Artificial intelligence for prenatal chromosome analysis

This review article delves into the rapidly advancing domain of prenatal diagnostics, with a primary focus on the detection and management of chromosomal abnormalities such as trisomy 13 ("Patau syndrome)", "trisomy 18 (Edwards syndrome)", and "trisomy 21 (Down syndrome)". The objective of the study is to examine the utilization and effectiveness of novel computational methodologies, such as "machine learning (ML)", "deep learning (DL)", and data analysis, in enhancing the detection rates and accuracy of these prenatal conditions. The contribution of the article lies in its comprehensive examination of advancements in "Non-Invasive Prenatal Testing (NIPT)", prenatal screening, genomics, and medical imaging. It highlights the potential of these techniques for prenatal diagnosis and the contributions of ML and DL to these advancements. It highlights the application of ensemble models and transfer learning to improving model performance, especially with limited datasets. This also delves into optimal feature selection and fusion of high-dimensional features, underscoring the need for future research in these areas. The review finds that ML and DL have substantially improved the detection and management of prenatal conditions, despite limitations such as small sample sizes and issues related to model generalizability. It recognizes the promising results achieved through the use of ensemble models and transfer learning in prenatal diagnostics. The review also notes the increased importance of feature selection and high-dimensional feature fusion in the development and training of predictive models. The findings underline the crucial role of AI and machine learning techniques in early detection and improved therapeutic strategies in prenatal diagnostics, highlighting a pressing need for further research in this area.

Prevalence of cytogenetic abnormalities and FMR1 gene premutation in a Portuguese population with premature ovarian insufficiency

INTRODUCTION

Chromosome abnormalities contribute to about 10% of cases of premature ovarian insufficiency. Most are associated with X chromosome. Fragile mental retardation 1 (FMR1) gene premutation has an estimated prevalence of 1% - 7% in sporadic cases and up to 13% in familial cases. Our aim was to describe the clinical characteristics, cytogenetic and FMR1 testing of a Portuguese population with premature ovarian insufficiency.

MATERIAL AND METHODS

Women diagnosed with premature ovarian insufficiency in a Portuguese tertiary centre were retrospectivelyanalysed. Data were retrieved from electronic medical records including clinical characteristics, cytogenetic and FMR1 testing. The main outcome measures were the prevalence of chromosome abnormalities and FMR1 premutation in a Portuguese population with premature ovarian insufficiency.

RESULTS

Ninety-four patients were included, with a median age at menopause of 36 years. The prevalence of chromosome abnormalities was 16.5% (14/85) and most were X chromosome related (78.6%). The prevalence of FMR1 premutation was 6.7% (6/90). The prevalence of karyotypic abnormalities or FMR1 premutation did not differ significantly between familial and sporadic cases. Neither chromosome abnormalities nor FMR1 premutation influenced age at menopause or follicle stimulating hormone levels at diagnosis in premature ovarian insufficiency patients.

DISCUSSION

This is the first study describing the clinical characteristics and both cytogenetic and FMR1 testing in a Portuguese population with premature ovarian insufficiency. The rate of chromosome abnormalities in our sample was higher than in other populations, while the prevalence of FMR1 premutation was similar to previous reports.

CONCLUSION

Our results underline the importance of genetic screening in premature ovarian insufficiency patients in both etiological study and genetic counselling.

Three cases of low chiasma frequency associated with infertility in man

Three new cases of low chiasma frequency in infertile men are described. In the first case, all cells showed abnormal diakineses; in the second, 20% of the diakineses were desynaptic, while the remaining 80% were normal; in the third, all diakineses were desynaptic and showed chromosome fragmentation. The possible mechanisms leading to asynapsis, desynapsis or precocious chiasma terminalization are discussed.

Trisomy 18 in Kuwait

BACKGROUND

Trisomy 18 (Edwards' syndrome, T18) is the second most common trisomy in man. We describe 118 children with regular T18 who were ascertained clinically and cytogenetically in the Kuwait Medical Genetics Centre during 1980-1997.

METHODS

Ascertainment of T18 cases was performed shortly after birth. Chromosomal studies were carried out in addition to other relevant investigations. To investigate the factors associated with T18, a case-control study was carried out with 131 normal healthy newborns. Studied factors included maternal and paternal age, birth order, abortion, associated malformation, and survival. Multiple logistic regression analysis was used to adjust for confounding between variables.

RESULTS

There was a preponderance of females among T18 cases (female:male ratio 2.1:1). The majority of T18 cases (53%) died before the second week of life. The most common associated anomalies were: congenital heart (38.1%) and gastrointestinal (25.4%). Multiplicity of malformations was also observed. Significant seasonal variation in T18 cases was detected with a peak in spring. Of the 118 T18 cases, 59 were delivered during 1994-1997 (average overall T18 birth prevalence rate 8.95 per 10 000 live births [95% CI: 6.66-11.23]). Concerning maternal age, 30.5% of the T18 cases' mothers were > or =35 years compared to 10.7% in the control group. The difference was statistically significant, P = 0.002. Logistic regression analysis showed that maternal age >30 years was a significant risk factor for T18, after adjusting for confounding with paternal age. Paternal age and abortion were not found to be significant risk factors.

CONCLUSION

Trisomy 18 birth prevalence rate is high in Kuwait with advanced maternal age as a significant risk factor.

Impact of prenatal diagnosis and elective termination on the prevalence of selected birth defects in Hawaii

This study examined the effect of prenatal diagnosis and elective termination on the prevalence of neural tube defects, oral clefts, abdominal wall defects, and chromosomal anomalies in Hawaii by using actively ascertained surveillance data collected between 1987 and 1996 by the Hawaii Birth Defects Program. Because the Program has nearly universal access to prenatal diagnostic information and to follow-up data on elective terminations, Hawaii is an ideal setting in which to study their effects on prevalence rates of birth defects. Except for oral clefts, a large proportion of the defects studied were prenatally diagnosed: anencephaly (87%), spina bifida (62%), encephalocele (83%), cleft palate (0%), cleft lip with or without cleft palate (14%), omphalocele (60%), gastroschisis (76%), Down syndrome (43%), trisomy 18 (61 %), and trisomy 13 (40%). The effect of elective terminations on the birth prevalence rates for most of these birth defects was significant. Including electively terminated cases in the calculations of birth prevalence rates increased the rates by more than 50% for five of the 10 birth defects studied.

[Diagnosis and management of patients with sex differentiation disorders: experience at the Unit of Medical Genetics of the University of Zulia, Maracaibo, Venezuela]

Abnormalities of sexual differentiation (ASD) represent a group of entities, heterogeneous in their etiopathogenesis and clinical manifestations. In order to characterize and analyze the epidemiologic, clinical, endocrine and genetic aspects of patients with ASD consulting UGM-LUZ between 1971-1996, the families that had at least one of its members affected were evaluated. Strict diagnostic criteria to each entity were applied. Cytogenetic, hormonal, radiological, echographic and anatomopathological evaluations were done in each patient. From 391 families, 429 patient consulted with ASD. They represent 5.4% of the patient who consulted to UGM-LUZ in the same period. 214 (50%) patients with definitive diagnosis of ASD were identified to fill the established inclusion criteria. The distribution was the following: 139 with anomalies of the sexual chromosomes; 36 with congenital adrenal hyperplasia; 21 with complete androgen insensitivity syndrome; 14 with mixed gonadal dysgenesis; and 4 with true hermaphroditism. 183 (42.7%) patients with male pseudohermaphroditism and 17 (3.9%) with female pseudohermaphroditism were diagnosed as they did not fulfill the established diagnostic criteria. 15 (3.4%) patients presented ASD associated to a polymalformative syndrome. The ASD are very complex entities, they need the participation of an interdisciplinary team for their diagnosis and management process.

[Termination of pregnancy in the 2nd trimester using intra-amniotic administration of prostaglandins]

INTRODUCTION

The method used to terminate pregnancy on medical grounds during the second trimester must be safe, rapid, psychologically feasible and associated with a minimal risk of long-term sequelae. The objective of the present work was a critical analysis of the author's standard protocol of termination of pregnancy during the second trimester.

MATERIAL AND METHODS

For induction of abortion during the second trimester the authors used a synthetic prostaglandin analogue (PG) F2 alpha-Dinoprost which was administered in a single dose of 30 mg by the intraamniotic route. At the time of onset of uterine contractions the authors administered peridural anaesthesia. The authors investigated indications, mean period of induction, correlation between the period of induction of abortion and the indications for termination of pregnancy, the week of pregnancy and parity of the mother. They recorded also the type and number of complications.

RESULTS

From January 1991 till June 1997 179 pregnancies were terminated by intraamniotic PG administration. After a single intraamniotic PG administration 72% women aborted within 24 hours. In 26% women the intraamniotic administration was repeated twice and in 2% women three times. The mean induction period, i.e. the interval between the administration and abortion of the foetus was 22.6 hours. The interval was significantly longer (28 hours) in foetuses where pregnancy was terminated because of a neural tube defect (p < 0.01). The authors did not detect a correlation between the period of induction and the indication, week of gestation and parity of the mother.

COMPLICATIONS

once a general reaction to intraamniotic administration, in three patients a major blood loss replaced by transfusion of erythrocyte mass, no uterine rupture.

CONCLUSION

In all instances the therapeutic effect was achieved and there was no need to perform section minor. The disadvantage of the method is the high price of the preparation and need of repeated intraamniotic administration of PG in 29% of the patients.

Age-related decline in fertility: a link to degenerative oocytes?

OBJECTIVE

To determine whether the age-related decline in fertility is due to degenerative oocytes or to aneuploidy.

DESIGN

Retrospective.

SETTING

Fertility center of a public and tertiary institution.

PATIENT(S)

One hundred fifty-one women (ages 24 to 44 years) undergoing 158 cycles of conventional IVF or IVF with intracytoplasmic sperm injection (ICSI) between January 1993 and December 1995 were divided into three age groups (group 1, < or = 34 years; group 2, between 35 and 39 years; and group 3, > or = 40 years). They were selected on the basis of available oocytes that remained unfertilized after IVF and that had analyzable chromosomes.

INTERVENTION(S)

Standard pituitary down-regulation and ovarian stimulation with FSH and hMG were done for both IVF and ICSI patients. In addition, all patients were given luteal phase support with P, administered orally, via pessaries, or by IM injections from the day of transfer.

MAIN OUTCOME MEASURE(S)

Fertilization rates and pregnancy rates (PRs), and cytogenetic analyses of unfertilized oocytes.

RESULT(S)

Although fertilization rates were not different among women in groups 1, 2, and 3 (50.9%, 49.3%, and 37.9%, respectively), PRs were significantly lower between groups 1 and 3 (43.2% versus 14.3%). A total of 383 oocytes were examined, of which 287 (75%) could be karyotyped. Of these, 201 oocytes showed a normal 23,X karyotype (70%), 40 (13.9%) were aneuploid, 24 (8.4%) were diploid, 12 (4.2%) had structural aberrations, and 13 (4.5%) had single chromatids only. No increase in the aneuploidy rate was detected between groups 1 and 2 (14.8% versus 12.4%). However, highly significant differences in the rate of oocyte chromosome degeneration, characterized by chromosomes splitting into unassociated chromatids, were observed with increasing age (group 1, 23.7%; group 2, 52.0%; and group 3, 95.8%).

CONCLUSION(S)

It seems that the age-related decline in fertility may be due more to degenerative oocytes than to aneuploidy. A decline in the number of oocytes retrieved with age may be of less importance than the decline in oocyte quality. Women in the older age group have a higher chance of achieving pregnancy from ovum-donation programs than by persisting in using their own aged oocytes, which have a very poor prognosis for success.

Norplant subdermal contraceptive system: experience in Taiwan

From November 1988 to December 1994, a total of 567 female volunteers were enrolled in Norplant implant studies at the National Taiwan University Hospital. After a median follow-up of 29 months, only 3 of the 529 available cases became pregnant (a cumulative rate of 1.2 pregnancies per 100 users over 5 years). Chromosome analysis of 2 of the 3 abortuses revealed 46,XX/46,XX,inv(3) and 46,XX. Menstrual problems were the most common adverse effects and were also the main reason for discontinuation (65%, 108/166). The continuation rate was 90%, 78%, 70%, 61%, and 42% at the end of 1, 2, 3, 4, and 5 years after insertion, respectively. In the 21 patients who wished to become pregnant, fertility recurred soon after removal of the Norplant implants. The data suggested that the Norplant implants system is a highly effective, safe, and long-acting method of reversible contraception. It would be worthwhile to introduce this contraceptive system to Taiwan's family planning program.

Pregnancy and lifestyle study: the long-term use of the contraceptive pill and the risk of age-related miscarriage

Maternal ageing is a very important factor in aneuploidy. It is associated with an increased risk of a liveborn trisomy, especially Down's syndrome, and with a dramatic increase in trisomic conceptions, the majority of which miscarry. A total of 585 volunteer couples who were planning pregnancies participated in a prospective study of reproduction. The couples answered extensive questionnaires and early pregnancy tests (day 28) were conducted each month. The number of years of contraceptive pill use was correlated with pregnancy outcome. Lowered rates of miscarriage were found with increased years of pill use. The cut-off point for this positive effect appeared to be 9 years. Use of oral contraceptives for > or = 9 years was associated with a spontaneous abortion rate of 11.3%, which is about half the rate (23%) which was found in couples who had not used the pill. However, the effect of pill taking was correlated with female age, and when age was examined as an independent factor, the reduction in miscarriage was only statistically significant in women > 30 years old, where the rate of abortion reduced from 28 to 7%. Because age-related aneuploidy in humans probably occurs as a direct or an indirect result of follicle depletion, it is proposed that the long-term use of the oral contraceptive pill protects against abortion due to aneuploidy by preserving the number of follicles.

Family planning decisions after prenatal detection of fetal abnormalities

OBJECTIVE

Our purpose was to assess the family planning decisions made by women found to be carrying fetuses with chromosome abnormalities or neural tube defects.

STUDY DESIGN

We studied the family planning decisions of 132 women carrying fetuses with chromosome abnormalities (n = 91) or neural tube defects (n = 41) with regard to prenatal diagnosis, pregnancy management decision, patient's gravidity, and maternal and gestational age.

RESULTS

Twenty women (17 carrying fetuses with chromosome abnormalities and 3 with fetal neural tube defects) elected permanent sterilization after completion of the affected pregnancy. Only maternal age and fetal chromosome abnormalities were associated with a decision to obtain permanent sterilization.

CONCLUSIONS

Most women carrying fetuses with chromosome abnormalities or neural tube defects will not choose permanent sterilization after completion of the pregnancy. Delaying such decisions until resolution of grief and depression is now facilitated by the availability of safe, reliable, and relatively long-term reversible contraceptive agents.

Previous use of oral contraceptives and spontaneous abortion

This analysis tests the hypothesis that women who conceive within 3 months after stopping oral contraceptives ("the pill") have an intrinsically lower risk of chromosomally normal loss. About 30% of women show evidence of endocrine dysfunction, including anovulation, for 1-3 months after stopping the pill. In women who recover rapidly, and therefore are at risk of pregnancy, a common endocrinologic factor may account for both the quick return to normal functioning and improved intrauterine survival of the chromosomally normal conceptus. The hypothesis was tested in women with chromosomally normal (N = 334) and chromosomally aberrant (N = 239) spontaneous abortions. Women were classified according to the number of months between last pill use and last menstrual period. The adjusted odds ratios relating conception in months 0 and 1 after stopping the pill to chromosomally normal (vs chromosomally aberrant) loss were each 0.4, with upper 95% confidence limits of 1.0 and 0.9, respectively. The odds ratios for conception at longer intervals after stopping were 1.1 [95% confidence interval (CI) = 0.4-3.1], 0.7 (95% CI = 0.3-1.2), and 0.9 (95% CI = 0.5-1.5) for 2, 3-11, and > or = 12 months, respectively. Rates of spontaneous abortion in previous pregnancies were lowest in women who conceived quickly after stopping the pill. Further support for an endocrinologic explanation requires direct measures of endocrine functioning in the post-pill period among women with varying reproductive histories.

Attitudes of women of childbearing age towards prenatal diagnosis in southeastern France

The objective of this study was to explore women's attitudes towards prenatal diagnosis of trisomy 21 and to examine some of the factors possibly responsible for these attitudes before implementing in real practice serological screening of pregnant women at risk for trisomy 21. We carried out a telephone survey on a representative sample of women who had recently had a normal livebirth delivery in the Marseille district in 1990. The participation rate was 80 per cent and the average age of the mothers was 28.9 years. Among the 514 women interviewed, 78 per cent stated that they would ask for an amniocentesis for a 1 per cent risk of trisomy 21 at their next pregnancy. When adjusting for confounding factors, the decision to have or not to have an amniocentesis was found to depend not only on the women's attitude towards induced abortion, but also on their understanding of the risk involved and on the social context (knowing a handicapped child, discussion with the father). It also depended on the women's age and on what they knew about amniocentesis from the medical point of view. The risk of miscarriage can influence a woman's choice but this objection was not found to affect the women's decisions significantly in our survey. The data showed the existence of a high potential demand for fetal karyotyping.

Norplant-2 subdermal contraceptive system: experience in Taiwan

Subdermal Norplant-2 implantation, developed for contraception based on sustained release of levonorgestrel, has already been conducted in many countries around the world. From October 1986 to November 1988, a total of 267 female volunteers were enrolled in Norplant studies at the National Taiwan University Hospital. After a follow-up of 36 months, only one of the 231 evaluable cases (0.4%) became pregnant. The continuation rate was 84.5%, 61.3%, and 52.0% at the end of 12, 24 and 36 months after insertion, respectively. Menstrual problems were the most common adverse effects and were also the main reason for discontinuation. In the 23 patients who wished to become pregnant, fertility occurred soon after removal of the Norplant implant. After insertion, serum total cholesterol and triglyceride levels significantly decreased and the hemoglobin concentrations were increased. No liver or renal toxicities were detected. The data suggest that Norplant-2 is a highly effective, safe and long-acting method of reversible contraception. It would be worthwhile to introduce this contraceptive system into Taiwan's family planning program.

Low-dose sulprostone for pregnancy termination in cases of fetal abnormality

Thirty-two pregnancies (11 primi- and 21 multi-gravid) with an abnormal fetus were terminated between 16 and 35 weeks (mean 22 weeks; median 20 weeks) and a continuous intravenous infusion of 1 microgram of the prostaglandin analogue sulprostone. All pregnancies were terminated vaginally, 31 of them with this regimen in a median induction-expulsion interval of 23 h (range 8-52 h). Complete expulsion of the placenta occurred in 72 per cent of cases. Median blood loss was 100 ml (range 20-2000 ml). There were only a few side-effects. We conclude that this induction regimen is both appropriate and safe for pregnancy termination in cases of fetal anomaly.

[Chorionic villus needle sampling by the transabdominal route or by placental centesis. A series of 930 cases]

The authors report on a series of 930 chorion villus sampling diagnoses made with a needle by the transabdominal route, from January 1991 to October 1992 at the Prenatal Diagnosis Center in Marseille. Indications for prenatal diagnosis were: raised maternal age in 75% of cases (N:698); ultrasound findings in 11% (N:106), chromosome abnormalities in the family in 6% cases (N:53), raised human chorionic gonadotrophin in 4% cases (N:38), parental rearrangement in 2% cases (N:20), and sex linked disease in 1% (N:15). The success rate was 97% with 29 failures; the number of needle insertions was one in 97% cases and two in 3% cases. The average gestational age at sampling was related to the indications; 16 weeks of amenorrhoea for raised maternal age, and 22 weeks of amenorrhoea for ultrasound findings. Thirty one abnormalities were observed, four balanced translocations, and seven placental mosaicisms. Forty eight pregnancies terminated in abortion. The rate of fetal loss was 3.5% (7 cases) for the 200 first cases and 1% (8 cases) for the 730 following cases. Choriocentesis through the transabdominal route provides a diagnosis within a few days and the rate of fetal loss is close to that of amniocentesis. These arguments are in favour of an extension of this method of sampling.

Reproductive behaviour and prenatal diagnosis following genetic termination of pregnancy in women of advanced maternal age

One hundred and fifty-one women of advanced maternal age who underwent genetic termination of pregnancy (TOP) were studied for their reproductive behaviour and the type of procedure for prenatal diagnosis in a subsequent pregnancy. A total of 59 women (39 per cent) had a further pregnancy. In all continuing pregnancies prenatal diagnosis was performed, of which 75 per cent consisted of chorionic villus sampling (CVS). Reproductive behaviour following a genetic termination was negatively correlated with maternal age and parity. Both reproductive behaviour and the choice to undergo a diagnostic procedure in the next pregnancy were independent of the type of diagnostic procedure in the previous affected pregnancy.

FDA requirements for nonclinical testing of contraceptive steroids

Written guidelines for the preclinical testing of contraceptive steroids have not been revised since 1968 despite the fact that many important changes have been implemented by the FDA's Division of Metabolism and Endocrine Drug Products. This paper describes the new preclinical testing requirements and the rationale for their implementation.

Health effects of consanguinity in Pondicherry

Of 1000 pregnant women studied, consanguinity was observed in 30.8%, with a higher frequency among women from rural areas, and among Hindus. In the consanguineous group, first cousin marriages were present in 47.4%, and uncle niece marriages in 23.4% of women. Coefficient of inbreeding was highest in Harijans (0.0258), followed by non-Brahmins (0.0220) and Brahmins (0.0204). Fertility was not influenced by consanguinity. There was a significantly higher rate of still births and infant mortality in consanguineous matings as compared with non-consanguineous. Total morbidity was higher in the consanguineous group as compared with the non-consanguineous (p less than 0.01), especially that due to neonatal infections and jaundice. There was no significant difference in the prevalence of congenital malformations, chromosomal and genetic disorders between the two groups, although the number of abnormal births in this group was small.

Chorionic villus sampling and selective termination of a chromosomally abnormal fetus in a triplet pregnancy

Transabdominal chorionic villus sampling (CVS) was performed on a patient with a triplet pregnancy. The karyotypes were as follows: 46,XX; 46,XY; and 46,XY/47,XXY. Selective termination was done on the affected fetus successfully by intrathoracic potassium chloride (KCl) injection. Amniocentesis which was performed at the same time confirmed the CVS results, showing the same mosaic findings. Following the procedure, the pregnancy proceeded uneventfully and two normal newborns were delivered at term.

Prevention of hemoperitoneum during ovulation by oral contraceptives in women with type III von Willebrand disease and afibrinogenemia. Case reports

The follicle ruptures at the time of ovulation and fills with blood, forming a corpus hemorrhagicum. Minor bleeding from the follicle into the abdominal cavity may cause peritoneal irritation and, when it occurs in a patient with a defect of primary hemostasis, hemoperitoneum can occur. Von Willebrand disease and afibrinogenemia are two important bleeding disorders in which both primary hemostasis and coagulation are involved. Bleeding during ovulation is one major clinical complication in women with these disease. We have studied three patients with this hemorrhagic complication. Our data show that oral contraceptives are an effective way to avoid hemoperitoneum.

Incidence of numerical chromosome anomalies in human pregnancy estimation from induced and spontaneous abortion data

Induced abortion data provided an estimate of 4.7% numerical chromosome anomalies for women with a clinically recognized pregnancy at the end of the 7th week after the last menstrual period (LMP). This frequency requires that 51.9% of spontaneous abortions occurring after the 7th week should be chromosomally abnormal if the frequency of numerical chromosome anomalies at term (live and stillbirths combined) is 0.53%. Cytogenetic data from surveys of spontaneous abortion suggested a lower incidence of 39.7%. However, this figure is likely to be an underestimate because chromosome anomalies are almost certainly over-represented among the many early abortuses which lack embryonic tissue and hence are not karyotyped. The frequency of numerical chromosome anomalies at conception, arising from meiotic errors, was estimated from sperm karyotype data combined with information on the relative frequencies of maternal and paternal errors in the aetiology of trisomies. This provided a minimum estimate of 20%.

Fertility after contraception or abortion

There is a very small correlation, if any, between the prior use of OCs and congenital malformations, including Down's syndrome. There are few, if any, recent reports on masculinization of a female fetus born to a mother who took an OC containing 1 mg of a progestogen during early pregnancy. However, patients suspected of being pregnant and who are desirous of continuing that pregnancy should not continue to take OCs, nor should progestogen withdrawal pregnancy tests be used. Concern still exists regarding the occurrence of congenital abnormalities in babies born to such women. The incidence of postoperative infection after first trimester therapeutic abortion in this country is low. However, increasing numbers of women are undergoing repeated pregnancy terminations, and their risk for subsequent pelvic infections may be multiplied with each succeeding abortion. The incidence of prematurity due to cervical incompetence or surgical infertility after first trimester pregnancy terminations is not increased significantly. Asherman's syndrome may occur after septic therapeutic abortion. The pregnancy rate after treatment of this syndrome is low. The return of menses and the achievement of a pregnancy may be slightly delayed after OCs are discontinued, but the fertility rate is within the normal range by 1 year. The incidence of postpill amenorrhea of greater than 6 months' duration is probably less than 1%. The occurrence of the syndrome does not seem to be related to length of use or type of pill. Patients with prior normal menses as well as those with menstrual abnormalities before use of OCs may develop this syndrome. Patients with normal estrogen and gonadotropin levels usually respond with return of menses and ovulation when treated with clomiphene. The rate for achievement of pregnancy is much lower than that for patients with spontaneous return of menses. The criteria for defining PID or for categorizing its severity are diverse. The incidence of PID is higher among IUD users than among patients taking OCs or using a barrier method. The excess risk of PID among IUD users, with the exception of the first few months after insertion, is related to sexually transmitted diseases and not the IUD. Women with no risk factors for sexually transmitted diseases have little increased risk of PID or infertility associated with IUD use. There appears to be no increased risk of congenital anomalies, altered sex ratio, or early pregnancy loss among spermicide users. All present methods of contraception entail some risk to the patient. The risk of imparied future fertility with the use of any method appears to be low.(ABSTRACT TRUNCATED AT 400 WORDS)

Impact of advanced maternal age on the outcome of pregnancy

We assessed the impact of advanced maternal age on the outcome of pregnancy by studying all 1,328 women who were primarily cared for and delivered at our institution between 14 September 1984 and 12 February 1985. Important peripartum maternal complications were no more frequent in women aged 35 years or more than in women 20 to 34 years old, although operative delivery was significantly more common. Similarly, adverse outcomes of infants were no more frequent. Perinatal mortality tended to be lower. In addition, we noted a trend for fewer infants with congenital anomalies to be born among older women. This trend was related, in part, to the choice to terminate the pregnancy by women with fetuses that had documented chromosomal anomalies. We conclude that advanced maternal age was not associated with an excess of adverse pregnancy outcome and suggest that, with early registration and careful surveillance during pregnancy, women aged 35 years or more can experience excellent pregnancy outcomes.

An evaluation of 75 terminations of pregnancy based on abnormal laboratory findings at first trimester CVS

Seventy-five selective terminations, based on abnormal laboratory findings at first-trimester CVS, were performed in 1581 consecutive pregnancies. In all cases a (semi-) direct method of cytogenetic analysis was used. The 75 abortions were analysed in number of ways. Confirmatory studies showed that three cases had to be considered as false-positive findings, and in one other case the results were inconclusive. Based on literature data, it was estimated that 41 of the 75 pregnancies would have resulted in seriously handicapped children, surviving beyond the age of 1 year, if no termination of pregnancy had taken place. Negative side-effects of the procedure include: spontaneous abortion of chromosomally normal fetuses due to the CVS procedure itself and the need for a number of secondary amniocenteses (5.1%). The advantage of DNA diagnosis in X-linked diseases is illustrated by comparing the CVS results with a previously published amniocentesis study.

Evaluation of transcervical chorionic villus sampling with a completed follow-up of 1550 consecutive pregnancies

Data from 1,550 consecutive pregnancies after first-trimester prenatal diagnosis by transcervical chorionic villus sampling (TC-CVS) are presented. The sampling efficacy was 97.8 per cent; the mean amount of collected villus tissue was 23 mg (range 5-100 mg). There were 97 affected fetuses, mainly (73.2 per cent) with a chromosomal abnormality or a male karyotype in carriers of X-linked disease. Pregnancy termination in these and four other women for social reasons resulted in 1449 continuing pregnancies. In these pregnancies, the fetal loss rate up to 28 weeks of gestation was 5.1 per cent with the highest loss rate (3.9 per cent) before 16 weeks. When relating this fetal loss rate to maternal age, this was 6.1 per cent in the advanced maternal age group (greater than or equal to 36 years) against 3.1 per cent in the younger age group. In 1,376 pregnancies continuing beyond 28 weeks, the perinatal mortality rate was 1.1 per cent; the percentage of non-genetic congenital anomalies was 0.9 per cent. The reproductive pattern of women at high genetic risk after CVS followed by pregnancy termination was evaluated. Within 12 months after the first CVS followed by pregnancy termination, 70 per cent of women again requested CVS in a subsequent pregnancy.

Evaluation of vasovasostomy candidates by deoxyribonucleic acid flow cytometry of testicular aspirates

Flow cytometry can be performed on testicular aspirates of vasovasostomy candidates preoperatively. On the basis of ploidy ratios and debris components, DNA histograms can be classified as normal or abnormal. Using this method, the likelihood of the presence of sperm may be predicted.

Consanguinity, twinning and secondary sex ratio in the population of Karnataka, south India

Consanguineous marriages are strongly favoured in the state of Karnataka. Of 65,492 marriages studied 33.07% were consanguineous, equivalent to a coefficient of inbreeding (F) of 0.0298. The twinning rate was low, 6.9 per thousand, whereas the secondary sex ratio, 0.5221, was higher than in comparable major human populations. Consanguinity exerted no significant effect on either parameter. The results also indicate that consanguinity is not associated with excess antenatal losses and suggest the possibility of enhanced selection against mutations at X chromosome loci.

Selective termination of multiple gestations

Twenty-two selective terminations in multiple gestations were performed by a number of different methods. In 17 dichorionic pregnancies there was a successful delivery in surviving singletons or twins. In five monochorionic pregnancies undergoing selective termination there was a successful delivery in only one and a pregnancy loss in the other four. Six of the 18 delivered pregnancies were complicated by premature labor and delivery. Among the several methods used for selective termination, intracardiac potassium chloride injection appears to be the procedure of choice in dichorionic pregnancies.

Mifepristone (RU486) and therapeutic late pregnancy termination: a double-blind study of two different doses

An antiprogesterone, mifepristone (RU486), was administered to 35 patients undergoing a therapeutic interruption of pregnancy during the second and third trimester for maternal or fetal indications. A randomized double-blind study test was performed using 150 and 450 mg of mifepristone as pretreatment prior to prostaglandins. No toxicity or maternal morbidity were recorded. In three patients the onset of labour occurred spontaneously before prostaglandin administration. Mifepristone produced a modification in the consistency of the cervix with a statistical improvement in cervical calibration in the two groups, but the cervical effect was independent of the dose.

Steroid contraceptive use and pregnancy outcome

Contraceptive use in relation to pregnancy outcome was studied in 8,816 births in Chiang Mai, northern Thailand, by examination of newborn infants and interviews with their mothers. Four thousand twenty-three women used no contraception before the index pregnancy, 1,229 used the injectable contraceptive Depo Provera (DMPA), and 3,038 used oral contraceptives prior to or during pregnancy. No differences were observed between these groups with respect to still births, multiple pregnancies, and birthweight. Women who used oral contraceptives had unexpectedly low rates of major defects and may have been affected by self-selection bias, whereas the noncontraceptors had rates similar to other populations. There was a significantly increased association of polysyndactyly among infants of DMPA users relative to the other groups, which was most pronounced in offspring of women under age 30 years, and persisted after exclusion of subjects with a family history or infants with multiple abnormalities. However, in five out of the ten polysyndactyly cases, the last injection of DMPA occurred more than 9 months before conception, and only three cases had definite gestational exposure. The association of chromosomal anomalies was also significantly increased in infants of mothers who used DMPA. The unrelated nature of these defects, the lack of confirmation from other studies, the distant preconceptional exposure to DMPA in many cases, and chance effects due to multiple statistical comparisons make a causal association unlikely. Other birth defects that had been previously reported in some publications to be associated with progestational steroid exposure, such as neural tube defects, heart malformations, and limb reduction defects, were not found in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiological studies of natural family planning

The prevalence of the use of natural family planning (NFP) can be estimated from sample surveys of married women in the reproductive ages (MWRA). Surveys in developed and developing countries during the past decade indicate that the prevalence of NFP use varies from 0 to 11%. In addition, if one considers NFP use in relation to other contraceptive methods, the percentage of all current contraceptors who use NFP varies from 1 to 35%. This suggests that NFP is an important method in certain countries. Pregnancy rates for NFP vary widely, but most reliable studies report 1-year life-table pregnancy rates between 10 and 25/100 woman-years. The Billings ovulation method consistently has higher pregnancy rates than the sympto-thermal method and NFP users generally have among the highest pregnancy rates compared to other methods. The major safety issue concerning NFP is the risk of adverse pregnancy outcomes associated with aged gametes. There are suggestions from a number of investigations that conceptions distant from ovulation have a higher risk of spontaneous abortion and a higher proportion of male births. The findings with respect to birth defects or multiple pregnancies are less consistent, although some studies have reported an increased risk of chromosomal anomalies.

Effect of betel chewing on the frequency of sister chromatid exchanges in pregnant women and women using oral contraceptives

The incidence of sister chromatid exchange (SCE) was investigated in the lymphocyte chromosomes of betel chewing and non-chewing normal women, pregnant women, and women using oral contraceptives. The frequency of SCE was found to be 7.82 +/- 0.24 and 8.27 +/- 0.27 in non-chewing pregnant women and women using oral contraceptives respectively, which were significantly higher than the mean value of 5.21 +/- 0.18 observed in non-chewing normal women. Betel chewing induced higher SCE in pregnant women and women using oral contraceptives, the frequencies being 11.79 +/- 0.38 and 12.51 +/- 0.44, respectively, which were significantly higher than the SCE frequency of 6.28 +/- 0.21 found in normal betel chewing females.

Menarche, menstruation, sexual relations and contraception of adolescent females with Down syndrome

Fifteen female adolescents with Down syndrome (DS) and 33 female controls without this syndrome were surveyed on age of menarche, menstruation, sexual relations and contraception. All probands and controls were born between 1 January 1965 and 31 December 1970. The day of census was December 31, 1985. All probands and controls were living permanently in the Danish county of Aarhus on this day. Persons close to the DS patients (parents/foster-parents/permanent staff) were interviewed on the above-mentioned topics. All controls were interviewed themselves. The average age of menarche was 13.6 years for probands and 13.5 years for controls. The average duration of the bleeding was 5.5 days for probands and 5.4 days for controls. The average length of the cycle was 28.3 days for probands and 28.6 days for controls. Thirteen DS patients had not had sexual intercourse (no information was available for 2 probands). Twenty-four controls had and 9 had not had sexual intercourse. There is a significant difference between probands and controls concerning use of oral and other contraceptives.

Spermicide use and pregnancy outcome

The relation between periconceptional vaginal spermicide use and sex ratio at birth, birthweight, and the frequency of congenital anomalies was examined in a cohort of 2,712 New York City obstetric patients, 149 of whom (5.5 per cent) became pregnant while using spermicides or had used spermicides before and after conception. Periconceptional spermicide use was not associated with any important variation in the expected sex ratio at birth, nor with major or minor congenital anomalies. Exposure to spermicides in the periconceptional period, defined dichotomously as present or absent, was not associated with decreased birthweight in male or female infants. There was a slight decrease in birthweight among female infants with increasing duration of postconceptional spermicide use; an estimated 7.4 grams decrease with each day of use. The size of the effect and its selectivity by sex suggest a chance finding.

[The first generation of the Saguenay population: origin, kinship, and rootedness]

The responsibility of demographic isolation for the high incidence of genetic disorders among the population of the Saguenay region of Quebec, Canada, is explored. The authors reject the view that "a few family founders are the ancestors of most of the current population....Actually, between 1838 and 1911, more than 28,000 immigrants (representing one third of the number of births) settled in Saguenay, a major fact that has to be taken into account if one sets out to explain the genetic structure of this population, particularly if one considers that most of these immigrants came from the same region and were grouped in kin-related families." (SUMMARY IN ENG AND SPA)

Reproductive patterns and thalassaemia major

A study of families affected by thalassaemia major demonstrated that before antenatal diagnosis became an option, premature curtailment of reproduction was the most common parental response to their understanding of the genetic implications of the diagnosis. Subsequently parents of younger patients used antenatal diagnosis to meet or almost meet their birth expectations. There was no evidence that antenatal diagnosis contributed to any process of ‘compensating’ for existing affected offspring.

Vaginal spermicides and spontaneous abortion of known karyotype

The relationship between spermicide use and spontaneous abortion was examined in a New York City case-control study carried out during 1974-1982. In a series of matched sample analyses, case groups categorized by karyotype of the abortus were compared to a control group of prenatal patients with respect to spermicide use. Spermicide use was defined in terms of proximity to the date of conception of the study pregnancy and duration of the episode of use most recent to the study pregnancy. There was no association between spermicide use defined either in terms of recency or duration of use and chromosomally normal abortions, which comprise about 60% of all spontaneous abortions. Similarly, there was no association between spermicide use and the various types of chromosomally abnormal abortions, with the exception of trisomic abortion. Spermicide use for more than one year at any time prior to conception was more common in the cases aborting trisomic conceptions than in the control group (odds ratio = 1.9, confidence limits = 1.2, 3.0). There was evidence to suggest that the association varied with maternal age and phase of entrance into the study.

Chromosomal abnormalities in the Kaiser-Permanente Birth Defects Study, with special reference to contraceptive use around the time of conception

Chromosomal abnormalities were studied in 33,551 abortions and births to women whose contraceptive histories had been recorded at their first antenatal visit in 1975-1977. Chromosome examinations were performed exclusively on clinical grounds. There were 45 de novo abnormalities detected (1.34/1,000); three of them were detected at amniocentesis. Trisomy 21 was observed in 27 cases (0.80/1,000), trisomy 18 in nine (0.27), other trisomies in three (0.09), and translocations or deletions in five (0.15). One case of triploidy and six cases of inherited abnormalities were detected. There were no significant racial variations. No increase in risk for chromosomal abnormalities was found among women who had used oral contraceptives prior to becoming pregnant or among women who experienced oral contraceptive breakthrough pregnancies. Two cases of trisomy 18 were observed among the 814 deliveries following oral contraceptive breakthrough conceptions (2.46/1,000), two cases of trisomy 21 occurred in 338 births following failures of rhythm contraception (5.92/1,000), and no cases of trisomy 21 or 18 among the 1,569 women using spermicides at the time of conception.