Early preterm delivery due to placenta previa is an independent risk factor for a subsequent spontaneous preterm birth

Maternal and Perinatal Outcomes in Placenta Previa: A Comprehensive Review of Evidence

Placenta previa poses significant risks to maternal and perinatal health, yet its management remains challenging. This comprehensive review synthesizes current evidence on maternal and perinatal outcomes in placenta previa, addressing its epidemiology, pathophysiology, diagnosis, and management strategies. Placenta previa complicates pregnancies, with increasing incidence linked to factors such as advanced maternal age and rising cesarean rates. Maternal complications, including hemorrhage and placenta accreta spectrum disorders, pose substantial risks. At the same time, perinatal outcomes are marked by increased rates of preterm birth, intrauterine growth restriction, and neonatal morbidity and mortality. Timely diagnosis and appropriate management, including antenatal corticosteroids and multidisciplinary care, are critical for optimizing outcomes. Future research should focus on improving diagnostic methods, evaluating novel interventions, and assessing long-term neurodevelopmental outcomes. This review underscores the importance of informed clinical practice and ongoing research efforts to enhance outcomes for women and infants affected by placenta previa.

Cerclage in complete placenta previa preventing preterm labor: A rare case report

Placenta previa often leads to antepartum hemorrhage, which warrants the patient for emergency room admission. The bleeding occurs mainly due to cervical dilation, which could be caused by cervical incompetence. Cervical cerclage has been considered as the primary treatment for cervical incompetence. However, evidence is lacking for its application in placenta previa. Here, we present a case of a 30-year-old pregnant woman diagnosed with complete placenta previa where a good obstetrical outcome could be achieved. The patient had antepartum hemorrhage during the 21st week of gestational age due to cervical dilation in a complete placenta previa case. An emergency cerclage using McDonald's technique was then performed, which prolonged the pregnancy to the 34th week of gestation. The patient had cesarean section and delivered a healthy baby girl weighing 2190 g. The mother and the baby had an uneventful recovery and were discharged after 2 days of hospitalization.

What more can be done? Prioritizing the most promising antenatal interventions to improve birth weight

BACKGROUND

Low birth weight (LBW) is associated with neonatal mortality and sequelae of lifelong health problems; prioritizing the most promising antenatal interventions may guide resource allocation and improve health outcomes.

OBJECTIVE

We sought to identify the most promising interventions that are not yet included in the policy recommendations of the World Health Organization (WHO) but could complement antenatal care and reduce the prevalence of LBW and related adverse birth outcomes in low- and middle-income settings.

METHODS

We utilized an adapted Child Health and Nutrition Research Initiative (CHNRI) prioritization method.

RESULTS

In addition to procedures already recommended by WHO for the prevention of LBW, we identified six promising antenatal interventions that are not currently recommended by WHO with an indication for LBW prevention, namely: (1) provision of multiple micronutrients; (2) low-dose aspirin; (3) high-dose calcium; (4) prophylactic cervical cerclage; (5) psychosocial support for smoking cessation; and (6) other psychosocial support for targeted populations and settings. We also identified seven interventions for further implementation research and six interventions for efficacy research.

CONCLUSION

These promising interventions, coupled with increasing coverage of currently recommended antenatal care, could accelerate progress toward the global target of a 30% reduction in the number of LBW infants born in 2025 compared to 2006-10.

Spontaneous preterm birth: Involvement of multiple feto-maternal tissues and organ systems, differing mechanisms, and pathways

Survivors of preterm birth struggle with multitudes of disabilities due to improper in utero programming of various tissues and organ systems contributing to adult-onset diseases at a very early stage of their lives. Therefore, the persistent rates of low birth weight (birth weight < 2,500 grams), as well as rates of neonatal and maternal morbidities and mortalities, need to be addressed. Active research throughout the years has provided us with multiple theories regarding the risk factors, initiators, biomarkers, and clinical manifestations of spontaneous preterm birth. Fetal organs, like the placenta and fetal membranes, and maternal tissues and organs, like the decidua, myometrium, and cervix, have all been shown to uniquely respond to specific exogenous or endogenous risk factors. These uniquely contribute to dynamic changes at the molecular and cellular levels to effect preterm labor pathways leading to delivery. Multiple intervention targets in these different tissues and organs have been successfully tested in preclinical trials to reduce the individual impacts on promoting preterm birth. However, these preclinical trial data have not been effectively translated into developing biomarkers of high-risk individuals for an early diagnosis of the disease. This becomes more evident when examining the current global rate of preterm birth, which remains staggeringly high despite years of research. We postulate that studying each tissue and organ in silos, as how the majority of research has been conducted in the past years, is unlikely to address the network interaction between various systems leading to a synchronized activity during either term or preterm labor and delivery. To address current limitations, this review proposes an integrated approach to studying various tissues and organs involved in the maintenance of normal pregnancy, promotion of normal parturition, and more importantly, contributions towards preterm birth. We also stress the need for biological models that allows for concomitant observation and analysis of interactions, rather than focusing on these tissues and organ in silos.

Prediction of iatrogenic preterm birth in patients with scarred uterus: a retrospective cohort study in Northeast China

BACKGROUND

To build a novel and simple model to predict iatrogenic preterm birth in pregnant women with scarred uteri.

METHODS

In this retrospective, observational, single-centre cohort study, data from 2315 patients with scarred uteri were collected. Multiple logistic regression analysis and mathematical modelling were used to develop a risk evaluation tool for iatrogenic preterm birth. After modelling, the calibration and discrimination of the model along with decision curve analysis were checked and performed to ensure clinical applicability.

RESULTS

Among the 2315 patients, 417 (18.0%) had iatrogenic preterm births. The following variables were included in the model: interpregnancy interval (0 to < 12 months, OR 5.33 (95% Cl 1.79-15.91), P = 0.003; 13 to < 24 months (reference), 25 to < 60 months, OR 1.80 (95% CI 0.96-3.40), P = 0.068; ≥ 60 months, OR 1.60 (95% Cl 0.86-2.97), P = 0.14), height (OR 0.95, (95% CI 0.92-0.98), P = 0.003), parity (parity ≤1 (reference), parity = 2, OR 2.92 (95% CI 1.71-4.96), P < 0.0001; parity ≥3, OR 8.26, (95% CI 2.29-29.76), P = 0.001), number of vaginal bleeding (OR 1.81, (95% Cl 1.36-2.41), P < 0.0001), hypertension in pregnancy (OR 9.52 (95% CI 6.46-14.03), P < 0.0001), and placenta previa (OR 4.21, (95% CI 2.85-6.22), P < 0.0001). Finally, a nomogram was developed.

CONCLUSIONS

In this study, we built a model to predict iatrogenic preterm birth for pregnant women with scarred uteri. The nomogram we created can assist doctors in evaluating the risk of iatrogenic preterm birth and help in making referrals; thus, better medical care can be given to improve the prognosis of patients and foetuses.

New model for predicting preterm delivery during the second trimester of pregnancy

In this study, a new model for predicting preterm delivery (PD) was proposed. The primary model was constructed using ten selected variables, as previously defined in seventeen different studies. The ability of the model to predict PD was evaluated using the combined measurement from these variables. Therefore, a prospective investigation was performed by enrolling 130 pregnant patients whose gestational ages varied from 17⁺⁰ to 28⁺⁶ weeks. The patients underwent epidemiological surveys and ultrasonographic measurements of their cervixes, and cervicovaginal fluid and serum were collected during a routine speculum examination performed by the managing gynecologist. The results showed eight significant variables were included in the present analysis, and combination of the positive variables indicated an increased probability of PD in pregnant patients. The accuracy for predicting PD were as follows: one positive – 42.9%; two positives – 75.0%; three positives – 81.8% and four positives – 100.0%. In particular, the combination of ≥2× positives had the best predictive value, with a relatively high sensitivity (82.6%), specificity (88.1%) and accuracy rate (79.2%), and was considered the cut-off point for predicting PD. In conclusion, the new model provides a useful reference for evaluating the risk of PD in clinical cases.

Clinical evaluation of balloon occlusion of the lower abdominal aorta in patients with placenta previa and previous cesarean section: A retrospective study on 43 cases

BACKGROUND

This study investigated the efficacy of balloon occlusion of the lower abdominal aorta in cesarean section surgery for the patients with placenta previa and previous cesarean section.

METHODS

The patients who had placenta previa and underwent cesarean section (CS) were evaluated. The patients treated with CS to terminate the pregnancy were used as control group (23 cases); the patients treated with the preset abdominal aorta balloon before CS was taken as study group (20 cases). The investigated indicators included the intraoperative blood loss, blood loss within postoperative 24 h, the transfusion amount of red cell suspension (RCS), hospital stay, incidence rate of disseminated intravascular coagulation (DIC), the asphyxia, premature delivery and the mortality of the newborns.

RESULTS

The two groups are comparable. The intraoperative blood loss, blood loss within postoperative 24 h, the transfusion amount of RCS and the percentage of uterus resection in the study group were significantly lower (P < 0.05) than that in the control group. The percentage of uterine cavity filling with ribbon gauze in the study group was higher than the control group (P < 0.05).

CONCLUSIONS

The balloon occlusion of lower abdominal aorta seems effective in reducing postpartum hemorrhage and the blood transfusion and decreasing the risk of hysterectomy without harming the newborns.

Placental implantation abnormalities and risk of preterm delivery: a systematic review and metaanalysis

We sought to evaluate the extent of the association between placental implantation abnormalities (PIA) and preterm delivery in singleton gestations. We conducted a systematic review of English-language articles published from 1980 onward using PubMed, MEDLINE, EMBASE, CINAHL, LILACS, and Google Scholar, and by identifying studies cited in the references of published articles. Search terms were PIA defined as ≥ 1 of the following: placenta previa, placenta accreta, vasa previa, and velamentous cord insertion. Observational and experimental studies were included for review if data were available regarding any of the aforementioned PIA and regarding gestational age at delivery or preterm delivery. Case reports and case series were excluded. Studies were reviewed and data extracted. The primary outcome was gestational age at delivery or preterm delivery <37 weeks' gestation. Secondary outcomes included birthweight, 1- and 5-minute Apgar scores, neonatal intensive care unit (NICU) admission, neonatal and perinatal death, and small for gestational age. Of the 1421 studies identified, 79 met the defined criteria; 56 studies were descriptive and 23 were comparative. Based on the descriptive studies, the preterm delivery rates for low-lying/marginal placenta, placenta previa, placenta accreta, vasa previa, and velamentous cord insertion were 26.9%, 43.5%, 57.7%, 81.9%, and 37.5%, respectively. Based on the comparative studies using controls, there was decreased pregnancy duration for every PIA; more specifically, there was an increased risk for preterm delivery in patients with placenta previa (risk ratio [RR], 5.32; 95% confidence interval [CI], 4.39-6.45), vasa previa (RR, 3.36; 95% CI, 2.76-4.09), and velamentous cord insertion (RR, 1.95; 95% CI, 1.67-2.28). Risks of NICU admissions (RR, 4.09; 95% CI, 2.80-5.97), neonatal death (RR, 5.44; 95% CI, 3.03-9.78), and perinatal death (RR, 3.01; 95% CI, 1.41-6.43) were higher with placenta previa. Perinatal risks were also higher in patients with vasa previa (perinatal death rate RR, 4.52; 95% CI, 2.77-7.39) and velamentous cord insertion (NICU admissions [RR, 1.76; 95% CI, 1.68-1.84], small for gestational age [RR, 1.69; 95% CI, 1.56-1.82], and perinatal death [RR, 2.15; 95% CI, 1.84-2.52]). In singleton gestations, there is a strong association between PIA and preterm delivery resulting in significant perinatal morbidity and mortality.