The association between induction of labour in nulliparous women at term and subsequent spontaneous preterm birth: a retrospective cohort study

OBJECTIVES

To evaluate the rate of subsequent spontaneous preterm birth in patients with previous induction of labour at term compared to women with previous spontaneous labour at term.

METHODS

This was a retrospective cohort study of all women with consecutive births at the Royal Brisbane and Women's Hospital between 2014 and 2018. All nulliparous women with a singleton pregnancy and induction of labour at term or in spontaneous labour at term in the index pregnancy were included. Data was extracted from electronic medical records. The outcome of spontaneous preterm birth in the subsequent pregnancy was compared between patients with previous term induction of labour and in previous term spontaneous labour.

RESULTS

A total of 907 patients with consecutive births met the inclusion criteria; of which 269 (29.7%) had a term induction of labour and 638 (70.3%) had a term spontaneous labour in the index pregnancy. The overall subsequent spontaneous preterm birth rate was 2.3%. Nulliparous women who underwent term induction of labour were less likely to have a subsequent preterm birth compared to nulliparous women in term spontaneous labour (0.74 vs. 2.98%; odds ratio [OR], 0.25; 95% confidence interval, 0.06-1.07; p=0.0496) in the index pregnancy. This however was not significant once adjusted for confounders (adjusted OR, 0.29; p=0.10). Spontaneous preterm birth was associated with a previous spontaneous labour compared to induction of labour between 37 to 37⁺⁶ and 38 to 38⁺⁶ weeks (adjusted OR 0.18 and 0.21; p=0.02 and 0.004 respectively).

CONCLUSIONS

Term induction of labour does not increase the risk of subsequent spontaneous preterm birth compared to spontaneous labour at term in nulliparous women. Further research is needed to validate these findings in a larger cohort of women and to evaluate the effect of elective IOL among low-risk nulliparous women.

Does the length of second stage of labour or second stage caesarean section in nulliparous women increase the risk of preterm birth in subsequent pregnancies?

OBJECTIVES

This study aimed to investigate the role of prolonged second stage of labour and second stage caesarean section on the risk of spontaneous preterm birth (sPTB) in a subsequent pregnancy.

METHODS

This was a retrospective cohort study of nulliparous women with two consecutive singleton deliveries between 2014 and 2017 at a tertiary centre. In the vaginal delivery cohort, subsequent pregnancy outcomes for women with a prolonged second stage (>2 h) were compared with those with a normal second stage (≤2 h). In the caesarean delivery cohort, women with a first stage or a second stage were compared with the vaginal delivery cohort. The primary outcome was subsequent sPTB.

RESULTS

A total of 821 women met inclusion criteria, of which 74.8% (614/821) delivered vaginally and 25.2% (207/821) delivered by caesarean section. There was no association between a prolonged second stage in the index pregnancy and subsequent sPTB (aOR 0.70, 95% CI 0.13-3.83, p=0.7). The risk of subsequent sPTB was threefold for those with a second stage caesarean section; however this did not reach statistical significance.

CONCLUSIONS

A prolonged second stage of labour in the index pregnancy is not associated with an increased risk of subsequent sPTB. A second stage caesarean section in the index pregnancy may be associated with an increased risk of subsequent sPTB, however there was no statistically significant difference. These findings are important for counseling and suggest that the effects of these factors are not clinically significant to justify additional interventions in the subsequent pregnancy.

Sleep quality and endometriosis: A group comparison study

Introduction:

Endometriosis affects around 10% of women of reproductive age with symptoms of pelvic pain, dysmenorrhoea, dyspareunia, dyschezia, and infertility. Current research highlights a possible relationship between endometriosis and poor sleep quality. The aim of this study was to assess the relationship between sleep quality and endometriosis. Outcomes measured included sleep quality and quality of life and pain score.

Methods:

Thirty women with a histological diagnosis of endometriosis and 30 control patients completed an online questionnaire that assessed sleep quality (Pittsburgh Sleep Quality Index) and quality of life (WHO-QOL-BREF). Pain scores within the endometriosis group were evaluated using a visual analogue scale.

Results:

Women with endometriosis had significantly poorer sleep quality (80% vs 50%, p = 0.015) and lower quality of life scores when compared to the control group. Within the endometriosis group, there were trends between poor sleep, a reduced quality of life, and higher pain scores; however, these did not reach statistical significance.

Discussion:

Sleep quality and quality of life were significantly reduced in women with endometriosis when compared to controls.

The role of the endocannabinoid system in aetiopathogenesis of endometriosis: A potential therapeutic target

Endometriosis affects a large proportion of women during their reproductive years and is associated with pain and infertility, also affecting psychological wellbeing and quality of life. The pathogenesis of the disease remains unclear, although it is believed to be multifactorial. The endocannabinoid system (ECS) consists of a number of ligands, receptors and enzymes, and has gained interests in endometriosis research. This review aims to summarise all available evidence reporting the roles of the ECS in endometriosis. A literature search of the PubMed, EMBASE, and Web of Science electronic medical databases was performed. Original and review articles published in peer-reviewed journals were included. No publication date or publication status restrictions were imposed. Significant differences in the concentrations and expressions of the components of the ECS were reported in the eutopic and ectopic endometrium, and the systemic circulation of women with endometriosis compared to controls. Endometriosis appears to be associated with downregulation of CB1 receptors and upregulation of TRPV1 receptors. The role of CB1 and progesterone in anti-inflammatory action and the role of TRPV1 in inflammation and pain are of particular interests. Furthermore, the ECS has been reported to be involved in processes relevant to endometriosis, including cell migration, cell proliferation, apoptosis, inflammation, and interacts with sex steroid hormones. The ECS may play a role in disease establishment, progression, and pain in endometriosis. However, reports are based on studies of limited size and there are inconsistencies among the definition of their control groups. There are also conflicting reports regarding precise involvement of the ECS in endometriosis. Future research with larger numbers, strict inclusion and exclusion criteria and detailed clinical information is imperative.

The risk of preterm delivery and pregnancy outcomes in women with asymptomatic short cervix: a retrospective cohort study

OBJECTIVE

Routine cervical length measurement in asymptomatic pregnant women to prevent preterm birth has not been universally adopted due to poor predictive accuracy. The purpose of our study was to evaluate the risk of preterm delivery and pregnancy outcomes in women with asymptomatic short cervix and examine the implications of gestational age at presentation on these outcomes.

STUDY DESIGN

This was a retrospective cohort study of women with singleton pregnancies who presented prior to or at 32 + 0 weeks with an asymptomatic short cervix (≤25 mm) between April 2014 to March 2018 at a single tertiary maternity center. Women with cervical length ≤25 mm were grouped into four cohorts according to gestational age at presentation: Obstetric outcomes were compared between the cohorts and the general cohort of women delivering during the same period. Outcomes were compared using Mann-Whitney U, chi-square tests, and logistic regression. Survival analysis was carried out to compare the probability of delivery for each subgroup.

RESULTS

The rate of spontaneous preterm birth <37 weeks was highest in the cohort presenting at 25 + 0-27 + 6 weeks, and lowest in the first cohort presenting at <22 + 0 (60.0 versus 22.2%, p < .05). When compared with the general cohort, the rate of spontaneous preterm birth at <37-week gestation was significantly higher in the asymptomatic short cervix cohort (40.4 versus 8.7%, p < .001), with a 7.1-fold increase in the relative risk of spontaneous PTB.

CONCLUSIONS

In asymptomatic women, cervical shortening showed significant increase in the risk of preterm birth. Our study findings suggest that routine cervical screening may be helpful in predicting risk of preterm birth even in women who are considered low-risk for preterm birth.

Laparoscopic Surgery for Ovarian Pregnancy using Diathermy Hook with Conservation of Ovary: A Case Report and Literature Review

A 31-year-old woman presented with a 7-week history of irregular vaginal bleeding without abdominal pain. She had been using the intrauterine contraceptive device (IUD) for the last 3 years. A pregnancy test was positive and subsequent serum beta human chorionic gonadotropin (β-HCG) was 4992 mIU/mL. A transvaginal ultrasound scan demonstrated an empty uterus with an associated adnexal mass but no free fluid. A right primary ovarian ectopic pregnancy was diagnosed a laparoscopy. This was managed laparoscopically using monopolar diathermy hook with conservation of the ovary and minimal blood loss. Ovarian pregnancy is rare, especially in women without the classical risk factors for tubal pregnancy, and efforts should be made to exclude ectopic pregnancy in the absence of abdominal pain in a woman of reproductive age presenting with prolonged and irregular vaginal bleeding. Methods to conserve the ovary are also encouraged in cases of ovarian pregnancy.

Impact of reference gene selection for type 2 cannabinoid receptor gene expression studies in human spermatozoa

Quantitative real-time polymerase chain reaction (qRT-PCR) has been employed to study the gene expression profiles in human spermatozoa, but accurate analysis is dependent upon normalisation of data against an endogenous control. β-Actin (ACTB) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are the most commonly used reference genes for normalisation of gene expression in human spermatozoa, but the expression of these genes in many tissues has considerable variation under different physiological, pathological and experimental conditions which limits their effectiveness in normalisation. The expression stability of a panel of 12 reference genes was studied in normal and pathological human spermatozoa using geNorm and NormFinder software. Although there were some discrepancies in the ranking of reference gene stability, each software program ranked B2 M, ACTB, CYC1 and 18S RNA within the top 5 and recommended the combined use of at least two reference genes. Normalisation of qRT-PCR data for the cannabinoid receptor type 2 in spermatozoa using the different housekeeping genes demonstrated how, without validation, conflicting results are obtained. We recommend that the arbitrary use of reference genes should be avoided and the validation of reference gene stability should be undertaken prior to every study. For normalisation of CB2 expression, we would recommend using the geometric mean of B2 M and ACTB.

Smoking induces differential miRNA expression in human spermatozoa: a potential transgenerational epigenetic concern?

Recent work has suggested that environmental chemicals, including those contained in cigarette smoke, can have adverse effects on the exposed individuals as well as their future progeny. The mechanisms underlying transmission of environmentally induced phenotypes through the germ line are not well understood. However, a predominant process appears to be the establishment of permanent heritable epigenetic alterations, and a number of studies have implicated microRNAs in such processes. Here, we show that cigarette smoke induces specific differences in the spermatozoal microRNA content of human smokers compared with non-smokers, and that these altered microRNAs appear to predominantly mediate pathways vital for healthy sperm and normal embryo development, particularly cell death and apoptosis. microRNA-mediated perturbation of such pathways may explain how harmful phenotypes can be induced in the progeny of smokers.

Variation in stability of endogenous reference genes in fallopian tubes and endometrium from healthy and ectopic pregnant women

RT-qPCR is commonly employed in gene expression studies in ectopic pregnancy. Most use RN18S1, β-actin or GAPDH as internal controls without validation of their suitability as reference genes. A systematic study of the suitability of endogenous reference genes for gene expression studies in ectopic pregnancy is lacking. The aims of this study were therefore to evaluate the stability of 12 reference genes and suggest those that are stable for use as internal control genes in fallopian tubes and endometrium from ectopic pregnancy and healthy non-pregnant controls. Analysis of the results showed that the genes consistently ranked in the top six by geNorm and NormFinder algorithms, were UBC, GAPDH, CYC1 and EIF4A2 (fallopian tubes) and UBC and ATP5B (endometrium). mRNA expression of NAPE-PLD as a test gene of interest varied between the groups depending on which of the 12 reference genes was used as internal controls. This study demonstrates that arbitrary selection of reference genes for normalisation in RT-qPCR studies in ectopic pregnancy without validation, risk producing inaccurate data and should therefore be discouraged.

Endocannabinoids and pregnancy

Acylethanolamides such as anandamide (AEA), and monoacylglycerols like 2-arachidonoylglycerol are endocannabinoids that bind to cannabinoid, vanilloid and peroxisome proliferator-activated receptors. These compounds, their various receptors, the purported membrane transporter(s), and related enzymes that synthesize and degrade them are collectively referred to as the "endocannabinoid system (ECS)". Poorly defined cellular and molecular mechanisms control the biological actions of the ECS. Over the last decade evidence has been emerging to suggest that the ECS plays a significant role in various aspects of human reproduction. In this review, we summarize our current understanding of this role especially the involvement of AEA and related ECS elements in regulating oogenesis, embryo oviductal transport, blastocyst implantation, placental development and pregnancy outcomes, and sperm survival, motility, capacitation and acrosome reaction. Additionally, the possibility that plasma and tissue AEA and other cannabinoids may represent reliable diagnostic markers of natural and assisted reproduction and pregnancy outcomes in women will be discussed.