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Biomedical subjects

A Drugan

Publications and source records attributed to A Drugan.

At least 19 recordsLinked to original sources

Screening for neural tube defects.

Neural tube defects are separated into two main categories: (1) abnormalities of the skull and brain (anencephaly, acrania, and encephalocele) and (2) malformations of the spine (meningomyelocele or spina bifida). The cause of neural tube defects is not always clear, and include chromosomal abnormalities, single gene mutations, maternal disease, or maternal exposure to teratogens. Mostly the disorder emerges as a multifactorial trait. Routine screening for neural tube defects was introduced in the United Kingdom in the mid-1970s and the United States in the mid-1980s. The use of screening has resulted in a marked decline in the frequency of neural tube defects diagnosed at birth.

Female↗

Sonographic findings of the umbilical cord: implications for the risk of fetal chromosomal anomalies.

In this review we summarize current knowledge on sonographic findings of the umbilical cord and the risk they impose for chromosomal abnormalities of the fetus. A Medline search of the literature was performed and the pertinent English-language literature was reviewed. Anatomical and Doppler abnormalities of the umbilical cord may be associated with an increased risk of chromosomal aberrations in the fetus. Therefore, level II prenatal sonography should also include a careful examination of the umbilical cord.

Chromosome Aberrations↗

Ultrasound screening for fetal chromosome anomalies.

Ultrasound evidence for aneuploidy may be found in almost every organ of the fetus and can be used to modify the risk of aneuploidy. The diagnosis of these minor anomalies on second-trimester ultrasonography will increase the risk of an abnormal karyotype whereas the absence of these findings may reduce this danger. The most specific and most ominous isolated markers for fetal aneuploidy are nuchal findings (edema or cysts), indicating the need to obtain a fetal karyotype in all cases irrespective of maternal age or results of biochemical serum screening. Hyperechoic fetal bowel is apparently also a strong indicator of fetal aneuploidy. Other isolated sonographic markers may increase the risk of an abnormal karyotype three- to ninefold. Most sonographic markers for aneuploidy specify an increased risk for Down syndrome, but choroid plexus cysts are apparently more specific for trisomy 18. Along with other screening methods, ultrasound screening for fetal aneuploidy should be used routinely to identify additional pregnancies at need for evaluation of fetal karyotype.

Aneuploidy↗

Unequal pronuclear size--a powerful predictor of embryonic chromosome anomalies.

PURPOSE: Our purpose was to evaluate whether pronuclei of unequal size, observed in 13.7% of zygotes evaluated after in vitro fertilization (IVF), are predictive of chromosome anomalies in the developing embryo. METHODS: Five ploidy of 38 embryos grown from zygotes with unequal-sized pronuclei was assessed by fluorescent in situ hybridization (FISH). Twenty-six embryos developed after intracytoplasmic injection of sperm (ICSI) and 12 embryos were derived from conventional IVF. RESULTS: Chromosome anomalies were documented in the ICSI and IVF groups in 88.5 and 50% of cases, respectively. CONCLUSIONS: We suggest that FISH should be employed to examine the ploidy of zygotes with unequal pronuclei, prior to embryo transfer.

Adult↗

Early transvaginal embryo aspiration: a safer method for selective reduction in high order multiple gestations.

Assisted reproduction technologies and ovulation induction for treatment of infertility continue to cause high order multiple gestations. Increased perinatal morbidity and mortality, as well as maternal morbidity, may complicate these pregnancies. Selective fetal reduction, an acceptable therapeutic approach in these cases, is usually performed at or after the ninth week of gestation, with KCl injected in the vicinity of the fetal heart, and is associated with a total pregnancy loss rate of 11.7%. We report our experience with 90 women who underwent early (mean 7.5 weeks gestation, range 7. 0-8.0 weeks) transvaginal selective embryo aspiration. The mean number of viable embryos before and after reduction was 3.5 and 2.1 respectively. Six (6.7%) pregnancies were lost before 24 gestational weeks. One miscarriage occurred at the tenth gestational week. The other five pregnancies were aborted at 17.3-21.6 weeks gestation. Additional interventions were performed in three of these pregnancies: genetic amniocentesis in two cases and cervical suture in one case. In the subset of 39 patients with>/=4 embryos, only one (2.6%) pregnancy loss was recorded. This loss rate is significantly lower (P < 0.05) than the 15.3% loss rate in patients with >/=4 fetuses calculated from other work. Four (4.4%) other pregnancies were complicated by premature delivery (25-28 weeks gestation). Mean gestational age of delivered pregnancies in our series was 35.7 weeks. In conclusion, early transvaginal embryo aspiration is a simple and relatively safe method for multiple pregnancy reduction. The overall pregnancy loss rate associated with early embryo aspiration is similar to that of procedures performed at later gestational age, but is significantly lower when the initial number of embryos is four or greater.

Evaluation Studies as Topic↗

A missense mutation (His42Arg) in the T-protein gene from a large Israeli-Arab kindred with nonketotic hyperglycinemia.

Nonketotic hyperglycinemia (NKH) is caused by a mutation in the genes encoding the components of the glycine cleavage multi-enzyme system. More than 80% of the patients have defects in the gene encoding P-protein, whereas the rest of the patients have defects in the gene encoding T-protein. We have found a large Israeli-Arab kindred with NKH. At least 14 children were affected, and all the patients had seizures and respiratory failure within 2 days after birth. Enzymatic analysis revealed that T-protein activity was deficient in the liver specimen from one propositus. We screened this family for a mutation in the protein-coding region and exon/intron boundaries of T-protein gene by direct sequencing analysis. A missense mutation was found in exon 2; this resulted in an amino acid substitution from histidine to arginine at position 42 (H42R). Histidine 42 is conserved in human, bovine, chicken, pea, and Escherichia coli, suggesting that it has an important role in catalytic functions. Genotype analyses of 26 family members confirmed that the homozygous H42R mutation was completely associated with the onset of NKH. The availability of DNA testing facilitates the prenatal diagnosis of NKH and the identification of carriers, which is necessary for genetic counseling in the affected families.

Amino Acid Metabolism, Inborn Errors↗

Ultrasound imaging of fetal neck anomalies: implications for the risk of aneuploidy and structural anomalies.

This study summarizes 24,000 transvaginal ultrasound examinations which were performed in a predominantly low-risk population at 14-16 weeks' gestation. 1254 (5.2 per cent) fetuses had a nuchal fold or a non-septated cystic hygroma. Of these fetuses, 140 (11.1 per cent) had additional structural anomalies. Cardiovascular anomalies were the most commonly detected structural malformations. Forty-three (3.4 per cent) fetuses were aneuploid. Trisomy 21 was the most common chromosomal anomaly (n = 27). Aneuploidy was significantly more common in fetuses who had a nuchal finding and an associated structural anomaly. The prevalence of nuchal fold and non-septated cystic hygroma, as well as the incidence of their associated structural anomalies, was similar. Based on these data, it is concluded that a complete ultrasonic survey of the fetus and karyotyping are advocated in fetuses with a nuchal abnormality, irrespective of maternal age or triple serum screening results.

Adolescent↗

The geriatric gravida: multifetal pregnancy reduction, donor eggs, and aggressive infertility treatments.

OBJECTIVE: Recent technologic advances and societal acceptance have dramatically increased the use of donor eggs for infertile couples who require assisted reproductive technologies. Now many "older" couples can access assisted reproductive technologies to achieve pregnancies. We sought to evaluate the changing pattern of patients referred for multifetal pregnancy reduction as a result of donor eggs and age factors in aggressive infertility treatment. STUDY DESIGN: Patients undergoing multifetal pregnancy reduction from 1986 to 1996 were included and categorized by year groupings, age, and the use of donor eggs. RESULTS: A total of 523 patients were referred for and underwent multifetal pregnancy reduction. Before 1994, only 4 of 226 (1.8%) had received donor eggs, whereas in 1994 to 1996, 29 of 297 (9.8%) had received donor eggs (chi 2 = 12.6, p < 0.001). Eight of 9 patients aged > or = 45 years undergoing multifetal pregnancy reduction received donor eggs. There were no patients aged > or = 45 years before 1994 but 9 in 1994 to 1996. Four of 9 patients aged > or = 45 years with multifetal pregnancies chose reduction to singleton gestation. The proportions of patients aged > or = 40 years have increased from 0% to 11% in the last 8 years. CONCLUSIONS: The availability of donor eggs has dramatically increased the use of assisted reproductive technologies and subsequent use of multifetal pregnancy reduction in older patients. Older patients are more inclined to want reduction to singleton gestation; they cite parental demands, financial issues, and their ability to parent in their 60s and 70s as reasons for reduction to singleton gestation.

Adult↗

Race-ethnicity-specific variation in multiple-marker biochemical screening: alpha-fetoprotein, hCG, and estriol.

OBJECTIVE: To identify any race-ethnicity-specific differences in serum alpha-fetoprotein (AFP), hCG, and unconjugated estriol (E3) levels in women between 14 and 21 weeks' gestation. METHODS: Data from the 3-year period 1992-1994 were analyzed from 208,257 women who had AFP screening, of whom 155,142 also had hCG and 62,121 also had E3 screened, between 14 and 21 weeks' gestation. Subjects were categorized into four groups: white, black, Asian, and Hispanic. RESULTS: There was a consistent pattern of analyte differences across gestational ages. Levels for AFP were generally higher in Asian and black women than in Hispanic and white women (median AFP at 16 weeks-31.2, 30.9, 27.4, 27.3, respectively), and levels of hCG and E3 were highest in Asians (hCG at 16 weeks-34.7, 30.3, 28.2, 26.8, respectively). Weight correction for AFP, hCG, and E3 levels did not compensate for the ethnic differences. CONCLUSIONS: Because hCG and E3 demonstrate the same general pattern of differences as AFP among ethnic groups, averaging values for all ethnic groups tends inappropriately to lower calculated Down syndrome risks for black and Asian women. Additionally, the slopes of the curves are not parallel, such that separate data bases are preferable to multiplicative correction factors. Separate data bases should be used in laboratories with volume sufficient to permit the establishment of race-ethnicity-specific regressions. Use of separate data bases should result in more accurate screening.

Chorionic Gonadotropin↗

Parental decisions to terminate/continue following abnormal cytogenetic prenatal diagnosis: "what" is still more important than "when".

This study was undertaken to determine if parental decisions to continue or terminate following the diagnosis of a cytogenetic abnormality have changed over the past 8 years at the same center. Parental decisions in 310 prenatal chromosomal abnormalities were stratified by procedure (chorionic villus sampling [CVS] vs. amniocentesis) and the severity of the anomaly (severe vs mild-moderate). Patients with severe anomalies were much more likely to terminate regardless of gestational age. There was a trend (P = .107) toward a lower rate of termination for mild-moderate degrees in the second trimester. There was no change in patient's decisions over time. Patients' decisions about termination are focused on the severity of the disorder and only marginally influenced by when in gestation the decision is made.

Abortion, Eugenic↗

Aneuploidy among prenatally detected neural tube defects.

We have reported previously a 10% aneuploidy detection rate among 39 cases of fetal neural tube defects (NTD). Subsequently we amassed an additional experience of over 17,000 prenatal diagnosis cases over a 5-year period. During this period 106 cases of NTDs were identified; 44 with anencephaly, 62 with open spina bifida. The average maternal age of this population with NTDs was 29 years (15-40); 6 patients declined amniocentesis. Six of 100 cytogenetic studies were aneuploid; one anencephalic fetus had inherited a maternal marker chromosome, and 5 NTD cases had trisomy 18. The average maternal age of the aneuploid cases was 31 (19-40); 3 were 35 years or older. Four of 5 trisomy 18 cases had multiple congenital anomalies (MCA). The overall aneuploidy detection rate in our cohort was 5-6%, while aneuploidy occurred in 2% of the isolated NTD cases, and 24% of the MCA cases. Combining the earlier experience, 4/39 aneuploidy (2 trisomy 18, 4p+, del 13q) yields an aneuploidy detection frequency of 10/145 (7%), of which most (7/10) had trisomy 18. These data support fetal karyotyping for accurate diagnosis, prognosis, and recurrence-risk counseling.

Adolescent↗

Second-trimester minor ultrasound anomalies: impact on the risk of aneuploidy associated with advanced maternal age.

OBJECTIVE: To determine the impact of the presence or absence of minor ultrasound anomalies for the risk of aneuploidy in patients already at high risk because of advanced maternal age. METHODS: Eleven hundred forty-four women having amniocentesis for advanced maternal age were divided into those with minor ultrasound anomalies (n = 62) and those without (n = 1082). Two hundred fifty-nine women younger than 35 years but with minor anomalies on ultrasound were also included. RESULTS: Fetal aneuploidy was found in six of 62 (9.7%) women of advanced maternal age with minor ultrasound anomalies, in five of 1082 (0.5%) women older than 35 years with normal ultrasound results, and in five of 259 (1.9%) women younger than 35 years with minor ultrasound anomalies. CONCLUSION: Minor ultrasound anomalies increase considerably the risk of aneuploidy in women older than 35 years, and their absence lowers that risk slightly. Minor ultrasound anomalies in the fetuses of women younger than 35 raises their risk to that of a 39-year-old women in her second trimester. Ultrasound can be used to modify genetic risks at counseling and may help patients in their decision to have invasive testing.

Adult↗

Faint and positive amniotic fluid acetylcholinesterase with a normal sonogram.

OBJECTIVE: Both faint and positive amniotic fluid acetylcholinesterase determinations have been associated with fetal abnormalities. We evaluated the effect of a normal sonogram and positive or faint acetylcholinesterase level on the risk for anomalies. STUDY DESIGN: Between Jan. 1, 1989, and Feb. 1, 1995, 4859 amniocenteses were performed. Twenty-three cases of abnormal acetylcholinesterase determinations combined with normal sonograms were identified, and pregnancy outcomes were determined. RESULTS: One abnormal karyotype was identified (45,X/47,XXX mosaic). No neural tube defects were seen in infants with an abnormal acetylcholinesterase determination and normal sonogram. One fetus of a twin pregnancy had a ventral wall defect that was not detected on ultrasonography. Seventy-three percent of infants were normal at birth, but 27% of the pregnancies had abnormal outcomes. CONCLUSIONS: Advances in ultrasonography have led to improved detection of fetal abnormalities. With a normal karyotype, repeat invasive testing may not be necessary.

Acetylcholinesterase↗

Differential diagnosis and management of very low second trimester maternal serum unconjugated estriol levels, with special emphasis on the diagnosis of X-linked ichthyosis.

Incorporation of maternal serum unconjugated estriol into the calculation of risk may increase the yield of serum screening performed during pregnancy for detection of fetal chromosomal and structural anomalies. The differential diagnosis of very low and undetectable levels of unconjugated estriol in maternal serum is discussed, with special emphasis on the prenatal diagnosis of X-linked ichthyosis. The prenatal detection of these findings dictates skilled genetic counseling, targeted sonographic evaluation and examination of fetal karyotype and fetal cDNA for Xp 22.32 with amniotic fluid levels of cortisol, STS, and ASC.

Adult↗

Early prenatal diagnosis of polycystic pancreas with narrow thorax and short limb dwarfism.

We describe the ultrasound findings of polycystic pancreas with short rib dwarfism in the early second trimester. Radiologic, morphologic, and histologic examination after pregnancy termination confirmed the findings and also disclosed dysplastic kidneys. The skeletal anomalies are similar to those in Verma Naumoff type of short rib polydactyly, but the extraskeletal malformations have never been reported before in this syndrome.

Abnormalities, Multiple↗

Risk of anomalies as a function of level of elevated maternal serum alpha-fetoprotein.

OBJECTIVE: Most neural tube defects risks are not actual but mathematical extrapolations. We sought to evaluate this risk and to compare actual performance. STUDY DESIGN: This was a retrospective study of a referral population with elevated maternal serum alpha-fetoprotein results between 1987 and 1992. Ultrasonography results, delivery records, and autopsy results were compared with entry levels of maternal serum alpha-fetoprotein, and the percentage of fetal anomalies detected in this study was evaluated. RESULTS: A total of 773 patients with elevated maternal serum alpha-fetoprotein levels were evaluated. There was a progressive increase in the incidence of anomalies as a direct function of the level of the maternal serum AFP, varying from 3.4% at a level of 2.5 to 40.3% at a level > 7.0. CONCLUSION: Data from this study support the correlation of maternal serum AFP levels with the risk of neural tube defect and ventral wall defects.

Congenital Abnormalities↗