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Biomedical subjects

T E Cohen-Overbeek

Publications and source records attributed to T E Cohen-Overbeek.

31 records · Page 2Linked to original sources
PubMed1994

Cordocentesis for rapid karyotyping in fetuses with congenital anomalies or severe IUGR.

The objective was to determine the role of percutaneous umbilical blood sampling (cordocentesis) as a rapid technique for chromosome analysis in a high risk obstetric population. Cordocentesis was attempted in 167 pregnant women (168 fetuses) with IUGR, a single anomaly or multiple anomalies. Gestational age ranged between 17 and 37 weeks. The procedure was successful in 152 (90%) fetuses with a blood sample withdrawan at first attempt in 80%. Neither technique was associated with any false negative or false positive findings. Postprocedural complications included one case of persistent fetal bradycardia, but no fetal death. In nine cases amniotic fluid was collected, resulting in 161 fetal blood or amniotic fluid samples for chromosome analysis. An abnormal chromosome pattern (n = 26) was established in 1/12 cases (8%) of severe IUGR, 6/88 cases (7%) with a single structural anomaly and 19/61 cases (31%) with multiple structural anomalies. In the presence of an abnormal chromosome pattern, the perinatal mortality rate was as high as 96%. There is a high association between multiple fetal anomalies and abnormal chromosome pattern.

Amniotic Fluid↗
PubMed1994

Maternal serum markers in second-trimester oligohydramnios.

The levels of the maternal serum markers alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), and unconjugated oestriol (uE3) in 35 pregnant women with early second-trimester oligohydramnios differed from those in a reference population of 1699 singleton pregnancies. Maternal serum AFP levels above the 95th centile of the population distribution were observed in 80 per cent (16/20) of oligohydramnios cases with a normal fetus and in only 20 per cent (3/15) of the cases with a fetus displaying urogenital tract malformations. Elevated levels of hCG (above the 95th centile) and decreased levels of uE3 (below the fifth centile) were encountered in 26 per cent (9/35) and 17 per cent (6/35) of the women, irrespective of the fetal condition. The abnormal profile of the serum markers in early second-trimester oligohydramnios resulted in 57 per cent (20 out of 35) of screen-positive cases for either fetal Down's syndrome or neural tube defects, compared with 8.4 per cent (143 out of 1699) in the reference population.

Chorionic Gonadotropin↗
PubMed1993

Severe limb abnormalities: analysis of a cluster of five cases born during a period of 45 days.

We report on 5 individuals with severe limb abnormalities born in our hospital within a period of 45 days. Detailed clinical descriptions, photographs, and radiographs are presented. Etiological evaluations included genetic background, obstetric history, invasive procedures during pregnancy, maternal infectious diseases or maternal hyperthermia, drug use before and during pregnancy, and occupational or recreational exposures of both parents.

Abnormalities, Multiple↗
PubMed1993

Fetal renal artery flow velocity waveforms in the presence of congenital renal tract anomalies.

Colour Doppler flow mapping of the renal arteries and subsequent pulsed Doppler measurement of impedance to flow in these vessels were attempted in 33 fetuses with postnatally confirmed renal pathology. The majority presented with unilateral or bilateral hydronephrosis (n = 21) and bilateral renal agenesis (n = 8). Renal artery blood flow could be visualized in all, except for the eight cases of bilateral renal agenesis. Bilateral flow velocity recordings were collected in six out of 12 cases of bilateral hydronephrosis and in five out of nine cases of unilateral hydronephrosis. The pulsatility index (PI), as a measure of downstream impedance, was in the normal range in 16 out of 18 kidneys (88 per cent) in bilateral hydronephrosis and in 12 out of 14 kidneys (85 per cent) in unilateral hydronephrosis. The PI was significantly higher in severe hydronephrosis compared with mild hydronephrosis. In four cases of unilateral multicystic kidney, the PI was always higher on the affected side. Colour Doppler flow mapping and pulsed Doppler evaluation may be helpful in our understanding of renal vascularization in renal pathology and in confirming the diagnosis of renal agenesis.

Fetal Diseases↗
PubMed1993

The predictive value of uterine artery flow velocity waveforms in miscarriage in older women.

OBJECTIVE: To determine whether uterine artery blood flow velocity measurements can predict miscarriage in older women. DESIGN: Prospective study. SUBJECTS: Three hundred and ninety-three women aged 35 years and older in the first trimester of pregnancy. MAIN OUTCOME MEASURES: Miscarriage, genetic abortion, pulsatility index (PI), maternal age, gestational age at intake. RESULTS: Twenty women miscarried; 10 pregnancies were terminated because of chromosomal anomalies. Maternal age and gestational age at intake were significantly associated with miscarriage rate (P = 0.01 and P = 0.001, respectively). Uterine artery PI values declined significantly during the first trimester (P = 0.001). However, no association was found between uterine artery PI values and miscarriage rate. PI, maternal age and gestational age at intake were not essentially different between women who miscarried before or after chorionic villus sampling. No association was found between PI, maternal age, and gestational age at intake and genetic abortion rate. CONCLUSIONS: Uterine artery blood flow velocity waveforms, as expressed by the pulsatility index, bear no relation to miscarriage.

Abortion, Spontaneous↗
PubMed1992

Maternal serum alpha-fetoprotein levels and fetal outcome in early second-trimester oligohydramnios.

Early second-trimester oligohydramnios was associated with normal maternal serum alpha-fetoprotein (MSAFP) levels in nine out of 26 cases (35 per cent). Congenital malformations of the fetal urinary tract resulting in fetal anuria were present in nine cases; in seven of them, normal MSAFP levels were measured. In contrast, normal MSAFP levels were established in only 2 out of the 17 cases without fetal malformations. These data suggest that fetal urine is the major source of elevated AFP in the maternal compartment in early second-trimester oligohydramnios. This is further supported by the lack of any relationship between concentrations of MSAFP non-reactive with Concanavalin A, originating mainly from the yolk sac-derived amniotic fluid AFP pool, and the presence of fetal diuresis. Three out of 26 women had experienced early second-trimester oligohydramnios in a previous pregnancy, suggesting the existence of a recurrence risk for this condition.

Concanavalin A↗
PubMed1991

Transcervical (TC) and transabdominal (TA) CVS for prenatal diagnosis in Rotterdam: experience with 3611 cases.

Data from 3611 consecutive CVS (TC, N = 1780; TA, N = 1831) were analysed with emphasis put on influence of maternal and gestational age at CVS on the fetal loss rate less than 28 weeks. For TC-CVS the gestational age varied from 9.3-11.6 weeks, for TA-CVS from 9.3-20 weeks. Sampling efficacy at first attempt was 86.5 per cent and 95 per cent respectively. In 4.6 per cent an abnormal result was established. In older mothers (N = 2362) the fetal loss rate was significantly higher (p = less than 0.05) when sampled before 12 weeks (TC-CVS 6.2 per cent, TA-CVS 5.8 per cent). When the CVS (TA) was performed after 12 weeks the fetal loss rate decreased to 2.4 per cent. In 1079 younger women the fetal loss rate remained low (TC 2.8 per cent; TA less than 12 weeks 1.8 per cent; TA greater than 12 weeks 1.7 per cent) and was not influenced by gestational age at the time of sampling. We concluded both methods safe and reliable when the choice of application considers maternal age.

Abortion, Therapeutic↗
PubMed1990

Spontaneous abortion rate and advanced maternal age: consequences for prenatal diagnosis.

Maternal age related and procedure-related fetal abortion rates were studied in 384 women aged 36 and over scheduled for transabdominal chorionic villus sampling (TA-CVS) at 12-14 weeks of gestation. The pre-TA-CVS abortion rate within 30 days of intake (at 6-10 weeks of gestation) rose from 1.9% at age 35-36 years to 10.9% at 40 years and older. Women entering in the 6th week of gestation had a greater probability of aborting before TA-CVS than women entering after day 48. 26 women aborted spontaneously before TA-CVS, the majority of abortions occurring at 10-12 weeks. TA-CVS was done in 346 women. 11 pregnancies were terminated because of genetic anomalies, and 8 women had spontaneous fetal loss. These findings justify delaying prenatal diagnosis in older pregnant women until 12 weeks of gestation.

Abortion, Spontaneous↗
PubMed1990

Transabdominal villus sampling in early second trimester: a safe sampling method for women of advanced age.

Transabdominal chorionic villus sampling (TA-CVS) was performed in 707 viable singleton pregnancies to exclude chromosomal abnormalities. Maternal age ranged between 36 and 49 years (mean 37.9 years); gestational age varied between 10.2 and 18.3 weeks (mean 13.3 weeks). In 639 women (90.4 per cent), a sufficient amount of chorionic tissue (greater than or equal to 10 mg) was obtained after one needle insertion; in 66 women (9.3 per cent) two insertions were needed. An abnormal chromosome pattern was established in 19 cases (2.9 per cent). Vaginal bleeding or spotting within 28 days after TA-CVS occurred in 11 cases (1.5 per cent). The completed follow-up of 678 chromosomally normal pregnancies showed an overall fetal loss rate of 2.6 per cent before 28 weeks. The overall perinatal mortality was 0.9 per cent. When relating fetal loss to gestational age at TA-CVS, this was 6.6 per cent in women sampled before 12 weeks against only 1.8 per cent after 12 weeks. At the same time, the percentage of fetal loss occurring within 2 weeks following the procedure was 75 and 30 per cent, respectively. It is suggested that these data reflect the decline in spontaneous abortion rate during this particular period of pregnancy. It is concluded that TA-CVS is an effective procedure which, when performed after the natural decrease of fetal loss, appears to be a safe option for women of advanced maternal age.

Abdomen↗
PubMed1990

Uterine bloodflow velocity waveforms before and after transcervical chorionic villus sampling.

Flow velocity waveforms from the left and right uterine artery were studied relative to transcervical chorionic villus sampling (CVS) between 9 and 11 weeks of gestation in 12 uncomplicated pregnancies and 5 pregnancies resulting in second trimester fetal loss. There was no significant difference in mean pulsatility index (PI) as a measure of downstream impedance, between the left and right uterine artery. There were also no significant changes in PI relative to the CVS procedure both in uncomplicated pregnancies and in pregnancies ending in second trimester fetal loss.

Adult↗
PubMed1990

Uterine and fetal umbilical artery flow velocity waveforms in normal first trimester pregnancies.

In 85 normal singleton pregnancies between 8 and 13 weeks gestation, Doppler flow velocity waveform recordings were attempted from the left and right uterine artery and fetal umbilical artery. Acceptable waveforms were obtained from the uterine arteries in 83 and from the fetal umbilical artery in 61 of the 85 pregnancies. There was virtually no difference between the left and right uterine artery on average. The marked decrease in pulsatility (PI) and resistance (RI) indices from both uterine arteries reflects the ongoing process of secondary trophoblast invasion into the muscular part of the spiral arteries. Absent end-diastolic velocities were observed in 59 of 61 fetal umbilical artery flow velocity waveform recordings. PI values from the fetal umbilical artery suggest unaltered umbilical placental vascular resistance during the first trimester of pregnancy.

Blood Flow Velocity↗
PubMed1983

New doppler technique for assessing uteroplacental blood flow.

Gated, pulsed, doppler ultrasound was used to study blood flow velocity profiles in the uterine vessels (arcuate arteries) during the second and third trimesters of pregnancy. A frequency index profile nomogram was constructed from 30 normal pregnancies; this demonstrated high diastolic velocity and low pulsatility. Among 31 pregnancies with complications 14 showed waveform changes suggesting raised vascular resistance; these pregnancies were complicated with a high frequency of proteinuric hypertension, poor fetal growth, and fetal hypoxia. This non-invasive technique may give early warning of impaired uteroplacental perfusion and can be used to evaluate methods of improving uterine blood flow.

Doppler Effect↗