Frances R. Tennant

Amniocentesis before 15 weeks' gestation: Outcome, risks, and technical problems☆

Between January 1, 1979, and May 30, 1986, 4750 amniocenteses were performed by a single physician at the University of California, Davis, Medical Center. Of these procedures 541 (11.4%) were considered early amniocenteses (performed before the fifteenth week since last menstrual period). The medical records were reviewed for maternal age, amniocentesis indication, ultrasound findings, location of the placenta, location of the needle insertion (transplacental versus nontransplacental), color of the amniotic fluid, results of prenatal testing, complications of procedure, and pregnancy outcome. Complete follow-up data were possible for 308 subjects and obtained for 298 (96.8%). There were 11 miscarriages (3.6%), two stillbirths (0.7%), and one neonatal death (0.3%), resulting in a total postprocedural loss rate of 4.7% (14/298). If those patients with a preamniocentesis history of bleeding are eliminated, the total postprocedural rate of loss is 3.3% (7/211). Miscarriage within 2 weeks of amniocentesis occurred in 1.7% of procedures (5/298). No significant difference in pregnancy outcome was noted between transplacental and nontransplacental amniocentesis.

Analysis of 2136 genetic amniocenteses: experience of a single physician.

Between 1979 and 1984, 2136 midtrimester genetic amniocenteses were performed by a single physician at the University of California (Davis) Medical Center. The medical records were reviewed for maternal age, amniocentesis indication, ultrasound findings, location of placenta, location of the needle insertion (transplacental versus nontransplacental), color of the amniotic fluid, results of prenatal testing, complications of procedure, and pregnancy outcome. Follow-up data were available for 88% of the pregnancies. There were 38 miscarriages (1.9%), 18 stillbirths (0.9%), and four neonatal deaths (0.2%), resulting in a total postprocedural loss rate of 3.1%. Miscarriage within 2 weeks of amniocentesis occurred in only 0.4% of procedures (seven of 1918). No significant difference in pregnancy outcome was noted between transplacental and nontransplacental amniocentesis. Greenish brown discolored amniotic fluid was found in 3.6% of procedures (76 of 2136). In this group there was a 14.5% fetal loss rate with an overall 22.4% adverse outcome.

Analysis of the significance of discolored amniotic fluid detected at midtr mester amniocentesis

In 110 midtrimester amniocenteses of the 3349 procedures done at the University of California, Davis, Medical Center between 1979 and 1984, the fluid obtained was noted to be discolored. The significance of this finding was evaluated with review of pregnancy history and outcome and by using biochemical techniques. A significant increase in miscarriage was seen in the pregnancies where discolored fluid was obtained (9%), in comparison with the entire group of pregnancies in which amniocentesis was done at the same institution over the same period (1.6%). This increase was most marked in the pregnancies in which, in addition to discolored fluid, there was a prior history of pregnancy bleeding. Thirty-four discolored fluid samples and 18 clear fluid samples were studied with spectrophotometry, electrophoresis, isoelectric focusing, and chromatography. These studies indicate that in most cases the discoloring pigment is blood rather than fetal bowel contents, as had been suggested by others.

The roles of ultrasonography and amniocentesis in evaluation of elevated maternal serum α-fetoprotein

A total of 681 pregnant women were referred for evaluation of elevated maternal serum alpha-fetoprotein levels. Ultrasonographic examination yielded an explanation for the elevation of maternal serum alpha-fetoprotein in 42% of patients. Diagnoses made by ultrasonography included incorrect fetal dating, multiple gestation, fetal death, open neural tube defect, abdominal wall defect, placental abnormalities, cystic hygroma, renal anomalies, and oligohydramnios. Optimal prenatal diagnosis of fetal anomalies also requires the use of amniocentesis in many patients. Amniocentesis may be obviated if fetal dating is incorrect, if an unsuspected multiple gestation is discovered, or if there is a clear anomaly and the parents do not desire genetic counseling based on karyotype information. If the fetus appears normal, the ultrasonographic results are equivocal, or the parents desire more detailed genetic counseling when an anomaly is found by ultrasonography, then amniocentesis should be performed. Thirteen abnormalities were diagnosed by amniocentesis alone in this group.

A prenatal diagnostic center's first-year experience with the California a-Fetoprotein Screening Program

The University of California Davis Medical Center has offered secondary and tertiary care to pregnant patients with abnormal maternal serum alpha-fetoprotein levels since the start of the California alpha-Fetoprotein Screening Program in April 1986. In our first year of involvement with this method of prenatal screening, 452 patients were referred to our center for further evaluation and follow-up of either high or low maternal serum alpha-fetoprotein levels, as determined by the standard multiple of the median adjusted for maternal weight, race, and presence of insulin-dependent diabetes mellitus. This article presents the first-year results of our clinical experience. Information is presented concerning medical complications, screening and diagnostic test results and their confirmation, clinical procedures performed, and postpartum follow-up reports. Findings of pregnancy outcomes associated with low and high alpha-fetoprotein levels are presented and discussed.

A novel Y/13 familial translocation

A novel Y/13 translocation was discovered in a female fetus during amniocentesis. The familial translocation is present in a phenotypically normal female sibling and in the father who also possesses a pericentric inversion. Karyotype of the father is 46,XY,-13,+der(13)t(Y;13)(q12;p12),inv(22)(p13q12.1).