Visual biofeedback for shortening second stage of labor: randomized controlled trial

OBJECTIVE

To determine whether visual biofeedback can be used during labor as an effective tool for shortening the second stage of labor and reducing the need for instrumental delivery.

METHODS

This was a single-center randomized controlled trial. Nulliparous women under epidural anesthesia were randomized at the point of full dilation into the biofeedback group (n = 50) or the control group (n = 50). Both groups received coached maternal pushing during four consecutive contractions, while an experienced obstetrician performed transperineal ultrasound. Only women in the biofeedback group observed the ultrasound display screen. Following this intervention, labor was managed routinely by the obstetric team. Angle of progression (AOP) was measured at rest and while pushing, before and during the first and fourth contractions. Second-stage duration and delivery outcomes were compared between groups.

RESULTS

Visual biofeedback did not affect the duration of the second stage, which lasted for a median of 2.28 (interquartile range (IQR), 1.25-3.10) h in the biofeedback group vs 2.08 (IQR, 1.58-3.02) h in the control group (P = 0.981). AOP was significantly higher in the biofeedback group compared with the control group, both at rest before the fourth contraction (mean ± SD, 142.6° ± 15.9° vs 136.8° ± 13.1°; P = 0.049) and while pushing during the fourth contraction (mean ± SD, 159.3° ± 19.2° vs 149.4° ± 15.1°; P = 0.005). The increase in AOP was significantly higher in the biofeedback compared with the control group between rest and pushing at the last push (mean ± SD, 16.6° ± 11.0° vs 12.6° ± 8.3°; P = 0.041) and between the first rest and last push (mean ± SD, 24.4° ± 13.6° vs 17.9° ± 11.3°; P = 0.011). The rate of intact perineum was similar between groups (12% vs 8%; P = 0.505).

CONCLUSIONS

Visual biofeedback during the second stage of labor may facilitate descent of fetal head during maternal pushing without affecting second-stage duration, possibly due to the short duration of the intervention. Future studies should focus on continuous intervention throughout the second stage of labor. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Prediction of morbidly adherent placenta using a scoring system

OBJECTIVE

To evaluate the accuracy of an ultrasound-based scoring system for diagnosing morbidly adherent placenta (MAP).

METHODS

This study included pregnant women referred to our ultrasound unit during 2013-2015 because of suspected MAP on a previous ultrasound examination or because they had at least one previous Cesarean delivery. All women were assessed using a scoring system based on the following: number and size of placental lacunae; obliteration of the demarcation between the uterus and placenta; placental location; color Doppler signals within placental lacunae; hypervascularity of the placenta-bladder and/or uteroplacental interface zone; and number of previous Cesarean deliveries. Each criterion was assigned 0, 1 or 2 points and the sum of points yielded the final score. Patients were classified into low, moderate or high probability for MAP based on the final score. The presence of MAP was determined by the surgeon at delivery and clinical descriptions were documented in the electronic patient file. Pathological diagnoses were available only in cases that underwent hysterectomy.

RESULTS

In total, 258 pregnant women were included in the study, of whom 23 (8.9%) were diagnosed with MAP. There was a statistically significant difference in the prevalence of MAP when women were grouped according to the scoring system, with 0.9%, 29.4% and 84.2% in the low, moderate and high probability groups, respectively (P < 0.0001). All sonographic criteria of the scoring system were significantly associated with MAP (P < 0.0001). Receiver-operating characteristics (ROC) curves for prediction of MAP using the number of placental lacunae and obliteration of the uteroplacental demarcation yielded an area under the ROC curve of 0.94 (95% CI, 0.86-1.00).

CONCLUSIONS

Our proposed scoring system is highly predictive of MAP in patients at risk. This allows an adequate multidisciplinary team approach for the planning and timing of delivery in such cases. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Evaluation of Fetal Weight Estimation Formulas in Assessing Small-for-Gestational-Age Fetuses

PURPOSE

The aim of this study was to compare the accuracy of multiple sonographic fetal weight estimation models in assessing small-for-gestational-age (SGA) fetuses.

MATERIALS AND METHODS

The cohort included all singleton pregnancies recorded at a single medical center from January 2004 to September 2011, with a minimum of 24 weeks of gestation. SGA was defined as a fetal weight of less than the 10th percentile. We used birth weight (BW) distribution curves for our population, matched according to fetal gender and gestational age. Predicted birth weights were calculated using 26 sonographic fetal weight estimation models, including targeted formulas for SGA fetuses.

RESULTS

1218 cases of SGA fetuses that underwent sonographic fetal weight estimation within one week prior to delivery were found. Prediction of fetal weight was significantly less accurate in SGA fetuses than in the general population. The random error for SGA fetuses ranged from 7.2 % to 13.9 % in different models, while the systematic error ranged from -12.8 % to 26 %. Most non-targeted formulas showed a specificity of over 90 % but a sensitivity of only 20 - 35 % in the detection of SGA fetuses, while most targeted formulas had a low specificity but a high sensitivity. The model by Scott et al. was found to be the most accurate in assessing SGA fetuses in our population.

CONCLUSION

Estimation of fetal weight in SGA fetuses is less accurate than in the general population. Some formulas which are designed for SGA are more accurate than others and their use might increase the sensitivity in identifying SGA fetuses, with only a small decline in specificity.

A search for the most accurate formula for sonographic weight estimation by fetal sex - a retrospective cohort study

OBJECTIVE

The aim of this study was to assess the effect of fetal sex on the accuracy of multiple formulas for sonographic estimation fetal weight (SEFW).

METHODS

The cohort included all singleton live births recorded at a single medical center from January 2004 to September 2011. The accuracy of SEFW was compared between male and female fetuses using 6575 SEFW performed within 3 days prior to delivery. Fetal weight was estimated using 27 models.

RESULTS

The accuracy of different formulas in predicting birth weight of male and female fetuses was found to be significantly different in almost every accuracy index that was compared (P < 0.05). The model by Sabbagha et al. was found to be the most accurate in assessing female fetuses. The most accurate model for male fetuses was a sex-specific formula by Melamed et al. We also found that a combination of the most accurate formula for each sex to one combined sex-specific model increased SEFW accuracy significantly.

CONCLUSION

The accuracy of SEFW is significantly related to fetal sex. The combination of the formulas by Melamed et al. and Sabbagha et al. for male and female fetuses accordingly allowed more accurate SEFW in our research population.

Antenatal sonographic diagnosis of testicular torsion

Antenatal testicular torsion is a well-established condition diagnosed and treated after birth. This report describes the antenatal diagnosis of testicular torsion with surgical and pathological confirmation. Antenatal and postnatal sonographic findings included enlarged testis and epipdidymis surrounded by hemorrhagic fluid organized in two concentric compartments ('double ring hemorrhage' image). A contralateral hydrocele with bulging of the scrotal septum towards the unaffected side were also present. Pathological examination demonstrated a recent extravaginal torsion, which is the predominant mechanism for testicular torsion in the fetus and neonate. Recognition of this phenomenon and the ultrasonographic images associated with it may enable the diagnosis of antenatal testicular torsion to be made on prenatal sonography of the fetus.

Prenatal age-specific reference intervals for measuring all five digits of the fetal hand

OBJECTIVE

To construct prenatal age-specific reference intervals for measurement of five digits in normal fetuses.

PATIENTS AND METHODS

Prospective cross-sectional study of fetuses assessed at an antenatal ultrasound unit in a university-affiliated general hospital. The study cohort comprised 302 pregnant women attending our clinic for routine fetal biometry or anomaly scan between December 1997 and June 2000. They all fulfilled the study inclusion criteria: singleton fetuses with normal anatomy, accurate gestational age and no medical complications of pregnancy. Each fetus was scanned once only and the finger measurements of one hand were obtained. Electronic calipers were placed on the outer margin of the proximal phalanx to the outer margin of the distal phalanx level. Those measurements and the relevant gestational age were registered in a computerized database.

RESULTS

The linear increase of size of each of the five fingers was plotted across the evaluated range of gestation (P < 0.001; r2 between 0.85 and 0.86 for fingers I to V). Tables showing the 5th, 50th and 95th centiles of finger lengths between 14 and 27 weeks' gestation were created based on the reference interval charts.

CONCLUSIONS

Second-trimester measurement of all five digits of the fetal hand is feasible. This may assist in the evaluation of fetuses that are primarily suspected of having genetic abnormalities that might be expressed by deviation in finger length.

A comparison of clinical and ultrasonic estimation of fetal weight

OBJECTIVE

To compare the accuracy of routine ultrasonic and clinical birth weight estimation.

METHODS

The study sample included 1717 women with singleton pregnancies, admitted in early labor with an ultrasonic estimated fetal weight (EFW) performed during the preceding week. Clinical EFW was obtained before rupture of the membranes by the attending senior resident, who was unaware of the ultrasonic EFW. Accuracy was determined by the percentage error, the absolute percentage error, and the proportion of estimates within 10% of the actual birth weight (birth weight +/- 10%). Statistical analysis was done by the paired t test, the comparison of correlated variances, the Wilcoxon sign test, and the chi2 test. Actual birth weight in the study sample averaged 3334+/-607 g (+/- standard deviation, [SD]) and ranged between 690 and 5320 g.

RESULTS

The means of all error terms of the clinical EFW were significantly smaller than those of the ultrasonic EFW. However, the rates of estimates within 10% of birth weight were not significantly different (72 and 69%, respectively). In birth weights less than 2500 g, both methods overestimated the birth weight, but the mean errors of the ultrasonic EFW were significantly smaller than those of the clinical EFW. The ultrasonic EFW had significantly higher rates of birth weight +/- 10% than the clinical EFW (63 compared to 49%, respectively). In the 2500-4000 g birth weight, only the clinical EFW had no systematic error, whereas the ultrasonic EFW underestimated the birth weight. The mean errors of the clinical EFW were significantly smaller and the rate of birth weight +/- 10% significantly higher than those of the ultrasonic EFW. In the birth weight greater than 4000 g, both methods underestimated the birth weight, and the mean errors and the rate of estimates within 10% of birth weight were similar for both methods.

CONCLUSION

Clinical estimation of birth weight in early labor is as accurate as routine ultrasonic estimation obtained in the preceding week. In the lower range of birth weight (less than 2500 g), ultrasonic estimation is more accurate; in the 2500-4000 g range, clinical estimation is more accurate. In the higher range of birth weight (greater than 4000 g), both methods have similar accuracy.

Hepatic mesenchymal hamartoma: a pediatric tumor that may be diagnosed prenatally

Hepatic mesenchymal hamartoma is a benign tumor, defined as an excessive focal overgrowth of mature normal cells and stroma native to the liver. The increasing popularity of antenatal scanning has resulted in in utero diagnosis of congenital malformations and anomalies that previously became apparent only after delivery. Herein, we present a rare case of fetal mesenchymal hamartoma of the liver, which was initially sonographically detected at 29 weeks of gestation. A brief literature survey and obstetric recommendations for management and monitoring of such rare cases are included.

Chorioamnionitis caused by gram-negative bacteria as an etiologic factor in preterm birth

The role and microbiological causes of infection and inflammation of the chorioamnion were studied in 85 patients with spontaneous preterm deliveries (< 37 weeks) and in 85 control patients with full term deliveries. Microorganisms were isolated from the freshly separated chorioamnion in 55% of preterm and 26% of term deliveries (p < 0.001). Isolation rates of gram-negative enteric bacteria were significantly higher in preterm deliveries than in term deliveries (p < 0.001), whereas differences in the isolation of other bacterial species were not significant. Histological chorioamnionitis was noted in 49% of preterm and 14% of term deliveries (p < 0.001), and was strongly associated with a positive chorioamniotic culture in both groups (p < 0.001). Histological chorioamnionitis was noted in 94%, 54%, and 4% of membranes with gram-negative rods, other microbial species and negative cultures, respectively (p < 0.001). Preterm deliveries were also associated with significantly higher rates of bacterial vaginosis (38% vs. 14%) and isolation of vaginal pathogens (85% vs. 65%). In the case of the majority (88%) of chorioamniotic isolates the same species was isolated in the vagina. The findings suggest that gram-negative enteric rods are important placental pathogens responsible for sub-clinical chorioamnionitis and possibly preterm birth. The findings support the concept that microorganisms ascending from the lower genital tract produce local inflammation, which may result in preterm labour and delivery.

Ripening of the unfavorable cervix with extraamniotic catheter balloon: clinical experience and review

The use of an extraamniotic catheter balloon, inflated above the internal cervical os, has been advocated as a nonpharmacological, mechanical method of cervical ripening before induction of labor. Additional measures may include applying traction on the catheter, or the infusion of normal saline (1 ml/min) via the catheter's port into the extraamniotic space. The results of catheter balloon cervical ripening are reviewed from 13 published reports and a departmental series of 190 pregnancies with unfavorable cervix, encompassing nearly 1000 patients. A mean change in cervical score of at least 3 points, was noted in most studies after balloon expulsion or removal. The present series and other studies suggest that oxytocin use for induction and/or augmentation of labor is increased after balloon ripening, compared with its use in spontaneous labor or after cervical ripening by prostaglandins. In 11 studies, catheter balloon ripening was compared with cervical ripening by other mechanical, or pharmacological (i.e., oxytocin or prostaglandins) methods. Of these, eight were prospective and randomized-controlled and three were case-controlled studies. It is suggested that ripening efficacy by catheter balloon is similar, or better, than other methods; but there is no significant difference in the mode of delivery or perinatal outcome. This review also suggests that cervical ripening with extraamniotic catheter balloon has the advantages of simplicity, low cost, reversibility, and lack of systemic or serious side effects.