BJOG : An International Journal of Obstetrics and Gynaecology

OBJECTIVE: To evaluate the discrepancy between historical and more recent descriptions of the first stage of labour by testing whether the statistical techniques used recently (repeated measures polynomial and interval censored regression) were appropriate for detection of periods of rapid acceleration of cervical dilatation as might occur at the time of transition from a latent to an active phase of labour. DESIGN AND SETTING: A simulation study using regression techniques...

OBJECTIVES: To evaluate the recurrence risk of stillbirth. DESIGN: Retrospective cohort study. SETTING AND POPULATION: All births 1992-2017, Alberta, Canada METHODS: Retrospective cohort study. MAIN OUTCOME MEASURES: Stillbirth was defined as the death in utero of a fetus with gestational age ≥ 20 weeks or weighing ≥ 500 grams. Stillbirths were further subdivided into those occurring before labor and in labor. RESULTS: We identified 744897 births from 308,478 women...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

No abstract text is available yet for this article.

Fadl et al1 describe a case control study evaluating whether gestational diabetes mellitus (GDM) is associated with increased risk of future cardiovascular disease (CVD) and whether this risk differs for different subgroups of women. One subgroup they looked at was weight status (normal or overweight). It was concluded that GDM is indeed a useful marker of CVD risk, and the increase in risk of CVD indicated by GDM is higher in women who are overweight. It was therefore concluded that weight status is an effect modifier...

Linear regression is used to describe the relationship between a continuous dependant variable of interest (outcome) and other patient characteristics or predictors (independent continuous, categorical or dichotomous variables). Fitting a linear regression model estimates a constant, predictor coefficients and their corresponding 95% confidence intervals (95%CI). In a univariable analysis only one independent variable is included in the model and the model shows the association between that variable and the outcome, without any consideration of other characteristics...

In a randomised controlled trial (RCT) we are usually trying to answer the question of which treatment is best. Sometimes, though, we may be considering a treatment that we do not believe will perform better than an existing option but has other benefits. For instance, it could be cheaper, easier to deliver or more acceptable to patients. For example, the need for urodynamic testing compared to simple office evaluation before stress incontinence surgery was evaluated in an RCT (Nager et al. N Engl J Med. 2012;366:1987-97)...

A case-control study used logistic regression to examine factors associated with maternal death due to direct pregnancy complication using 14 previously identified risk factors (Nair M et al. BJOG 2015;122:653-662). In a univariable analysis only one predictor is included in the model and the model shows the association between the single predictor and outcome, without any consideration of other characteristics. In a multivariable analysis more than one predictor is included in the model. Multivariable models depict the relationship between multiple characteristics and the outcome, allowing for the impact of other characteristics...

Type 1 errors arise when a hypothesis is rejected (i.e. a treatment is concluded to work) but the corresponding association is not true. Studies are usually designed so that the type 1 error is 5%, that is, we accept that we might make this mistake in about 5% of studies. When we increase the number of statistical tests, the risk of making a type I error increases. The issue of type I error comes to the forefront with multiple comparison groups. Consider an example.

Simple statistical procedures, like testing for differences in the means or proportions of groups, become complicated when many groups are involved. This setting arises naturally and frequently in science: a study may include multiple treatment arms, important sub-groups, interim analyses, or multiple outcomes. We must correct for the number of statistical tests-called multiple comparisons-or face increased risk of invalid results. To truly grasp the problem, we must delve into the specifics of hypothesis testing...

OBJECTIVE: To assess the benefits and safety of early human fibrinogen concentrate in postpartum haemorrhage (PPH) management. DESIGN: Multicentre, double-blind, randomized placebo-controlled trial. SETTING: 30 French hospitals. POPULATION: patients with persistent PPH after vaginal delivery requiring a switch from oxytocin to prostaglandins. METHODS: Within 30 min after introduction of prostaglandins, patients received either 3 g fibrinogen concentrate or placebo...

OBJECTIVE: To create a personalized machine-learning model for prediction of severe adverse neonatal outcomes (SANO) during the second stage of labor. DESIGN: Retrospective Electronic-Medical-Record (EMR) based study. POPULATION OR SAMPLE: A cohort of 73,868 singleton, term deliveries that reached the second stage of labor, including 1,346 (1.8%) deliveries with SANO. METHODS: A gradient boosting model was created, analyzing 21 million data points from antepartum features (e...

OBJECTIVE: To examine the longitudinal associations of fetal growth with adverse child growth outcomes and to assess whether maternal metabolic factors modify the associations. DESIGN: Prospective cohort study. SETTING: Born in Guangzhou Cohort Study, China. POPULATION: A total of 4,818 mother-child pairs. METHODS: Fetal growth was assessed according to estimated fetal weight (EFW) from week 22 of gestation until birth and birth weight...

In 1972, two landmark papers in this journal described the partograph,1,2 a chart designed to provide finite referral criteria for midwives working in peripheral clinics who needed to refer women in labour to Harare Hospital, Zimbabwe (then Rhodesia). This innovation coincided with influential reports from the National Maternity Hospital in Dublin of the 'active management of labour' (early amniotomy, proactive use of oxytocin and one-to-one nursing care) with the objective of achieving birth within a limited time frame...

OBJECTIVE: To quantify the proportion of postpartum VTE readmissions, including those that occur at different hospitals from index admission, and describe risk factors for this outcome. DESIGN: Retrospective observational study. SETTING: United States hospitals included in the Nationwide Readmissions Database. SAMPLE: A total of 3,719,238 patients >14 years of age with a delivery-associated hospitalization in 2014...

High risk HPV primary screening is replacing organised cytology-based screening based on increased sensitivity to detect high grade intra-epithelial neoplasia and the very high negative predictive value which will allow extended screening intervals. The benefit of increased CIN detection and cancer prevention needs to balance against the disbenefits to screen positive women in over investigation not least the psychological impact.

OBJECTIVE: To document pregnancy outcome in homozygous sickle cell (SS) disease and in age-matched controls with a normal haemoglobin genotype followed from birth for up to 45 years. METHODS: A total of 100,000 consecutive non-operative deliveries screened for sickle cell disease at the main Government maternity hospital in Kingston, Jamaica between 1973-1981 detected 311 (149 female) babies with SS disease who were matched by age and gender with 250 (129 female) controls with an AA haemoglobin phenotype...

BACKGROUND: In vitro methods of conception are associated with adverse perinatal outcomes. It is unclear if the risk of stillbirth is increased also. OBJECTIVE: This systematic review and meta-analysis aimed to estimate the risk of stillbirth in singleton gestations following in vitro methods of conception compared to non-in vitro conceptions. SEARCH STRATEGY: A comprehensive search in PubMed, Embase, CINAHL, and Cochrane Library was undertaken from database inception to February 2021, with backward citation tracking...

OBJECTIVE: To describe the prevalence and incidence of endometriosis and to estimate the risk of cardiovascular outcomes in women with endometriosis. DESIGN: Population-based cohort study using The Health Improvement Network database. SETTING: UK primary care POPULATION: Women aged 16-50 years were followed through from 1995 to 2018 METHODS: Adjusted hazard ratios (aHR) for cardiovascular outcomes comparing women with endometriosis to those without endometriosis were estimated using multivariable Cox regression models...