Outcome of twin pregnancy with two live fetuses at 11–13 weeks' gestation

In a study to evaluate the reproducibility and accuracy of the sonar technique of measurement of the in vivo fetal crown-rump length (Robinson, 1973), a series of in vivo and in vitro experiments was performed in which the random and systematic errors inherent in the technique were assessed. The potential sources of random error were those of operator judgement, movement of the fetus and mother, machine sensitivity settings and measurement from the photograph; while the sources of systematic error were those of oscilloscope scale factor, and velocity calibration inaccuracies, and the effect of beam width. The overall effect of the random errors, that is, the reproducibility of the technique, was assessed in an in vivo blind trial in which three independent measurements were made of the fetus. In a series of 30 experiments the average standard deviation of the three readings was found to be 1.2 mm. Evaluation of the systematic errors by in vivo experimentation, on the other hand, showed that the basic sonar measurements were in error by an overestimate of 1 mm for the beam width effect and 3.7 per cent for the scale factor and velocity calibration errors. A weighted non-linear regression analysis of 334 measurements was performed in order to obtain a "curve of best fit" for the period covering 6 to 14 weeks of menstrual age. The values obtained were corrected for the systematic errors and compared with widely quoted anatomical figures. In the second part of this investigation the original data was further analyzed to determine on a statistical basis the accuracy of the technique as a method of estimating maturity. It was shown that such an estimate could be made to within 4.7 days with a 95 per cent probability on the basic of a single measurement, and to within 2.7 days if three independent measurements were made.

The purpose of this study was to evaluate the prognostic value of sonographic and clinical parameters to develop a staging classification of twin-twin transfusion syndrome (TTTS). Severe TTTS was defined as the presence of polyhydramnios (maximum vertical pocket of > or = 8 cm) and oligohydramnios (maximum vertical pocket of < or = 2 cm). Nonvisualization of the bladder in the donor twin (-BDT) and absence of presence of hydrops was also noted. The middle cerebral artery, umbilical artery, ductus venosus, and umbilical vein in both fetuses were assessed with pulsed Doppler. Critically abnormal Doppler studies (CADs) were defined as absent/reverse end-diastolic velocity in the umbilical artery, reverse flow in the ductus venosus, or pulsatile flow in the umbilical vein. TTTS was staged as follows: stage I, BDT still visible; stage II, BDT no longer visible, no CADs; stage III, CADs; stage IV, hydrops; stage V, demise of one or both twins. Laser photocoagulation of communicating vessels (LPCV) or umbilical cord ligation was performed depending on the severity of the condition. The study was approved by the Institutional Review Board of St. Joseph's Hospital in Tampa and by the Fetal Therapy Board at Hutzel Hospital, Detroit, and all patients gave informed consent. A total of 80 of 108 referred patients met criteria for surgery, but only 65 were treated surgically: 48 with LPCV and 17 with umbilical cord ligation. Complete Doppler data were obtainable in 41 of 48 LPCV patients. Survival rates by stage for one or two fetuses were statistically different (chi-squared analysis = 12.9, df = 6, p = 0.044). Neither percent size discordance nor gestational age at diagnosis were predictive of outcome. Staging of TTTS using the proposed criteria has prognostic significance. This staging system may allow comparison of outcome data of TTTS with different treatment modalities.

BACKGROUND The efficacy of vaginal progesterone for preventing preterm birth and adverse perinatal outcomes in singleton gestations with a short cervix has been questioned after publication of the OPPTIMUM study. OBJECTIVE To determine whether vaginal progesterone prevents preterm birth and improves perinatal outcomes in asymptomatic women with a singleton gestation and a midtrimester sonographic short cervix. DATA SOURCES MEDLINE, EMBASE, LILACS, and CINAHL (from their inception to September 2017), Cochrane databases, bibliographies, and conference proceedings. STUDY ELIGIBILITY CRITERIA Randomized controlled trials comparing vaginal progesterone with placebo/no treatment in women with a singleton gestation and a midtrimester sonographic cervical length ≤25 mm. STUDY APPRAISAL AND SYNTHESIS METHODS Systematic review and meta-analysis of individual patient data. The primary outcome was preterm birth <33 weeks of gestation. Secondary outcomes included adverse perinatal outcomes and neurodevelopmental and health outcomes at 2 years of age. Individual patient data were analyzed using a two-stage approach. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Quality of evidence was assessed using the GRADE methodology. RESULTS Data were available from 974 women (498 assigned to vaginal progesterone, 476 assigned to placebo) with a cervical length ≤25 mm participating in five high-quality trials. Vaginal progesterone was associated with a significant reduction in the risk of preterm birth <33 weeks of gestation (RR 0.62, 95% CI 0.47-0.81, P =0.0006; high-quality evidence). Moreover, vaginal progesterone significantly decreased the risk of preterm birth <36, <35, <34, <32, <30 and <28 weeks of gestation, spontaneous preterm birth <33 and <34 weeks of gestation, respiratory distress syndrome, composite neonatal morbidity and mortality, birthweight <1500 and <2500 g, and admission to the neonatal intensive care unit (RRs from 0.47 to 0.82; high-quality evidence for all). There were seven (1.4%) neonatal deaths in the vaginal progesterone group and 15 (3.2%) in the placebo group (RR 0.44, 95% CI 0.18-1.07, P =0.07; low-quality evidence). Maternal adverse events, congenital anomalies, and adverse neurodevelopmental and health outcomes at 2 years of age did not differ between groups. CONCLUSIONS Vaginal progesterone decreases the risk of preterm birth and improves perinatal outcomes in singleton gestations with a midtrimester sonographic short cervix, without any demonstrable deleterious effects on childhood neurodevelopment.