Significant Reduction In Preterm Birth Research Articles

Protective effect of maternal immunization on birth outcomes: A data linkage study.

To explore the impact of maternal immunization on adverse pregnancy outcomes including preterm birth (PTB) and stillbirth. The authors performed a data linkage study for women who delivered a singleton baby between January 2017 and May 2021. They used Poisson models to estimate incidence rates of adverse pregnancy outcomes and Cox proportional hazards models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs), accounting for the time-dependent nature of the exposure and adjusting for confounders. This study included 10 938 women who received at least one vaccine, and 4029 unvaccinated women. Influenza vaccine was associated with a significant reduction in stillbirth (adjusted HR [aHR], 0.55 [95% CI, 0.33-0.94]), but not in PTB (aHR, 0.92 [95% CI, 0.77-1.10]). Pertussis vaccine was associated with a significant reduction in PTB (aHR, 0.78 [95% CI, 0.64-0.94]) and a similar point estimate for reduction in stillbirth (aHR, 0.59 [95% CI, 0.31-1.10]), although not significant. Reductions in PTB and stillbirth associated with maternal immunization suggest possible protective effects beyond pathogen-specific protection. These findings may strengthen justification for scaling up maternal immunization in low-income settings where there remains a high burden of these adverse pregnancy outcomes.

Birthing on country service compared to standard care for First Nations Australians: a cost-effectiveness analysis from a health system perspective

Preterm birth is the leading cause of morbidity and mortality for children under five years with First Nations babies experiencing twice the rate of other Australians. The Birthing in Our Community (BiOC) service was implemented in a metropolitan centre in Australia and showed a significant reduction in preterm birth. We aimed to assess the cost-effectiveness of the BiOC service in reducing preterm births compared to Standard Care, from a health system perspective. Women who were carrying a First Nations baby and attending the Mater Mothers Public Hospital (Brisbane, QLD, Australia) were allocated to either BiOC or Standard Care service. Birth records were extracted from the hospital's routinely collected and prospectively entered database. The time horizon extended from first presentation in pregnancy up to six weeks after birth for mothers and 28 days for infants, or until discharged from hospital. All direct antenatal, birth, postnatal and neonatal costs were included. The proportion of preterm birth was calculated, and cost was estimated in 2019 Australian dollars. The incremental cost and proportion of preterm birth differences were adjusted using inverse probability of treatment weighting methods. Between Jan 1 2013, and Jun 30, 2019, 1816 mothers gave births to 1867 First Nations babies at the Mater Mothers Public Hospital. After exclusions, 1636 mother-baby pairs were included in the analyses: 840 in the Standard Care group and 796 in the BiOC service. Relative to Standard Care, the BiOC service was associated with a reduced proportion of preterm birth (-5.34%, [95% CI-8.69%,-1.98%]) and cost savings (-AU$4810, [95% CI-7519,-2101]) per mother-baby pair. The BiOC service was associated with better outcomes and cost less than Standard Care. The BiOC service offers a cost-effective alternative to Standard Care in reducing preterm birth for Australian First Nations families. The cost savings were driven by less interventions and procedures in birth and fewer neonatal admissions. Investing in comprehensive, community-led models of care improves outcomes at reduced cost. The Australian National Health and Medical Research Council (APP1077036).

Effectiveness of brief alcohol interventions for pregnant women: a systematic literature review and meta-analysis

BackgroundPrenatal alcohol exposure (PAE) can result in a range of adverse neonatal outcomes, including Fetal Alcohol Spectrum Disorder (FASD). This systematic review and meta-analysis sought to investigate the effectiveness of brief interventions (BIs) in eliminating or reducing 1) alcohol consumption during pregnancy; and 2) PAE-related adverse neonatal outcomes; and 3) cost-effectiveness of BIs.MethodWe conducted a systematic literature search for original controlled studies (randomized control trials (RCTs); quasi-experimental) in any setting, published from 1987 to 2021. The comparison group was no/minimal intervention, where a measure of alcohol consumption was reported. Studies were critically appraised using the Centre for Evidence-based Medicine Oxford critical appraisal tool for RCTs (1). The certainty in the evidence for each outcome was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) (2). Meta-analysis of continuous and binary estimates of effect-size for similar outcome measures for BIs versus control groups were pooled and reported as mean difference (MD) Hedges’ g and odds ratios (ORs), respectively.ResultsIn total, 26 studies, all from high income countries, met inclusion criteria. Alcohol abstinence outcome available in 12 studies (n = 2620) found modest effects in favor of BIs conditions by increasing the odds of abstinence by 56% (OR = 1.56, 95% confidence interval (CI) = 1.15–2.13, I2 = 46.75%; p = 0.04). BIs effects for reduction in mean drinks/week (Cohen’s d = − 0.21, 95%CI = - 0.78 to 0.36; p = 0.08) and AUDIT scores (g = 0.10, 95%CI = − 0.06 to 0.26; p = 0.17) were not statistically significant. Among seven studies (n = 740) reporting neonatal outcomes, BI receipt was associated with a modest and significant reduction in preterm birth (OR = 0.67, 95% CI = 0.46–0.98, I2 = 0.00%; p = 0.58). No statistically significant differences were observed for mean birthweight or lower likelihood of low birth weight (LBW). Certainty in the evidence was rated as ‘low’. No eligible studies were found on cost-effectiveness of BIs.ConclusionBIs are moderately effective in increasing abstinence during pregnancy and preventing preterm birth. More studies on the effectiveness of BIs are needed from low- and middle-income countries, as well as with younger mothers and with a broader range of ethnic groups.

Antenatal visits and obstetric outcomes during nationwide COVID-19 lock down period in a tertiary hospital of Nepal

Introduction: Maternity services were disrupted during nationwide COVID-19 lock down period. This study aimed to evaluate the impact of nationwide COVID-19 lock down on antenatal visits and obstetric outcomes in a tertiary hospital of Nepal.
 Method: A study was conducted at Patan hospital, Nepal with regard to antenatal visits and obstetric outcomes during COVID-19 lockdown period (24th March to 14th June 2020) and was compared to non COVID-19 period (24th March to 14th June 2019). A Chi-square test was used to determine the association between the outcome variables. The data was taken as statistically significant when the p-value was <0.05.
 Result: A total of 4,157pregnant women visited antenatal clinic (ANC) during nationwide COVID-19 lock down period while 7,029 patients visited during same period a y back (non COVID-19 period) which is a 40.86 percentage decline. There was significant reduction in deliveries during COVID-19 lock down period (1604 during non COVID-19 and 1140 deliveries during COVID-19 lockdown period respectively) but mode of delivery was similar. Maternal complications like postpartum hemorrhage (PPH), intensive care stay (ICU), sepsis and cesarean hysterectomy were similar during both the period.
 There was a significant reduction in preterm deliveries during COVID-19 lock down period (13 during non COVID-19and 8.7 percentage during COVID-19 period respectively). However, early neonatal sepsis (EONS) was significantly higher during COVID-19 lock down period.
 Conclusion: While, there was a significant reduction in preterm births and increase in early neonatal sepsis during COVID-19 lockdown period, there was no difference in maternal outcome.

Increase in preterm stillbirths in association with reduction in iatrogenic preterm births during COVID-19 lockdown in Australia: a multicenter cohort study

BackgroundThe COVID-19 pandemic has been associated with a worsening of perinatal outcomes in many regions around the world. Melbourne, Australia, had one of the longest and most stringent lockdowns worldwide in 2020 while recording only rare instances of COVID-19 infection in pregnant women.ObjectiveThis study aimed to compare the stillbirth and preterm birth rates in women who were exposed or unexposed to lockdown restrictions during pregnancy.Study DesignThis was a retrospective, multicenter cohort study of perinatal outcomes in Melbourne before and during the COVID-19 lockdown. The lockdown period was defined as the period from March 23, 2020 to March 14, 2021. Routinely-collected maternity data on singleton pregnancies ≥24 weeks gestation without congenital anomalies were obtained from all the 12 public hospitals in Melbourne. We defined the lockdown-exposed cohort as those women for whom weeks 20 to 40 of gestation occurred during the lockdown and the unexposed control group as women from the corresponding calendar periods 12 and 24 months before. The main outcome measures were stillbirth, preterm birth, fetal growth restriction (birthweight < third centile), and iatrogenic preterm birth for fetal compromise. We performed multivariable logistic regression analysis to compare the odds of stillbirth, preterm birth, fetal growth restriction, and iatrogenic preterm birth for fetal compromise, adjusting for multiple covariates.ResultsThere were 24,817 births in the exposed group and 50,017 births in the control group. There was a significantly higher risk of preterm stillbirth in the exposed group than the control group (0.26% vs 0.18%; adjusted odds ratio, 1.49; 95% confidence interval, 1.08–2.05; P=.015). There was also a significant reduction in the preterm birth of live infants <37 weeks (5.68% vs 6.07%; adjusted odds ratio, 0.93; 95% confidence interval, 0.87–0.99; P=.02), which was largely mediated by a significant reduction in iatrogenic preterm birth (3.01% vs 3.27%; adjusted odds ratio, 0.91; 95% confidence interval, 0.83–0.99; P=.03), including iatrogenic preterm birth for fetal compromise (1.25% vs 1.51%; adjusted odds ratio, 0.82; 95% confidence interval, 0.71–0.93; P=.003). There were also significant reductions in special care nursery admissions during lockdown (11.53% vs 12.51%; adjusted odds ratio, 0.90; 95% confidence interval, 0.86–0.95; P<.0001). There was a trend to fewer spontaneous preterm births <37 weeks in the exposed group of a similar magnitude to that reported in other countries (2.69% vs 2.82%; adjusted odds ratio, 0.95; 95% confidence interval, 0.87–1.05; P=.32).ConclusionLockdown restrictions in Melbourne, Australia were associated with a significant reduction in iatrogenic preterm birth for fetal compromise and a significant increase in preterm stillbirths. This raises concerns that pandemic conditions in 2020 may have led to a failure to identify and appropriately care for pregnant women at an increased risk of antepartum stillbirth. Further research is required to understand the relationship between these 2 findings and to inform our ongoing responses to the pandemic.

Widespread implementation of a low-cost telehealth service in the delivery of antenatal care during the COVID-19 pandemic: an interrupted time-series analysis

BackgroundLittle evidence is available on the use of telehealth for antenatal care. In response to the COVID-19 pandemic, we developed and implemented a new antenatal care schedule integrating telehealth across all models of pregnancy care. To inform this clinical initiative, we aimed to assess the effectiveness and safety of telehealth in antenatal care.MethodsWe analysed routinely collected health data on all women giving birth at Monash Health, a large health service in Victoria (Australia), using an interrupted time-series design. We assessed the impact of telehealth integration into antenatal care from March 23, 2020, across low-risk and high-risk care models. Allowing a 1-month implementation period from March 23, 2020, we compared the first 3 months of telehealth integrated care delivered between April 20 and July 26, 2020, with conventional care delivered between Jan 1, 2018, and March 22, 2020. The primary outcomes were detection and outcomes of fetal growth restriction, pre-eclampsia, and gestational diabetes. Secondary outcomes were stillbirth, neonatal intensive care unit admission, and preterm birth (birth before 37 weeks' gestation).FindingsBetween Jan 1, 2018, and March 22, 2020, 20 031 women gave birth at Monash Health during the conventional care period and 2292 women gave birth during the telehealth integrated care period. Of 20 154 antenatal consultations provided in the integrated care period, 10 731 (53%) were delivered via telehealth. Overall, compared with the conventional care period, no significant differences were identified in the integrated care period with regard to the number of babies with fetal growth restriction (birthweight below the 3rd percentile; 2% in the integrated care period vs 2% in the conventional care period, p=0·72, for low-risk care models; 5% in the integrated care period vs 5% in the conventional care period, p=0·50 for high-risk care models), number of stillbirths (1% vs 1%, p=0·79; 2% vs 2%, p=0·70), or pregnancies complicated by pre-eclampsia (3% vs 3%, p=0·70; 9% vs 7%, p=0·15), or gestational diabetes (22% vs 22%, p=0·89; 30% vs 26%, p=0·06). Interrupted time-series analysis showed a significant reduction in preterm birth among women in high-risk models (–0·68% change in incidence per week [95% CI −1·37 to −0·002]; p=0·049), but no significant differences were identified in other outcome measures for low-risk or high-risk care models after telehealth integration compared with conventional care.InterpretationTelehealth integrated antenatal care enabled the reduction of in-person consultations by 50% without compromising pregnancy outcomes. This care model can help to minimise in-person interactions during the COVID-19 pandemic, but should also be considered in post-pandemic health-care models.FundingNone.

The elements of success in a comprehensive state-wide program to safely reduce the rate of preterm birth.

In 2014, a whole-of-population and multi-faceted preterm birth prevention program was introduced in Western Australia with the single aim of safely lowering the rate of preterm birth. The program included new clinical guidelines, print and social media, and a dedicated new clinic. In the first full calendar year the rate of preterm birth fell by 7.6% and the reduction extended from the 28-31 week gestational age group upwards. The objective of this study was to evaluate outcomes in greater depth and to also include the first three years of the program. This was a prospective population-based cohort study of perinatal outcomes in singleton pregnancies before and after commencement of the program. There was a significant reduction in preterm birth in the tertiary center which extended from 28 weeks gestation onwards and was ongoing. In non-tertiary centers there was an initial reduction, but this was not sustained past the first year. The greatest reduction was observed in pregnancies classified at first attendance as low risk. No benefit was observed in the private sector, but a significant reduction was seen in the remote region of the Kimberley where the program was first launched and vaginal progesterone had been made free-of-charge. Preterm birth rates can be safely reduced by a multi-faceted and whole-of-population program but the effectiveness requires continuing effort and will be greatest where the strategies are most targeted.

Invited Commentary: The Power of Preterm Birth to Motivate a Cleaner Environment.

This commentary reflects on a natural experiment reported by Casey et al. (Am J Epidemiol. 2018;187(8):1586-1594) that tested the association between living near a coal or oil power plant and preterm birth. They found that retiring power plants resulted in a significant reduction in preterm birth, with larger effects observed for late preterm birth and among non-Hispanic black mothers and infants. Natural experiments, in particular the Utah Valley Steel Mill closure, have played a prominent role in the evidence base for air pollution regulation due to their demonstrated impact on cardiopulmonary effects in adults. Reproductive health, including infant mortality and preterm birth associated with poor air quality, has generally received less attention. Even small reductions in preterm birth can have a large population health impact, both in terms of preventing mortality in the short-term an in preventing lifelong disability among affected infants.

Inhibition of gingipains prevents Porphyromonas gingivalis-induced preterm birth and fetal death in pregnant mice

Accumulating epidemiological evidence indicates that infection with Porphyromonas gingivalis which is a major periodontal pathogen, causes preterm birth and low birth weight. However, virulence factors of P. gingivalis responsible for preterm birth/low birth weight remain to be elucidated. In this study, using P. gingivalis-infected pregnant mice as an in vivo model, we investigated whether gingipains—cysteine proteinases produced by P. gingivalis—affect preterm birth and low birth weight. We found that intravenous infection of pregnant mice with P. gingivalis induced higher accumulation of the bacterium in the placenta than that in other organs. Compared to infection with P. gingivalis wild-type, infection with a gingipain-deficient P. gingivalis mutant KDP136 led to significant reduction in preterm birth and pregnancy loss. Although repetitive low-level infections of P. gingivalis failed to induce preterm birth and fetal death, it induced suppressive effects on IFN-γ production. Therapeutically, treatment with ginginpain inhibitors prevented fetal death and preterm birth caused by P. gingivalis infection and resulted in recovery of IFN-γ suppression caused by repetitive chronic P. gingivalis infection. These results indicate that gingipains are major virulence factors of P. gingivalis responsible for preterm birth/low birth, and gingipain inhibitors may be useful not only as a therapeutic agent for periodontal diseases, but also as a preventive medicine for preterm birth/low birth weight.

Association Between Maternal Multivitamin Use and Preterm Birth in 24 States, Pregnancy Risk Assessment Monitoring System, 2009-2010.

Objectives The study objective was to examine the prevalence of maternal multivitamin use and associations with preterm birth (<37weeks gestation) in the United States. We additionally examined whether associations differed by race/ethnicity. Methods Using the Pregnancy Risk Assessment Monitoring System, we analyzed 2009-2010 data among women aged ≥18years with a singleton live birth who completed questions on multivitamin use 1month prior to pregnancy (24 states; n=57,348) or in the last 3months of pregnancy (3 states, n=5095). Results In the month prior to pregnancy, multivitamin use ≥4 times/week continued to remain low (36.8%). In the last 3months of pregnancy, 79.6% of women reported using multivitamins ≥4 times/week. Adjusting for confounders, multivitamin use 1-3 times/week or ≥4 times/week prior to pregnancy was not associated with preterm birth overall. Though there was no evidence of dose response, any multivitamin use in the last 3months of pregnancy was associated with a significant reduction in preterm birth among non-Hispanic black women. Conclusions for Practice Multivitamin use during pregnancy may help reduce preterm birth, particularly among populations with the highest burden, though further investigations are warranted.

Progesteron za preprečevanje prezgodnjega poroda

Background: Progesterone is important in maintaining pregnancy. Progesterone supplementation may reduce risk of preterm birth in certain populations of pregnant women. The objective of this review was to develop evidence-based clinical recommendation for progesterone treatment in the prevention of preterm birth.Methods: A search in the Medline database was performed using keywords: progesterone, pregnancy, preterm birth, preterm labour, preterm delivery, randomized trial, and randomized controlled trial. We only included studies of vaginal progesterone treatments for the prevention of preterm birth and excluded studies on 17-α-hydroksiprogesterone caproate.Results: We report findings from twelve randomized trials conducted since 2003. These trials differ regarding inclusion criteria, progesterone dose, vehicle used, and duration of treatment. Inclusion criteria were: short uterine cervix (two trials), history of previous preterm birth (two trials), signs and symptoms of preterm labour (three trials), twin pregnancies (three trials), and multiple risk factors (among these history of previous preterm birth was the most common) (two trials). Six of these twelve trials showed a significant reduction in preterm birth in the progesterone groups.Conclusions: Based on current evidence we recommend treatment with 200 mg of micronized progesterone daily, administered vaginally, in pregnant women found to have a short cervix (≤ 25 mm) at 19-24 weeks. The treatment should be continued until 37 weeks.

Routine Use of an Antenatal Infection Screen-and-Treat Program to Prevent Preterm Birth: Long-Term Experience at a Tertiary Referral Center.

Vaginal infection in early pregnancy is associated with preterm birth. This study evaluates long-term results after integrating an antenatal screen-and-treat program for asymptomatic vaginal infections into routine pregnancy care. We retrospectively analyzed data of all women with singleton high-risk pregnancies delivering at our tertiary referral center between 2005 and 2014. The intervention group included women who presented for a prenatal visit for a planned birth between 10+0 and 16+0 gestational weeks. Women were routinely screened for asymptomatic infections using Gram stain. In cases of bacterial vaginosis, candidiasis or trichomoniasis, women were treated according to our clinical protocol. The control group included women who did not undergo the program. Prenatal care was equal in both groups. Preterm birth served as the primary outcome variable. Of the 20,052 women with singleton pregnancies, 8,490 (42.3%) participated in the antenatal prevention program. The mean gestational age at birth was 38.8±2.6weeks and 37.5±4.3weeks in the intervention and control groups, respectively (p<0.001). The incidence of preterm birth was significantly lower in the intervention group than in the control group (9.7% vs 22.3%; p<0.001). Low-birthweight neonates, stillbirths, and late miscarriages were less frequent in the intervention group (p<0.001). Long-term results support the use of an antenatal infection screen-and-treat program to prevent preterm birth. If integrated into routine pregnancy care at a high-risk obstetrical setting, this simple public health intervention could lead to a significant reduction in preterm birth, low infant birthweight, and adverse pregnancy outcomes.

Effect of Smoke-Free Legislation on Perinatal and Child Health

Smoking kills approximately 5.7 million people each year. Although smoke-free legislation and tobacco controls are keys to reducing this death toll, most studies on their effectiveness have involved only adults. Children are known to be especially vulnerable to the adverse effects of second-hand smoke, which has been linked to many adverse outcomes during early life and the development of noncommunicable diseases in later life. This review was conducted to evaluate the effect of smoke-free legislation on perinatal and child health. The search included online databases for studies published from January 1975 to May 2013. Eligible studies investigated the association between introduction of a smoking ban in work or public places and one or more prespecified health outcomes in children. The study included children 12 years or younger to minimize potential confounding by self-smoking but accepted ages up to 20 years if most of the population met the original age criterion. Primary outcomes were preterm birth, low birth weight, and asthma. Secondary outcomes included various perinatal mortality indicators. Parental or maternal smoking was defined as the main confounder for which adjustment was recorded. Of 9228 screened titles, 20 potentially eligible studies were found and 11, reported between 2008 and 2013, were included in the analysis. Four studies described the effect on pediatric asthma; all others reported on perinatal outcomes. Three of 5 studies reported a significant reduction in preterm births after introduction of smoke-free legislation. Meta-analysis of 4 studies showed that smoke-free legislation was associated with a clinically important and statistically significant drop in preterm birth (1,366,862 participants; 10.4%; 95% confidence interval [CI], 18.8 to 2.0) with no later effect on preterm birth rate change over time. One of 6 studies reported a reduction in neonates with low birth weight (<2500 g) after smoke-free legislation. Three of 4 studies reported a significant drop in hospital attendance because of asthma after introduction of legislation. An immediate reduction was reported in 3 studies (225,753 events; 10.1%; 95% CI, 15.2 to 5.0), and an additional nonsignificant trend toward an annual rate decrease was reported in 3 studies (241,846 events; 7.5% per year; 95% CI, 16.0 to 0.9). One study reported a reduction in very preterm birth, and 1 of 2 studies found a significant effect on the rate of neonates with very low birth weight (<1500 g). Two of 3 studies showed a significant step reduction in small for gestational age. These reductions were statistically significant after pooling (1,305,965 participants; step change: 5.3%; 95% CI, 5.4 to 5.2; slope change: 0.6%; 95% CI, 0.604% to 0.596%). In a small study, no effect was noted on birth defects. This study provides evidence supporting the effectiveness of smoke-free legislation to improve perinatal and child health outcomes. Rates of preterm birth and pediatric hospital admissions for asthma were reduced by 10% along with reductions in the risk for being born very small for gestational age. The results support mandates for worldwide implementation of smoke-free legislation to improve population health. Early-life protection from involuntary second-hand smoke exposure has the potential to reduce disease burdens and associated economic losses in society.

Treatment of Thyroid Disorders Before Conception and in Early Pregnancy

Thyroid disorders are associated with pregnancy complications. Universal screening is currently not recommended because of a lack of evidence on the effectiveness of treatment. Women with hyperthyroidism and hypothyroidism evidently require treatment but this is less clear for women with subclinical hypothyroidism and thyroid autoimmunity. Therefore, we conducted a systematic review to provide a comprehensive overview on the available treatment interventions. Relevant studies were identified by searching Medline, EMBASE and Cochrane Controlled Trials Register, published until December 2011. From a total of 7334 primary selected titles, 22 articles were included for the systematic review and 11 were appropriate for meta-analyses. Eight studies reported on hyperthyroidism. Propylthiouracil (PTU) and methimazole reduce the risk for preterm delivery [risk ratio (RR): 0.23, confidence interval (CI): 0.1-0.52], pre-eclampsia (RR: 0.23, CI: 0.06-0.89) and low birthweight (RR: 0.38, CI: 0.22-0.66). The nine studies that reported on clinical hypothyroidism showed that levothyroxine is effective in reducing the risk for miscarriage (RR: 0.19, CI: 0.08-0.39) and preterm delivery (RR: 0.41, CI: 0.24-0.68). For treatment of subclinical hypothyroidism, current evidence is insufficient. The five studies available on thyroid autoimmunity showed a not significant reduction in miscarriage (RR: 0.58, CI: 0.32-1.06), but significant reduction in preterm birth by treatment with levothyoxine (RR: 0.31, CI: 0.11-0.90). For hyperthyroidism, methimazole and PTU are effective in preventing pregnancy complications. For clinical hypothyroidism, treatment with levothyroxine is recommended. For subclinical hypothyroidism and thyroid autoimmunity, evidence is insufficient to recommend treatment with levothyroxine. The overall lack of evidence precludes a recommendation for universal screening and is only justified in a research setting

Effect of Zinc Supplementation on Pregnancy and Infant Outcomes: A Systematic Review

Poor maternal zinc status has been associated with foetal loss, congenital malformations, intra-uterine growth retardation, reduced birth weight, prolonged labour and preterm or post-term deliveries. A meta-analysis completed in 2007 showed that maternal zinc supplementation resulted in a small but significant reduction in preterm birth. The purposes of this analysis are to update that previous review and expand the scope of assessment to include maternal, infant and child health outcomes. Electronic searches were carried out to identify peer-reviewed, randomised controlled trials where daily zinc supplementation was given for at least one trimester of pregnancy. The co-authors applied the study selection criteria, assessed trial quality and abstracted data. A total of 20 independent intervention trials involving more than 11,000 births were identified. The 20 trials took place across five continents between 1977 and 2008. Most studies assessed the zinc effect against a background of other micronutrient supplements, but five were placebo-controlled trials of zinc alone. The provided dose of supplemental zinc ranged from 5 to 50 mg/day. Only the risk of preterm birth reached statistical significance (summary relative risk 0.86 [95% confidence interval 0.75, 0.99]). There was no evidence that supplemental zinc affected any parameter of foetal growth (risk of low birth weight, birth weight, length at birth or head circumference at birth). Six of the 20 trials were graded as high quality. The evidence that maternal zinc supplementation lowers the risk of preterm birth was graded low; evidence for a positive effect on other foetal outcomes was graded as very low. The effect of zinc supplementation on preterm birth, if causal, might reflect a reduction in maternal infection, a primary cause of prematurity. While further study would be needed to explore this possibility in detail, the overall public health benefit of zinc supplementation in pregnancy appears limited.

Treatment of thyroid disorders before conception and in early pregnancy: a systematic review

Thyroid disorders are associated with pregnancy complications. Universal screening is currently not recommended because of a lack of evidence on the effectiveness of treatment. Women with hyperthyroidism and hypothyroidism evidently require treatment but this is less clear for women with subclinical hypothyroidism and thyroid autoimmunity. Therefore, we conducted a systematic review to provide a comprehensive overview on the available treatment interventions. Relevant studies were identified by searching Medline, EMBASE and Cochrane Controlled Trials Register, published until December 2011. From a total of 7334 primary selected titles, 22 articles were included for the systematic review and 11 were appropriate for meta-analyses. Eight studies reported on hyperthyroidism. Propylthiouracil (PTU) and methimazole reduce the risk for preterm delivery [risk ratio (RR): 0.23, confidence interval (CI): 0.1-0.52], pre-eclampsia (RR: 0.23, CI: 0.06-0.89) and low birthweight (RR: 0.38, CI: 0.22-0.66). The nine studies that reported on clinical hypothyroidism showed that levothyroxine is effective in reducing the risk for miscarriage (RR: 0.19, CI: 0.08-0.39) and preterm delivery (RR: 0.41, CI: 0.24-0.68). For treatment of subclinical hypothyroidism, current evidence is insufficient. The five studies available on thyroid autoimmunity showed a not significant reduction in miscarriage (RR: 0.58, CI: 0.32-1.06), but significant reduction in preterm birth by treatment with levothyoxine (RR: 0.31, CI: 0.11-0.90). For hyperthyroidism, methimazole and PTU are effective in preventing pregnancy complications. For clinical hypothyroidism, treatment with levothyroxine is recommended. For subclinical hypothyroidism and thyroid autoimmunity, evidence is insufficient to recommend treatment with levothyroxine. The overall lack of evidence precludes a recommendation for universal screening and is only justified in a research setting.

Cervical Length Measurement for the Prediction of Preterm Birth in Multiple Pregnancies: A Systematic Review and Bivariate Meta-Analysis

Transvaginal sonography of the cervix can identify pregnancies at increased risk for preterm birth in both symptomatic and asymptomatic pregnant women. A previous randomized controlled trial has shown that vaginal progesterone is effective in preventing preterm birth in singleton women with asymptomatic cervical shortening during the second trimester. Randomized trials in women with multiple pregnancies have failed to show a significant reduction in preterm birth after treatment with progesterone. Overdistention of the cervix in previous pregnancies may limit the predictive value of cervical length measurement during the second trimester for preterm birth in multiple pregnancies. The aim of this meta-analysis was to review the predictive value of cervical length assessment for preterm birth in asymptomatic women with multiple pregnancies. The investigators conducted electronic searches of MEDLINE and Embase for published articles to 2009 as well as searches of reference lists of relevant articles not found with the electronic search. Two-by-two tables cross-classifying cervical length and gestational age were constructed from articles to score extracted descriptive data and study characteristics. The meta-analysis used a bivariate regression model analysis to construct summary receiver-operating characteristic (ROC) curves estimating sensitivity and specificity for changes in cervical length. A total of 21 studies involving 2757 women were identified Although there was a large variation in the gestational age, cutoff points of cervical length, and the exact definition of preterm birth, summary ROC curve estimates indicated that progressive shortening of cervical length was a good predictor of preterm birth before 34 weeks of gestation. ROC summary estimates showed sensitivity and specificity of 78% and 66%, respectively, at a cervical length of 35 mm, 41% and 87% at 30 mm, 36% and 94% at 25 mm, and 30% and 94% at 20 mm. These findings show that assessment of second-trimester cervical length in women with multiple pregnancies is a strong predictor of preterm birth.

Reducing the rate of preterm birth through a simple antenatal screen-and-treat programme: a retrospective cohort study

Objective To assess whether a simple screen-and-treat strategy in pregnancy, previously tested in a randomised controlled study, also effectively lowers the rate of preterm delivery under real-life conditions. Study design In a retrospective cohort study, data were enrolled of 2986 women with singleton pregnancies presenting for routine antenatal care between 11 and 24 weeks and registering for delivery. Data of 1273 women in the intervention group were collected between 1 September 2004 and 31 August 2005. The data of 1713 women in the control group had been collected 2 years previously. All women were screened for asymptomatic vaginal infection using Gram stain, differentiating between bacterial vaginosis, vaginal candidiasis, trichomoniasis, or combinations of any of the three. Women with infection received standard treatment and follow-up. Prenatal care was the same for women in the intervention and control groups, the only difference being the absence of screening and treating for vaginal infection in the control group. The primary outcome variable was the rate of preterm delivery at less than 37 weeks. Secondary outcome variables were preterm delivery at less than 37 weeks combined with birth weights ≤2500 g, ≤2000 g, ≤1500 g, or ≤1000 g. Results In the intervention group, the rate of preterm birth was significantly lower than in the control group (8.2% vs. 12.1%, p < 0.0001), as was the number of preterm infants with birth weights of 2500 g or below. Also, a significant difference between groups was found for very preterm deliveries, i.e., those occurring before 33 weeks (1.9% vs. 5.4%, p < 0.0001). Conclusion Integration of a simple screen-and-treatment programme for common vaginal infections into routine antenatal care led to a significant reduction in preterm births in a general population of pregnant women.

Effectiveness of Cerclage According to Severity of Cervical Length Shortening: A Meta-Analysis

A finding of a short cervical length (CL) during the second trimester on transvaginal ultrasound predicts preterm birth. Previous data from a meta-analysis and a large trial have shown that cerclage prevents preterm birth in singleton women with a previous preterm birth, once a short cervix has been detected on ultrasound imaging. Because the CL at which cerclage was performed varied between ≤15 mm and <25 mm in these studies, it is unclear whether the efficacy of ultrasound-indicated cerclage depends on the degree of cervical shortening. Some investigators have suggested that cerclage may not be very effective for the very short (<6 mm) or mildly shortened (15-24 mm) cervix. The present study estimated the effectiveness of cerclage in women with different degrees of CL shortening. The data were obtained from a meta-analysis of 4 randomized trials evaluating the use of cerclage in singleton women with a CL <25 mm on second-trimester transvaginal ultrasound imaging. A total of 208 women who had a previous preterm birth and 344 who had no such history were randomized to cerclage or no cerclage. The efficacy of ultrasound-indicated cerclage in preventing the primary outcome of preterm birth <35 weeks was evaluated in women with different degrees of cervical shortening. In women with both a previous preterm birth and CL <25 mm, cerclage resulted in a significant reduction in preterm birth <35 weeks; the relative risk was 0.61, with a 95% confidence interval of 0.40 to 0.92. Cerclage also resulted in a significant reduction in preterm birth <37 weeks for CL ≤5.9 mm, ≤15.9 mm, 16 to 24.9 mm, and <25 mm. For women without a previous preterm birth, cerclage did not decrease the risk of preterm birth for any CL. These findings suggest that ultrasound-indicated cerclage has similar effectiveness for reducing preterm birth among singleton women with a previous preterm birth and CL <25 mm, regardless of the degree of CL shortening.

Effectiveness of cerclage according to severity of cervical length shortening: a meta‐analysis

To estimate the effectiveness of cerclage according to degree of cervical length (CL) shortening. A meta-analysis was carried out of trials of women with singleton gestations and second-trimester transvaginal sonographic CL < 25 mm randomized to cerclage or no cerclage. The degree of CL shortening was correlated to the efficacy of cerclage in preventing preterm birth. There was a significant reduction in preterm birth < 35 weeks in the cerclage compared with no cerclage groups in 208 singleton gestations with both a previous preterm birth and CL < 25 mm (relative risk, 0.61; 95% CI, 0.40-0.92). In these women, preterm birth < 37 weeks was significantly reduced with cerclage for CL < or = 5.9 mm, < or = 15.9 mm, 16-24.9 mm and < 25 mm. None of the analyses for 344 women without a previous preterm birth was significant. Cerclage, when performed in women with a singleton gestation, previous preterm birth and cervical length < 25 mm, seems to have a similar effect regardless of the degree of cervical shortening, including CL 16-24 mm, as well as CL < or = 5.9 mm.