. There was no clear difference between groups for preterm birth (RR 1.02, 95%CI 0.94 to 1.11; 7 studies, n=53,661, moderate-quality).
Whitworth, M., et al. (2011) Specialised antenatal clinics for women with a pregnancy at high risk of preterm birth (excluding multiple pregnancy) to improve maternal and infant outcomes. DOI: 10.1002/14651858.CD006760.pub2 Studies included in more recent SLR Wisanskoonwong, P., et al. (2011). "The effectiveness of medical interventions aimed at preventing preterm birth: A literature review." Women and Birth 24(4): 141-147. Does not answer research question (medical not holistic intervention)