Lower Risk Of Preterm Delivery Research Articles

Maternal occupation during pregnancy, birth weight, and length of gestation: combined analysis of 13 European birth cohorts.

We assessed whether maternal employment during pregnancy - overall and in selected occupational sectors - is associated with birth weight, small for gestational age (SGA), term low birth weight (LBW), length of gestation, and preterm delivery in a population-based birth cohort design. We used data from >200 000 mother-child pairs enrolled in 13 European birth cohorts and compared employed versus non-employed women. Among employees, we defined groups of occupations representing the main sectors of employment for women where potential reproductive hazards are considered to be present. The comparison group comprised all other employed women not included in the occupational sector being assessed. We performed meta-analyses of cohort-specific estimates and explored heterogeneity. Employees had a lower risk of preterm delivery than non-employees [adjusted odds ratio (OR adj) 0.86, 95% confidence interval (95% CI) 0.81-0.91]. Working in most of the occupational sectors studied was not associated with adverse birth outcomes. Being employed as a nurse was associated with lower risk SGA infants (OR adj0.91, 95% CI 0.84-0.99) whereas food industry workers had an increased risk of preterm delivery (OR adj1.50, 95% CI 1.12-2.02). There was little evidence for heterogeneity between cohorts. This study suggests that, overall, employment during pregnancy is associated with a reduction in the risk of preterm birth and that work in certain occupations may affect pregnancy outcomes. This exploratory study provides an important platform on which to base further prospective studies focused on the potential consequences of maternal occupational exposures during pregnancy on child development.

Birth Outcomes of Foreign‐Born, Native‐Born, and Mixed Couples in Sweden

Many births in industrialised countries are to immigrant parents, or to one immigrant and one domestically born parent. Their newborn outcomes have not been well studied. We conducted a study of 1,690,423 singleton infants born in Sweden between 1987 and 2008, including those of immigrants from East Asia, South Asia, Sub-Saharan Africa, and East Africa. Preterm delivery and small for gestational age (SGA) were assessed among infants of (i) immigrant parents from the same world region, (ii) an immigrant mother and a Swedish-born father, and (iii) a Swedish-born mother and an immigrant father; each compared to (iv) two Swedish-born parents. Log binomial regression analysis generated adjusted risk ratios (ARRs) and 95% confidence intervals (CIs) for preterm delivery and SGA. Compared with infants of two Swedish-born parents, infants born to immigrant mothers from East Asia, South Asia, and Sub-Saharan African were at higher risk of preterm delivery (ARR ranging from 1.2 to 1.9), irrespective of whether the father was from the same world region or Swedish-born, with the only exception of East African women, who had lower risk. Infants born to two foreign-born parents had the highest risks of SGA, particularly South Asians (ARR 4.69; 95% CI 4.29, 5.12). Mixed couples exhibited intermediate risks of SGA. Adverse birth outcomes differ according to a couple's ethnic composition. Having a Swedish-born partner is associated with lower risk of SGA among immigrant mothers and fathers, and with lower risk of preterm delivery among immigrant fathers but not mothers.

Maternal dietary patterns and preterm delivery: results from large prospective cohort study

Objective To examine whether an association exists between maternal dietary patterns and risk of preterm delivery. Design Prospective cohort study. Setting Norway, between 2002 and 2008. Participants 66 000 pregnant...

Revisiting the immigrant paradox in reproductive health: The roles of duration of residence and ethnicity

The immigrant paradox refers to the contrasting observations that immigrants usually experience similar or better health outcomes than the native-born population despite socioeconomic disadvantage and barriers to health care use.This paradox, however, has not been examined simultaneously in relation to varying degrees of exposure to the receiving society and across multiple outcomes and risk factors. To advance knowledge on these issues, we analysed data of the Maternity Experiences Survey, a nationally representative cross-sectional survey of 6421 Canadian women who delivered singleton infants in 2006–07. We compared the prevalence of adverse pregnancy outcomes and related risk factors according to women's ethnicity and time since migration to Canada. We calculated prevalences and prevalence ratios (PR) with 95% confidence intervals.Compared to Canadian-born women of European descent, recent immigrants were at lower risk of preterm delivery and morbidity during pregnancy despite having the highest prevalence of low income and low support during pregnancy among all groups, but the paradox was not observed among immigrants with a longer stay in Canada. In contrast, recent immigrants were at higher risk of postpartum depression. Immigrants of non-European origin also had higher prevalence of postpartum depression, irrespective of their length of residence in Canada, but immigrants from European-origin countries did not. Exposure to Canada was also positively associated with higher alcohol and tobacco consumption and body mass index. Canadian-born women of non-European descent were at higher risk of preterm birth and hospitalisation during pregnancy than their European-origin counterparts. Our findings suggest that the healthy migrant hypothesis and the immigrant paradox have limited generalisability. These hypotheses may be better conceptualised as outcome-specific and dependent on immigrants' ethnicity and length of stay in the receiving country.

Fetal Fibronectin Testing in Ontario: Successful Government-Sector Collaboration to Achieve High-Quality and Sustainable System Change

Ontario's province-wide implementation of fetal fibronectin (fFn) technology, a test to identify women unlikely to deliver within two weeks of presentation with symptoms of preterm labour, is a notable example of evidence-informed system improvement and productive government-sector partnership. Increasing demand for costly, high-risk maternal and newborn care in Ontario hospitals prompted a provincial review. Sector experts identified potentially avoidable maternal admissions and transfers to high-risk units for evaluation of suspected preterm labour as an opportunity for system improvement. Limited access to fFn testing was documented, and expert consensus posited that funding rapid clinical testing to identify women at low risk for preterm delivery would yield a significant return on investment. An expert panel recommended evidence-based clinical guidelines. The government swiftly secured funding and initiated a successful implementation strategy, capitalizing on regional perinatal networks. Amassing clinical and care utilization information, framing the data in a policy-relevant context and partnering sector expertise with ministry capability resulted in this technology being effectively implemented in a complex health system.

P17.04: Ultrasonic tissue characterization of the pregnant human cervix

Results: Difference of EI for anterior and posterior wall of the cervix was smaller in the group of patients who delivered at term, than in the group of women who delivered earlier (t-test, P = 0.049). Mean for group of patients with term delivery was 0.00 points of EI, in the group with preterm delivery it was 0.63. No patient with the same EI for anterior and posterior wall delivered before 37 weeks. No correlation of internal os EI and preterm delivery was found. Conclusions: Elastography as a new tool of evaluation of the risk of preterm delivery seems to be very helpful in managing patients with uterine contractions before 37 weeks of gestation. Elastography may stratify the patients to the groups of high and low risk of preterm delivery and manage them accordingly.

Likelihood ratios for the prediction of preterm delivery with biomarkers

To conduct a literature search for selected biomarkers on preterm delivery and estimate their likelihood ratios (LR). Structured review. Low and high-risk populations and women with symptoms of preterm delivery. METHODS. Publications were identified in PubMed. LR on selected biomarkers for preterm delivery. In asymptomatic women with low risk of preterm delivery, the following biomarkers gave major shifts in probability (LR above 5): twins (LR+ 10), Ureaplasma urealyticum in amniotic fluid (LR+ of 10), cervical length <25mm (LR+ 6), salival estriol (LR+ 5) and various combined tests. In asymptomatic women with high risk of preterm delivery, short cervical length (LR+ 11, LR- 0.7), high serum tumor necrosis factor-alpha (LR+ 10, LR- 0.6) gave major shifts in probability. In women with symptoms of preterm delivery, major shifts in probability can be obtained from the following amniotic fluid biomarkers: high matrix metalloproteinase-8 (LR+ 23, LR- 0.6), Ureaplasma urealyticum (LR+ 19, LR- 0.8), high interleukin (IL)-6 (LR+ 9, LR- 0.2), IL-8 (LR+10, LR- 0.2) and tumor necrosis factor-alpha (LR+ 8, LR- 0.4). In serum IL-6 (LR+ 12, LR- 0.2), Cluster of Differentiation 163 (LR+9, LR-0.8) and various combined tests. Vaginal fetal fibronectin (LR+ 3 and LR- 0.5) and short cervical length (LR+ 2, LR- 0.3) gave LRs of some importance (LR below 5). Several biomarkers have been identified for assessment of risk of preterm delivery. Their clinical relevance depends on the efficacy of the interventions which can be offered to these patients.

Community Remoteness, Perinatal Outcomes and Infant Mortality among First Nations in Quebec~!2009-12-02~!2010-04-12~!2010-07-06~!

OBJECTIVE: Little is known about community remoteness in relation to birth outcomes among Indigenous populations. We assessed whether community remoteness matters for perinatal outcomes and infant mortality in Quebec First Nations communities. STUDY DESIGN: A retrospective cohort study of all births (n=11,033) to residents of First Nations communities in Quebec 1991-2000, using linked vital statistics data. First Nations communities were grouped by community remoteness into four zones from the least to most remote. RESULTS: Preterm birth rates declined progressively from the least remote (8.0%) to the most remote (5.7%) zones (p=0.002). In contrast, total fetal and infant mortality rose progressively from the least remote (10.4 per 1000) to the most remote (22.7 per 1000) zones (p<0.001). The excess infant mortality in the more remote zones was mainly due to higher rates of postneonatal mortality. Similar patterns were observed after adjusting for maternal age, education, parity and marital status. Substantially elevated risks in most remote communities remained for perinatal death (adjusted OR=2.1), postneonatal death (adjusted OR=2.7), and total fetal and infant death (adjusted OR=2.3). CONCLUSION: Living in more remote First Nations communities was associated with a substantially higher risk of fetal and infant death, especially postneonatal death, despite a lower risk of preterm delivery. There is a need for more effective perinatal and infant care programs in more remote First Nations communities to reduce perinatal and infant mortality.

Phosphorylated insulin‐like growth factor binding protein‐1 in cervical secretions and sonographic cervical length in the prediction of spontaneous preterm delivery

The aim of this study was to evaluate the efficacy of the test for the decidual phosphorylated isoform of insulin-like growth factor binding protein-1 (phIGFBP-1) in endocervical secretions in predicting preterm delivery in women with uterine contractions. The study included 210 women with a singleton pregnancy with documented uterine contractions and intact membranes at between 24 and 34 weeks' gestation who underwent the cervicovaginal phIGFBP-1 test and transvaginal sonographic measurement of cervical length. A receiver-operating characteristics (ROC) curve was used to determine the most useful cut-off point for cervical length. A multivariate logistic regression model was used in order to analyze the combination of significant predictive variables for preterm delivery following univariate analysis. ROC curves indicated that 26 mm was the optimal cut-off value for cervical length in predicting preterm delivery. A cervical length of < 26 mm and the presence of phIGFBP-1 were statistically significant in univariate logistic regression analyses (P < 0.0001) with odds ratios of 16.18 and 9.29 for preterm delivery, respectively. Multivariate analysis of cervical length and phIGFBP-1 showed that they were independent and therefore useful in combination for predicting preterm delivery. Cervical length and the phIGFBP-1 test are independent variables that can be used together to predict preterm delivery in women with uterine contractions. A sonographically measured cervical length of > 26 mm with a negative phIGFBP-1 test in a patient with regular uterine contractions before 37 weeks' gestation seems to indicate a low risk of preterm delivery and may therefore allow avoidance of unnecessary therapies.

The effects of maternal body mass index on pregnancy outcome

The increasing prevalence of obesity is presenting a critical challenge to healthcare services. We examined the effect of Body Mass Index in early pregnancy on adverse pregnancy outcome. We performed a population register-based cohort study using data from the North Western Perinatal survey (N = 99,403 babies born during 2004-2006), based at The University of Manchester, UK. The main outcome measures were Caesarean section delivery, preterm birth, neonatal death, stillbirth, Macrosomia, small for gestational age and large for gestational age. The risk of preterm birth was reduced by almost 10% in overweight (RR = 0.89, [95% CI: 0.83, 0.95]) and obese women (RR = 0.90, [95% CI: 0.84, 0.97]) and was increased in underweight women (RR = 1.33, [95% CI: 1.16, 1.53]). Overweight (RR = 1.17, [95% CI: 1.09, 1.25]), obese (RR = 1.35, [95% CI: 1.25, 1.45]) and morbidly obese (RR = 1.24, [95% CI: 1.02, 1.52]) women had an elevated risk of post-term birth compared to normal women. The risk of fetal macrosomia and operative delivery increased with BMI such that morbidly obese women were at greatest risk of both (RR of macrosomia = 4.78 [95% CI: 3.86, 5.92] and RR of Caesarean section = 1.66 [95% CI: 1.61, 1.71] and a RR of emergency Caesarean section = 1.59 [95% CI: 1.45, 1.75]). Excessive leanness and obesity are associated with different adverse pregnancy outcomes with major maternal and fetal complications. Overweight and obese women have a higher risk of macrosomia and Caesarean delivery and lower risk of preterm delivery. The mechanism underlying this association is unclear and is worthy of further investigation.

Maternal Smoking, Preeclampsia, and Infant Health Outcomes in New York City, 1995-2003

A number of previous studies have reported an inverse association between maternal smoking and preeclampsia. Additionally, some have suggested that smokers who develop preeclampsia have worse maternal and fetal outcomes than nonsmokers who develop preeclampsia. The authors examined the relation of smoking to preeclampsia among 674,250 singleton pregnancies in New York City between 1995 and 2003. Although smoking was associated with a reduced risk of preeclampsia overall (adjusted odds ratio = 0.88, 95% confidence interval: 0.82, 0.94), no association was found for preeclampsia superimposed on chronic hypertension (adjusted odds ratio = 1.04, 95% confidence interval: 0.90, 1.21). Furthermore, the apparent protection conferred by maternal smoking was restricted to women aged < or =30 years. Contrary to previous reports, the authors found evidence of a negative interaction between smoking and preeclampsia with respect to preterm delivery and birth weight; smokers who developed preeclampsia had a lower risk of preterm delivery, and a lower adjusted mean difference in birth weight, than would have been expected based on the independent effects of smoking and preeclampsia. These data suggest that smoking is only protective against preeclampsia without pre gestational hypertension, and even then principally among younger women. Additionally, smokers who develop these disorders have no increased risk of adverse birth outcomes relative to nonsmokers who develop the same conditions.

Screening for Preterm Labor

Preterm delivery is one of the main causes of perinatal mortality and morbidity and it accounts for 60 to 80% of deaths of infants without congenital anomalies.1 Moreover, preterm neonates are at high risk of developing cerebral palsy, visual and hearing impairment and chronic lung disease, while 40 to 60% of them will need special educational support. The preterm delivery rate varies between 5 to 7% in Europe and 11 to 12% in the United States. Despite the advances in obstetric care and neonatology the rate of preterm delivery was not decreased but in fact increased.2 This is mainly attributed to the increased number of preterm births among multiple gestations, the trend towards iatrogenic premature delivery in conditions such as hypertension or intrauterine growth restriction as well as the more accurate estimation and registration of gestational age. Neonatal survival improves as gestational age progresses. It increases from approximately 50% at 25 weeks’ gestation to over 97% at 33 weeks’ gestation.2 It is therefore, logical as the major benefits from delaying delivery are seen in this period, that greater attention has been focused on early preterm labor, before 32 weeks. Extensive research has been made so far, in methods of predicting preterm delivery in both asymptomatic and symptomatic patients. The absence of reliable criteria for the selection of at risk patients, as well as the absence of effective interventions to prevent prematurity are responsible for the controversial results reported in different studies. During the last few years a clear relationship has been established between decreased cervical length and the risk of spontaneous preterm delivery. Many studies dealing with the ultrasonographic evaluation of the cervix during the course of pregnancy have suggested that cervical changes may detect or exclude the risk of preterm delivery. Unfortunately, the heterogeneity of most of them resulted in mixed performance of this procedure as a screening test. Ultrasound examination of the cervix has been applied mainly in five categories: 1. Women with symptoms of preterm labor 2. Asymptomatic women at high risk of preterm delivery 3. Asymptomatic women at low risk of preterm delivery 4. Women with multiple gestations 5. Pregnancies complicated by preterm premature rupture of membranes (PPROM).

Screening for Bacterial Vaginosis in Pregnancy to Prevent Preterm Delivery: U.S. Preventive Services Task Force Recommendation Statement

Update of the 2001 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for bacterial vaginosis in pregnancy. The USPSTF weighed the benefits and harms of screening for bacterial vaginosis in pregnancy by identifying new evidence addressing previously identified gaps from the 2001 USPSTF recommendation. Published literature on this topic was identified by using MEDLINE, Cochrane Library databases, the Database of Abstracts of Reviews of Effects, reference lists, and consultation with experts and was systematically reviewed. When data allowed, a series of meta-analyses (using new and 2001 report data) was done to estimate the pooled effect of treatment on preterm delivery (<37 weeks, <34 weeks, or <32 weeks) and on low birthweight and preterm, premature rupture of membranes. Do not screen for bacterial vaginosis in pregnant women at low risk for preterm delivery. (D recommendation) Current evidence is insufficient to assess the balance of benefits and harms of screening for bacterial vaginosis in pregnant women at high risk for preterm delivery. (I statement).

Presence of the Sickle Cell Trait and Preterm Delivery in African-American Women

To estimate the association between presence of the sickle cell trait and preterm delivery among African-American women. A retrospective cohort study was conducted to study all deliveries by African-American women at one institution between 1976 and 2001. The primary predictor of interest was the presence of the sickle cell trait, and the primary outcome was preterm delivery. Post hoc analyses were conducted to explore the relationship between presence of sickle cell trait and multiple gestations, an apparent modifier of the relationship between sickle cell trait and preterm delivery. Of the 5,028 African-American women eligible for inclusion, 6.5% carried the sickle cell trait. In adjusted analyses, the presence of sickle cell trait was associated with a lower risk of preterm delivery at less than 32 weeks (adjusted odds ratio 0.15, 95% confidence interval 0.05-0.49), and was found to be associated with an increased odds of multiple gestations (adjusted odds ratio 1.94, 95% confidence interval 1.22-2.09). A significant interaction exists between the presence of multiple gestation and sickle cell trait and the odds of preterm delivery, such that the protective effect of sickle cell trait on preterm delivery risk is greater among those with multiple gestations than those with singletons. Among African-American women, the presence of the sickle cell trait was associated with lower odds of early preterm delivery despite adjustment for potential confounders. An increased odds of multiple gestations was also noted among these women, possibly suggesting a persistence of selection for the hemoglobin S trait in nonmalarial settings. II.

The use of a variable cut‐off value of cervical length in women admitted for preterm labor before and after 32 weeks

To determine whether the optimal cut-off value to predict low risk of preterm delivery in women admitted for preterm labor should be adjusted for gestational age. A cohort of 333 women with singleton pregnancies admitted with preterm labor and intact membranes between 24 and < 36 weeks' gestation was studied. The women were categorized according to prematurity into one of two groups: those admitted at < 32 weeks (Group 1, very preterm) and those admitted at >or= 32 weeks (Group 2, preterm). Transvaginal ultrasound was performed 24-48 h after admission and cervical length measured. The predictive value of different cut-off points was explored. Outcome variables were spontaneous preterm delivery within 7 days of admission and delivery at < 34 weeks. The mean ( +/- SD) gestational ages at admission and delivery were 31.9 ( +/- 2.6) and 37.5 ( +/- 2.2) weeks, respectively, and the mean ( +/- SD) cervical length was 30.4 ( +/- 8.9) mm. The rates of spontaneous delivery within 7 days and at < 34 weeks were 6.3 and 7.0%, respectively. The cut-off value of 15-mm cervical length showed a sensitivity, negative predictive value and false positive rate for delivery within 7 days of 0, 96.5 and 2.7% in the very preterm group, and 35.3, 94.6 and 4% in the preterm group, respectively. For a cut-off point of 25 mm, these values were 75, 99 and 14.3%, and 70.6, 96.8 and 24.5%. The predictive value of different cut-off points of cervical length is similar at different gestational ages. However, the higher false positive rate after 32 weeks' gestation might justify the adoption of gestational-age related cut-off values in clinical protocols. In women admitted at < 32 weeks' gestation, a cut-off point of 25 mm may be used to predict a low risk of preterm delivery, whereas in women admitted at 32 weeks or later, 15 mm might be more appropriate. Published by John Wiley & Sons, Ltd.

Management of Cervical Insufficiency and Bulging Fetal Membranes

To evaluate the efficacy of emergency cerclage in cases with dilated cervix and protruding fetal membranes in a group of women considered at low risk for preterm delivery by their obstetric histories. All cases of cervical dilatation and bulging membranes were detected through a transvaginal ultrasonographic screening for preterm delivery between 18 and 26 weeks during a 6-year study period. Twenty-nine women underwent an emergency cervical cerclage and composed the cerclage group, whereas 17 others refused and formed the bed rest group. All patients were given antibiotics and prophylactic tocolysis. The mean prolongation of pregnancy (8.8 weeks) and the mean birth weight (2,101 g) after cerclage placement differed significantly from those of the bed rest group (3.1 weeks and 739 g, respectively). Twenty-five of the 29 pregnancies in the cerclage group ended in live birth, compared with 7 of the 17 pregnancies in the bed rest group (P = .001) (relative risk [RR] 0.33, 95% confidence interval [CI] 0.11-0.98). Neonatal survival was 96% in the cerclage group and 57.1% in the bed rest group (P = .025) (RR 0.09, 95% CI 0.01-0.76). The preterm delivery rate less than 32 weeks was 31% and 94.1% in the cerclage and the bed rest groups, respectively (P < .001) (RR 0.33, 95% CI 0.19-0.57), whereas the admission to neonatal intensive care unit was 28% and 85.7% in the 2 groups, respectively, (P = .01) (RR 0.33, 95% CI 0.16-0.66). Emergency cervical cerclage can be accomplished safely in women with dilated cervix and bulging membranes. It can reduce preterm delivery before 32 weeks and improve neonatal survival compared with bed rest. II-1.

Preterm Delivery in Boston Before and After September 11th, 2001

We hypothesized that stress induced by the terrorist attacks of September 11, 2001 might shorten pregnancy. To test this hypothesis, we compared gestational duration and risk of preterm delivery among women who were pregnant on September 11 with women who had delivered before that date. We conducted a matched cohort study among pregnant women enrolled in the Boston-based cohort study Project Viva between 1999 and 2001. Each of 606 participants, pregnant on September 11, 2001, was matched to 1 or 2 participants who delivered before that date. Compared with women who delivered before September 11th, women who were pregnant on September 11th had mean gestation length that was 0.13 weeks longer (95% confidence interval = -0.05 to 0.30) and an odds ratio for preterm delivery before 37 weeks' gestation of 0.60 (0.36 to 0.98). Only women exposed in the first trimester had longer gestation. Contrary to expectation, Boston-area women who were pregnant on September 11th had a lower risk of preterm delivery than women who delivered before that date. Although the interpretation of this finding is difficult, it is clear that the acute psychologic stress documented nationwide after the terrorist attacks did not increase the risk of preterm delivery in this population at some distance from the attacks.

A longitudinal follow-up of cervical length during pregnancy

A prospective longitudinal study of cervical length during pregnancy included 60 women. Three groups of patients were analyzed: group I--cervical length was measured in all three trimesters, group II--cervical length was measured in the first and second trimesters, and group III--length was measured in the second and third trimesters. Cervical length was measured in each group individually, with the aim of establishing the trend of change. In the group in which the cervical length was measured in all three timesters, there was either a mild progressive cervical shortening or cervix remained of the same length. The number of examined women is very small, though, so more valid is the information that the trend of mild shortening occurs in the second and third trimesters. None of the trends is particulary explicit and shows that there is a period in an uncomplicated singleton pregnancy of low risk for preterm delivery, during which there is a significant shortening before delivery takes place. During pregnancy there are different, individual modes of cervical changes, which leads to individualization when estimating the risk for preterm delivery. Reference values should be established for cervical length in order to assess risk for preterm delivery, rather than use the "cut-off" value after which the risk is considered higher.

Cost-effectiveness of screening and treatment for bacterial vaginosis in early pregnancy among women at low risk for preterm birth

Background. Bacterial vaginosis (BV) is an important risk factor for preterm birth. BV is detected in 10–30% of pregnant women and is often asymptomatic. Treatment of BV during pregnancy seems to reduce the risk of preterm delivery among high-risk women. We performed a cost-effectiveness analysis of screening and treatment for BV in early pregnancy among asymptomatic women at low risk for preterm delivery. Methods. A decision tree was built with two arms. For the screening (and treatment) arm the probabilities were derived from our earlier randomized trial on screening and treatment for BV, consisting of BV-positive women treated with intravaginal clindamycin cream or placebo and also of BV-negative pregnant women. The probabilities of outcomes among these women were collected from antenatal clinic records and hospital records, and for the no-screening arm mainly from the Finnish Perinatal Statistics. The outcomes considered were preterm delivery, mode of delivery, peripartum infections and postpartum complications. The unit costs associated with these outcomes were mainly based on disease-related groups (DRGs). No-screening was compared with two screening programs (one with clindamycin, the other with metronidazole treatment) and subjected to sensitivity analyses. Results. There was no significant difference between screening and no-screening strategies in the costs and in the rate of preterm deliveries but the screening strategy produced significantly fewer peripartum infections and postpartum complications. Sensitivity analyses suggested that the screening strategy may become cost-saving if the rate of preterm deliveries exceeds 3%. Conclusion. Screening and treatment for BV in early pregnancy may not reduce costs compared to no-screening in a population at low risk for preterm birth but would produce, at the same cost, more health benefits in terms of fewer peripartum infections and postpartum complications. However, it may be cost-saving if the rate of preterm deliveries is higher than 3%.

Cost-effectiveness of screening and treatment for bacterial vaginosis in early pregnancy among women at low risk for preterm birth.

Bacterial vaginosis (BV) is an important risk factor for preterm birth. BV is detected in 10-30% of pregnant women and is often asymptomatic. Treatment of BV during pregnancy seems to reduce the risk of preterm delivery among high-risk women. We performed a cost-effectiveness analysis of screening and treatment for BV in early pregnancy among asymptomatic women at low risk for preterm delivery. A decision tree was built with two arms. For the screening (and treatment) arm the probabilities were derived from our earlier randomized trial on screening and treatment for BV, consisting of BV-positive women treated with intravaginal clindamycin cream or placebo and also of BV-negative pregnant women. The probabilities of outcomes among these women were collected from antenatal clinic records and hospital records, and for the no-screening arm mainly from the Finnish Perinatal Statistics. The outcomes considered were preterm delivery, mode of delivery, peripartum infections and postpartum complications. The unit costs associated with these outcomes were mainly based on disease-related groups (DRGs). No-screening was compared with two screening programs (one with clindamycin, the other with metronidazole treatment) and subjected to sensitivity analyses. There was no significant difference between screening and no-screening strategies in the costs and in the rate of preterm deliveries but the screening strategy produced significantly fewer peripartum infections and postpartum complications. Sensitivity analyses suggested that the screening strategy may become cost-saving if the rate of preterm deliveries exceeds 3%. Screening and treatment for BV in early pregnancy may not reduce costs compared to no-screening in a population at low risk for preterm birth but would produce, at the same cost, more health benefits in terms of fewer peripartum infections and postpartum complications. However, it may be cost-saving if the rate of preterm deliveries is higher than 3%.