BackgroundThe rationale for fetal surveillance in monochorionic twin pregnancies is timely intervention to prevent the increased fetal/perinatal morbidity and mortality attributed to twin–twin transfusion syndrome and intrauterine growth restriction. We investigated the residual risk of fetal death after viability in otherwise uncomplicated monochorionic diamniotic twin pregnancies.Methods and FindingsWe searched an electronic database of 480 completed monochorionic pregnancies that underwent fortnightly ultrasound surveillance in our tertiary referral fetal medicine service between 1992 and 2004. After excluding pregnancies with twin–twin transfusion syndrome, growth restriction, structural abnormalities, or twin reversed arterial perfusion sequence, and monoamniotic and high-order multiple pregnancies, we identified 151 uncomplicated monochorionic diamniotic twin pregnancies with normal growth, normal liquor volume, and normal Doppler studies on fortnightly ultrasound scans. Ten unexpected intrauterine deaths occurred in seven (4.6%) of 151 previously uncomplicated monochorionic diamniotic pregnancies, within 2 wk of a normal scan, at a median gestational age of 34+1 wk (weeks+days; range 28+0 to 36+3). Two of the five cases that underwent autopsy had features suggestive of acute late onset twin–twin transfusion syndrome, but no antenatal indicators of transfusional imbalance or growth restriction, either empirically or in a 1:3 gestation-matched case–control comparison. The prospective risk of unexpected antepartum stillbirth after 32 wk was 1/23 monochorionic diamniotic pregnancies (95% confidence interval 1/11 to 1/63).ConclusionDespite intensive fetal surveillance, structurally normal monochorionic diamniotic twin pregnancies without TTTS or IUGR are complicated by a high rate of unexpected intrauterine death. This prospective risk of fetal death in otherwise uncomplicated monochorionic diamniotic pregnancies after 32 wk of gestation might be obviated by a policy of elective preterm delivery, which now warrants evaluation.
The best predictive scores for post-natal outcome in fetal PAIVS/CPS are a combination of morphologic and physiological variables, which predict a BV circulation with a sensitivity of 92% and specificity of 100% before 26 weeks.
Objective: Approximately 2.8% of pregnancies are Ro/La antibody positive. 3-15% of fetuses develop complete heart block (CHB). First-degree atrioventricular heart block (1˚AVB) is reported in a third of Ro/La fetuses but as most have a normal postnatal ECG this may reflect inadequacies of Doppler measurement techniques. Methods: Comparison was made between mechanical (mPR) and electrical (ePR) intervals obtained prospectively using Doppler and non-invasive fetal ECG (fECG) in 52 consecutive Ro/La pregnancies in 46 women carrying 54 fetuses in an observational study at a fetal medicine unit. 121 mPR and 37 ePR intervals were recorded in 49 Ro/La fetuses. Five were referred with CHB and excluded. ePR was measured successfully in 35/37 (94%) and mPR was measured in all cases. 1˚AVB was defined as PR .95% CI. Logistic regression predicted abnormal final fetal rhythm from first mPR or ePR.Results: The ePR model gave 66.7% sensitivity (6 of 8 final abnormal fetal rhythm cases were predicted correctly in fetuses .20 weeks) and 96.2% specificity. mPR gave 44.4% sensitivity (4 of 9 cases) and 88.5% specificity. Z scores for ePR (zPR) were calculated from 199 normal fetuses. The area under the receiver operator characteristic (ROC) curve was 0.88 (95% CI, 0.754 to 1.007). A cut-off of 1.65 gave a sensitivity of 87.5% and specificity of 95% for those with prolonged and normal ePR intervals, respectively. Conclusion: zPR is better than mPR at differentiating between normal and prolonged PR intervals, suggesting that fECG is the diagnostic tool of choice to investigate the natural history and therapy of conduction abnormalities in Ro/La pregnancies. A nti-Ro or La antibody positive pregnancies (Ro/La) have been found in about 2.8% of the pregnant population. The most serious consequence of transplacental transfer of these antibodies to the fetus is complete heart block (CHB), which affects 3% of Ro/La pregnancies, with the risk rising to 15% in a subsequent pregnancy. [1][2][3][4] In addition to the morbidity and mortality associated with pacing procedures in young infants, 5 6 progressive myocardial fibrosis has been reported which affects long-term cardiac function and may necessitate transplantation.7-9 The alloimmune process is thought to exert its effect in more than the 3% of fetuses affected by CHB with PR interval prolongation (first-degree atrioventricular heart block or 1˚AVB) described in up to a third of fetuses in studies using Doppler methods of measurement.10 As most babies have a normal outcome, with progression to CHB described in only a small proportion, there is some debate over whether these findings represent a transient biological response to the presence of antibodies or whether they may be due to inadequacies of the existing measurement techniques.
11A simple and robust method of monitoring the PR interval in affected pregnancies is required to enable studies to assess the extent and determinants of progression to CHB in Ro/La pregnancies. Such a tool would also permit the assessment of different trea...
Objective To determine if absent end-diastolic flow (AEDF) in the umbilical artery (UA) has a longer latency in monochorionic (MC) twin fetuses compared to singleton or dichorionic twin (DC) fetuses.
Methods
We report our experience with intracardiac administration of potassium chloride as safe and effective method for late termination of pregnancy (TOP) and to document the indications for feticide in a major tertiary unit. During the study period (January 2000 and December 2005), 239 late terminations of pregnancy were performed at a median gestational age of 22+6 weeks (range 20+6 to 36+3 weeks). The most frequent indication was represented by aneuploidy (24.3%), followed by brain abnormalities (17.6%). Maternal indications were responsible for 2.9% of the total number of terminations. No maternal complications occurred and complete asystole was achieved in all cases with a median volume of potassium chloride of 4.7 ml (range 2–10 ml). Potassium chloride injected directly in the left ventricle induces immediate asystole, and it is a safe and effective method of TOP. Interestingly, despite the widespread introduction of aneuploidy screening, chromosomal abnormalities, particularly trisomy 21, still represent the major indication for late TOP.
When this diagnosis occurs, tests could be limited to cytomegalovirus and parvovirus B19, whereas a complete TORCH screening is probably not necessary.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.