Problems posed by prenatal diagnosis of abdominal wall malformations

The authors present 6 observations of in utero detected abdominal wall defect : 2 laparoschisis and 4 omphaloceles. In three cases the diagnosis have been done prior week 20, by systematic AFP assay for amniocentesis performed for cytogenetic or metabolic reasons; the pregnancy was terminated. In three other cases, the pregnancy was complicated by hydramnios after week 30; amniocentesis for AFP and echography were performed to detect fetal malformations after associated with hydramnios. The detected abdominal wall anomaly was not alone: two fetus had an abnormal caryotype (trisomy 18), three other presented a polymalformative syndrome, a Beckwith-Wiedemann syndrome was discussed for the last child. The in utero diagnosis of omphalocele or laparoschisis implicates difficulties for genetic counselling, particularly if the diagnosis is done prior week 20. These anomalies can be treated with surgical management, but frequency of associated malformations must be underlined. it is important for genetic counselling to know the family history, the amniotic fluid cells caryotype, and an ultrasound scanning performed to reveal any other malformations.     

Biochemical markers of neural tube closure defects during the second half of pregnancy

Increasing number of amniocentesis done during the second half of gestation with indication "signe d'appel" made necessary for authors to study amniotic fluid markers in late pregnancy. Normal evolution curve must be established with samples obtained after 20 weeks gestation. Study reveals more false-negative results with AFP than before 20 weeks. AChE remains constantly positive in cases with NTD, band aspect being specific. For other malformations, AChE positivity seems inconstant, with a different aspect. Some normal gestation cases can be associated with faint AChE band.     

Results of an experiment in systematic prenatal screening for neural tube malformations by assay of alpha fetoproteins in dried blood samples (12,480 pregnancies)

Measurement of alpha-fetoprotein (AFP) in eluate of dried blood was carried out in 12,480 pregnant women, between the 10th and 30th weeks of amenorrhea. In 348 cases, AFP level was greater than normal (greater than 99th centile). 225 control measurements were performed (123 women dropped out of the study). In 173 cases, the AFP level returned to normal (1.4% false positives). In 52 cases, AFP title remained above the 99th centile: in 8 cases, the fetus was malformed (4 anencephalics, 1 spina bifida, 1 hydrocephalus, 1 laparoschisis, 1 exomphalos). Of the 44 remaining cases, 26 were multiple pregnancies, 5 were cases of acute fetal distress, 7 false positives normalized when a second control was made, 5 false positives up to the end of pregnancy, and 1 spina bifida (normal ultrasound scan on two different occasions). During this prenatal screening, 7 false negatives (0.56%) not detected by AFP assay should be noted: 3 anencephalics, 2 spina bifida, 1 hydrocephalus, 1 exomphalos. In all cases except one, the AFP test was carried out too early (before the 10th week) or too late (after the 30th week). The authors stress that screening must be done during the precise period between the 16th and 20th weeks of amenorrhea, and that close collaboration with a competent ultrasonographist is necessary. In 5 cases of false negatives where AFP assay and ultrasound scan had been carried out, the two methods are compared. Measurement of AFP in eluate of dried blood thus seems a reliable test which could be the first stage in a plan for systematic prenatal screening for certain serious fetal malformations with high incidence (1,2% in the Midi-Pyrenees region).     

A retrospective study of pregnancy complications among 828 cases of arthrogryposis

828 cases with multiple congenital contractures (arthrogryposis) were categorized and histories were reviewed to identify pregnancy complications. 53.0% of cases had a specified diagnosis or known cause and no diagnosis was found for 47.0% of which 27.2% were though to probably have a genetic basis and 19.8% were of unknown etiology. Our data provides no evidence to support the suggestion that arthrogryposis is frequently a result of environmental or structural causes including uterine structural anomaly, intra-uterine infection, etc. Normal frequencies of bleeding, hormone treatment during gestation, amniotic fluid leakage, uterine anomaly, maternal illness, and maternal and paternal age were noted. Apparent, increased frequencies of twinning, severe nausea, polyhydramnios and oligohydramnios were observed. In particular, the frequency of polyhydramnios was dramatically increased among lethal cases (vs survivors) and thus, polyhydramnios appears to be a poor prognostic sign when associated with decreased fetal movement. Large case control studies with complete pregnancy histories are needed to confirm these results and to definitively identify pregnancy complications that are useful "flags" to indicate decreased fetal movement in utero and thus, aid in the identification of primary causes of arthrogryposis.     

Distribution of alpha 1-fetoprotein in fetal plasma, allantoic fluid, amniotic fluid and maternal plasma of cows.

Maximal concentrations of AFP, measured by RIA, were obtained in fetal plasma and amniotic and allantoic fluid between the 3rd and 4th month of gestation, with levels declining thereafter until term. AFP values in maternal plasma were unchanged. Throughout gestation, AFP values were higher in allantoic than in amniotic fluid and the ratio of allantoic fluid/amniotic fluid AFP was significantly correlated with gestational age.     

A simple two-step purification of human and monkey alpha fetoprotein from amniotic fluid and serum.

We developed a two-step purification system to characterize alpha fetoprotein (AFP) in early gestation amniotic fluid and late gestation fetal serum or cord blood from monkey and human. It involves only two chromatographic steps, allows preparative purification using up to 12 ml of starting sample, can purify up to 350 micrograms of AFP at one time, and can be used to purify both fetal serum or amniotic fluid AFP from two different species. This procedure will allow detailed biochemical analysis of purified AFP from different stages of fetal development.     

Rat alpha-fetoprotein: isolation, radioimmunoassay and fetal-maternal distribution during pregnancy.

A method is described for the isolation of mg quantities of two forms of rat alpha-fetoprotein (AFP) from amniotic fluid by preparative disc-gel column electrophoresis using a continuous elution system. AFP isolated by this method is suitable for use as an antigen, can be labelled for use in a radioimmunoassay and serves as a reference standard. The characteristics of a new antiserum to AFP are also described. The protocol for a radioimmunoassay is outlined which permits the measurement of AFP in several fetal-maternal physiological compartments throughout gestation. Levels of AFP in fetal liver and fetal plasma suggest that secretion of AFP from liver occurs soon after synthesis with minimal hepatic storage. The pattern for AFP in maternal serum parallels that observed in amniotic fluid and fluctuations in maternal serum levels of AFP appear to be buffered by AFP accumulation in amniotic fluid. Fetal clearance of AFP under normal conditions may be relatively constant from Days 11-20 of gestation since an amniotic fluid: maternal serum AFP ratio of 30:1 is maintained during this period.     

Distribution of alpha-fetoprotein in fetal plasma and in amniotic and allantoic fluids of the pig

The concentration of AFP in the plasma of fetal pigs was highest in early gestation (Days 15-30) and declined with advancing gestation. This pattern was comparable to those observed in other mammals with similar lengths of gestation. In contrast, allantoic and amniotic fluid AFP concentrations were highest during the middle third of gestation but these concentrations were much lower than those in fetal plasma throughout gestation. The allantois appears to be a significant distribution space for AFP in early gestation.     

On the significance of true trisomy 20 mosaicism in amniotic fluid culture

Summary Nine new cases of prenatally detected true mosaic trisomy 20 (T20) are reported. In three instances the fetuses were aborted. One fetus showed multiple malformations associated with a high percentage of T20 cells among amniotic fluid (AF) cells and fibroblasts of different fetal tissues. In two other fetuses only a slight facial dysmorphy was seen which was accompanied by a low percentage of T20 cells among AF cells. In five instances the pregnancies were carried to term, and normal somatic and psychomotor development of the children has been observed, in one case up to the age of 24 months. In one case the pregnancy is continuing. The T20 cells were not detected among cultured lymphocytes of these children.A review of the hitherto known cases of prenatally detected mosaic T20 indicates a relationship between the prenatal findings and the fetal development. This may serve as a provisory basis for genetic counselling: in the case of a percentage above 50% of T20 cells among AF cells there seems to be a risk of about 50% for the fetus to be affected by severe anomalies. However, in cases of a prenatally detected mosaic T20 with a percentage equal to or less than 50, fetal or congenital malformations have not been observed among 23 individuals so far examined.     

Fetal toxicity of valsartan and possible reversible adverse side effects

BACKGROUND: Published cases suggest that the use of angiotensin II receptor antagonists is fetotoxic during the third trimester, but not in early pregnancy. CASE: We report a case in which the adverse fetal effect of angiotensin II receptor antagonist treatment was reversed. A woman with chronic hypertension was treated with valsartan until gestation week (GW) 20, when a complete anhydramnios was observed. Six days after interruption of the treatment, amniotic fluid reappeared. It reached a normal level at GW 23.5. The plasmatic creatinine level and the renal ultrasound examination were within normal limits at the six-month follow-up. CONCLUSIONS: Whereas angiotensin-II-receptor antagonist generates a severe renal toxicity, this case suggests that, at least in the first half of pregnancy, these effects can be reversed.     

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development.

Aliquotes of human amniotic fluid (AF), fetal serum (FS), and cord blood (CB) were obtained as by-products of routine clinical diagnostic procedures at term or in the second trimester of pregnancy. When samples of CB were applied to a pH 5.5-4 chromatofocusing gradient, three isoforms of AFP could be resolved; a pl 4.57 form (isoform IA, 52% AFP), a pl 4.27 form (isoform IB, 43% AFP), and one species that was bound to the column but could be eluted with 1.0 M NaCl (isoform II, pl less than 4.00, 5% AFP). Term AF displayed a profile similar to that observed in term CB. When samples of 15-20-week gestation AF were chromatofocused, the immunoreactive AFP recovered was distributed between isoform IA and IB (60%) and isoform II (40%). FS and AF obtained from same pregnancy (23-26 weeks) displayed an identical chromatofocusing profile. Aliquotes of AF subjected to conA revealed 83% reactive variants compared with greater than 95% reactive variants for CB. FS displayed a conA profile identical to CB. When individual CB charge isoforms were isolated and subjected to conA analysis, greater than 97% of the AFP bound to conA. In contrast, when AFP isoform IA and IB were isolated from midgestation AF, approximately 22% of the AFP did not bind to the lectin while 100% of isolated AFP isoform II eluted as the reactive variant. These data suggest that human AFP exists as at least three charge and two lectin variants and that the charge profile may change during fetal development.     

Glial origin of rapidly adhering amniotic fluid cells.

Rapidly adhering cells (RA cells) from the amniotic fluid of a pregnancy with fetal anencephaly were investigated by immunofluorescence assay with an antiserum against glial cells. After 24 hours'' cultivation a high proportion of the cells showed positive glial-specific fluorescence, whereas no staining was seen in cells from samples of normal amniotic fluid. At the 24th week the mother was delivered of a stillborn infant with anencephaly. Immunofluorescence staining of RA cells with glial-specific antiserum may be used for the differential diagnosis of fetal abnormalities associated with a high alpha-fetoprotein concentration in amniotic fluid.     

alpha-Fetoprotein values in monkey (Macaca mulatta) pregnancy.

The pregnant rhesus monkey's (Macaca mulatta) potential as a model for understanding the dynamics of alpha-fetoprotein (AFP) metabolism in human pregnancy was evaluated. AFP levels in maternal and fetal serum and amniotic fluid were determined by radioimmunoassay. Significant correlations were found between decreasing maternal serum, fetal serum and amniotic fluid AFP concentrations and increasing gestational age. However, these data are not consistent with the AFP changes reported in human pregnancy. It appears that this animal has limited applicability as a model in this aspect of human pregnancy.     

Iron and copper concentrations in the maternal and fetal serum, placenta and amniotic fluid during the reproductive stadium as well as in the milk of rabbits

Serum concentrations of iron and copper from rabbits (New Zealand White hybrids; N = 12) were determined during the reproductive stadium (gestation and four weeks of lactation). Samples of serum from fetuses, placental tissue and amniotic fluid were also examined. Iron: a decrease of iron in the maternal serum during the second half of gestation was observed, whilst a significant rise occurred in the first week of lactation. The content of iron in the fetal serum dropped from day 21 to day 28 of gestation. The iron concentration in the placental tissue decreased during this time. A rise of the iron level in the amniotic fluid was determined from day 21 to day 28 of gestation. The iron content in the milk was about 33 mumol/l (first and second day of lactation). Copper: in the first half of pregnancy the copper level diminished slightly compared with the content of non-pregnant, non-lactating rabbits, while a rise was observed in the fourth week of this period. The copper concentration decreased in the first week of lactation and then reached the peak level in the second week of this phase. The copper level in the fetal serum declined from day 21 to day 28 of gestation, while the copper content in the amniotic fluid increased significantly on day 28, in comparison with day 21 of gestation. In contrast, a decline of the copper concentration in the placental tissue was noticed from day 21 to day 28 of this period. The copper content in the milk was nearly 25 mumol/l (first and second day of lactation).     

Ultrasonography in early pregnancy diagnosis and measurements of fetal size in reindeer (Rangifer tarandus tarandus)

Transrectal or transabdominal examinations of 13 pluriparous reindeer (Rangifer tarandus tarandus) by ultrasonography from the start of mating until week 20 of gestation were conducted to find out when pregnancy could first be detected and to describe fetal development in early pregnancy. The examinations (n=35 per animal) were performed with a 5 MHz linear transducer from 7th October until 1st January and with a 3 MHz sector transducer from that time until 24th February. Time of pregnancy diagnosis by ultrasonography, the first fetal heartbeat and measurements of crown-rump length, chest width and chest depth were recorded during the examinations. Pregnancy was diagnosed by transrectal ultrasonography between the weeks 3 and 7 of gestation. The accuracy of the pregnancy diagnosis, defined as the proportion of females correctly detected to be pregnant, was 15% at week 3, 46% at week 4, 77% at week 5, and 92% at week 6 of gestation. Fetal heartbeat was first detected between the weeks 5 and 8 of gestation. The first measurements of crown-rump length were made on week 3 of gestation, of chest width on week 4 and of chest depth on week 5 of gestation. Chest width and depth were detectable until the end of the study at week 20 of gestation. Transrectal ultrasonography is an efficient tool in early pregnancy diagnosis of reindeer. The fetal growth curves obtained by ultrasonography resembled those obtained in previous morphological studies.     

Pregnancy-specific protein B (PSPB), progesterone and some biochemical attributes concentrations in the fetal fluids and serum and its relationship with fetal and placental characteristics of Iraqi riverine buffalo (Bubalus bubalis)

This study was carried out to demonstrate the pregnancy-specific protein B (PSPB), progesterone and some biochemical parameters concentrations in amniotic fluid, allantoic fluid and fetal serum collected from slaughtered Iraqi riverine pregnant buffaloes at three different months of gestation (6th, 7th and 8th). Ten out of 22 adult buffaloes of 4.6 ± 0.97 years old were used in this study. The buffaloes were mated naturally by monitoring the estrus cycles via appearance of vaginal fluids and mounting by bulls. Pregnancy was checked for these buffaloes by non-returning to estrus for three estrus cycles and assured by rectal palpation on day 61 post-mating (PM). Buffaloes were slaughtered at three different periods of gestation (three at 6th month, four at 7th month and three at 8th month of gestation) to verify the progesterone and PSPB as well as some blood attributes levels (glucose, cholesterol, total protein, albumin, globulins and albumin: globulins ratio) in amniotic fluid (AF), allantoic fluid (LF) and fetal serum (FS). Progesterone was higher (P<0.01) in LF at the 8th month of gestation and lower in FS during the 7th and 8th months of pregnancy. PSPB concentrations were greater in FS (6th and 8th months in particular) than in both AF and LF. The overall mean of cholesterol concentration was higher in FS (P<0.05) followed by AF and LF that had the lowest concentration. The FS exhibited higher total protein during the three gestation periods. Most of fetal and placental measurements increased as the pregnancy advanced. In conclusion, these results described, for the first time, the PSPB and progesterone concentrations and blood characteristics in fetal fluids and serum in water riverine buffaloes during different stages of pregnancy. Progesterone concentrations were greater in allantoic fluid than in other fluids. In contrast, PSPB and other blood attributes were higher in fetal serum than other fluids of Iraqi riverine buffaloes. These findings reflect the changes in hormones, proteins and other metabolites during different gestation periods.     

Amniotic fluid beta-2 microglobulin in normal and complicated pregnancies

Beta-2 microglobulin concentrations were measured in amniotic fluid samples obtained from normal pregnant women at various stages of gestation and complicated pregnancies during weeks 32-42 of gestation by the ELISA method. The concentration of beta-2 microglobulin in amniotic fluid increases markedly up to the 20-24th weeks of pregnancy and reaches a peak during the second trimester, occasionally reaching an eightfold value compared to the maternal serum concentration, while at term the values are similar. The decrease of amniotic fluid beta-2 microglobulin level in the third trimester reflects the maturation of foetal renal tubular function and suggests that this test may be of significance in determining foetal age. Our results revealing elevated concentrations of beta-2 microglobulin in patients with diabetes, toxaemia and placental insufficiency may indicate slower renal maturation of the foetus.     

Concentrations of serum cortisol, progesterone, estradiol-17 beta, cholesterol and cholesterol ester in the doe during the reproductive stadium, in the fetal serum, in the amniotic fluid and in the milk of rabbits, as well as correlations between these parameters

1. Serum progesterone, estradiol-17 beta and cortisol, as well as cholesterol and cholesterol ester concentrations in pregnant and lactating rabbits (New Zealand white hybrids, n = 9), were measured. These parameters were also studied in the amniotic fluid, the milk and the fetal serum (28-day old fetuses). 2. Serum progesterone and estradiol-17 beta were significantly enhanced during gestation, while the content of cortisol showed a marked elevation at the end of pregnancy. The concentrations of these hormones decreased before parturition. 3. Serum cholesterol and cholesterol ester concentrations markedly decreased in the second half of gestation (74 and 76%, respectively) and elevated after parturition and in the first week of lactation.     

Anencephaly in trisomy 18 associated with elevated alpha-1-fetoprotein in amniotic fluid

Summary Elevated levels of alpha-1-fetoprotein (AFP) were found in the amniotic fluid of a 36-year-old woman in the 15th week of gestation. Because of this and the results of repeated ultrasonography, abortion was induced. An anencephalic fetus with trisomy 18 was delivered. The possible correlation among neural-tube defects, chromosomal abnormalities, and level of AFP is discussed.     

Risk of minor and major fetal malformations in diabetics with high haemoglobin A1c values in early pregnancy.

Maternal haemoglobin A1c (HbA1c) values were measured before the end of the 15th week of gestation in 142 pregnancies in women with insulin dependent diabetes. In pregnancies complicated by fetal malformations (n = 17) the mean initial HbA1c value was 9.5 (SD 1.8)% of the total haemoglobin concentration, which was significantly (p less than 0.001) higher than in pregnancies without malformations (8.0 (SD 1.4)%; n = 125). HbA1c values did not differ between pregnancies complicated by minor and major fetal malformations, but the rate of malformations showed a positive relation to the HbA1c value in early pregnancy (chi 2 = 11.9; p = 0.001). Fetal malformations occurred in six out of 17 pregnancies (35.3%) in mothers whose initial HbA1c value was 10% or more, in eight out of 62 pregnancies (12.9%) in mothers with initial values between 8.0% and 9.9%, and in only three out of 63 pregnancies (4.8%) in mothers with an initial value below 8.0%. These data support the hypothesis that the increased incidence of fetal malformations in mothers with insulin dependent diabetes is associated with maternal hyperglycaemia during organogenesis. Hence diabetic women who are planning to have a child--especially those with a high HbA1c value--should receive intensified metabolic control.