Juan Carlos Melchor

Objectives: Cervical length (CL) measurement ≤ 25 mm on mid‐trimester ultrasound scan is a known risk factor for preterm birth, for which vaginal progesterone is recommended. The aims of this study were to evaluate whether CL measurement is affected by observer bias and to assess the impact on short cervix prevalence of masking CL measurement during routine mid‐trimester ultrasound scan.Methods: This was a flash study designed for a 2‐month period (October and November 2018) at Cruces University Hospital (Bizkaia, Spain), in which all CL measurements from routine mid‐trimester scans were masked. During the study period, there was no modification of the routine screening method, and women with a short cervix were prescribed 200 mg vaginal progesterone daily as per usual. The control group included women examined in a 2‐month period (April and May 2018) prior to the study, in which CL measurements were taken as usual by a non‐blinded operator. The primary outcome was the prevalence of short cervix in each group.Results: A total of 983 CL measurements were analyzed, including 457 in the blinded group and 526 in the control group. The prevalence of short cervix was 2.7% in the non‐blinded group and 5.5% in the blinded group (P = 0.024). We identified a statistically significant difference in the incidence of CL of 24–25 mm between the two groups, with a lower prevalence in the non‐blinded vs blinded group (0.6% vs 2.4%; P < 0.005). Moreover, the distribution of CL values was normal in the blinded group, in contrast to the non‐blinded group, which was characterized by skewed distribution of CL values.Conclusions: Expected‐value bias exists and should be taken into account when measuring CL in mid‐trimester preterm birth screening. Blinding has demonstrated to be an effective strategy to improve the performance of CL screening in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

To assess the opinion and the level of satisfaction of patients concerning analgesia during external cephalic version (ECV), we present the results of a survey of 120 women undergoing ECV at term during a randomised controlled trial (July 2012 to February 2013) comparing remifentanil and nitrous oxide. Overall, 110 (91.7%) women said they would repeat the procedure and 111 (92.5%) that they would recommend it to another pregnant woman, with no significant differences by type of analgesia. The administration and sense of comfort were rated better in the remifentanil group (p < .01). In conclusion, the use of analgesia during ECV is associated with a high rate of willingness among women to repeat the procedure and recommend it to other pregnant women.

Background: Obesity in pregnancy is increasing worldwide, reaching epidemic proportions in many countries and frequently creating challenges for obstetricians. We conducted this study to assess the effects of maternal obesity on maternal and perinatal outcomes. Methods: A historical cohort study was performed on 16,609 women who delivered singleton babies in a 5-year period (2013–2017). Data were retrieved from the Cruces Perinatal Database (CPD) and only women whose prepregnancy body mass index (BMI) was known were included. Women were categorized according to the World Health Organization (WHO) classification: normal weight (BMI 20–24.9 kg/m²) and obesity (BMI ≥ 30 kg/m²). Obstetric, perinatal and neonatal outcomes were compared, and adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated using the normal-weight group as the reference. Results: Compared to women of normal weight (n = 9778), obese women (n = 2207) had a higher risk of preeclampsia (aOR 2.199, 95% CI: 1.46–3.29), rectovaginal group B streptococcus colonization (aOR 1.299, 95% CI: 1.14–1.47), induction of labor (aOR 1.593, 95% CI: 1.44–1.75), cesarean section (aOR 2.755, 95% CI: 2.46–3.08), cesarean section in women with a history of cesarean delivery (aOR 1.409, 95% CI: 1.03–1.92), fetal weight ≥4000 g (aOR 2.090, 95% CI: 1.803–2.422) and admission to the neonatal intensive care unit (NICU) (aOR 1.341, 95% CI: 1.12–1.59). No association was found with preterm birth (aOR 0.936, 95% CI: 0.77–1.13), stillbirth (aOR 0.921, 95% CI: 0.41–2.02) or neonatal mortality (aOR 2.205, 95% CI: 0.86–5.62). Conclusion: Maternal obesity is associated with a higher risk of adverse pregnancy and perinatal outcomes. Pregnancy in this population of women should be considered and managed as high risk.

Objective: To assess the accuracy of placental alpha microglobulin‐1 (PAMG‐1), fetal fibronectin (fFN) and phosphorylated insulin‐like growth factor‐binding protein‐1 (phIGFBP‐1) tests in predicting spontaneous preterm birth (sPTB) within 7 days of testing in women with symptoms of preterm labor, through a systematic review and meta‐analysis of the literature. The test performance of each biomarker was also assessed according to pretest probability of sPTB ≤ 7 days.Methods: The Cochrane, MEDLINE, PubMed and ResearchGate bibliographic databases were searched from inception until October 2017. Cohort studies that reported on the predictive accuracy of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB within 7 days of testing in women with symptoms of preterm labor were included. Summary receiver–operating characteristics (ROC) curves and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and positive (LR+) and negative (LR–) likelihood ratios were generated using indirect methods for the calculation of pooled effect sizes with a bivariate linear mixed model for the logit of sensitivity and specificity, with each diagnostic test as a covariate, as described by the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy.Results: Bivariate mixed model pooled sensitivity of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB ≤ 7 days was 76% (95% CI, 57–89%), 58% (95% CI, 47–68%) and 93% (95% CI, 88–96%), respectively; pooled specificity was 97% (95% CI, 95–98%), 84% (95% CI, 81–87%) and 76% (95% CI, 70–80%) respectively; pooled PPV was 76.3% (95% CI, 69–84%) (P < 0.05), 34.1% (95% CI, 29–39%) and 35.2% (95% CI, 31–40%), respectively; pooled NPV was 96.6% (95% CI, 94–99%), 93.3% (95% CI, 92–95%) and 98.7% (95% CI, 98–99%), respectively; pooled LR+ was 22.51 (95% CI, 15.09–33.60) (P < 0.05), 3.63 (95% CI, 2.93–4.50) and 3.80 (95% CI, 3.11–4.66), respectively; and pooled LR– was 0.24 (95% CI, 0.12–0.48) (P < 0.05), 0.50 (95% CI, 0.39–0.64) and 0.09 (95% CI, 0.05–0.16), respectively. The areas under the ROC curves for PAMG‐1, fFN and phIGFBP‐1 for sPTB ≤ 7 days were 0.961, 0.874 and 0.801, respectively.Conclusions: In the prediction of sPTB within 7 days of testing in women with signs and symptoms of preterm labor, the PPV of PAMG‐1 was significantly higher than that of phIGFBP‐1 or fFN. Other diagnostic accuracy measures did not differ between the three biomarker tests. As prevalence affects the predictive performance of a diagnostic test, use of a highly specific assay for a lower‐prevalence syndrome such as sPTB may optimize management. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

To assess the performance of the PAMG-1 and fFN tests using real-world data for the prediction of spontaneous preterm delivery (sPTD) in patients presenting to an emergency obstetrical unit with threatened preterm labour (PTL) by conducting a retrospective audit of patient medical records over two different one-year time periods during which either fFN or PAMG-1 was used as the standard of care biochemical test. A retrospective cohort study chart review of women with threatened PTL electronic medical records (EMR) from a Level III maternity hospital was conducted for two periods of one year each: (1) the “Baseline” time period, during which the qualitative fFN test with a cutoff of 50 ng/ml was used as standard of care biochemical test for the risk assessment of preterm delivery, and (2) the “Comparative” time period, during which the PAMG-1 test with a cutoff of 1 ng/mL was used as the standard of care biomarker test. Patients with singleton gestations between 24⁺⁰ to 34⁺⁶ weeks of gestation with symptoms of early preterm labour, clinically intact membranes, and cervical dilation 4 times more reliable than a positive fFN test in predicting imminent sPTD. Fewer positive biomarker test results that are more reliable is associated with a reduction in unnecessary admissions, avoidable treatments, and preventable use of hospital resources.

The aims of this study were to (i) compare the concentrations of two neural injury markers, S100B protein and neuron-specific enolase (NSE), in intrauterine growth-restricted (IUGR) fetuses and in fetuses with appropriate growth-for-gestational-age (AGA), and (ii) investigate potential relationships between concentrations of these markers, Doppler abnormalities, and adverse perinatal or neonatal outcomes. This was a case-controlled, cooperative, prospective study among Spanish Maternal and Child Health Network (Retic SAMID) hospitals. At inclusion, biometry for estimated fetal weight and feto-placental Doppler were measured. At the time of delivery, maternal venous blood and fetal umbilical arterial blood samples were collected. S100B and NSE concentrations were determined from these samples. In total, 254 pregnancies were included. Among these, 147 were classified as IUGR and 107 as AGA. There were no differences between the groups in S100B concentrations. However, levels of NSE in maternal and umbilical cord serum differed significantly between these groups (2.31 in AGA vs. 2.51 in IUGR in (PP<0.05), respectively). No differences were observed in these neurological markers when stratified by perinatal or neonatal complications. Although some variations exist in these neurological markers, they did not correlate with perinatal or neonatal complications.

Introduction: Our objective was to compare the effect of two pain relief methods (remifentanil vs. nitrous oxide) on the success rate of external cephalic version.Material and methods: We conducted a randomized open label parallel‐group controlled single‐center clinical trial with sequential design, at Cruces University Hospital, Spain. Singleton pregnancies in noncephalic presentation at term that were referred for external cephalic version were assigned according to a balanced (1:1) restricted randomization scheme to analgesic treatment with remifentanil or nitrous oxide during the procedure. The primary endpoint was external cephalic version success rate. Secondary endpoints were adverse event rate, degree of pain, cesarean rate and perinatal outcomes.Results: The trial was stopped early after the second interim analysis due to a very low likelihood of finding substantial differences in efficacy (futility). The external cephalic version success rate was the same in the two arms (31/60, 51.7%) with 120 women recruited, 60 in each arm. The mean pain score was significantly lower in the remifentanil group (3.2 ± 2.4 vs. 6.0 ± 2.3; p < 0.01). No differences were found in external cephalic version‐related complications. There was a trend toward a higher frequency of adverse effects in the remifentanil group (18.3% vs. 6.7%, p = 0.10), with a significantly higher incidence rate (21.7 events/100 women vs. 6.7 events/100 women with nitrous oxide, p = 0.03). All reported adverse events were mild and reversible.Conclusions: Remifentanil for analgesia decreased external cephalic version‐related pain but did not increase the success rate of external cephalic version at term and appeared to be associated with an increased frequency of mild adverse effects.

Objective: The objective of this study was to analyze the effect of using inhaled nitrous oxide (N₂O) for analgesia in external cephalic version (ECV) at term on the success rate of the procedure, on pain, and on obstetric and perinatal outcomes. Methods: A prospective comparative cohort study among 300 women with singleton pregnancy in breech presentation at term undergoing an ECV with inhaled N₂O in a 50:50 mix with oxygen for analgesia and 150 ECVs with no analgesia. Results: The success rate was 52.3% in the N₂O cohort and 52.7% in the controls (P=0.94), whereas the median level of pain was statistically lower in women given N₂O (median, 6; range, 4–7, vs. median, 7; range, 5–8; P2O inhalation. Conclusions: N₂O inhalation at a concentration of 50% for analgesia during ECV decreases the level of severe pain experienced by women, appears to be safe both for mother and child, and has no influence on the success rate of ECV or the perinatal outcomes.