A randomized multicenter study to determine the efficacy of activity restriction for preterm labor management in patients testing negative for fetal fibronectin

Impact of Physical Activity Interventions on High-Risk Pregnancies: A Systematic Review and Meta-Analysis

Pregnant women with absolute contraindications may be advised against physical activity throughout pregnancy. In this context, bed rest elevates the short-term risk of neonatal complications, thereby exacerbating negative long-term effects on childhood development. The aim of the current study was to investigate the impact of various physical activity interventions during bed rest or activity restriction in pregnancy on factors such as birth weight, preterm birth, maternal hypertension, gestational age at delivery, and the incidence of cesarean sections. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was designed. The protocol was registered in the International Prospective Registry of Systematic Reviews (PROSPERO) (CRD42022370875). Nine studies, with a total sample of 3173 women, from six countries on four continents were included. There were significant differences in the relationship between bed rest status and birth weight (Z = 2.64; p = 0.008) (MD = 142.57, 95% CI = 36.56, 248.58, I2 = 0%, Pheterogeneity = 0.45) favourable to active groups. No significant differences were found in other analyzed outcomes. Pregnant women who experience this problem must maintain a minimum of daily activity to alleviate these physiological complications and the medical field must understand the consequences of physical inactivity during pregnancy.

Maintenance tocolysis, tocolysis in preterm premature rupture of membranes and in cervical cerclage - a Germany-wide survey on the current practice after dissemination of the German guideline

OBJECTIVES

To investigate the adherence of German perinatal specialist units and those of basic obstetric care to the national guideline we compared data from a nation-wide survey on the practice of maintenance tocolysis, tocolysis in preterm premature rupture of membranes and in the perioperative setting of cervical cerclage, and bedrest during and after tocolysis with recommendations from the current German Guideline 015/025 "Prevention and Treatment of Preterm Birth".

METHODS

632 obstetric clinics in Germany were approached and received a link to an online questionnaire. Data were descriptively analyzed by performing measures of frequency. To compare two or more groups Fisher's exact test was used.

RESULTS

The response rate was 19%; 23 (19.2%) of respondents did not perform maintenance tocolysis, while 97 (80.8%) conducted maintenance tocolysis; 30 (25.0%) of obstetric units performed cervical cerclage without tocolysis and 90 (75.0%) combined cervical cerclage with tocolysis; 11 (9.2%) of respondents did not use tocolytics in patients with preterm premature rupture of membranes, while 109 (90.8%) conducted tocolysis in these patients; 69 (57.5%) of obstetric units did not recommend bed rest during tocolysis, whereas 51 (42.5%) favored bedrest. Perinatal care centers of basic obstetric care recommend bed arrest during tocolysis statistically significant more often to their patients than those of higher perinatal care levels (53.6 vs. 32.8%, p=0.0269).

CONCLUSIONS

The results of our survey are in accordance to others from different countries and reveal considerable discrepancies between evidence-based guideline recommendations and daily clinical practice.

Activity restriction and preterm birth prevention

PURPOSE OF REVIEW

Since the 1900s, activity restriction (AR) has been widely prescribed as a strategy for preventing preterm birth (PTB). Over the past decade, the practice has been called into question as numerous studies have demonstrated that AR does not improve obstetrical and perinatal outcomes but does confer significant physical and psychological risks. The purpose of this review is to offer clinicians a summary of the latest data on the risks, benefits, and efficacy of AR for the prevention of PTB.

RECENT FINDINGS

Both retrospective and prospective studies have demonstrated that AR does not significantly prolong pregnancy including those with multiple gestations, short cervices, ruptured membranes, and increased body mass indexes. Several studies have also shown that physical activity during pregnancy is associated with a higher incidence of vaginal delivery, a lower incidence of gestational diabetes mellitus, and a lower incidence of hypertensive disorders without increasing the risk of adverse neonatal outcomes.

SUMMARY

The culmination of these data led to the Society for Maternal-Fetal Medicines' release of an updated committee recommendation in August of 2020; AR should not be routinely prescribed as a treatment to prevent PTB.

Special Considerations Regarding Antenatal Care and Pregnancy Complications in Dichorionic Twin Pregnancies

Twin pregnancies account for about 3.3% of all deliveries in the United States with the majority of them being dichorionic diamniotic (DCDA). Maternal physiological adaption in twin pregnancies is exaggerated and the rate of almost every maternal and fetal complication is higher when compared to singleton pregnancies. Therefore, twin pregnancies necessitate closer antenatal surveillance by care providers who are familiar with the specific challenges unique to these pregnancies, and there is evidence that following women with twins in a specialized twin clinic can result in improved obstetrical outcomes. The importance of the first antenatal visit in twin pregnancies cannot be over emphasized and should preferably take place early in gestation as it is the optimal period to correctly identify the number of fetuses and the type of placentation (chorionicity and amnionicity). This will allow the patients, families, and caregivers to make the appropriate modifications and to tailor an optimal antenatal follow-up plan. This plan should focus on general recommendations such as weight gain and level of activity, education regarding complications specific to twin pregnancies along with the relevant symptoms and indications to seek care, as well as on close maternal and fetal monitoring. In this review, we summarize available evidence and current guidelines regarding antenatal care in DCDA twin pregnancies.

Society for Maternal-Fetal Medicine Consult Series #50: The role of activity restriction in obstetric management: (Replaces Consult Number 33, August 2014)

Despite current recommendations against its use, activity restriction remains a common intervention used to prevent preterm birth in multiple clinical settings. Hypertensive disorders of pregnancy, preterm premature rupture of membranes, multiple gestations, vaginal bleeding, short cervical length, placenta previa, and fetal growth restriction are also common reasons for antepartum hospital admission and frequently lead to a recommendation for activity restriction. However, numerous reports have shown that activity restriction does not prevent adverse obstetrical outcomes but does confer significant physical and psychosocial risks. This consult reviews the current literature on activity restriction and examines the evidence regarding its use in obstetrical management. The recommendations by the Society for Maternal-Fetal Medicine are as follows: (1) we recommend against the routine use of any type of activity restriction in pregnant women at risk of preterm birth based on preterm labor symptoms, arrested preterm labor, or shortened cervix (GRADE 1B); (2) we recommend against the use of routine inpatient hospitalization and activity restriction for the prevention of preterm birth in women with multiple gestations (GRADE 1A); and (3) given the lack of data definitively demonstrating that activity restriction improves perinatal outcome in pregnancies complicated by fetal growth restriction, preterm premature rupture of membranes, or hypertensive diseases of pregnancy, coupled with evidence of adverse effects of activity restriction, we suggest that activity restriction not be prescribed for the treatment of pregnancies complicated by fetal growth restriction, preterm premature rupture of membranes, or hypertensive disease (GRADE 2B).

Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/025, February 2019) - Part 2 with Recommendations on the Tertiary Prevention of Preterm Birth and the Management of Preterm Premature Rupture of Membranes

Aims This is an official guideline of the German Society for Gynecology and Obstetrics (DGGG), the Austrian Society for Gynecology and Obstetrics (ÖGGG) and the Swiss Society for Gynecology and Obstetrics (SGGG). The aim of this guideline is to improve the prediction, prevention and management of preterm birth based on evidence obtained from recently published scientific literature, the experience of the members of the guideline commission and the views of self-help groups. Methods The members of the participating medical societies and organizations developed Recommendations and Statements based on the international literature. The Recommendations and Statements were adopted following a formal consensus process (structured consensus conference with neutral moderation, voting done in writing using the Delphi method to achieve consensus). Recommendations Part 2 of this short version of the guideline presents Statements and Recommendations on the tertiary prevention of preterm birth and the management of preterm premature rupture of membranes.

Fetal fibronectin testing for reducing the risk of preterm birth

BACKGROUND

Fetal fibronectin (FFN) is an extracellular matrix glycoprotein localized at the maternal-fetal interface of the amniotic membranes, between chorion and decidua, where it is concentrated in this area between decidua and trophoblast. In normal conditions, FFN is found at very low levels in cervicovaginal secretions. Levels greater than or equal to 50 ng/mL at or after 22 weeks have been associated with an increased risk of spontaneous preterm birth. In fact, FFN is one of the best predictors of preterm birth in all populations studied so far, and can help in selecting which women are at significant risk for preterm birth. This is an update of a review first published in 2008.

OBJECTIVES

To assess the effectiveness of management based on knowledge of FFN testing results for preventing preterm birth.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register (7 September 2018), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 September 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials of pregnant women screened with FFN for risk of preterm birth. Studies included are based exclusively on knowledge of FFN results versus no such knowledge, and we have excluded studies including women with only positive or only negative FFN results.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We identified 16 trials, of which six were eligible for inclusion. The six included studies randomized 546 women with singleton gestations and threatened preterm labor (PTL) at 23 0/7 to 34 6/7 weeks. A total of 277 women were randomized to knowledge and 269 to no knowledge of FFN. No trials were identified on asymptomatic women or multiple gestations.The risk of bias of included studies was mixed. For selected important outcomes, preterm birth before 37, 34, and 32 weeks, and maternal hospitalization, we graded the quality of the evidence and created a 'Summary of findings' table. For these outcomes, the evidence was graded as mainly low quality due to the imprecision of effect estimates.Management based on knowledge of FFN results may reduce preterm birth before 37 weeks (21.6%) versus controls without such knowledge (29.2%) (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.52 to 1.01; 4 trials; 357 women; low-quality evidence). However, management based on knowledge of FFN results may make little or no difference to preterm birth before 34 (RR 1.09, 95% CI 0.54 to 2.18; 4 trials; 357 women; low-quality evidence) or maternal hospitalization (RR 1.06, 95% CI 0.79 to 1.43; 5 trials; 441 women; low-quality evidence). The evidence for preterm birth before 32 weeks is uncertain because the quality was found to be very low (average RR 0.79, 95% CI 0.16 to 3.96; 4 trials; 357 women; very low-quality evidence).For all other outcomes, for which there were available data (preterm birth less than 28 weeks; gestational age at delivery (weeks); birthweight less than 2500 g; perinatal death; tocolysis; steroids for fetal lung maturity; time to evaluate; respiratory distress syndrome; neonatal intensive care unit (NICU) admission; and NICU days), knowledge of FFN results may make little or no difference to the outcomes.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that management based on knowledge of FFN results may reduce preterm birth before 37 weeks. However, our confidence in this result is limited as the evidence was found to be of low quality. Effects on other substantive outcomes are uncertain due to serious concerns in study design, inconsistency, and imprecision of effect estimates. No trials were identified on asymptomatic women, or multiple gestations.Future studies are needed that include specific populations (e.g. singleton gestations with symptoms of preterm labor), a study group managed with a protocol based on the FFN results, and that report not only maternal but also important perinatal outcomes. Cost-effectiveness analyses are also needed.

Prenatal bed rest in developed and developing regions: a systematic review and meta-analysis

BACKGROUND

Bed rest is prescribed by most maternity health care professionals for high-risk pregnancy complications, but the impact of bed rest at home and in hospital has not been explored. Our aim was to quantify the influence of bed rest on maternal/fetal health outcomes in developed and developing regions.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials. We conducted a structured search through MEDLINE, Embase, CINAHL, Web of Science and the Cochrane Library through Mar. 7, 2019. Trials comparing standard care to standard care plus bed rest after 20 weeks' gestation were assessed. Outcomes included infant birth weight, being small for gestational age, gestational age, premature or very premature birth, perinatal death, admission to the neonatal intensive care unit, preterm rupture of membranes, hypertensive disorders of pregnancy, preeclampsia and gestational diabetes mellitus.

RESULTS

We identified 1191 publications, of which 43 were assessed for eligibility. Sixteen publications reporting on 14 unique studies (2608 women, 3328 infants) were included in the analysis. Overall, maternal/newborn outcomes were similar between women on bed rest and those not on bed rest. In subgroup analyses of developed and developing regions, length of gestation was shorter with bed rest (weighted mean difference -0.77 wk, 95% confidence interval [CI] -1.26 to -0.27, I ² = 0%), and the risk of a very premature birth was increased (risk ratio 2.07, 95% CI 1.15 to 3.73, I ² = 0%) in developed countries.

INTERPRETATION

In developed regions, treatment of complicated pregnancies with more than 1 week of bed rest results in worse newborn outcomes. Additional studies are required to determine whether bed rest or hospital admission improves outcomes in developing regions. PROSPERO Trial registration number: CRD42018099237.

The fetal fibronectin test: 25 years after its development, what is the evidence regarding its clinical utility? A systematic review and meta-analysis

Background: The identification of women at risk for preterm birth should allow interventions which could improve neonatal outcome. Fetal fibronectin, a glycoprotein which acts normally as glue between decidua and amniotic membranes could be a good marker of impending labour when its concentration in cervicovaginal secretions between 22 and 36 weeks of gestation is ≥50 ng/mL. Many authors worldwide have tested this marker with many different methodologies and clinical settings, but conclusions about its clinical use are mixed. It is time for a comprehensive update through a systematic review and meta-analysis.Methods: We searched PubMed, Cochrane Library, and Embase, supplemented by manual search of bibliographies of known primary and review articles, international conference papers, and contact with experts from 1-1990 to 2-2018. We have selected all type of studies involving fetal fibronectin test accuracy for preterm delivery. Two authors independently extracted data about study characteristics and quality from identified publications. Contingency tables were constructed. Reference standards were preterm delivery before 37, 36, 35, 34, and 32 weeks, within 28, 21, 14, or 7 d and within 48 h. Data were pooled to produce summary likelihood ratios for positive and negative tests results.Results: One hundred and ninety-three primary studies were identified allowing analysis of 53 subgroups. In all settings, none of the summary likelihood ratios were >10 or <0.1, thus indicating moderate prediction, particularly in asymptomatic women and in multiple gestations.Conclusions: The fetal fibronectin test should not be used as a screening test for asymptomatic women. For high-risk asymptomatic women, and especially for women with multiple pregnancies, the performance of the fetal fibronectin test was also too low to be clinically relevant. Consensual use as a diagnostic tool for women with suspected preterm labor, the best use policy probably still depends on local contingencies, future cost-effectiveness analysis, and comparison with other more recent available biochemical markers.

Activity restriction and risk of preterm delivery. J Matern Fetal Neonatal Med 2017;31:2136-2140. [PMID: 28573877 DOI: 10.1080/14767058.2017.1337738]

PURPOSE

We sought to determine whether activity restriction (AR) in a cohort of women at high risk for preterm delivery is associated with the risk of preterm delivery.

MATERIALS AND METHODS

This is a secondary analysis of the Maternal-Fetal Medicine Units MFMU's Preterm Prediction Study; a multicenter prospective cohort study designed to identify risk factors of preterm birth (PTB). The study group consisted of women with a singleton gestation that at their first study visit (23-24 weeks) had at least one of the following criteria: patient reported contractions, severe back pain, a cervical length <15 mm, spotting, protruding membranes, or positive fetal fibronectin. Women were assessed for AR at a 27- to 29-week study visit. Associations between AR and preterm delivery (<37 weeks) were examined through logistic regression models before and after adjustment for confounders.

RESULTS

Of the 1086 women that met the inclusion criteria, 16.5% (n = 179) delivered preterm. In this cohort, 9.7% (n = 105) of women were recommended AR, with 37.1% (n = 39) having a PTB. In the group not recommended AR (n = 981), 14.3% (n = 140) delivered preterm.

CONCLUSION

In this cohort of women at high risk for PTB, activity restriction was associated with an increased risk of PTB. The use of AR in this population should be discouraged.

Changing prevalence and the risk factors for antenatal obstetric hospitalizations in Denmark 2003-2012

Purpose

Population-based studies evaluating the use and extent of antenatal obstetric hospitalizations (AOH) are sparse. The objective of the present study was to describe the prevalence, time trend, and risk factors for AOH in Denmark.

Materials and methods

A retrospective national register-based cohort study was conducted that included all pregnancies with delivery after 22 gestational weeks in Denmark from 2003 to 2012. The outcomes were AOH and the diagnoses leading to these hospitalizations. AOH was defined as an antenatal hospitalization for at least 1 day with at least one obstetric International Classification of Diseases-10 diagnosis and admission date more than 3 days before delivery.

Results

The study included 617,906 pregnancies; 48,366 (7.8%) pregnancies were associated with 64,072 AOH before delivery. The percentage of pregnancies with AOH decreased from 8.6% to 7.1%. The median length of stay decreased from 3 to 2 days, and admission for at least 7 days was almost halved. Threatened preterm delivery was the most frequent diagnostic category for AOH. A decline was seen in all diagnostic categories except maternal diseases. Significant risk factors for AOH were multiple pregnancies, low or high maternal age and body mass index, nulliparity, lower educational levels, unemployment or being outside the workforce, single partner status, and smoking. The relative risk of very preterm delivery before gestational age of 34 weeks was higher in pregnancies with AOH compared with pregnancies without AOH (relative risk 15.2; 95% confidence interval: 14.6–15.8).

Conclusion

This study shows a shift toward less use and shorter duration of antenatal hospitalization in Denmark. The most common indication used in pregnancies with AOH was threatened preterm delivery, and more than one-third resulted in very preterm deliveries.

Activity in Pregnancy for Patients with a History of Preterm Birth

Preterm birth remains a leading cause of neonatal morbidity and mortality throughout the world. Numerous risk factors for preterm birth have been identified, including non-Hispanic black race, a variety of social and behavioral factors, infections, and history of a prior preterm delivery. Of these, a history of prior spontaneous preterm birth is one of the strongest risk factors. Traditionally, women with a history of preterm birth or those deemed at high risk for preterm delivery have been placed on bed rest or a reduced activity regimen during their pregnancy. However, there is little evidence to support this recommendation. Recent research has suggested that regular physical activity and exercise during pregnancy is safe and does not increase the risk of preterm delivery. Therefore, physicians should encourage women with a history of preterm birth to exercise throughout pregnancy according to guidelines published by the American College of Obstetricians and Gynecologists as long as they are receiving regular prenatal care and their current health status permits exercise. However, there are no randomized controlled trials evaluating exercise prescription in women with a history of preterm birth, hence additional research is needed in this area.

Recommendations of activity restriction in high-risk pregnancy scenarios: a Danish national survey

AIMS

To describe specific recommendations of activity restriction, place of care, expected beneficial and adverse effects, and recommended antithrombotic prophylaxis in nine clinical scenarios.

METHODS

A national survey. All members of the Danish Society of Obstetrics and Gynaecology and the Danish Association of Midwives were asked to complete a tested, structured questionnaire.

RESULTS

We sent 1815 invitations; the overall response rate was 54%. A majority of clinicians recommended some form of activity restriction in the nine scenarios. The midwives recommended strict or moderate activity restriction more often than obstetricians in five of the nine scenarios, in women with preterm premature rupture of membranes, preterm labour, cervical ripening, total placenta praevia, and intrauterine growth restriction, whereas no differences were found in the remaining scenarios. Compared to the obstetricians, the midwives also reported that they expected the recommendation to be more effective. Most midwives and obstetricians reported that they thought strict activity restriction was associated with severe or moderate adverse effect, and recommended antithrombotic prophylaxis.

CONCLUSIONS

Danish obstetricians and midwives prescribe activity restriction in most high-risk pregnancies. The degree of activity restriction and the presumed effect vary between clinicians. This may reflect different attitudes and lack of guidelines based on clinical studies of a possible benefit of activity restriction.

Bed rest in singleton pregnancies for preventing preterm birth

BACKGROUND

Bed rest in hospital or at home is widely recommended for the prevention of preterm birth. This advice is based on the observation that hard work and hard physical activity during pregnancy could be associated with preterm birth and with the idea that bed rest could reduce uterine activity. However, bed rest may have some adverse effects on other outcomes.

OBJECTIVES

To evaluate the effect of prescription of bed rest in hospital or at home for preventing preterm birth in pregnant women at high risk of preterm birth.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (18 December 2014), the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014, Issue 12), MEDLINE (December 2014), EMBASE (December 2014), LILACS (December 2014), and bibliographies of relevant papers.

SELECTION CRITERIA

Randomized, cluster-randomized and quasi-randomized controlled trials with reported data that assess clinical outcomes in women at high risk of spontaneous preterm birth who were prescribed bed rest in hospital or at home for preventing preterm birth, and their babies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

Two studies met the inclusion criteria. One study was not considered for the meta-analysis, since data combined singleton and multiple pregnancies. No differences in any maternal and perinatal outcomes were reported by the authors. This study was at low risk of selection, performance, detection and attrition bias. Only data from one study were included in the meta-analysis (1266 women). This study was at unclear risk of bias for most domains due to lack of reporting. Four hundred and thirty-two women were prescribed bed rest at home and a total of 834 women received a placebo (412) or no intervention (422). Preterm birth before 37 weeks was similar in both groups (7.9% in the intervention group versus 8.5% in the control group; risk ratio (RR) 0.92, 95% confidence interval (CI) 0.62 to 1.37). No other results were reported for any of the other primary or secondary outcomes.

AUTHORS' CONCLUSIONS

There is no evidence, either supporting or refuting the use of bed rest at home or in hospital, to prevent preterm birth. Although bed rest in hospital or at home is widely used as the first step of treatment, there is no evidence that this practice could be beneficial. Due to the potential adverse effects that bed rest could have on women and their families, and the increased costs for the healthcare system, clinicians should discuss the pros and cons of bed rest to prevent preterm birth. Potential benefits and harms should be discussed with women facing an increased risk of preterm birth. Appropriate research is mandatory. Future trials should evaluate both the effectiveness of bed rest, and the effectiveness of the prescription of bed rest, to prevent preterm birth.

Prevention of preterm birth in modern obstetrics

Spontaneous preterm labor is a complex process characterized by the interplay of multiple different pathways. Prevention of preterm labor and delivery is also complicated. The most effective interventions for prevention of preterm birth (PTB) are progestin prophylaxis and lifestyle modifications, with cerclage placement also playing a role in selected populations. Interventions such as activity modification, home tocometry, and routine antibiotic use have fallen out of favor because of lack of effectiveness and possibility of harm. The solution to the problem of PTB remains elusive, and researchers and clinicians must collaborate to find a cure for preterm labor.

Prevention of periviable birth: bed rest, tocolysis, progesterone, and cerclage

The periviable period is associated with a rapid improvement in both mortality and morbidity with increasing gestational age. Therapies that can prolong gestation have the potential for markedly improving outcome compared to later in pregnancy. The therapies commonly prescribed in order to prolong gestation include bed rest, tocolysis, progesterone, and cerclage. Although these therapies are used to prevent preterm birth throughout gestation, their impact on perinatal outcome during the periviable period remains largely unknown. These therapies are discussed relative to the periviable period exploring available data and possible impact on perinatal outcome. Studies specifically evaluating therapeutic interventions during the periviable period are lacking.

Activity restriction among women with a short cervix

OBJECTIVE

To estimate determinants of and outcomes associated with activity restriction among women with a short cervix.

METHODS

This was a secondary analysis of a randomized trial of 17-α hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression.

RESULTS

Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, P<.001). After controlling for potential confounding factors, preterm birth remained more common among those placed on activity restriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation.

CONCLUSION

Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix.

Lack of evidence for prescription of antepartum bed rest

Antepartum bed-rest treatment is based on assumptions that it is both effective and safe for mother and fetus. However, research indicates, that bed-rest treatment is ineffective for preventing preterm birth and fetal growth restriction, and for increasing gestational age at birth and infant birthweight. Studies of women treated with pregnancy bed-rest identify numerous side effects, including muscle atrophy, bone loss, weight loss, decreased infant birthweight in singleton gestations and gestational age at birth, and psychosocial problems. Studies conducted by aerospace scientists who have used bed rest as a model for the study of weightlessness in space using nonpregnant individuals report similar results. Antepartum bed-rest treatment should be discontinued until evidence of effectiveness is found.

Antepartum bed rest for pregnancy complications: efficacy and safety for preventing preterm birth

Preterm birth is the major maternal-child health issue across developed nations and the leading cause of perinatal mortality and morbidity. Of all deaths of infants <1 year of age in the United States in 2005, 68.6% occurred in infants born prior to term. Although the preterm birth rate in European countries is 5-7%, the U.S. preterm birth rate is 12.7%, representing an increase of 9% since 2000. Antepartum bed rest/activity restriction (ABR/AR) has been a mainstay of treatment to prevent preterm birth for the past 30 years prescribed for nearly 1 million women in the United States annually, despite a lack of evidence for its effectiveness. In fact, there is increasing evidence that ABR causes several adverse physiologic and psychological side effects among women and their infants. Unfortunately, these findings have had little impact on clinical practice. This integrative review of literature provides a comprehensive analysis of the evidence for the practice of prescribing ABR and its physiologic, behavioral, and experiential side effects. It also presents a model to guide continuing research about the effects of maternal bed rest as well as evidence supporting the use of home care with bed rest, a different, safe, and feasible model of prenatal care for treating women with pregnancy complications used particularly in other countries. Finally, suggestions to improve the health of high-risk pregnant and postpartum women and their infants are provided.

Maternal activity restriction and the prevention of preterm birth

Activity restriction is 1 of the most common interventions used in obstetrics. Although it is used for many reasons, 1 of the most common is to prevent preterm birth in those at risk. This review of the literature describes the potential advantages, disadvantages, and efficacy of activity restriction for the prevention of preterm birth.

Negative fetal fibronectin: who is still treating for threatened preterm labor and does it help?

OBJECTIVE

Fetal fibronectin (fFN) has a high negative predictive value for delivery in the next seven days in patients at risk for preterm birth. Providers sometimes disregard a negative result and manage the patient for threatened preterm labor. Our objective was to identify the rate at which patients with a negative fFN were managed for threatened preterm labor and if delivery outcomes were improved with such management.

STUDY DESIGN

Retrospective chart review of 111 patients at a single institution evaluated in the obstetrical triage unit for symptoms of threatened preterm labor with negative fFN results over a 19-month period between November 2004 and June 2006. Charts were reviewed for baseline patient characteristics such as gestational age at presentation to triage and fFN testing, prior obstetrical history, cervical examination and contraction frequency. Gestational age at delivery was documented. Rates of admission to the hospital and treatments for threatened preterm labor in this cohort were reviewed.

RESULTS

Thirty-seven of patients (33%) with a negative fFN result were managed for threatened preterm labor (admitted to the hospital, given tocolytics, steroids, or intravenous antibiotics) by their provider. Patients undergoing these interventions were more likely to have cervical dilatation, effacement and were contracting more frequently. Only one of the patients delivered within 7 or 14 days of fFN testing. There was no advantage seen to management of threatened preterm labor in the setting of a negative fFN in terms of pregnancy prolongation, even when analyzing the patients with meaningful clinical findings (dilated 2 cm, effaced >or=80%, or contracting >or=12 times/h).

CONCLUSION

Patients with meaningful clinical findings suspicious for preterm labor are more likely to undergo interventions by their physicians in the face of a negative fFN. This management does not improve length of gestation.

Fetal fibronectin testing for reducing the risk of preterm birth

BACKGROUND

Fetal fibronectin (FFN) is an extracellular matrix glycoprotein localized at the maternal-fetal interface of the amniotic membranes, between chorion and decidua, where it is concentrated in this area between decidua and trophoblast. In normal conditions, FFN is found at very low levels in cervico-vaginal secretions. Levels greater than or equal to 50 ng/mL at or after 22 weeks have been associated with an increased risk of spontaneous preterm birth. In fact, FFN is one of the best predictors of preterm birth in all populations studied so far, and can help selecting which women are at significant risk for preterm birth.

OBJECTIVES

To assess the effectiveness of management based on knowledge of FFN testing results for preventing preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008), MEDLINE (1966 to December 2007) and all references in identified articles.

SELECTION CRITERIA

Randomized controlled trials of pregnant women between the gestational ages of 22 and 34 weeks screened with FFN for risk of preterm birth. Studies included are based exclusively on knowledge of FFN results versus no such knowledge, and we have excluded studies including women with only positive or only negative FFN results.

DATA COLLECTION AND ANALYSIS

All four authors assessed studies for inclusion and quality and extracted data.

MAIN RESULTS

We identified 13 trials, of which five were eligible for inclusion. The five included studies randomized 474 women, of which 235 were randomized to knowledge and 249 to no knowledge of FFN.Preterm birth less than 37 weeks was significantly decreased with management based on knowledge of FFN results (15.6%) versus controls without such knowledge (28.6%; risk ratio 0.54; 95% confidence interval 0.34 to 0.87). All other outcomes for which there were available data (preterm birth at less than 34, 32, or 28 weeks; gestational age at delivery; birthweight less than 2500 grams; perinatal death; maternal hospitalization; tocolysis; steroids for fetal lung maturity; and time to evaluate) were similar in the two groups. No other maternal or neonatal outcome was available for meaningful analysis.

AUTHORS' CONCLUSIONS

Although FFN is commonly used in labor and delivery units to help in the management of women with symptoms of preterm labor, currently there is not sufficient evidence to recommend its use. Since this review found an association between knowledge of FFN results and a lower incidence of preterm birth before 37 weeks, further research should be encouraged.

The Mother's House: a new concept in antepartum care

OBJECTIVE

High-risk antepartum patients often require long and costly hospitalization. The Mother's House facility has been used to house antepartum women on hospital property as an alternative to inpatient management. This study looked at the cost effectiveness of this facility.

STUDY DESIGN

A retrospective chart review on occupants (n = 111) of the Mother's House from 2003-2005 was performed. Admission, discharge, and outcome data were collected. A comparison of the cost of management at the Mother's House with the estimated cost of inpatient management was then performed.

RESULTS

A cost savings of $2.1 million was seen over a 3-year period with the use of the Mother's House. Demographic data show that patients with positive drug screens are more likely to fail Mother's House management.

CONCLUSION

The Mother's House is a cost effective alternative to inpatient management of some antepartum patients. Admission criteria should be modified to exclude patients with positive drug screens.

Bed rest in singleton pregnancies for preventing preterm birth

BACKGROUND

Bed rest in hospital or at home is widely recommended for the prevention of preterm birth. This advice is based on the observation that hard work and hard physical activity during pregnancy could be associated with preterm birth and with the idea that bed rest could reduce uterine activity. However, bed rest may have some adverse effects on other outcomes.

OBJECTIVES

To evaluate the effect of prescription of bed rest in hospital or at home for preventing preterm birth in pregnant women at high risk of preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (July 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (July 2003), LILACS (July 2003), EMBASE (July 2003), POPLINE (July 2003) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials with reported data that assess clinical outcomes in women at high risk of spontaneous preterm birth who were prescribed bed rest in hospital or at home for preventing preterm birth, and their babies.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

One study met the inclusion criteria (1266 women). This trial has uncertain methodological quality due to lack of reporting. Four hundred and thirty-two women were prescribed bed rest at home and a total of 834 women received a placebo (412) or no intervention (422). Preterm birth before 37 weeks was similar in both groups (7.9% in the intervention group versus 8.5% in the control group), and the relative risk was 0.92 with a 95% confidence interval from 0.62 to 1.37. No other results were available.

REVIEWER'S CONCLUSIONS

There is no evidence, either supporting or refuting the use of bed rest at home or in hospital, to prevent preterm birth. Although bed rest in hospital or at home is widely used as the first step of treatment, there is no evidence that this practice could be beneficial. Due to the potential adverse effects that bed rest could have on women and their families, and the increased costs for the healthcare system, clinicians should not routinely advise women to rest in bed to prevent preterm birth. Potential benefits and harms should be discussed with women facing an increased risk of preterm birth. Appropriate research is mandatory. Future trials should evaluate both the effectiveness of bed rest, and the effectiveness of the prescription of bed rest, to prevent preterm birth.