The management of preterm labour

Nanomedicine strategies to improve therapeutic agents for the prevention and treatment of preterm birth and future directions

The World Health Organisation (WHO) estimates 15 million babies worldwide are born preterm each year, with 1 million infant mortalities and long-term morbidity in survivors. Whilst the past 40 years have provided some understanding in the causes of preterm birth, along with development of a range of therapeutic options, notably prophylactic use of progesterone or uterine contraction suppressants (tocolytics), the number of preterm births continues to rise. Existing therapeutics used to control uterine contractions are restricted in their clinical use due to pharmacological drawbacks such as poor potency, transfer of drugs to the fetus across the placenta and maternal side effects from activity in other maternal systems. This review focuses on addressing the urgent need for the development of alternative therapeutic systems with improved efficacy and safety for the treatment of preterm birth. We discuss the application of nanomedicine as a viable opportunity to engineer pre-existing tocolytic agents and progestogens into nanoformulations, to improve their efficacy and address current drawbacks to their use. We review different nanomedicines including liposomes, lipid-based carriers, polymers and nanosuspensions highlighting where possible, where these technologies have already been exploited e.g. liposomes, and their significance in improving the properties of pre-existing therapeutic agents within the field of obstetrics. We also highlight where active pharmaceutical agents (APIs) with tocolytic properties have been used for other clinical indications and how these could inform the design of future therapeutics or be repurposed to diversify their application such as for use in preterm birth. Finally we outline and discuss the future challenges.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Effectiveness and Safety of Isoxsuprine Hydrochloride as Tocolytic Agent in Arresting Active/Threatened Preterm Labor and Its Role in Maintenance Tocolysis: A Prospective, Open-Label Study

OBJECTIVE

The aim of the study is to obtain insights on the short and long-term safety and effectiveness of isoxsuprine hydrochloride as a tocolytic agent in the management of PTL.

STUDY DESIGN

In this prospective, single-center, noncomparative study, patients (with preterm labor at gestational age of 24-37 weeks) were administered intravenous (IV) infusion of 40-mg isoxsuprine hydrochloride until uterine quiescence, followed by intramuscular (IM) injection of isoxsuprine hydrochloride 10 mg/4-hourly for first 24 hours and maintained with retard 40-mg sustained release capsule (two times a day) till the time of delivery or 37 completed weeks of pregnancy.

RESULTS

All patients (n = 50) achieved successful tocolysis in 24 hours and 48 hours postadministration of isoxsuprine hydrochloride (IV/IM/oral). Mean (±SD) gestation age at the time of delivery was 39.8 ± 2.1 weeks, with latency period of 58.5 ± 18.7 days. Pregnancy outcomes were normal in all the patients and no congenital anomaly/fetal infection was reported. Mean (±SD) fetal birth weight was 2.7 ± 0.3 kg; mean (±SD) Apgar score at 1 and 5 minutes were 7.5 ± 0.6 and 9.2 ± 0.4, respectively. Maternal tachycardia and vomiting (8.0% each) were the commonly reported adverse drug reactions, which were resolved with dose adjustment.

CONCLUSION

Isoxsuprine was found to be an effective and well-tolerated tocolytic agent in arresting PTL, in turn resulting in the overall improvement in maternal and perinatal outcomes.

Risk assessment of preterm birth through identification and stratification of pregnancies using a real-time scoring algorithm

Introduction:

Preterm birth poses a significant challenge. This study evaluated a real-time scoring algorithm to identify and stratify pregnancies to indicate preterm birth.

Methods:

All claims data of pregnant women were reviewed between 1 January 2014 and 31 October 2018 in Kentucky.

Results:

A total of 29,166 unique women who were matched to a live newborn were documented, with the pregnancy identified during the first trimester in 54.1% of women. Negative predictive values, sensitivity, and positive likelihood ratios increased from the first to third trimesters as pregnant women who were matched to a live newborn had more visits with their physicians. The area under the receiving-operating characteristics curve on test data classifying preterm birth was 0.59 for pregnancies identified during the first trimester, 0.62 for pregnancies identified in the second trimester, and 0.73 for pregnancies identified in the third trimester.

Conclusions:

This study presents a real-time scoring algorithm of indicating preterm birth in the first trimester of gestation which permits stratification of pregnancies to provide more efficient early care management.

IRAK1 Is a Critical Mediator of Inflammation-Induced Preterm Birth

Preterm birth (PTB) is a major cause of neonatal mortality and morbidity, often triggered by chorioamnionitis or intrauterine inflammation (IUI) with or without infection. Recently, there has been a strong association of IL-1 with PTB. We hypothesized that IL-1R-associated kinase 1 (IRAK1), a key signaling mediator in the TLR/IL-1 pathway, plays a critical role in PTB. In human fetal membranes (FM) collected immediately after birth from women delivering preterm, p-IRAK1 was significantly increased in all the layers of FM with chorioamnionitis, compared with no-chorioamnionitis subjects. In a preterm rhesus macaque model of IUI given intra-amniotic LPS, induction of p-IRAK1 and downstream proinflammatory signaling mediators were seen in the FM. In a C57BL/6J wild-type PTB mouse model of IUI given intrauterine LPS, an IRAK1 inhibitor significantly decreased PTB and increased live birth in a dose-dependent manner. Furthermore, IRAK1 knockout mice were protected from LPS-induced PTB, which was seen in wild-type controls. Activation of IRAK1 was maintained by K63-mediated ubiquitination in preterm FM of humans with chorioamnionitis and rhesus and mouse IUI models. Mechanistically, IRAK1 induced PTB in the mouse model of IUI by upregulating expression of COX-2. Thus, our data from human, rhesus, and mouse demonstrates a critical role IRAK1 in IUI and inflammation-associated PTB and suggest it as potential therapeutic target in IUI-induced PTB.

Maternal and cord blood prolactin level and pregnancy complications

Objectives

To explore the correlation between maternal and cord blood prolactin, the correlation between cord prolactin and birth weight, and to compare cord blood prolactin in new-borns of women with normal pregnancy and women with pregnancy complications namely; gestational hypertension, gestational diabetes and preterm labour.

Methods

This study was performed from September to December 2018. Thirty-two women, delivered at Baghdad teaching hospital, and their newborns (32) were included. Maternal blood (5 ml) was taken before labour and cord blood (5 ml) was collected after placenta expulsion. Maternal and cord blood prolactin were analysed using fluorescence immunoassay.

Results

Cord blood prolactin was higher in babies born to hypertensive women (405.28±77.52 ng/ml) than normal pregnancy women (244.80±60.80 ng/ml), P=0.000. Also, cord prolactin in gestational hypertension group was significantly higher than diabetic (P=0.006) and preterm labour (P=0.000) groups. No significant difference was noticed in cord blood prolactin in newborns of diabetic and normal pregnancy women (299.28±37.01, 244.80±60.80 ng/ml respectively, P=0.053). Preterm babies had lower cord prolactin (204.57±22.90 ng/ml) than normal pregnancy babies (244.80±60.80 ng/ml), however the difference was non-significant, P=0.118. Positive correlation was found between cord and maternal prolactin (P=0.000) and between cord prolactin and birth weight (P=0.018).

Conclusion

Cord blood prolactin is high in newborns of hypertensive women, low in preterm neonates. Diabetes has no effect on cord prolactin level.

Uterosacral Nerve Stimulation via Cuff Electrode: A Preliminary Animal Study for Potential Application to Treatment of Preterm Labor

Preterm labor occurs in about 12% of all pregnancies, accounting for at least 75% of neonatal deaths. The neonatal outcomes depend on mainly the gestational age at delivery. The lower the gestational age, the higher the risk of morbidity and mortality. The management of preterm labor involves early detection of high-risk women, prevention and treatment. In this study, the feasibility and stability of implantable cuff electrodes detection and inhibition of uterine contractions for preterm labor treatment were investigated by in-vivo mouse test. In order to check functionality of implanted electrodes, acute in-vivo test at mouse uterosacral ligament was performed by using cuff electrode which stimulate and record nerve activity. As results, the electrical stimulation via a stimulating cuff electrode at mouse uterosacral ligament was properly applied and nerve fiber's signal was recorded via the recording electrode. In addition, the implanted cuff electrodes could obtain stable recording signal to the periodic electrical stimulation for 7 weeks.

Effect of Single Dose Betamethasone Administration in Pregnancy on Maternal and Newborn Parameters

INTRODUCTION

Antenatal corticosteroids play an important role in preventing Respiratory Distress Syndrome (RDS) but benefits related to time between corticosteroid administration and delivery need to be explored.

AIM

To observe the effect of betamethasone administration in pregnant women at risk of preterm delivery and on foetal parameters, in terms of development of RDS.

MATERIALS AND METHODS

It was a prospective observational study on pregnant women at risk of preterm delivery who were administered a single dose 24 mg injection betamethasone. Outcome of 111 newborns of enrolled mothers was observed in terms of respiratory distress, Downe's and Silverman Anderson score, need of NICU admission and ventilation. Paired t-test was used to compare means of maternal parameters before and after betamethasone. Independent sample t-test for comparison of scores for respiratory distress in neonates was used.

RESULTS

There was a significant decrease in maternal haematological parameters like mean Red Blood Cell (RBC) and mean Platelet Count (PC) whereas increase in mean Total leucocyte Count (TC) after betamethasone administration. Out of 111 newborn babies, 71 were born within 24 hours and rest were born after 24 hours of betamethasone administration. Twelve out of 71 newborns who were born within 24 hours of betamethasone administration, developed RDS. Mean Downe's score and mean Silverman Anderson score in neonates born within 24 hours of injection administration were significantly higher than those born after 24 hours.

CONCLUSION

Betamethasone administration affects the haematological parameters in mothers in antenatal period nearing term. A minimum of 24 hours have to elapse between corticosteroid administration and delivery of the preterm for benefits to occur.

Obesity in pregnancy: a novel concept on the roles of adipokines in uterine contractility

Obesity is a global health problem even among pregnant women. Obesity alters quality of labor, such as preterm labor, prolonged labor, and higher oxytocin requirements in pregnant women. The most important factors to play a role in the altered gestational period and serve as drug targets to treat the consequences are female sexual hormones, calcium channels, adrenergic system, oxytocin, and prostaglandins. However, we have limited information about the impact of obesity on the pregnant uterine contractility and gestation time. Adipose tissue, which is the largest endocrine and paracrine organ, especially in obesity, is responsible for the production of adipokines and various cytokines and chemokines, and there are no reliable data available describing the relation between body mass index, glucose intolerance, and adipokines during pregnancy. Recent data suggest that the dysregulation of leptin, adiponectin, and kisspeptin during pregnancy contributes to gestational diabetes mellitus and pre-eclampsia. A preclinical method for obese pregnancy should be developed to clarify the action of adipokines and assess their impact in obesity. The deeper understanding of the adipokines-induced processes in obese pregnancy may be a step closer to the prevention and therapy of preterm delivery or prolonged pregnancy. Gestational weight gain is one of the factors that could influence the prenatal development, birth weight, and adiposity of newborn.

Pregnancy course and outcome in women with hereditary neuromuscular disorders: comparison of obstetric risks in 178 patients

OBJECTIVE

Information about pregnancy and delivery in hereditary neuromuscular disorders (NMD) is limited and largely restricted to small case series and single case reports. Further data of obstetric histories in clinically and genetically defined subgroups are required.

STUDY DESIGN

We reviewed the obstetric histories of 178 patients with myotonic dystrophy type 1 (DM1) and 2 (DM2), Charcot-Marie-Tooth disease (CMT), spinal muscular atrophy (SMA), limb-girdle muscular dystrophy (LGMD), facioscapulohumeral muscular dystrophy (FSHD), and congenital myopathy (CM) by means of questionnaires and medical reports. Patients were recruited in the period 1992-2010 after they had at least completed one pregnancy. A total of 380 pregnancies resulting in 315 children were documented.

RESULTS

Compared to the normal German population, the number of miscarriages and hypertensive diseases in pregnancy was not increased in the cohort. Patients with NMD delivered more frequently by vaginal operations (8.9-18.2%) and by cesarean births with significantly high rates in DM1 (36.7%) and SMA (42.4%). Preterm deliveries were recorded in 30.7% of DM1, 12.6% of DM2, and 29.4% of SMA gestations. Abnormal fetal presentation occurred significantly more frequently in DM1 (34.6%) and LGMD (26.7%) deliveries and was a feature of chairbound patients. Considering a possible influence of pregnancy on the disease course, about half of LGMD, one-third of SMA, and one fifth of CMT patients reported a deterioration of symptoms in pregnancy. Neonatal outcome was favorable in all NMD but DM1, where infantile morbidity and mortality is often but not exclusively related to congenitally affected children.

CONCLUSION

Our data are important for obstetric care and genetic counseling of women with NMD who are contemplating pregnancy.

Hospital Pharmacy Pulse - Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest will be abstracted monthly regarding a broad scope of topics. Suggestions or comments may be addressed to: Jacyntha Sterling, Drug Information Specialist at Saint Francis Hospital, 6161 S Yale Ave., Tulsa, OK 74136 or e-mail: jasterling@saintfrancis.com .