Adjuvant 17-hydroxyprogesterone caproate in women withultrasound-indicated cerclage: a systematic review and meta-analysis

Prediction and prevention of preterm birth in pregnant women living with HIV on antiretroviral therapy

INTRODUCTION

The rate of spontaneous preterm-birth among pregnant women living with HIV on antiretroviral therapy (ART) is 3- to 4-fold higher when compared to HIV-negative women. The pathophysiology of preterm-birth related to HIV or ART remains unknown, especially as women living with HIV are often excluded from preterm birth studies.

AREAS COVERED

This review discusses the currently available evidence on the prediction and prevention of preterm-birth in pregnant women living with HIV. A review of the literature was conducted of primary articles between 2005 and 2021 measuring the association or lack thereof between combination ART and preterm birth, as well as of other predisposing factors to preterm birth in women living with HIV, including cervical length, vaginal microbiome, and cervico-vaginal biomarkers.

EXPERT OPINION

Further research into the effect of ART exposure on preterm-birth risk is critical, and development of preterm-birth predictive tools in this population should be a priority. Vaginal progesterone supplementation deserves further investigation as a therapeutic option to prevent recurrent preterm birth in pregnant women living with HIV. The ProSPAR study, a multicenter randomized controlled trial studying progesterone supplementation in pregnant women on protease inhibitor-based regimens, has been designed but is not yet recruiting patients.

"Does the use of gestation-specific centiles for cervical length change the management of pregnancies at risk of recurrent spontaneous preterm birth?"

INTRODUCTION

Preterm birth is the leading cause of neonatal morbidity and mortality. Spontaneous Preterm Birth (sPTB) has many and varied causes but is known to be strongly associated with a short or shortening cervix in the midtrimester of pregnancy. The strongest risk factor for sPTB is a previous sPTB. In women with a history of sPTB, we can offer surveillance and treatments which have been proven to reduce the risk of sPTB, such as cervical cerclage and vaginal progesterone supplementation. Alongside other indications, we currently use 25 mm or shorter as a "trigger threshold" for offering cervical cerclage treatment in the Preterm Birth Prevention Clinic at The National Maternity Hospital.

AIM

To determine if using gestation-specific centiles instead of a 25 mm cut-off for cervical length changes the antenatal management of women at high risk of sPTB.

METHOD

This was a retrospective chart review of all women attending the preterm birth clinic over the 2-year period 2018-2020 in a large tertiary referral unit in Dublin, Ireland. Demographic details, obstetric history, preterm birth risk factors and preventative treatments offered were collected and analysed. Cervical lengths were measured with ultrasound using a standardised protocol and all performed or supervised by 2 experienced sonographers.

RESULTS

A total of 200 patients with known risk factors for sPTB attended the Preterm Birth Surveillance Clinic at the National Maternity Hospital during the study period. Of these, 36/200 (18%) went on to deliver again prior to 37 weeks despite attending the clinic +/- receiving interventions & this group are the focus of this paper. The indications for surveillance in this group that had a recurrent sPTB included recurrent second-trimester pregnancy losses/preterm delivery < 34 weeks (26/36 (72%)), cervical trauma (including treatment of CIN) (12/36 (33%)), congenital abnormalities (1/36 (2.8%)), uterine anomaly (1/36 (2.8%)) and placental bleeding (1/36 (2.8%)). There was one smoker in this series. Funnelling was observed in 3/36 cases (8.3%). Of the 36 patients, an additional 15 would have received a cerclage had gestation-specific centiles, i.e., <5th centile, been used and an additional 10/36 (28%) would have been offered progesterone therapy.

CONCLUSION

In those at high risk of preterm birth, the use of gestation-specific centiles for cervical length increases the proportion of patients that would be eligible for cervical cerclage. It is unclear whether this would change clinical outcome.

Severe ischaemic gangrene of scalp in an extreme preterm: a fatal case of combined aetiology

A 24+5-week preterm neonate with a severe scalp lesion was admitted to the neonatal intensive care unit (NICU) after caesarean section due to maternal chorioamnionitis (MC). An Arabin pessary had been inserted in addition to a previous cervical cerclage due to cervix insufficiency at 21+5 weeks of pregnancy (wp). At 23+5 wp, preterm rupture of membranes was evidenced. Both devices were kept to provide fetal viability. On 24+4 wp, she developed MC. Urgent caesarean section was performed. Transvaginal manual manipulation was required during the procedure. On NICU, she presented severe shock which required high-dose vasopressors and blood products. Following surgical repair, a bilateral grade IV intracranial haemorrhage was evidenced. Subsequently, it was agreed to withdraw life support. We hypothesise that MC and local infection could have acted as predisposing factors, with the presence of a pessary in the setting causing uterine contractions and its manipulation acting as a precipitating factor.

Cervical stitch (cerclage) in combination with other treatments for preventing spontaneous preterm birth in singleton pregnancies

BACKGROUND

Preterm birth (PTB) remains the foremost global cause of perinatal morbidity and mortality. Thus, the prevention of spontaneous PTB still remains of critical importance. In an attempt to prevent PTB in singleton pregnancies, cervical cerclage, in combination with other treatments, has been advocated. This is because, cervical cerclage is an intervention that is commonly recommended in women with a short cervix at high risk of preterm birth but, despite this, many women still deliver prematurely, as the biological mechanism is incompletely understood. Additionally, previous Cochrane Reviews have been published on the effectiveness of cervical cerclage in singleton and multiple pregnancies, however, none has evaluated the effectiveness of using cervical cerclage in combination with other treatments.

OBJECTIVES

To assess whether antibiotics administration, vaginal pessary, reinforcing or second cerclage placement, tocolytic, progesterone, or other interventions at the time of cervical cerclage placement prolong singleton gestation in women at high risk of pregnancy loss based on prior history and/or ultrasound finding of 'short cervix' and/or physical examination. History-indicated cerclage is defined as a cerclage placed usually between 12 and 15 weeks gestation based solely on poor prior obstetrical history, e.g. multiple second trimester losses due to painless dilatation. Ultrasound-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation for transvaginal ultrasound cervical length < 20 mm in a woman without cervical dilatation. Physical exam-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation because of cervical dilatation of one or more centimetres detected on physical (manual) examination.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (26 September 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included published, unpublished or ongoing randomised controlled trial (RCTs). Studies using a cluster-RCT design were also eligible for inclusion in this review but none were identified. We excluded quasi-RCTs (e.g. those randomised by date of birth or hospital number) and studies using a cross-over design. We also excluded studies that specified addition of the combination therapy after cervical cerclage because the woman subsequently became symptomatic. We included studies comparing cervical cerclage in combination with one, two or more interventions with cervical cerclage alone in singleton pregnancies.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts of all retrieved articles, selected studies for inclusion, extracted data, assessed risk of bias, and evaluated the certainty of the evidence for this review's main outcomes. Data were checked for accuracy. Standard Cochrane review methods were used throughout.

MAIN RESULTS

We identified two studies (involving a total of 73 women) comparing cervical cerclage alone to a different comparator. We also identified three ongoing studies (one investigating vaginal progesterone after cerclage, and two investigating cerclage plus pessary). One study (20 women), conducted in the UK, comparing cervical cerclage in combination with a tocolytic (salbutamol) with cervical cerclage alone in women with singleton pregnancy did not provide any useable data for this review. The other study (involving 53 women, with data from 50 women) took place in the USA and compared cervical cerclage in combination with a tocolytic (indomethacin) and antibiotics (cefazolin or clindamycin) versus cervical cerclage alone - this study did provide useable data for this review (and the study authors also provided additional data on request) but meta-analyses were not possible. This study was generally at a low risk of bias, apart from issues relating to blinding. We downgraded the certainty of evidence for serious risk of bias and imprecision (few participants, few events and wide 95% confidence intervals). Cervical cerclage in combination with an antibiotic and tocolytic versus cervical cerclage alone (one study, 50 women/babies) We are unclear about the effect of cervical cerclage in combination with antibiotics and a tocolytic compared with cervical cerclage alone on the risk of serious neonatal morbidity (RR 0.62, 95% CI 0.31 to 1.24; very low-certainty evidence); perinatal loss (data for miscarriage and stillbirth only - data not available for neonatal death) (RR 0.46, 95% CI 0.13 to 1.64; very low-certainty evidence) or preterm birth < 34 completed weeks of pregnancy (RR 0.78, 95% CI 0.44 to 1.40; very low-certainty evidence). There were no stillbirths (intrauterine death at 24 or more weeks). The trial authors did not report on the numbers of babies discharged home healthy (without obvious pathology) or on the risk of neonatal death.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to evaluate the effect of combining a tocolytic (indomethacin) and antibiotics (cefazolin/clindamycin) with cervical cerclage compared with cervical cerclage alone for preventing spontaneous PTB in women with singleton pregnancies. Future studies should recruit sufficient numbers of women to provide meaningful results and should measure neonatal death and numbers of babies discharged home healthy, as well as other important outcomes listed in this review. We did not identify any studies looking at other treatments in combination with cervical cerclage. Future research needs to focus on the role of other interventions such as vaginal support pessary, reinforcing or second cervical cerclage placement, 17-alpha-hydroxyprogesterone caproate or dydrogesterone or vaginal micronised progesterone, omega-3 long chain polyunsaturated fatty acid supplementation and bed rest.