The effect of diet supplementation and addition of zinc in vitro on the growth-supporting property of amniotic fluid in African women

The effect of diet supplementation throughout pregnancy on third-trimester amniotic fluid growth-supporting activity (GSP) was studied in 100 African women; 32 were given zinc supplementation, 22 each animal and vegetable supplements, respectively, and 24 served as control subjects. No difference in GSP was noted in any of the four groups, the majority of fluids (65%) being noninhibitory. Zinc levels in fluids from African women were much lower than those described for other population groups at corresponding periods of gestation. Although zinc levels in liquor rose following dietary zinc supplementation, these remained lower than values described in white patients. In vitro addition of zinc (up to 153 mu moles per liter final concentration) to 17 noninhibitory African liquors resulted in these fluids becoming inhibitory.

Down syndrome: prevalence at birth, mortality and survival. A 17-year study

Analysis of comprehensive records over a period of 15 yr permits calculation of the total prevalence of Down Syndrome in an industrial city. The prevalence at birth is shown to have fallen from 1.70 per 1000 births in the period 1961--65 to 0.84 per 1000 births in 1971--75. The fall in prevalence can be shown to be largely due to a change in distribution of maternal age. An earlier increase in the number of Down Syndrome children is shown to reflect a greatly improved survival in the first 5 yr of life to a continuing level of 81%. The number of Down Syndrome children is unlikely to increase much even with increase of birth rate unless older mothers have further pregnancies. For these reasons the policies of amniocentesis of older women and termination of affected pregnancies will have progressively less effect on the number of affected children if this demographic trend continues. A further effect is that special schools will have a proportionately greater burden as the younger children being admitted have less prospect of development and may be more demanding of staff than Down Syndrome children.

Amniotic fluid testosterone and follicle-stimulating hormone in the determination of fetal sex

To determine whether hormone analysis could be used for accurate determination of fetal sex, we measured testosterone (T) and follicle-stimulating hormone (FSH) in 130 amniotic fluid samples at midgestation. The mean unconjugated T in amniotic fluid of 73 patients carrying male fetuses was 202 pg. per milliliter (95 per cent confidence limits [CL]: 70 to 580) and all but three had levels higher than 90 pg. per milliliter. The mean amniotic fluid unconjugated T for 49 patients carrying female fetuses of 41 pg. per milliliter (95 per cent CL: 11 TO 125) was fivefold lower than that for the male fetuses and all but three patients carrying female fetuses had amniotic fluid T levels of 90 pg. per milliliter or lower. The mean amniotic fluid FSH of 0.7 ml. U. per milliliter (95 per cent CL: less than 0.5 to 3.4) for subjects with male fetuses was tenfold lower than that for patients with female fetuses. Amniotic fluid FSH levels less than 2.0 ml. U. per milliliter were found in 88 per cent of patients carrying male fetuses and in only one patient with a female fetus, and levels greater than 10 ml. U. per milliliter were found in those with female fetuses only. In eight patients (7 per cent of cases), neither amniotic fluid T nor FSH determinations were indicative of fetal sex. Measurement of unconjugated T and FSH in amniotic fluid may be an adjunct to other methods of determining fetal sex.

Prenatal diagnosis of neural tube defects. III. A reevaluation of the alpha-fetoprotein assay

Alpha-fetoprotein was measured in 2209 amniotic fluid samples under improved assay conditions. All cases of open neural tube defects had elevated values greater than 5 SD above the mean. The false positive rate based on the 3 SD cutoff is estimated at less than 9.15%. Alpha-fetoprotein assays are recommended for all patients undergoing second trimester amniocentesis, optimally between 14 and 16 weeks' gestation.

Antenatal sex determination in Macaca arctoides

Transabdominal amniocentesis was performed on 11 Macaca arctoides, between the 10th and 20th weeks of gestation, for the purpose of antenatal sex determination. The technique employing Y-chromatin fluorescence was unsuccessful in predicting sex, but the sexes were differentiated with complete accuracy by examining amniotic cells stained by a modified Papanicolaou technique. Of the cells from male fetuses, fewer than 10% contained X-chromatin (Barr bodies); of those from females, more than 45% contained X-chromatin.

Amniotic cell 4-methylumbelliferyl-alpha-glucosidase activity for prenatal diagnosis of Pompe's disease

Using a simple fluorometric assay for alpha-glucosidase activity of cultured amniotic cells, we have monitored two pregnancies from families at risk for Pompe's disease. The fetus was judged to be affected in one, the pregnancy being terminated and unaffected in the other. The accuracy of these predictions was confirmed. These results suggest that this assay allows accurate prenatal diagnosis of Pompe's disease, three weeks after diagnostic amniocentesis.

Amniotic fluid alpha-fetoprotein as a marker in prenatal diagnosis of neural tube defects

The prenatal diagnosis of anencephaly and spina bifida (neural tube defect, NTD) through amniotic fluid analysis for alpha-fetoprotein (AFP) is gradually gaining clinical recognition. AFP concentrations were determined in 237 amniotic fluids from normal pregnancies ranging between 7 and 42 weeks of gestation. A steady decline in AFP from 26 mug/ml at 7-9 weeks to 155 ng/ml at term is observed. AFP concentration was determined in 35 amniotic fluids from 33 confirmed neural tube defective pregnancies. In 14 cases where amniotic fluid was examined prior to the 26th week of gestation. AFP was markedly elevated when compared with the normal range of the same gestational period. In 21 amniotic fluids past the 26th week, 17 cases (85-) had markedly elevated AFP levels; however, 2 cases of anencephaly, 1 of spina bifida, and 1 of hydrocephaly gave levels within the normal range. It is concluded that elevated AFP in the amniotic fluid is a reliable but nonspecific marker for open neural tube defects prior to the 26th week of pregnancy, but may become normal after the 26th week in a small percentage of patients.

Antenal sex determination using amniotic fluid of the baboon (Papio sp.)

Antenatal determination of sex in the baboon was performed by evaluating the percentage of sex chromatin bodies present in the epithelial cells of amniotic fluid obtained during or immediately following cesarean section. Female sex chromatin patterns revealed a mean of 39.2% positive sex chromatin; the mean in males was less than 5%. This procedure is accurate and simple to perform.

Protein measurements in the early prenatal diagnosis of spina bifida

Measurement of beta-lipoprotein concentration in amniotic fluid is introduced as a new parameter for the early prenatal diagnosis of spina bifida. It was successful in 15 cases of spinal bifida, but failed in 5 cases of open spina bifida and 2 cases of closed spina bifida. All assays were performed before the end of the second trimester and most between 15 and 20 weeks of pregnancy. beta-lipoprotein was compared with alpha-fetoprotein and alpha2-macroglobulin in its effectiveness in diagnosing spina bifida at an early enough date to allow a termination of pregnancy.

Diagnostic use of meternal serum alpha-fetoprotein levels

Alpha-fetoprotein (AFP) levels in human maternal serum were elevated in 14 patients when measured by a radioimmunoassay. In 8 patients the elveated serum levels of AFP correlated with increased concentration of AFP in amiotic fluid and were diagnostic of fetal defects. The elevated AFP levels in the remaining 6 patients were shown to be the result of fetomaternal transfusion from either amniocentesis or natural causes. Serum samples drawn after amniocentesis through an anterior placenta may show false-positive elevations. The use of both maternal serum and amniotic fluid samples in pregnancies at high risk for neural tube defects can decrease the risk of diagnostic errors due to mistakes in gestational datind and may increase the diagnostic sensitivity of amniocentesis.

Laminaria augmentation of intra-amniotic PGF2 for midtrimester pregnancy termination

In our hands, intra-amniotic PGF2alpha 40 mg for midtrimester pregnancy termination had a mean infusion to abortion interval of 29.4 hr. However, pretreatment of 230 patients with laminaria tents inserted 14-18 hr before PGF2alpha infusion resulted in a dramatically reduced time to abortion (14.3 hr mean) with a low incidence of gastrointestinal and other side effects. Laminaria tents inserted at the same time as PGF2alpha infusion in 26 patients also resulted in reduced time to abortion (18.6 hr mean). In the laminaria pretreated group, the infusion to abortion interval was indirectly related to the number of laminaria inserted and not to the nulliparous or parous state. Although we have made significant strides in shortening the abortion interval in the hospital, retained placentae and blood loss persist as problems related to the use of prostaglandin for abortion.