Management of a woman with a previous preterm birth

Reducing the impact of preterm birth is one of the challenges in modern obstetric practice. This article provides a case-based discussion of management of women with a previous preterm birth. Estimating the risk of a subsequent preterm delivery can be improved by assessment of obstetric history. Primary preventative strategies include lifestyle advice and modification of pre-pregnancy risk factors. Antenatal care involves increased monitoring and supportive care. The usefulness of screening for preterm birth using cervical length ultrasound or biochemical tests of cervicovaginal secretions lie mainly in their negative predictive value, allowing recognition of women in whom subsequent preterm birth is unlikely. Potential prophylactic therapies in high-risk women include marine oils, progesterone pessaries and cervical cerclage, but none have been shown to improve neonatal outcome. The need for further research is highlighted.     

Management of a woman with a previous spontaneous preterm birth

Preterm birth is an important cause of neonatal morbidity and mortality and has long term adverse health consequences. Worldwide, close to 15 million babies are born preterm each year, and there is no sign that the rate of preterm birth is slowing. A history of a previous spontaneous preterm birth is a significant risk factor for a subsequent spontaneous preterm birth; identifying these women provides an opportunity to optimise care in future pregnancies. Antenatal identification of women at the highest risk of preterm birth is challenging, as tests that accurately identify asymptomatic women who go on to deliver preterm are lacking. Furthermore, the short- and long-term benefits of interventions such as cerclage and progesterone remain unclear. Research is underway to develop biomarkers that can accurately predict women who will deliver preterm. However, without effective strategies that diminish rates of preterm birth and improve perinatal outcomes, the clinical role of these tests is less well defined.     

Management of women with a previous preterm birth

Preterm birth (PTB) is the principal cause of perinatal morbidity and mortality of non-anomalous fetuses. It poses major health economic burdens on families and society. Extreme PTB is associated with a high risk of long-term ill-health and disability. Although advances in neonatal care and use of antenatal corticosteroids have improved the survival of preterm babies over the last two decades, the incidence of PTB and its long-term sequelae remain relatively unchanged. Recent strategies for identifying women at risk of PTB include ultrasound assessment of the cervix and the detection of fetal fibronectin on genital swabbing. Progestogen therapy in women at risk may prolong gestation and improve neonatal outcomes, but the optimal regimen and the women most suitable for this therapy remain to be clarified. Further work is required to identify screening methods with high positive predictive values, and to formulate effective therapies that substantially prolong gestation and minimise the proportion of extremely premature births.     

Preconceptional antibiotic treatment to prevent preterm birth in women with a previous preterm delivery

This article addresses the question of whether the uterine cavity is normally sterile and reviews the difficulties in conducting microbiologic studies of the endometrium, the limitations of conventional microbiologic techniques (cultivation-dependent), and the potential contribution of molecular microbiology to examine microbial diversity and burden of the endometrium. Issues pertaining to the diagnosis of chronic endometritis and the need for information about the prognostic value of this finding in subsequent pregnancies are discussed. The results of a randomized clinical trial of antibiotic administration versus placebo in women with a previous preterm birth are reviewed and commentary is provided. The emerging picture is that microbial-host interactions in the endometrial cavity are important for reproductive success. This is a US government work. There are no restrictions on its use.     

The impact of interpregnancy interval and previous preterm birth on the subsequent risk of preterm birth

OBJECTIVE: To examine the impact of the interpregnancy interval and a previous preterm birth on the subsequent risk of a preterm birth. METHODS: A retrospective analysis was conducted on a group of 4072 women who had at least two consecutive births, excluding multiple gestation, fetal anomalies, cervical incompetence, and stillbirth. Multivariate logistic regression was used to investigate the association between interpregnancy interval, preterm birth of the first child in the pair (index pregnancy), and the risk of a preterm birth of the second child in the pair (outcome pregnancy). RESULTS: Women with interpregnancy intervals of less than 12 months (odds ratio [OR] 1.3; 95% confidence interval [CI] 1.0-1.7) were at increased risks of preterm birth with the outcome pregnancy. Furthermore, there was an increased risk for a subsequent preterm birth in women who had a preterm birth in the index pregnancy (OR 4.2; 95% CI 3.0-6.0). The risk decreased as the interpregnancy interval increased, with a relatively low risk at 18 to 48 months; subsequently, it increased sharply. In contrast, women who had delivered their previous infants at term carried an increased risk of preterm birth with the outcome pregnancy only if the interval was less than 6 months. CONCLUSION: A difference was found in the impact of the interpregnancy interval on the subsequent risk of preterm birth between women with a prior preterm birth and those who previously delivered an infant at term.     

Weight gain and spontaneous preterm birth: the role of race or ethnicity and previous preterm birth

OBJECTIVE: To study how the relationship between gestational weight gain and spontaneous preterm birth interacts with maternal race or ethnicity and previous preterm birth status. METHODS: This was a retrospective cohort study of singleton births to women of normal or low prepregnancy body mass index. Gestational weight gain was measured as total weight gain divided by weeks of gestation at delivery, and weight gain was categorized as low (less than 0.27 kg/wk,), normal (0.27-0.52 kg/wk), or high (more than 0.52 kg/wk). Univariable and multivariable analyses were performed on the relationship between weight gain categories and spontaneous preterm birth, stratified by maternal race or ethnicity and history of previous preterm birth. RESULTS: Overall, low weight gain was associated with spontaneous preterm birth (adjusted odds ratio [AOR] 2.5, 95% confidence interval [CI] 2.0-3.1). Although low gain was consistently associated with increased spontaneous preterm birth, some differences were found in subgroup analysis. Among African Americans with a previous preterm birth, both low and high weight gain were associated with increased odds of spontaneous preterm birth (AOR for low weight gain 4.3, 95% CI 1.2-15.5; AOR for high weight gain 6.1, 95% CI 1.8-20.2). For all other groups, high weight gain was not associated with spontaneous preterm birth. Among Asians with a previous preterm birth, low weight gain was not statistically significantly associated with spontaneous preterm birth (AOR 1.9, 95% CI 0.5-7.7). Among Asians there was also a non-statistically significant inverse relationship between high weight gain and spontaneous preterm birth (AOR 0.5, 95% CI 0.3-1.1). CONCLUSION: These results confirm an association between low maternal weight gain and spontaneous preterm birth. The effect modification of maternal race or ethnicity and history of previous preterm birth on this association deserves further study. LEVEL OF EVIDENCE: II-2.     

Late preterm birth and previous cesarean section: a population-based cohort study

Background: Late preterm birth (LPB) is increasingly common and associated with higher morbidity and mortality than term birth. Yet, little is known about the influence of previous cesarean section (PCS) and the occurrence of LPB in subsequent pregnancies. We aim to evaluate this association along with the potential mediation by cesarean sections in the current pregnancy.

Methods: We use population-based birth registry data (2005–2012) to establish a cohort of live born singleton infants born between 34 and 41 gestational weeks to multiparous mothers. PCS was the primary exposure, LPB (34–36 weeks) was the primary outcome, and an unplanned or emergency cesarean section in the current pregnancy was the potential mediator. Associations were quantified using propensity weighted multivariable Poisson regression, and mediating associations were explored using the Baron-Kenny approach.

Results: The cohort included 481,531 births, 21,893 (4.5%) were LPB, and 119,983 (24.9%) were predated by at least one PCS. Among mothers with at least one PCS, 6307 (5.26%) were LPB. There was increased risk of LPB among women with at least one PCS (adjusted Relative Risk (aRR): 1.20 (95%CI [1.16, 1.23]). Unplanned or emergency cesarean section in the current pregnancy was identified as a strong mediator to this relationship (mediation ratio?=?97%).

Conclusions: PCS was associated with higher risk of LPB in subsequent pregnancies. This may be due to an increased risk of subsequent unplanned or emergency preterm cesarean sections. Efforts to minimize index cesarean sections may reduce the risk of LPB in subsequent pregnancies.     

Fatal amnioinfusion with previous choriocarcinoma in a parturient woman

The case of 36-year-old tercipare is described who developed choriocharcinoma in a previous pregnancy. During the first term labour the patient developed cardiac arrest, so reanimation and sectio cesarea was performed. A male new-born was delivered in good condition, but even after intensive therapy and reanimation occurred death of parturient woman with picture of disseminate intravascular coagulopathia (DIK). On autopsy and on histology there was no sign of malignant disease, so it was not possible to connect previous choricarcinoma with amniotic fluid embolism. Maybe was place of choriocarcinoma "locus minoris resistentiae" which later resulted with failure in placentation what was hard to prove. On autopsy we found embolia of lung with a microthrombosis of terminal circulation with punctiformis bleeding in mucous, what stands for DIK.     

Successful water birth in a woman with vaginismus

Vaginismus is a common sexual dysfunction. The case of a successful water birth in a woman with vaginismus is presented. Water birth should be considered as an alternative method of birth in women with vaginismus.     

Management of pregnancy at increased risk of preterm birth

The Department of Health's ‘Safer Maternity Care’ report extended the ‘Maternity 4 Safety Ambition’ to include reducing preterm births from 8% to 6%. This new element focuses on three areas of intervention to improve outcomes; prediction and prevention of preterm birth, and better preparation when preterm birth is unavoidable. This article describes how the preterm birth prevention clinic operates at the University Hospitals of Leicester, and uses a variety of clinical scenarios to illustrate this.     

Management of pregnancies with a previous cesarean

The cesarean rate in France has reached 21% in 2010. With a maintained fertility rate, management of a pregnant woman with a previous caesarean scar is becoming a daily situation for most obstetrical teams. Considering the small rate of vaginal birth after cesarean (VBAC), we will try to establish an up-to-date review of the benefits and risks of encouraging trial of VBAC. This information can help professionals provide adequate counselling women or couples.     

Recurrence of preterm birth in twin pregnancies in the presence of a prior singleton preterm birth

Objective.?Despite the ubiquity of electronic fetal monitoring, the validity of the relationship between various fetal heart rate (FHR) patterns and fetal acidemia has not yet been established in a large unselected series of consecutive pregnancies. The aim of this study was to examine the published literature for evidence of such a relationship.

Methods.?Four hypotheses based on assumptions in common clinical use were examined. The literature was searched for relationships between certain aspects of FHR patterns (e.g., degree of FHR variability, depth of decelerations), and fetal acidemia, or fetal vigor (5-minute Apgar score ≥7). We also attempted to relate duration of these patterns to the degree of acidemia. Using standardized FHR nomenclature we defined patterns based on baseline FHR variability, baseline rate, decelerations, and accelerations.

Results.?The following relationships were observed: (1) Moderate FHR variability was strongly associated (98%) with an umbilical pH >7.15 or newborn vigor (5-minute Apgar score ≥7). (2) Undetectable or minimal FHR variability in the presence of late or variable decelerations was the most consistent predictor of newborn acidemia, though the association was only 23%. (3) There was a positive relationship between the degree of acidemia and the depth of decelerations or bradycardia. (4) Except for sudden profound bradycardia, newborn acidemia with decreasing FHR variability in combination with decelerations develops over a period of time approximating one hour. Most studies identified were observational and uncontrolled (grade III evidence of US Preventive Services Task Force); however, there was general agreement amongst the various studies, strengthening the validity of the observations.

Conclusions.?The validity of the relationship between certain FHR patterns and fetal acidemia and/or vigor, is supported by observations from the literature. In addition four assumptions commonly used in clinical management are supported. These conclusions need to be confirmed by a prospective examination of a large number of consecutive, unselected FHR patterns, and their relationship to newborn acidemia. Pending the completion of such studies, these observations can be used to justify certain aspects of current clinical management, and may assist in standardizing the diversity of opinions regarding FHR pattern management.