Effectiveness of progestogens to improve perinatal outcome in twin pregnancies: an individual participant data meta-analysis

BACKGROUND

In twin pregnancies, the rates of adverse perinatal outcome and subsequent long-term morbidity are substantial, and mainly result from preterm birth (PTB).

OBJECTIVES

To assess the effectiveness of progestogen treatment in the prevention of neonatal morbidity or PTB in twin pregnancies using individual participant data meta-analysis (IPDMA).

SEARCH STRATEGY

We searched international scientific databases, trial registration websites, and references of identified articles.

SELECTION CRITERIA

Randomised clinical trials (RCTs) of 17-hydroxyprogesterone caproate (17Pc) or vaginally administered natural progesterone, compared with placebo or no treatment.

DATA COLLECTION AND ANALYSIS

Investigators of identified RCTs were asked to share their IPD. The primary outcome was a composite of perinatal mortality and severe neonatal morbidity. Prespecified subgroup analyses were performed for chorionicity, cervical length, and prior spontaneous PTB.

MAIN RESULTS

Thirteen trials included 3768 women and their 7536 babies. Neither 17Pc nor vaginal progesterone reduced the incidence of adverse perinatal outcome (17Pc relative risk, RR 1.1; 95% confidence interval, 95% CI 0.97-1.4, vaginal progesterone RR 0.97; 95% CI 0.77-1.2). In a subgroup of women with a cervical length of ≤25 mm, vaginal progesterone reduced adverse perinatal outcome when cervical length was measured at randomisation (15/56 versus 22/60; RR 0.57; 95% CI 0.47-0.70) or before 24 weeks of gestation (14/52 versus 21/56; RR 0.56; 95% CI 0.42-0.75).

AUTHOR'S CONCLUSIONS

In unselected women with an uncomplicated twin gestation, treatment with progestogens (intramuscular 17Pc or vaginal natural progesterone) does not improve perinatal outcome. Vaginal progesterone may be effective in the reduction of adverse perinatal outcome in women with a cervical length of ≤25 mm; however, further research is warranted to confirm this finding.

The incidence and severity of shoulder dystocia correlates with a sonographic measurement of asymmetry in patients with diabetes

The objective of this paper is to examine the relationship between fetal asymmetry measured sonographically and the incidence and severity of shoulder dystocia in diabetic patients. Ultrasound data were collected retrospectively from examinations of women with gestational and pregastational diabetes who delivered at University of California, Irvine Medical Center from 1993-1995. Sonographic fetal asymmetry was quantified by calculating the difference between the abdominal diameter and the biparietal diameter in centimeters (AD-BPD). The residual AD-BPD was a patient's actual AD-BPD at the time of the ultrasound minus the mean AD-BPD obtained in our population at the patient's gestational age. The correlations between fetal asymmetry and the incidence and severity of shoulder dystocia were assessed using an analysis of variance as well as a logistic regression analysis. Mild shoulder dystocia was defined as a delivery requiring McRobert's maneuver and/or suprapubic pressure, while severe shoulder dystocia was assessed when delivery of the posterior arm with Wood's corkscrew maneuver was required. One hundred twenty-three women met the inclusion criteria for the study. Dividing the cohort into three groups based on AD-BPD residual values resulted in the following AD-BPD residual ranges and incidences of shoulder dystocia: Group I, -1.80 to -0.32 cm (9.8%), Group II, -0.31 to 0.32 cm (19.5%), and Group III .33 to 2.0 cm (34.1%), (p <0.03). The residual AD-BPD difference correlated with the incidence of shoulder dystocia after controlling for maternal age, weight, parity, birth weight, and the gestational age at ultrasound (P <0.03). Similar results were found with regards to dystocia severity as the mean residual AD-BPD difference between those with no dystocia, mild dystocia, and severe shoulder dystocia was -0.09, 0.23, and 0.46 cm, respectively, (p <0.006). The residual AD-BPD correlated with the severity of shoulder dystocia after controlling for the above-mentioned confounding variables (p <0.05) in a regression analysis. There is a direct correlation in diabetic patients between the level of fetal truncal asymmetry measured sonographically and the incidence and severity of shoulder dystocia.

Transfer rates from freestanding birth centers. A comparison with the National Birth Center Study

This article reviews retrospective data derived from Sharp The BirthPlace. San Diego for 1993-94 and from the University of California. Irvine, Birthing Center for 1994 and compares these findings to data obtained from the National Birth Center Study (NBCS). The focus of this article is on intrapartum transfer rates from the two freestanding birth centers as a critical clinical indicator. Cause-specific transfer rates were calculated for eight clinical conditions. Data suggest that cause-specific intrapartum transfer rates are influenced by factors such as risk profile of the client population, distance to the referral center and mechanisms of transfer, definitions and diagnostic criteria used, and clinical practice guidelines. Reports from the literature, such as NBCS data, might serve as points of reference, but are likely not appropriate baseline indicators (benchmarks of "best practice") for clinical events, against which individual performance can be measured; rather, these benchmarks should be individually defined, based on characteristics unique to each birth center.

Sonographic prediction of shoulder dystocia in infants of diabetic mothers

OBJECTIVE

To determine if the difference between the abdominal diameter and biparietal diameter (AD-BPD difference), as measured by ultrasound examination, predicts shoulder dystocia in borderline macrosomic infants of diabetic mothers.

METHODS

A retrospective study was performed of births occurring from January 1990 through June 1995. Eligibility requirements included diabetic pregnancy, ultrasound examination within 2 weeks of delivery, estimated fetal weight of 3800-4200 g, and vaginal delivery. The mean AD-BPD difference was compared in normal deliveries and those complicated by shoulder dystocia, using the Student t test and by multiple regression analysis. A receiver operating characteristic curve was generated to determine if an AD-BPD cutoff value could be used clinically to predict shoulder dystocia.

RESULTS

Thirty-one patients, six with dystocia, were eligible for the study. The mean AD-BPD differences for those with and without shoulder dystocia were 3.1 and 2.6 cm, respectively, a statistically significant difference (P = .05). Comparing the groups with and without shoulder dystocia, no significant differences could be found in mean age, parity, weight, birth weight, or gestational age. Shoulder dystocia occurred in six of 20 patients (30%) in whom the AD-BPD difference was at least 2.6 cm but in none of 11 patients in whom it was less than 2.6 cm, also a statistically significant difference (P = .05).

CONCLUSION

The AD-BPD difference was greater in borderline macrosomic fetuses of diabetic mothers who experienced shoulder dystocia than in those who had uncomplicated vaginal deliveries. Applying an AD-BPD cutoff value of 2.6 cm to this population prospectively would have provided excellent sensitivity, specificity, and predictive value in identifying those fetuses at high risk for birth injury.

Management of the nonvertex second twin: primary cesarean section, external version, or primary breech extraction

Six hundred eighty-two consecutive twin deliveries were reviewed. Included in the study were 136 sets of vertex-nonvertex twins with birth weights greater than 1500 gm. A primary attempt at delivery of the second twin by external version was performed on 41 twins, 55 twins underwent attempted breech extraction, and 40 patients had a primary cesarean section solely because of physician preference. There were no differences in the incidence of neonatal morbidity or mortality among the modes of delivery. External version was associated with a higher failure rate than primary breech extraction (p less than 0.01). External version was associated with complications (fetal distress, cord prolapse, and compound presentation) that were not seen in the other two groups. Primary breech extraction of the second nonvertex twin weighing greater than 1500 gm appears to be a reasonable alternative to either cesarean section or external version.

Fetal heart rate patterns in infants in whom necrotizing enterocolitis develops: a preliminary report

Perinatal changes in fetal heart rate (FHR) were monitored in infants in whom necrotizing enterocolitis (NEC) developed. Eleven of 16 monitoring strips indicated severe FHR changes consistent with perinatal hypoxia, two indicated mild changes, two indicated tachycardia alone, and only one was normal. Severe variable FHR decelerations indicating umbilical cord compression occurred in four cases, persistent late FHR decelerations occurred in two cases, persistent late and severe variable FHR decelerations occurred in two cases, prolonged bradycardia occurred in two cases, and bradycardia with persistent late FHR decelerations occurred in one case. These findings confirm that NEC does occur in infants with perinatal hypoxia and indicate that intestinal ischemia may occur before delivery and after delivery from hypoxia and acidosis from lung disease, exchange transfusion, or sepsis. Perinatal monitoring may become an important determinant in identifying the infant in whom NEC will develop.

Laparoscopic tubal sterilization using thermal coagulation

A technique using a low-voltage, rechargeable battery pack and a cautery hook assembly for thermal coagulation and division of the fallopian tube under laparoscopic visualization has been evaluated in 393 patients. The procedure is quick, easy to perform, and electrically safe. The gross extent of the burn to the fallopian tube by thermal coagulation and division was compared with that done by high-frequency unipolar electrocoagulation and division. The difference in the mean total gross tubal burn produced by the 2 methods is not statistically significant. The variance of total tubal burn in individual cases within each group is significantly greater in the electrocoagulation group. The authors assume that pregnancy rates in patients undergoing thermal coagulation and division will be no different than those reported in patients in the electrocoagulation and division group. Two hundred of the patients have been followed from 12 to 33 months and no method-failure pregnancies have occurred.

Perinatal outcome in the diabetic pregnancy: a retrospective analysis

A retrospective analysis was done of all pregnancies in class B through R diabetics over a two-and-one-half-year period. This study demonstrates that early hospitalization, assessment of fetal status via estriols and oxytocin challenge test, fetal maturity studies, close medical supervision of the diabetes problem and advances in neonatology have combined to significantly reduce perinatal morbidity and mortality. The expense of prolonged maternal hospitalization is justified by the savings in newborn and child care, which would otherwise be increased. This approach can be used in any obstetric center. The philosophic question is discussed of the increased incidence of congenital malformations and diabetes in offspring of diabetic mothers.