1109

with various gonadotropin releasing hormone (GnRH) analogue regimens. Having been infertile for the previous 6 years, with an ectopic pregnancy 2 years ago, the patient has now delivered successfully. In the first trimester, the concentrations of human chorionic gonadotropins (hCG) were in the normal range, increasing from 53 IU/1 on day 14 to 145 656 IU/1 on day 50 after triggering ovulation (10 000 IU hCG; Pregnyl). On these 2 days serum oestradiol values were 526 and 1918 pg/ml and serum progesterone 33 and 95 ng/ml, respectively. A vital singleton intrauterine pregnancy was shown by

ultrasonography at gestational age 7 weeks (day 38 after hCG). Crown-rump length was 9-4 mm. Alphafetoprotein after 15 weeks was normal (34-7 ng/ml). At 16-5 weeks the biparietal diameter was 3-8 cm. No fetal abnormalities were seen by ultrasound scans during the second and third trimester. The patient underwent a normal vaginal delivery at 39-5 weeks. A healthy girl was born weighing 3170 g; Apgar score was 9/10 (1/5 min). The first 45 completed treatment cycles have resulted in ten pregnancies after 38 embryo replacements, which included couples with tubal infertility (n = 17), male infertility (11), unexplained infertility (11), and endometriosis (6). Successful superovulation and pregnancies were established irrespective of the GnRH regimen applied. No drug-related adverse effects were noted. As far as we are aware, this is the first singleton term birth after the administration of FSH produced by recombinant DNA technology. Further clinical research is needed to study the properties of rhFSH compared with urinary gonadotropins, with special emphasis on the avoidance ofhyperstimulation and multiple pregnancy. Centre for Reproductive Medicine,

Teaching Hospital and Medical School, Free University Brussels, 1090 Brussels, Belgium

PAUL DEVROEY ANDRE VAN STEIRTEGHEM

Medical R & D Unit,

Organon International BV, PO Box 20, 5340 BH OSS, Netherlands

1. Devroey P,

Van

Steirteghem A,

BERNADETTE MANNAERTS HERJAN COELINGH BENNINK Mannaerts B,

Coelingh

Bennink H. Successful

in-vitro fertilisation and embryo transfer after treatment with recombinant human

FSH. Lancet 1992; i: 1170-71.

Ultrasound and fetal chromosome abnormalities SiR,—There are great difficulties in drawing practical inferences from Dr Nicolaides and colleagues’ report (Sept 19, p 704) of an association of the prenatal ultrasound diagnosis of malformation or growth retardation with subsequent detection of abnormal chromosomes in the fetus. Their findings are relevant to decisions to undertake invasive diagnostic procedures such as amniocentesis at a stage when a patient may still choose voluntary termination of pregnancy. In many areas of the USA at least, that stage by law is before 24 completed (menstrual) weeks of gestation-ie, about 22 weeks from the time of conception. Yet, judging from the median ages of "referral" of those with malformation or growth retardation cited in their study, most cases were well beyond this age. For instance, for those listed with oesophageal atresia the median age was 27 weeks, in those with growth retardation 28 weeks. And all categories studied included fetuses at or quite close to term. In older fetuses one can detect malformations much more readily than in those under 24 weeks-the stage of practical importance. Thus the strong association of karyotypic abnormality with malformation in Nicolaides’ report casts no light on the usefulness of data relevant to amniocentesis and voluntary termination in many jurisdictions. Furthermore, Nicolaides and colleagues’ report might suggest to some readers that detailed intensive ultrasound screening of all pregnancies should be undertaken to enhance non-invasive detection of those at high risk of karyotype abnormality. Indeed they cite a recent recommendation that every pregnant woman should be offered a "systematic search for defects" with ultrasound at about 20 weeks’ irrespective of pre-existing risk of abnormality. It is noteworthy therefore, that not only do the reported results bear little relevance to an association of ultrasound findings and abnormal karyotype at 20 weeks’, but also that targeted prenatal

ultrasound of even a single organ such as the heart or oropharynx in search of defects is time consuming and expensive, especially in the earlier stages of gestation when a patient may still make an informed decision on elective termination of pregnancy. Such targeted evaluation is not generally undertaken unless there is a reason to expect a malformation in a particular area. Targeted studies of all organ systems as implied by a "systematic search for defects" will be extraordinarily demanding of time and effort. Only careful examination of the costs as well as the yield of such procedures at the appropriate time in pregnancy will enable appropriate policy decisions. School of Public Health, University of California, Berkeley, California 94720, USA

Imposed

ERNEST B. HOOK

upper

airway obstruction

in

children SiR,—Dr Samuels and Professor Southall’s attempt (Sept 26, 787) to restate their position on the procedure for diagnosing imposed suffocation in children underlines the difficulty that they p

have created.

Firstly, they persist in their statement that covert video surveillence should be used to confirm the diagnosis from recordings that they "have repeatedly stated ... may be suggestive but not diagnostic of [imposed] suffocation". Had the latter statement been true, the concern about the use of their research physiological recording system for conviction of parents for this offence would not have arisen. Secondly, they concede that physiological recordings on videos are unlikely to produce any characteristic pattern because of their brevity. Then they seriously contradict themselves by proceeding to analyse clinically similar cyanotic episodes to those they recorded by video (which are too brief). More importantly, they ignore the limitations of their present recording methods. The improved methods to which they refer (which were agreed by a Commission of the European Communities working party of which Southall is a member) are equally portable but more comprehensive (6 channels), record continuously, and therefore do not depend on event-capture such as that of Southall which is based on a fall in tcp02’ measured at suboptimum temperature, below 2-66 kPa. The argument for continuous recording is that sleep cycles and activity, which are neurobehavioural indicators of health and affect cardiorespiratory pattern, greatly assist in interpreting unsupervised monitoring. Even so, video recording was favoured as an additional measurement for non-suspicious recording, as is the case in most sleep laboratories. Imposed suffocation is an important clinical problem for which I propose a monitoring procedure no less comprehensive than for any other unsupervised home sleep study. Economic video techniques that can be linked to physiological recordings are now available. It is therefore clinically and ethically untenable to persist with the notion that inclusion of video recording would merely drive the parent (or minder) intent on abuse to other means. The acceptance of covert video recording to achieve this diagnosis will soon be known to the public. Lengthy, costly, sinister, covert surveillance will then be negated by the offending and innocent minder alike, who will no doubt be accused on the initial evidence-namely, history and inadequate physiological recordings. This was precisely where the thrust of your July 11editorial would lead us. Since many more infants with identified problems, of which recurrent apnoeas are often a part, should benefit from the more advanced portable recording techniques, it is important that they do not all come under suspicion in this way. Hopefully the forthcoming working party of the British Paediatric Association (of which Southall is also a member) on methods of evaluating hidden suffocation will clarify this important issue for parents and the

profession. Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital,

Maternity Department, Headington, Oxford OX3 9DU, UK

PAUL JOHNSON