Surveillance of pregnant women with potential exposure to Zika virus following travel

AIM

To describe the experience of a single fetal medicine unit in evaluating pregnant women with potential exposure to Zika virus (ZIKV) following travel.

METHOD

Between February 2016 and June 2017, a multidisciplinary team evaluated pregnant women by developing a local pathway based on Public Health England guidance. All pregnant women were offered serial fetal ultrasound scans (USS). If they presented with a history of clinical symptoms consistent with ZIKV infection during or within two weeks of travel or fetal USS was suggestive of microcephaly, reverse transcriptase polymerase chain reaction (RT PCR) and/or serology was used.

RESULTS

69 women were referred. Eight patients reported symptoms consistent with ZIKV infection (11.6%) and six (8.7%) patients reported mosquito bites. Maternal exposure was mainly during the preconception period and the first trimester in 35 (50.8%) and 19 (27.5%) women, respectively. Prenatally, there was no evidence of microcephaly in any of the 69 referrals. Sixty-two live births and seven miscarriages were reported. One patient had serology confirming ZIKV infection during pregnancy. At birth, 57 babies had normal head circumference (HC) measurements, including the baby born to the Zika positive mother. Two babies had small HC measurements but were not infected and were small for gestational age.

CONCLUSIONS

One case of maternal ZIKV infection was detected but without any fetal congenital abnormalities postnatally. The number of potentially infected patients referred to our unit is a demonstration of the concern regarding perinatal ZIKV infection in the pregnant population.

Spontaneous live unilateral twin ectopic pregnancy - A case presentation

The incidence of ectopic pregnancy has increased in recent years and now is around one in 100 pregnancies. However, the incidence of live twin ectopic pregnancy in a spontaneous conception is still quite rare. A 34-year-old gravida 3, para 0 presented in the Early Pregnancy Unit with a positive pregnancy test, lower abdominal pain and vaginal spotting. Her quantitative serum Beta hCG was high, and the transvaginal scan revealed an empty uterine cavity with a twin ectopic pregnancy in the left adnexa with cardiac activity in both embryos. The patient was taken for laparoscopic surgery and a left ampullary twin pregnancy was confirmed. She underwent a left salpingectomy and is well on a one-year follow-up. This case report discusses the incidence, diagnoses and treatment of ectopic pregnancies in general.

Outpatient medical management of missed miscarriage using misoprostol

We wanted to evaluate the efficacy, safety and acceptability of misoprostol for outpatient management of missed miscarriage. This was a prospective observational study conducted in the early pregnancy unit of a university teaching hospital involving women attending the unit with a diagnosis of missed miscarriage. All women with a missed miscarriage of <12 weeks' gestation and opting to have medical management were eligible for inclusion. Women who consented to take part were given 800 microg of misoprostol in the unit and advised to take two further doses of 400 microg of misoprostol, orally, 3 h apart, the following day at home. Outcome measures included success rates, emergency admission rates, blood transfusion rates, pain scores, satisfaction scores, incidence rates of side-effects and number of women who would choose medical management in future. Of the 268 women diagnosed as having a missed miscarriage during the study period, 75 (28.0%) opted to have medical management. Over three-quarters (n = 58, 77.3%, 95% confidence interval (CI) 66.2 - 86.2) of the women achieved successful complete medical evacuation. Overall, five (6.7%; 95% CI 2.2 - 14.8) women presented for emergency admission. The mean visual analogue scale (VAS) score of all women was 6.7 (SD = 2.8) and the mean satisfaction score was 8.6 (SD = 2.1). Two-thirds of women (n = 50, 66.7%) said that they would choose to have medical evacuation in a future miscarriage, while seven (9.3%) were unsure. A total of 70 (93.3%) women said they preferred to have the treatment at home rather than in the hospital. We conclude that medical evacuation of missed miscarriage is efficacious, safe and acceptable in the outpatient setting.

Second trimester maternal serum biochemical screening for Down's syndrome: experience of a single obstetric unit

The objective of this study was to assess the effects of mid-trimester biochemical screening on the prenatal diagnosis of Down's syndrome. All patients booked for antenatal care at the Royal Free Hospital are offered a double marker biochemical screening test (alpha-fetoprotein and free beta human chorionic gonadotrophin). The results of double marker screening tests and the notes of all cases of trisomy 21 from 1 April 1993 to 31 March 1995 were reviewed. Of the 6170 women booked in the antenatal clinic during this 2-year period 4427 (71.8%) took up the offer of biochemical screening. Four hundred and twenty-nine (9.7% of those screened) were reported positive and 293 karyotypes were performed in this group (68.3% uptake) and 253 karyotypes were also performed for other indications. Thirteen of 21 affected pregnancies had biochemical screening. The detection rate of biochemical screening in women aged <37 years was 0% (0/2) with a 8.4% false positive rate. In women aged 37 years the detection rate was 100% (11/11) with a false positive rate of 23%. The overall detection rate for Down's syndrome was 84.6% and the false positive rate was 9.5%. In conclusion, biochemical screening successfully targeted affected pregnancies in women aged 37 years and was useful in reducing the fetal karyotyping rate. However, it was disappointing in the prenatal diagnosis of trisomy 21 in women <37 years old.

Menstrual problems in university students: an electronic mail survey

OBJECTIVE

To establish the prevalence of menstrual-related problems among university students.

MATERIALS AND METHODS

A questionnaire regarding gynecological, bleeding and family history was sent by electronic mail (e-mail) to all female students attending University College London (UCL).

RESULTS

A total of 767 students aged 18-39 years replied; 71% had a regular menstrual cycle. One in three (n = 264) had received some treatment for their menstrual periods (such as the combined oral contraceptive pill or simple analgesia). Those with heavy or painful periods were more likely to feel that their menstrual problems had a substantial impact on their academic and social life; however, even among those with light periods, one in every four females felt that their life was considerably affected.

CONCLUSION

A considerable prevalence of menstrual-related problems was demonstrated among this young healthy population. Additionally, the use of e-mail could present potential benefits as a research medium for this kind of study.

Screening for factor XI deficiency amongst pregnant women of Ashkenazi Jewish origin

A pilot study was conducted over a 6-month period to evaluate antenatal screening for factor XI (FXI) deficiency amongst Ashkenazi Jewish women booking for their pregnancy in a single obstetric unit. Fifty-four women of Ashkenazi Jewish origin were recruited during their visit for the routine first trimester ultrasound scan. They completed a questionnaire about their personal bleeding symptoms and had blood taken for FXI levels (FXI:C). Seven (13%) women had partial FXI deficiency. Five (9%) were newly diagnosed, and in the remaining two, the diagnosis was known previously. One infant with severe FXI deficiency was identified as a result of maternal testing. This study has shown that FXI deficiency is common amongst women of Ashkenazi Jewish origin and supports its antenatal screening in this population. However, further studies are required to evaluate its cost-effectiveness and the effect on pregnancy outcome.

Is primary postpartum haemorrhage a good predictor of inherited bleeding disorders?

A study was conducted to evaluate the value of screening for inherited bleeding disorders in women with primary postpartum haemorrhage (PPH). Over a 2-year period, women identified to have PPH (defined as >500 mL blood loss for spontaneous vaginal delivery, >700 mL for instrumental deliveries and >1000 mL for caesarean sections within 24 h of delivery) were invited to participate in this study testing for a possible underlying bleeding disorder at 3-9 months post-delivery. Women known to have an inherited bleeding disorder were excluded. Of the 5744 deliveries in our unit during the study period, 152 (3%) fulfilled the criteria for primary PPH and 50 women agreed to participate in the study. Of these, 25 (50%) had a spontaneous vaginal delivery, 8 (16%) had an instrumental delivery and 17 (34%) had a caesarean section. Half of the women were multiparous and five (20%) had PPH in their previous pregnancy. Nineteen (38%) and 12 (24%) reported at least one significant personal and family bleeding history, respectively. One (2%) woman was identified to have von Willebrand disease. In conclusion, primary PPH does not appear to be a strong predictor of inherited bleeding disorders. Further studies are required to assess the prevalence of inherited bleeding disorders among these women.

Identification and management of women with inherited bleeding disorders: a survey of obstetricians and gynaecologists in the United Kingdom

A mail survey of members and fellows of Royal College of Obstetricians and Gynaecologists was carried out to determine current practices of obstetricians and gynaecologists in the United Kingdom in the management of women with inherited bleeding disorders. In total, 3929 questionnaires were sent, 707 returned and analysis was limited to 545 valid questionnaires. In the past 5 years, 91% have managed women with inherited bleeding disorders. The majority (83%) considered inherited bleeding disorders to be under diagnosed in obstetrics and gynaecology. More than 80% considered the prevalence of von Willebrand's disease (VWD) to be <0.2% in the general population and <1% in women with menorrhagia and no gynaecological pathology, although the reported prevalence is 1% and 5-25% respectively. Twelve percent of the respondents would arrange testing for VWD when reviewing an 18-year-old with menorrhagia and no pelvic pathology, while only 2% would do the same for a 35-year-old with the same presentation. Twenty-one percent thought elective caesarean section is indicated in all fetuses known to be at risk of being affected by haemophilia. Eighty-four percent considered vacuum extraction unsafe in these cases, but 76% would consider the use of low forceps. In conclusion, obstetricians and gynaecologists underestimate inherited bleeding disorders as an underlying cause for menorrhagia. Increased awareness and management guidelines are essential in minimizing haemorrhagic complications and improving quality of care of these women.

The use of levonorgestrel-releasing intrauterine system for treatment of menorrhagia in women with inherited bleeding disorders

BACKGROUND

The levonorgestrel-releasing intrauterine system (LNG-IUS) is used commonly by gynaecologists as a contraceptive and to treat menorrhagia. However, its efficacy has not been examined in women with inherited bleeding disorders.

DESIGN

A prospective pilot study.

SETTING

A teaching hospital in north London with a designated haemophilia centre.

POPULATION

Female patients with a known inherited bleeding disorder.

METHODS

Sixteen women with subjective and objective menorrhagia caused by inherited bleeding disorders (13 von Willebrand's Disease, two factor XI deficiency and one Hermansky-Pudlak syndrome), who had previously undergone unsuccessful medical treatment were followed up for nine months after LNG-IUS insertion. Bleeding was measured by pictorial chart and haemoglobin concentration.

RESULTS

All women reported that their periods were improved, pictorial chart scores were lower and 56% became amenorrhoeic. None reported side effects.

CONCLUSION

The LNG-IUS is well tolerated and effective and improves quality of life.

Patient acceptance of transvaginal sonography in the early pregnancy unit setting

OBJECTIVE

To establish the acceptability of transvaginal scanning in patients attending an early pregnancy unit (EPU) due to problems in early pregnancy such as vaginal bleeding.

METHODS

An unselected group of pregnant women who were less than 8 weeks' gestation were invited to complete a questionnaire before the transvaginal scan regarding their views about the pregnancy and about the scan itself. They were asked to complete a second questionnaire after the scan had been performed. Information was collected about the presenting symptoms and the final diagnosis.

RESULTS

Of a total of 107 patients, the most common reason for attending the EPU was vaginal bleeding (51.4%). The primary concern for the majority of these women was their pregnancy, rather than the scan procedure itself. Their concerns about the scan were not altered by a previous history of miscarriages or by maternal age. After the scan, more than 77% of patients scored < or = 3 out of 10 with regard to discomfort, pain and embarrassment. Only 1.9% experienced marked discomfort, scoring > 8 out of 10. The scores were not altered by the patients' diagnoses. A total of 99% of patients said that they would agree to have a similar procedure in the future.

CONCLUSION

This questionnaire-based study confirms that patients attending with problems in early pregnancy find transvaginal sonography acceptable.

Examination of fetal nasal bone and repeatability of measurement in early pregnancy

OBJECTIVE

To evaluate the examination and measurement of fetal nasal bone at 10-14 weeks of gestation.

METHODS

The study included 501 fetuses in 496 consecutive pregnant women attending for the routine first-trimester ultrasound examination. The presence or absence of the fetal nasal bone was determined in the mid-sagittal plane and the length was measured by one of four examiners (measurement A; n = 501). A second measurement was taken by the same examiner (B, n = 300) and a different examiner repeated the measurement (C, n = 200) whenever possible. Measurements were made to the nearest 0.1 mm. The duration of one hundred consecutive examinations was recorded, as was that of another 100 consecutive routine first-trimester examinations without measuring the nasal bone.

RESULTS

The median nasal bone length was 1.6 (0.8-2.4) mm, the median gestational age was 12 (10-14) weeks and the median crown-rump length (CRL) was 63 (32-90) mm. The fetal profile was examined in all 501 cases and the fetal nasal bone was present in all but one case (99.8%). No transvaginal scans were needed for the examination of nasal bone only. The average time for the sonographic examination (8.3 min) was not significantly different from the average time for first-trimester scans in which the fetal nasal bone was not measured (8.0 min). The fetal nasal bone length increased from 1.1 mm at a CRL of 35 mm to 2.1 mm at a CRL of 90 mm (nasal bone = 0.016 x CRL + 0.619, P < 0.001, r = 0.655). The repeatability coefficient for intraobserver measurements was 0.080 mm and the coefficient for interobserver measurements was similar (0.083 mm).

CONCLUSIONS

The nasal bone can be detected from 10 weeks of gestation onwards. Consistent visualization and repeatable measurement of fetal nasal bone can be performed by an experienced sonographer in the first trimester without extending the length of time required for scanning or introducing the need for transvaginal sonography.

The use of three-dimensional ultrasound for fetal gender determination in the first trimester

The objective of this study was to examine the accuracy of fetal gender prediction at a routine first trimester scan using three-dimensional (3D) ultrasound. 200 women were recruited for this study and they agreed to have a transvaginal scan for their routine first trimester scan for fetal anatomy and nuchal thickness measurement. 3D volumes were obtained and stored. Two examiners independently reviewed all the volumes and recorded their diagnosis of fetal gender and measured the angle between the genital tubercle and the skin overlying the sacrum. After studying the 3D volumes both examiners recorded a diagnosis of male or female in 150 cases (81.5%). In 34 cases (18.5%) either both (n=21) or one of them (n=13) could not comment on fetal gender by studying the saved volume. From these 150 cases correct prediction of fetal gender by both examiners was achieved in 85.3% of cases. In 6.7% of cases both examiners predicted the wrong gender while for the rest 8% of cases each examiner assigned different gender to the fetus (k=0.84; standard error 0.045). Angle measurements performed from the saved 3D volumes were highly reproducible. Gestational age did not affect the accuracy of gender identification. This study demonstrates that 3D ultrasound can be an effective and fast way of identifying fetal gender in the first trimester. The advantages of 3D ultrasound stem from its ability to virtually reproduce all required views.

DDAVP nasal spray for treatment of menorrhagia in women with inherited bleeding disorders: a randomized placebo-controlled crossover study

To assess DDAVP (1-deamino-8-d-arginine vasopressin; desmopressin) nasal spray in the management of menorrhagia in patients with inherited bleeding disorders, 39 women (aged 18-50 years) with menorrhagia were recruited and were randomized to start 2 months' therapy with placebo or DDAVP (300 micro g) spray in a double-blind crossover study. Twenty-eight and 24 completed first and second period of treatment, respectively. Menstrual loss was assessed using the pictorial blood assessment chart (PBAC) during each treatment period. The main outcome measure was comparison of PBAC scores following DDAVP and placebo treatments. The safety of DDAVP spray was also assessed by monitoring side-effects. Overall, PBAC scores were significantly lower in the second treatment period than the first (P = 0.01). After adjusting for this differences, mean PBAC scores were slightly lower (mean difference 8; 95% confidence interval of - 15.5 to 31.6) in women receiving DDAVP than when receiving placebo, although this difference was not statistically significant (P = 0.51). In conclusion, although there was an indication that menstrual bleeding was less heavy when women received DDAVP than when receiving placebo, the small sample size meant that this difference was not significant.

The influence of maternal hematocrit on placental development from the first to the second trimesters of pregnancy

OBJECTIVES

To study the influence of maternal hematocrit (Ht) and hemoglobin (Hb) levels on placental size and growth in the first and mid-second trimesters of pregnancy.

SUBJECTS/METHODS

This was a prospective study performed at the fetal medicine unit of a university hospital. One hundred and eighty-one women with a singleton pregnancy were recruited at 11-14 weeks' gestation. For each case three scans of the placenta were performed, the first at recruitment and the following two at 3-week intervals. The volume of the placenta was measured at each visit using a three-dimensional ultrasound scanner. The maternal Hb and Ht were measured within 2 weeks of the first scan.

RESULTS

The placental growth during the second trimester was inversely related to the Ht levels (r = -0.29, P = 0.001). It was also related to the Hb level (r = -0.20, P = 0.021). An increase of 0.1 units of Ht was associated with 38% less growth of the placenta (95% confidence interval: 18-54% less growth).

DISCUSSION

This study demonstrates the effects of maternal environment on placental growth. Our data suggest that the levels of Ht appear to affect the placental growth during the second trimester. Further studies on the factors that regulate placental growth are needed to elucidate the pathophysiology of these interactions and their effect on pregnancy outcome.

Biochemical screening for Down syndrome in pregnancies following renal transplantation

OBJECTIVE

To assess the performance of the double marker test [free beta-human chorionic gonadotrophin (beta-hCG) and alpha-fetoprotein (AFP)] as a screening test for Down syndrome in pregnant patients who had a prior renal transplant.

DESIGN

A retrospective study.

SETTING

The Fetal Medicine Unit, Royal Free Hospital, London, UK.

METHODS

Detailed records of 14 post-renal transplant pregnancies were obtained from the Renal Unit of our hospital where the patients were followed up. The serum concentrations of urea, creatinine, free beta-hCG and AFP at the time of the double marker test were recorded, with a cut-off point of 1:250 for the double marker test. A control group of 14 normal pregnancies matched for age, parity and gestational age was used. The Mann-Whitney U-test and t-tests of unequal variance were applied to compare parameters of the study and the control groups.

RESULTS

Two patients in each group were high risk for Down syndrome and amniocentesis revealed normal karyotype. No babies with Down syndrome were delivered in either group. Regression analysis showed significant correlation between free beta-hCG and urea concentrations (p<0.001) and free beta-hCG and creatinine concentrations (p<0.001), but not for AFP.

CONCLUSIONS

The present study demonstrates that residual renal function alterations persisting after renal transplantation can affect the levels of free beta-hCG and AFP, thus resulting in false-positive screening for Down syndrome. First trimester nuchal translucency (NT) measurement in combination with second trimester ultrasonographic markers can be used in these patients, or alternatively the free beta-hCG levels should be corrected according to the serum creatinine levels.

Assessment of fetal anatomy in the first trimester using two- and three-dimensional ultrasound

The objective of this study was to perform a complete anatomical survey of the fetus at 12-13 weeks gestation using stored volumes acquired by a three-dimensional (3D) scanner. 159 consecutive women at 12-13 weeks gestation who had a routine early pregnancy scan in our unit were recruited. A complete survey of the fetal anatomy was attempted by two-dimensional (2D) transabdominal and, if needed, transvaginal ultrasound. Then, using a 3D transvaginal probe, two volumes of the whole fetus were acquired. A complete anatomical survey (excluding anatomy of the heart) was attempted using the stored data. A complete anatomical survey was achieved in 93.7% (149) of cases with 2D ultrasound compared to 80.5% (128) of cases with 3D volume acquisition (p<0.001). The nuchal translucency was measured with 2D scanning in 98.7% of cases and in 91.8% of cases using 3D volumes. The mean time to perform a 2D scan was 12.2 min standard deviation (SD 3.4 min) while the mean time to obtain and examine the stored volumes was 8.4 min (SD 1.45 min, p<0.001). Real-time 2D ultrasound is still the best way to examine fetal anatomy in the first trimester. However, 3D ultrasound can be a useful addition to clinical practice, providing views not easily obtained by conventional 2D ultrasound. It can potentially minimize actual scanning time and provides an excellent way to store scanned data.

Detailed three-dimensional fetal echocardiography facilitated by an Internet link

OBJECTIVES

To assess whether a complete virtual cardiological examination can be achieved in stored three-dimensional volumes of the fetal heart, transmitted to a tertiary fetal cardiology center via the Internet.

METHODS

Thirty sequential normal singleton pregnancies were included in the study. Four cardiac volumes were acquired using a three-dimensional ultrasound system. The volumes were sent via the Internet to a tertiary fetal cardiology center, where a detailed fetal cardiac examination was attempted using the three-dimensional volumetric dataset.

RESULTS

The median gestational age was 24 (range, 22-28) weeks. A complete heart examination was accomplished in 23 of 30 cases (76.7%; 95% confidence interval, 58-90%). The four-chamber view and the cardiac situs were seen in all cases. The right ventricular outflow tract was seen in 29 (96.7%) cases and the left ventricular outflow tract in 25 (83.3%) cases. The long-axis view of the aortic arch, superior vena cava, inferior vena cava and pulmonary veins were visualized in more than 80% of cases. The mean time of volume acquisition was 9.5 (standard deviation, 2.3) min and the mean examination time by the fetal cardiologist was 17 (standard deviation, 4.8) min.

CONCLUSIONS

These preliminary results demonstrate that a three-dimensional virtual examination of the fetal heart is possible. There are limitations such as the lack of flow and functional information but complete ascertainment of the main cardiac connections was possible in the majority of cases. The use of an Internet link has major implications, particularly for situations in which the scanning center is geographically remote from the tertiary referral center.

The use of nuchal translucency measurement and second trimester biochemical markers in screening for Down's syndrome

OBJECTIVE

To assess the effectiveness of antenatal screening for trisomy 21 by first trimester sonography followed by second trimester biochemical screening.

DESIGN

Retrospective five-year review.

SETTING

Maternity unit of a university hospital.

POPULATION

An unselected group of 7447 pregnant women who had a first trimester scan and nuchal translucency measurement in our unit after January 1995 and had an estimated date of delivery before 1 January 2000. 11.9% were > or = 37 years old. A subgroup (n = 4,864) also had second trimester biochemical testing by alpha-fetoprotein and free beta-human chorionic gonadotrophin.

MAIN OUTCOME MEASURES

Prenatal and postnatal diagnosis of trisomy 21. Results There were 23 fetuses affected with trisomy 21. The overall prenatal detection rate was 87% (20/23; 95% CI 66% to 97%) and we performed invasive procedures in 8.5% of our population. First trimester sonography identified 74% (95% CI 51.6% to 89.8%) of affected fetuses. Second trimester biochemical screening detected half of the fetuses with trisomy 21 which were missed by first trimester screening, increasing the sensitivity to 90.5% (19/21; 95% CI 69.6% to 98.8%) for an invasive procedure rate of 4.2% performed in screened positive women. However, the positive predictive value of the biochemical test was very low (0.5%). In screen negative women, karyotyping for advanced maternal age did not detect any affected fetuses.

CONCLUSION

First trimester nuchal translucency measurement is an effective screening test for the prenatal detection of fetuses with Down's Syndrome. Although the measurement of biochemical markers in the second trimester can detect additional affected fetuses this may be outweighed by the delay in diagnosis, the extra visits and cost so that the right time for biochemical screening is most likely to be in the first trimester.

Retrospective prenatal diagnosis of scimitar syndrome aided by three-dimensional power Doppler imaging

Scimitar syndrome is a rare malformation of the arterial supply and venous drainage of the lung. We report the case of a fetus that presented with cardiac asymmetry and malposition of the fetal heart. Postnatally, scimitar syndrome was confirmed at cardiac catheterization. Retrospective reconstruction of three-dimensional power Doppler volumes, obtained during fetal life, allowed direct visualization of the abnormal aortopulmonary collateral vessel. This had not been seen on conventional scans. This case demonstrates many of the strengths of three-dimensional sonographic techniques for the delineation of complex vascular anatomy. It confirms that a prospective diagnosis of scimitar syndrome should be possible during fetal life.

The role of three-dimensional ultrasound in obstetrics

Three-dimensional ultrasound is a relatively new imaging modality with several potential advantages over conventional two-dimensional sonography. There is now increasing evidence that three-dimensional ultrasound can in many ways assist in the examination of the fetus. The enthusiasm generated by some groups, however, is not universally shared. It is the aim of this review to summarize the contemporary role of three-dimensional ultrasound in obstetric sonography by giving a critical appraisal of the relevant literature published recently, with emphasis on first and second trimester anatomy and fetal organ and placenta volumetry.

Nuchal translucency measurement and pregnancy outcome in karyotypically normal fetuses

OBJECTIVE

The aim of the study was to evaluate the use of nuchal translucency measurement as a marker of adverse pregnancy outcome in karyotypically normal fetuses.

METHODS

During the years 1995-99, nuchal translucency (NT) measurement was routinely offered to all women who had their dating scan in our unit. From the data collected, we calculated the 95th and 99th centiles of the NT for a given crown-rump length using regression analysis. The NT measurements were analyzed in relation to pregnancy outcome, especially with regards to miscarriage, intrauterine death and diagnosis of fetal structural abnormalities, after excluding chromosomal abnormalities.

RESULTS

The pregnancy outcome was available in 6650 (89%) of the 7500 pregnancies. In fetuses with an NT over the 99th centile, 17.8% (relative risk 12.2, 95% CI 7.2-20.8) had an adverse pregnancy outcome (miscarriage, intrauterine death, or termination for fetal abnormality) versus 1.5% for those with a normal measurement. The incidence of structural abnormalities, especially heart defects, was significantly increased in the high-NT groups. Three out of 11 fetuses with major cardiac abnormalities had an NT measurement over the 99th centile. The calculated relative risk for major heart defects in fetuses with increased NT was 33.5 (95% CI 9-123).

CONCLUSION

In the setting of routine antenatal screening, an increased NT measurement is a marker of a high-risk pregnancy even in karyotypically normal fetuses. In addition, the increased incidence of structural abnormalities makes the close follow-up of these pregnancies imperative and should include specialized fetal echocardiography.

Folic acid supplementation

Neural tube defects represent one of a limited number of congenital conditions for which primary prevention strategies are available. Despite strong clinical evidence to support the preventive effect of supplementary folic acid given prior to conception and continued throughout the first 12 weeks of pregnancy, there is limited recent epidemiological data to support the effectiveness of national folic acid supplementation programs. Whether folic acid fortification of staple foods will provide a more effective means of achieving further reductions in the prevalence rates for this condition remains open to question. Recent advances associating folic acid supplementation, hyperhomocysteinaemia and neural tube defects provide a new insight into the possible pathological mechanism of this and possibly other related congenital conditions.

Ultrasonographic markers for chromosomal abnormalities in women with negative nuchal translucency and second trimester maternal serum biochemistry

OBJECTIVE

To analyze the value of second trimester ultrasound examination among those women whose fetuses were indicated to be at low risk of chromosomal anomalies on the basis of both first trimester nuchal translucency measurement and second trimester biochemical screening.

METHODS

A retrospective study of 5500 pregnancies carried out at the fetal medicine unit, Royal Free Hospital. During a period of over 3 years 5500 pregnancies underwent a first trimester scan and nuchal translucency measurement which enabled the detection of 62% (20 of 32) of all chromosomal anomalies. From the remaining pregnancies that underwent second trimester biochemical screening, 3548 were considered negative (risk < 1:250; using maternal serum free beta human chorionic gonadotrophin and alpha fetoprotein). The ultrasound markers that were examined were: shortened femur length, echogenic bowel, pyelectasis, choroid plexus cysts and echogenic intracardiac foci. The likelihood ratios for chromosomal aneuploides for each of these markers were calculated.

RESULTS

Of the 3548 screen negative pregnancies, 3541 (99.8%) had a normal karyotype. Seven (0.2%) fetuses had an abnormal karyotype including four (0.11%) with trisomy 21, one with trisomy 18 and two with 47XXY. Second trimester ultrasound markers were found in two of the five (40%) with severe chromosomal anomalies compared to 184 of 3541 (5.2%) with normal karyotypes. Detection of one or more ultrasound markers in a screen negative pregnancy increased the possibility of chromosomal aneuploidy and a negative ultrasound decreased the risk by a likelihood ratio of 0.6 (95% confidence interval, 0.3-1.3). The risk was considerably increased when two or more markers were detected and we would recommend karyotyping under these circumstances.

CONCLUSION

This preliminary data indicates a possible role for abnormal ultrasound markers in assessing the risk of chromosomal abnormalities in patients considered to be at low risk by nuchal translucency and serum screening. However analysis of a much larger study group will have to be conducted to assess the significance of individual markers.

Assessment of condoms as probe covers for transvaginal sonography

PURPOSE

This prospective study assessed the incidence of transvaginal probe contamination and breakage of condoms used to cover those probes during transvaginal sonography.

METHODS

Over a 9-month period, 214 women underwent transvaginal sonography with probes that had been coated with gel and then covered with a latex condom. Condom defects were detected after the scans by inspection, by adding hydrogen peroxide, and by filling the condoms with 500 ml of water. After the condoms were removed, the probe was either wiped with a dry tissue (during the first 18 weeks of the study) or wiped first with a dry tissue and then with a 70% isopropyl alcohol wipe. Probe head contamination was assessed by periodic swab sampling and culturing for bacteria and herpes simplex virus. Samples of the sonographic gel also were tested for bacterial contamination at approximately weekly intervals.

RESULTS

A total of 217 condoms were used, 3 of which broke and were discarded while being applied to the probe. Two of the 214 condoms used (0.9%) were found upon visual inspection to have perforations. None of the other 212 condoms leaked upon being filled with water; none of the 204 condoms tested with hydrogen peroxide showed bubbles. Only 1 of the 46 probe swab samples was positive for bacteria (Acinetobacter species); none of the 26 probe swab samples cultured for viruses or the 25 gel samples cultured for bacteria were positive.

CONCLUSIONS

Condoms used to cover transvaginal probes showed a low rate of perforation. Disinfection of the probe with isopropyl alcohol wipes further reduced the risk of contamination.

Reproductive choices of women in families with haemophilia

To assess women's experiences in pregnancy and attitudes towards their reproductive choices, a structured questionnaire was sent to all obligate and potential carriers of haemophilia (A and B), aged 14-60 years, registered with our haemophilia centre. One hundred and ninety-seven of 545 (36%) returned completed questionnaires. Clinical details, including type and severity of the disease in the family and results of DNA analysis for carrier detection, were obtained from patient notes. One hundred and sixty women had been pregnant at least once, of whom 36 (23%) had received a prenatal diagnostic test. Of the 41 women who had pregnancy terminations, haemophilia was the main reason in only 11 (27%) women. This decision was affected by the woman's religion and results of DNA studies. Living close to a haemophilia centre, proper counselling at the centre and awareness of the availability of prenatal diagnostic tests influenced the women's decision to become pregnant in 14% and 10% of first and subsequent pregnancies, respectively. These factors were considered more frequently in women with severe haemophilia in the family (P = 0.002) and in confirmed carriers of haemophilia (P = 0.04). When women made a conscious decision not to have children, the reasons were fear of passing haemophilia onto their child (44%), previous experience with haemophilia (6%) and the stress of going through prenatal tests (7%). Severity of the disease in the family, haemophilia diagnosis, results of DNA studies, religion and year of birth had no effect on this decision. Our data indicate that haemophilia and related factors in the family have an influence on women's reproductive choices.

Variations in coagulation factors in women: effects of age, ethnicity, menstrual cycle and combined oral contraceptive

To assess variations of coagulation factors in women, 123 women were included in a cross-sectional study of the effect of age, ethnic origin, blood group and menstrual cycle on surface induced coagulation time (activated partial thromboplastin time) and plasma levels of Factor VIII clotting assay, von Willebrand factor antigen, von Willebrand factor activity and factor XI. The effect of menstrual cycle was further assessed in a longitudinal study including 39 Caucasian women, 20 of whom were using combined oral contraceptives. Activated partial thromboplastin time was longer in women with blood groups B or O, and plasma levels of factor VIII clotting assay, von Willebrand factor antigen and von Willebrand factor activity were significantly higher in black women. Fibrinogen, von Willebrand factor antigen and von Willebrand factor activity concentrations showed strong cyclic variations with peak values in the luteal phase. This pattern was dampened for von Willebrand factor antigen and von Willebrand factor activity but completely disappeared for fibrinogen with the use of combined oral contraceptives. There was a cyclical pattern for factor VIII clotting assay in pill users, evidence of which was not evident in non-pill users. There were strong associations between the levels of von Willebrand factor antigen and von Willebrand factor activity and age, with levels rising by an average of 0.17 and 0.15 U/ml, respectively, for each 10 year increase in age. In conclusion, there are great inter- and intraindividual variations in coagulation markers in women due to different physiological conditions such as age, ethnicity, blood group and phases of the menstrual cycle. However, there were no significant associations between coagulation markers and weight, alcohol consumption or smoking status.

The value of sonography in early pregnancy for the detection of fetal abnormalities in an unselected population

OBJECTIVE

To determine the value of early pregnancy sonography in detecting fetal abnormalities in an unselected obstetric population. DESIGN Prospective cross-sectional study. All women initially underwent transabdominal sonography and when the anatomical survey was considered to be incomplete, transvaginal sonography was also performed (20.1%). Nuchal translucency was measured and karyotyping was performed as appropriate.

SETTING

University Department of Obstetrics and Gynaecology.

PARTICIPANTS

6634 sequential unselected women (mean maternal age 29.9 years, range 13-50; mean gestational age 12+4 weeks, range 11+0-14+6), carrying 6443 live fetuses participated in this study.

MAIN OUTCOME MEASURE

Detection rate of fetal anomalies and the associated cost per case detected in early pregnancy.

RESULTS

The incidence of anomalous fetuses was 1.4% (92/6443) including 43 chromosomal abnormalities. The detection rate for structural abnormalities was 59.0% (37/63, 95% CI 46.5-72.4) and the specificity was 99.9% in early pregnancy. When the first and second trimester scans were combined, the detection for structural abnormalities was 81.0% (51/63, 95% CI 67.7-89.2). Seventy-eight percent (31/40) of chromosomal abnormalities (excluding three cases of XXY) were diagnosed at 11-14 weeks, either because of a nuchal translucency greater than or equal to the 99th centile for gestational age (43%; 17/40, 95% CI 27.4-60.4), or due to the presence of structural abnormalities (35%; 14/40, 95% CI 21.2-52.8). Sixty-five percent (15/23) of cases of trisomy 21 were also diagnosed either because of having a nuchal translucency greater than or equal to the 99th centile (57.0%; 13/23) or due to the presence of a structural abnormality (9.0%; 2/23). Overall, the detection rate of structurally abnormal fetuses was 59% (37/63) in early pregnancy and 81% in combination with the second trimester scan. The cost per abnormality diagnosed in early pregnancy is estimated to be pound sterling 6258 per structurally abnormal fetus, pound sterling 7470 per chromosomal abnormality and pound sterling 4453 per anomalous fetus.

CONCLUSION

The majority of fetal structural and chromosomal abnormalities can be detected by sonographic screening at 11-14 weeks, but the second trimester scan should not be abandoned.

The sonographic identification of fetal gender from 11 to 14 weeks of gestation

OBJECTIVE

To determine the feasibility of correctly identifying fetal gender from 11 to 14 weeks' gestation.

METHODS

A prospective cross-sectional study in a university Department of Obstetrics and Gynaecology, London. A total of 524 women from an unselected population underwent a detailed assessment of fetal anatomy at 11-14 weeks of gestation (confirmed by crown-rump length) by means of transabdominal sonography, and transvaginal sonography (26%) when necessary. Fetal gender was identified in the transverse and sagittal planes, and was confirmed at birth.

RESULTS

The overall success of correctly assigning fetal gender increased with gestational age from 46% to 75%, 79% and 90% at 11, 12, 13 and 14 weeks, respectively. The ability of the operator to assign fetal gender significantly improved with increasing gestational age (p < 0.0001), being 59%, 87%, 92% and 98% at 11, 12, 13 and 14 weeks, respectively. The accuracy of correctly identifying fetal gender when attempted did not change with gestational age. Fetal gender or the performance of the scan by different operators did not affect the results.

CONCLUSION

Whilst the accuracy of sonographic determination of fetal gender at 11-14 weeks is good, it still falls significantly short of invasive karyotyping tests.

The 'Mickey Mouse' sign and the diagnosis of anencephaly in early pregnancy

OBJECTIVES

To assess the sonographic screening for anencephaly in the first trimester in a low-risk obstetric population.

METHODS

Since 1994, 5388 women attended our clinic for a first-trimester scan (11-14 weeks of gestation) and screening for structural and chromosomal abnormalities. The patients underwent transabdominal scanning, and transvaginal scanning if necessary.

RESULTS

The ultrasonographic appearances of anencephaly in the first trimester are different from the familiar second-trimester signs. The cerebral hemispheres are present and exposed to the surrounding amniotic fluid. The ultrasound appearances in the coronal section of the head are best described as 'Mickey Mouse face'. There were six cases of anencephaly (incidence 1.1:1000). All cases were diagnosed in the first trimester and five demonstrated this sign. There were no false-positive diagnoses. The crown-rump length was significantly reduced in all affected fetuses.

CONCLUSION

First-trimester ultrasonographic diagnosis of anencephaly is accurate, but sonographers should be familiar with the ultrasound appearances that are different from those in the second trimester.

Factor XI deficiency in women

Factor XI (FXI) deficiency is an uncommon autosomally transmitted coagulopathy found predominantly in Jewish kindreds. It is associated with variable bleeding tendency that usually manifests after trauma, surgery, or other challenges to hemostasis. Therefore, women with FXI deficiency are at risk of excessive bleeding during their menstrual periods, childbirth, and after surgery. Increased awareness and close collaboration among hematologists, obstetricians, and gynecologists and availability of management guidelines is essential to minimize these risks. This review provides data from current research in FXI deficiency and pregnancy care, menstrual problems, and the role of screening for this disorder in women referred with menorrhagia.

Assessment of menstrual blood loss and gynaecological problems in patients with inherited bleeding disorders

Menstrual blood loss and gynaecological problems in patients with inherited bleeding disorders were assessed in this study. One hundred and sixteen women, including 66 with von Willebrand's disease (vWD), 30 carriers of haemophilia and 20 with factor XI (FXI) deficiency were interviewed and their gynaecological history obtained. Their case records were also reviewed and menstrual loss was objectively assessed using a pictorial blood assessment chart (PBAC). Comparison with an age-matched control group (69 women) was performed. Menorrhagia (PBAC score> 100) was confirmed in 74%, 57% and 59% of women with vWD, carriers of haemophilia and FXI deficiency, respectively, in comparison with 29% in the control group (P = 0.001). PBAC scores were higher in vWD patients with a von Willebrand factor activity (vWF:Ac) of </= 30 IU dL-1 compared to those with higher levels, but the difference was not statistically significant. However, there was no relation between PBAC score and the severity of the disease in FXI deficient patients and carriers of haemophilia. Duration of menstruation was significantly longer (P = 0.001) and episodes of flooding was significantly more common (P = 0.001) in patients with inherited bleeding disorders compared to the control group. However, there was no difference in the passage of clots during menstruation. Forty-seven per cent of patients with inherited bleeding disorders had consultations with their family practitioner or gynaecologist for menorrhagia, 36% had medical treatment and 27% had surgical procedures, including 10 hysterectomies. Post-operative bleeding followed in four out of 28 cases of hysteroscopy and/or dilatation and curettage. Bleeding complications following hysterectomy were reported in five out of 10 patients. In conclusion, menorrhagia is a common and major problem in patients with inherited bleeding disorders, especially vWD. Increased awareness among gynaecologists and haematologists of the high prevalence of menorrhagia and the treatment options available is necessary for optimal management of these patients. Appropriate preoperative assessment and haemostatic control during any gynaecological procedure, however minor, and in collaboration with the local haemophilia centre is essential to minimize risks of haemorrhagic complications.

The significance of choroid plexus cysts, echogenic heart foci and renal pyelectasis in the first trimester

OBJECTIVE

To determine the significance of certain soft ultrasonographic markers for chromosomal abnormalities in the first trimester.

DESIGN

This was a prospective cross-sectional study.

SETTING

University Department of Obstetrics and Gynaecology, London, UK.

METHODS

A total of 5385 women from an unselected population underwent a detailed assessment of fetal anatomy at 11-14 weeks of gestation (confirmed by crown-rump length) by transabdominal sonography (5.0 MHz) and transvaginal sonography (6.0 MHz) when necessary.

RESULTS

In normal fetuses, the prevalences of choroid plexus cysts, pyelectasis and echogenic heart foci were 2.2, 0.9 and 0.6%, respectively in the first trimester and 2.0, 0.8 and 0.8%, respectively in the second trimester. Pyelectasis (likelihood ratio = 8.0, p = 0.03) and echogenic heart foci (likelihood ratio = 10.3, p = 0.02) were found to be associated significantly with fetal aneuploidy, while choroid plexus cysts were not.

CONCLUSIONS

Although the majority of aneuploidies were detected by increased nuchal translucency and/or the presence of structural abnormalities (78%; 25/32), the use of soft ultrasonographic markers in the first trimester would have increased the overall detection by a further 3%. These data are preliminary and many thousands of pregnancies will need to be examined to determine the significance of the individual markers in different chromosomal abnormalities.

Quality of life during menstruation in patients with inherited bleeding disorders

Menorrhagia is a common and major problem for patients with inherited bleeding disorders, especially vWD. Quality of life during menstruation was assessed in 99 patients with inherited bleeding disorders including vWD (n = 57), carriers of haemophilia A (n = 17), carriers of haemophilia B (n = 7) and FXI deficiency (n = 18), and comparison was performed with an age-matched control group (n = 69). A questionnaire was used that included four main sections: (i) general health, (ii) health and daily activities, (iii) dysmenorrhea and (iv) quality of life during the menstrual period. Although patients with inherited bleeding disorders felt that their health (in general) was very good, they had significantly poorer quality of life on all the scales used than controls. Thirty-nine per cent reported having cut down on the amount of time spent on work and other activities as a result of their menstruation; 47% felt that they accomplished less than they would like during this period, 38% felt that they were limited in the kind of work and other activities that they could do, and 40% found that it took extra effort to perform their work. Fifty-one per cent experienced moderate, severe or very severe dysmenorrhoea. Quality of life was statistically poorer in patients with vWD, menstrual scores > 100 according to the pictorial blood assessment chart (PBAC), those who had periods > or = 8 days and those who experienced flooding or passage of clots. In conclusion, menstruation has a negative effect on the quality of life in patients with inherited bleeding disorders especially in those with objectively confirmed menorrhagia.

The effect of fetal neck position on nuchal translucency measurement

OBJECTIVE

To determine the influence of the position of the fetal neck on nuchal translucency measurement.

DESIGN

A prospective cross-sectional study.

POPULATION

One hundred and ninety-six.

METHODS

Nuchal translucency was measured in the mid-sagittal plane, with the fetal neck in the flexed, neutral and extended positions. Measurements were made to the nearest 0.1 mm. Statistical analysis used the paired t-test for differences between the extended and neutral positions, [delta extended nuchal translucency] and the flexed and neutral positions [delta flexed nuchal translucency].

RESULTS

The mean extended nuchal translucency was 0.62 mm greater than the mean neutral nuchal translucency value [95% confidence interval 0.53 to 0.70, T = 14.33, P < or = 0.00001]. The mean flexed nuchal translucency was 0.40 mm less than the mean neutral nuchal translucency value [95% CI 0.34 to 0.47, T = 11.99; P = < 0.00001]. The repeatability coefficient was lower in the case of neutral nuchal translucency measurements [0.48] and was higher in the other groups [extended = 1.04, flexed = 0.70].

CONCLUSION

Fetal neck position can make a significant difference to nuchal translucency measurements. Repeatability of measurements are more accurate with the fetal neck in the neutral position. These findings have important implications for clinicians using nuchal translucency to screen the general obstetric population.

Increased nuchal translucency and CATCH 22

Recent developments in cytogenetics has shown that 22q11 microdeletion is related to a broad spectrum of malformations which are described under the acronym CATCH 22 (Cardiac, Abnormal faces, Thymic hypoplasia, Cleft palate, Hypocalcaemia and 22 chromosome deletion). We describe a case of a fetus with increased nuchal translucency at 12 weeks' gestation presenting with congenital cardiac defects of DiGeorge syndrome type and hypocalcaemia at birth. The neonate was also diagnosed as carrying the 22q11 microdeletion. When nuchal translucency measurement is increased, CATCH 22 spectrum of malformations should be considered and therefore a thorough karyotype analysis should be performed to exclude microdeletion of chromosome 22.

The optimal gestational age to examine fetal anatomy and measure nuchal translucency in the first trimester

The objective of this study was to determine the optimal gestational age for examining fetal anatomy and nuchal translucency in the first trimester. In a prospective cross-sectional study, 1288 women from an unselected population underwent a detailed assessment of fetal anatomy at 10-14 weeks of gestation (confirmed by crown-rump length) with the use of transabdominal sonography and transvaginal sonography, when necessary. Visualization of fetal anatomy improved with increasing gestational age: 6, 75, 96, and 98% of cases could be visualized at 10, 11, 12 and 13 weeks of gestation, respectively, and was similarly high (98%) at 14 weeks. The ability to measure nuchal translucency was similar from weeks 10 to 13 (100, 98, 98 and 98% success rate), but fell to 90% at 14 weeks. The need for transvaginal sonography steadily decreased with increasing gestational age, being 100, 42, 21, 15 and 11% at 10, 11, 12, 13 and 14 weeks, respectively. From these data it appears that the optimal gestational age to examine fetal anatomy and measure nuchal translucency in the first trimester is 13 weeks.

Apparent normalisation of fetal renal size in autosomal dominant polycystic kidney disease (PKD1)

We present a family with adult onset autosomal dominant polycystic kidney disease (ADPKD) in two generations, linked to the PKD1 locus and with paternal transmission to the fetus. The fetus carried the PKD1 haplotype and was, therefore a gene carrier. Progressive hyperechogenic renal enlargement, but no cysts, was documented by serial fetal ultrasounds at 21, 23 and 34 weeks of gestation. Surprisingly, the newborn renal scan showed normal sized kidneys with apparently normal corticomedullary differentiation. However, at 11 months of age, the evolution of cysts in one kidney, and then in the other kidney at 20 months, was documented by ultrasound in the absence of clinical symptoms or signs. The observed normalisation of fetal renal ultrasound appearances at birth has not previously been described in fetuses presenting with PKD1.

Pregnancy in women with von Willebrand's disease or factor XI deficiency

OBJECTIVE

To assess the obstetric outcome in women with von Willebrand's disease or factor XI deficiency.

SETTING

Haemophilia Centre and Haemostasis Unit, The Royal Free Hospital.

POPULATION

Women with von Willebrand's disease (n = 31) and with factor XI deficiency (n = 11) registered at the Royal Free Hospital Haemophilia Centre who had had a pregnancy within the previous 17 years (1980-1996), including 84 in women with von Willebrand's disease and 28 in women with factor XI deficiency.

METHODS

Women were interviewed and details of the obstetric history were obtained. The records of the Haemophilia Centre and the women's maternity records were also reviewed.

RESULTS

Threatened miscarriage occurred in 33% and 14% of pregnancies with von Willebrand's disease and factor XI deficiency, respectively. Excluding recurrent miscarriages, 14/68 (21%) of pregnancies with von Willebrand's disease and one pregnancy with factor XI deficiency miscarried spontaneously. There was an increased incidence of primary and secondary post-abortal bleeding complications. Factor VIII and von Willebrand factor antigen and activity levels increased significantly in pregnancy in all women apart from those with severe von Willebrand's disease. Factor XI, however, did not show any significant change. No neonatal haemorrhagic complications in association with the birth process were reported, although ventouse and difficult forceps deliveries were avoided. Extensive perineal bruising and haematoma was reported in three women with von Willebrand's disease; two of these were associated with forceps delivery. The incidence of primary postpartum haemorrhage was 18.5% in von Willebrand's disease and 16% in factor XI deficiency. Blood transfusion was required in six cases of von Willebrand's disease and two cases of factor XI deficiency. Ten of fourteen instances of primary postpartum haemorrhage occurred when maternal factor levels were < 50 IU/dL with no prophylactic treatment for labour. The incidence of secondary postpartum haemorrhage was 20% in von Willebrand's disease and 24% in factor XI deficiency. None of the women who had prophylactic treatment during labour or the puerperium suffered any significant bleeding complications. There were three neonatal bleeding complications.

CONCLUSION

Pregnancy, labour and the puerperium are associated with significant bleeding problems in women with von Willebrand's disease or factor XI deficiency, but these are largely preventable. Specialist obstetric care in close liaison with the haemophilia centre is essential to minimise maternal and neonatal complications.

Frequency of inherited bleeding disorders in women with menorrhagia

BACKGROUND

Although menorrhagia is a common gynaecological symptom, a specific cause is identified in less than 50% of affected women. We investigated the frequency of inherited bleeding disorders in women with menorrhagia.

METHODS

Women referred for investigation of menorrhagia whose pelvis was normal on clinical examination and who had an estimated menstrual blood loss of more than 80 mL were studied. A detailed menstrual history and history about other bleeding symptoms was taken. The activated partial thromboplastin time, factor VIII activity, von-Willebrand-factor antigen and activity, and factor XI (FXI) were measured in all patients; further tests were done when results were at or outside the limits of the assays.

FINDINGS

150 women were screened. An inherited bleeding disorder was diagnosed in 26 (17%) patients: the disorders were von Willebrand's disease of mild (15) or moderate severity (three), mild FXI deficiency (four), mild von Willebrand's disease and FXI deficiency (one), combined von Willebrand's disease, FXI deficiency, and factor X deficiency (one), carriage of haemophilia-A gene (one), and platelet dysfunction (one). The frequency of von Willebrand's disease and FXI deficiency were 13% (95% CI 7.9-18.8%) and 4% (1.5-8.5%), respectively. Menorrhagia since menarche was noted in 11 (8.9%) of 123 women without a bleeding disorder compared with 13 (65%) of 20 women with von Willebrand's disease (p=0.001) and four (66.7%) of six women with FXI deficiency (p<0.001).

INTERPRETATION

Inherited bleeding disorders are found in a substantial proportion of women with menorrhagia and a normal pelvis examination. We suggest that such patients should be investigated for these disorders-especially von Willebrand's disease-before invasive procedures are done.

First trimester sonographic detection of chromosomal abnormalities in an unselected population

OBJECTIVE

To investigate the role of first trimester sonography in detecting chromosomal abnormalities in an unselected obstetric population.

METHODS

2281 women (mean maternal age 30 years [range 16-47]; mean gestational age 12(+3) weeks [range 11-14]) underwent transabdominal scanning to assess fetal structure and, if anatomical survey was considered to be incomplete (31% of cases), transvaginal sonography was also performed. Measurement of nuchal translucency was included and karyotyping performed as considered appropriate.

RESULTS

There were 16 chromosomal abnormalities; 13 (81%) were diagnosed at 11-14 weeks either because of a nuchal translucency greater than or equal to the 99th centile for gestational age (7/16; 44% [95% CI 25-63]) or due to the presence of structural abnormalities (6/16; 38% [95% CI 14.2-61.8]). Seventy-five percent of cases of trisomy 21 were also diagnosed either because of having a nuchal translucency greater than or equal to the 99th centile (5/8; 63%) or due to the presence of a structural abnormality (1/8; 13%).

CONCLUSIONS

A significant proportion of fetal chromosomal abnormalities can be detected by first trimester sonographic screening to assess fetal structural appearance. The sensitivity of detection can be improved by combining measurement of nuchal translucency with detailed examination of fetal anatomy.

First trimester ultrasonographic diagnosis of fetal structural abnormalities in a low risk population

OBJECTIVES

Ultrasonographic screening between 12(+0) and 13(+6) weeks for fetal structural abnormalities using transabdominal sonography and, where necessary, transvaginal sonography in a low risk population.

DESIGN

A prospective observational study.

SETTING

London teaching hospital.

METHODS

Pregnant women with a total of 1632 low risk viable fetuses between 12(+0) and 13(+6) weeks of gestation were scanned using transabdominal and, where necessary, transvaginal sonography (40%). If the anatomical survey was normal, the women underwent routine 18-20 week anomaly scans. Pregnancy outcomes were obtained from radiological and neonatal computerised databases, and postal or telephone patient enquiry.

RESULTS

Seventeen (1.0%) major structural abnormalities were diagnosed in the study group. Of these, 11 (64.7%) were diagnosed at the 12-13 week scan, three diagnosed in the mid-trimester and three postnatally. Of the fetal abnormalities diagnosed antenatally, 78.6% were diagnosed in the first trimester. The sensitivity of abnormality detection by the combination of both first and second trimester scans was 82.3%. In addition, a significant number of missed abortions (n = 36) were also diagnosed by the first trimester scan.

CONCLUSION

This study has demonstrated the potential of screening a low risk population for fetal abnormalities at 12-13 weeks of gestation using transabdominal sonography and, where necessary, transvaginal sonography. Larger studies are required to establish the clinical value of the first trimester scan.

The role of ultrasonographic markers for trisomy 21 in women with positive serum biochemistry

OBJECTIVE

To assess the value of particular markers detected by second trimester ultrasound examination among those women whose fetuses were shown to be at increased risk of Down's syndrome on the basis of biochemical screening.

DESIGN

A retrospective study of 459 pregnancies.

SETTING

Fetal Medicine Unit, Royal Free Hospital.

PARTICIPANTS

Four hundred and fifty-nine pregnant women, including four twin pregnancies, registered at the Royal Free Hospital, who were considered screen positive (risk > 1:250) based on the results of mid-trimester biochemical markers (maternal serum free beta human chorionic gonadotrophin and alpha-fetoprotein).

MAIN OUTCOME MEASURES

The ultrasound markers that were examined included structural defects, shortened femur length, echogenic bowel, dilation of the renal pelvis and choroid plexus cysts. The likelihood ratios for trisomy 21 for each of these markers were calculated.

RESULTS

Of the 463 fetuses which were screen positive, 449 (97%) had a normal karyotype detected by amniocentesis (n = 344) or postnatal follow up (n = 105). Fourteen fetuses had an abnormal karyotype including 11 (2.4%) with trisomy 21. Ultrasound markers were found in 9/11 (81.8%) fetuses with trisomy 21, compared with 44/449 (9.8%) with a normal karyotype. Detection of one or more ultrasonographic markers in a screen positive pregnancy increased the risk of trisomy 21 by a likelihood ratio of 8.4, and the absence of such markers decreased the risk by a likelihood ratio of 0.2. The risk was considerably increased when the presence of two or markers were detected (likelihood ratio 41). In trisomy 21 fetuses the two most commonly detected markers, shortened femur and dilation of the renal pelvis, had likelihood ratios of 49.3 and 20.5, respectively. Choroid plexus cysts were detected in 27 of the normal karyotypic fetuses compared with none of those with trisomy 21.

CONCLUSION

The presence or absence of abnormal ultrasonographic markers can significantly change the risk of Down's syndrome among pregnant women already found to have abnormal serum biochemistry. This data may be useful in counselling such women.