Mosaic trisomy 16 ascertained through amniocentesis: evaluation of 11 new cases.

Trisomy 16, once thought to result uniformly in early pregnancy loss, has been detected in chorionic villus samples (CVS) from on-going pregnancies and was initially ascribed to a second, nonviable pregnancy. Prenatally detected trisomy 16 in CVS and its resolution to disomy has led to the reexamination of the viability of trisomy 16. This study evaluates 11 cases of mosaic trisomy 16 detected through second trimester amniocentesis. In 9 of the 11 cases, amniocenteses were performed in women under the age of 35 because of abnormal levels of maternal serum alpha-fetoprotein (MSAFP) or maternal serum human chorionic gonadotropin (MShCG). The other two amniocenteses were performed for advanced maternal age. Five of the 11 pregnancies resulted in liveborn infants, and six pregnancies were electively terminated. The liveborn infants all had some combination of intrauterine growth retardation (IUGR), congenital heart defects (CHD), or minor anomalies. Two of them died neonatally because of complications of severe congenital heart defects. The three surviving children have variable growth retardation, developmental delay, congenital anomalies, and/or minor anomalies. In the terminated pregnancies, the four fetuses evaluated by ultrasound or autopsy demonstrated various congenital anomalies and/or IUGR. Cytogenetic and fluorescent in situ hybridization studies identified true mosaicism in 5 of 10 cases examined, although the abnormal cell line was never seen in more than 1% of cultured lymphocytes. Placental mosaicism was seen in all placentas examined and was associated with IUGR in four of seven cases. Maternal uniparental disomy was identified in three cases. Mosaic trisomy 16 detected through amniocentesis is not a benign finding but associated with a high risk of abnormal outcome, most commonly IUGR, CHD, developmental delay, and minor anomalies. The various outcomes may reflect the diversity of mechanisms involved in the resolution of this abnormality. As 80% of these patients were ascertained because of the presence of abnormal levels of MSAFP or MShCG, the increased use of maternal serum screening should bring more such cases to clinical attention.

Intravascular exchange and bolus transfusion in the severely isoimmunized fetus.

Eight Rh-sensitized fetuses, between 21 weeks 2 days and 35 weeks of gestation, received 31 intravascular transfusions (13 exchange and 18 bolus) and one intraperitoneal transfusion under ultrasonographic guidance. The interval between transfusions was 13.4 +/- 4.7 days. Posttransfusion hematocrit dropped at a rate of 1.0% +/- 0.6% per day. Procedure time for the bolus transfusion was shorter than for the exchange transfusion (t test, p less than 0.001). Bleeding from the puncture site complicated 10 of the 31 intravascular transfusions, without apparent maternal or fetal consequences. Fetuses were delivered between 33 and 36 weeks of gestation, after lung maturity was achieved.

Use of the Greenfield filter for thromboembolic disease in pregnancy.

Recent technical advances in surgical intervention for thromboembolic disease have made the Greenfield filter a safe and effective treatment when heparin is contraindicated or recurrent emboli develop. One successful use of Greenfield filter placement in pregnancy has been reported. We report six additional cases. Maternal morbidity was negligible, and fetal outcomes were good. The use of the Greenfield filter as an adjunctive therapy for treatment of severe thromboembolic disease in pregnancy appears to be safe and should be considered in appropriate candidates.