Vanishing twins: the frequency of spontaneous fetal reduction of a twin pregnancy.

This study examines the outcome of 126 twin pregnancies diagnosed by ultrasound examination at 6-16 weeks' gestation. Fifty-nine patients conceived by in vitro fertilization (IVF) and embryo transfer and had a routine scan. The 67 non-IVF pregnancies had a scan for other clinical indications including threatened abortion. When live twins were detected prior to 7 weeks'gestation, only 71% of pregnancies resulted in live twin neonates. Each fetus of a multiple pregnancy had a 19% chance of dying in utero or in the neonatal period of diagnosed prior to 7 weeks, and 11% if both were found to be alive between 7 and 10 weeks. The fetal loss rate was similar for IVF and non-IVF pregnancies.

Transabdominal chorion villus sampling: a safe and reliable procedure.

A complete follow-up of the first 578 patients undergoing transabdominal chorion villus sampling (TACVS) in our combined practices was undertaken to determine the pregnancy loss rate. Factors contributing to losses and the problems incurred in achieving a clinically relevant result were also examined. It was found that increasing experience led to fewer procedural difficulties but that there persisted a higher problem rate in those women with a retroverted uterus. In 98.1% of patients an adequate volume of tissue was obtained and in 95.5% a clinically relevant result was achieved. This second figure rose to 96.3% in the latter part of the study. There was a total fetal loss rate of 2%, with only 0.5% (3 patients) having a missed abortion within 4 weeks of the procedure. It is concluded that TACVS is a reliable procedure with a high level of safety.

Plastic wrap for ultrasound transducers. Herpes simplex virus transmission.

Plastic wrap was investigated as an alternative cover for ultrasound transducers to ensure their sanitization or sterility. The wrap was found to have no gross defects, did not allow the passage of herpes simplex virus across it in vitro and made no difference to the quality of the ultrasound images. It is a simple, cheap, and safe alternative for use as a transducer cover and can be gas sterilized for sterile procedures.

The 'simple' ovarian cyst: aspirate or operate?

One hundred ultrasound-guided ovarian cyst punctures were performed in 88 patients. To minimize the risk of unexpected malignancy, only persistent or painful cysts less than 10 cm in diameter were aspirated, cysts with solid areas or multiple locules were excluded. Cytological diagnosis was not possible in 72 of the 100 fluids; of the others 20 contained cells suggestive of follicular or luteal cysts, four samples suggested endometriosis and four benign tumours of epithelial origin. Oestradiol levels were high in 54 cystic fluids, and a combination of oestradiol estimation and cytology facilitated the identification of a follicular origin. Most such patients would normally have undergone surgery, but this was eventually required in only 10 of 60 in whom the cyst fluid was clear or slightly blood-stained and in 16 of the 28 with heavily blood-stained fluid. Ultrasound-guided ovarian cyst puncture would appear to be a valid alternative to surgery for carefully selected benign ovarian cysts especially when the cyst is considered not to contain blood.

Monitoring early pregnancy with transvaginal ultrasound and choriogonadotrophin levels.

Serum human chorionic gonadotrophin levels were correlated with gestational sac size detected by transvaginal ultrasound in a series of 178 women undergoing in vitro fertilization. The improved resolution of transvaginal ultrasound enables pregnancy to be detected between 17 and 20 days post-ovum retrieval, when HCG levels were greater than an average threshold level of 1,300 IU/L. The lower HCG discriminatory zone enables improved evaluation of ectopic pregnancies. Also, higher HCG titres observed in multiple pregnancies enable estimation of implantation rates when more than one embryo is transferred.

Demonstration of ectopic pregnancy by transvaginal ultrasound.

Transvaginal ultrasound was used in the assessment of 148 patients clinically suspected of having an ectopic pregnancy. Transvaginal ultrasound allowed earlier demonstration of an intrauterine pregnancy without confusion with a pseudosac. Of the 36 patients with an ectopic pregnancy, this was strongly suspected in 29 (81%). A live extrauterine fetus was seen in 8 (22%), ectopic trophoblast or a gestation-sac-like structure in 19 (53%), and a pelvic haematoma in 2 (6%). Transvaginal ultrasound is advocated as the technique of choice in patients suspected of having an ectopic pregnancy.

Transabdominal chorionic villus sampling.

The first 100 patients undergoing first trimester transabdominal chorionic villus sampling (placental biopsy) in our hospital are reviewed. At the time of follow up 24 patients had delivered, 68 pregnancies were at 24 weeks or more and progressing normally, 7 pregnancies were terminated and there was only 1 spontaneous miscarriage. The advantages of the transabdominal approach are discussed.

Early diagnosis of pregnancy failure with transvaginal ultrasound.

Vaginal ultrasound was used to assess a consecutive series of 353 patients to determine the minimum mean gestation sac diameter at which a failed pregnancy could be diagnosed. Fetal heart movements could be demonstrated in all pregnancies with living fetuses when the mean sac diameter exceeded 1.2 cm. Vaginal ultrasound is superior to both static and transabdominal real-time ultrasound in the diagnosis of early pregnancy failure.

Early detection of intrauterine pregnancy with ultrasound.

Vaginal scanning is a relatively new technique for scanning early pregnancy. In a consecutive series of 27 patients on an in vitro fertilization program (and therefore certain dates of ovulation) we have demonstrated that pregnancies may be seen within the uterus even before 5 weeks amenorrhoea and have documented their size. Ultrasound examination at this early stage may be of clinical value, particularly in patients suspected of having an ectopic pregnancy.

Fetal intravascular transfusion for severe erythroblastosis: effects on haematology and survival.

Since February 1984, 8 fetuses (including a set of hydropic twins) with severe erythroblasts in the second trimester have received intravascular transfusions guided by ultrasound. These transfusions were associated with a decreasing fetal reticulocytosis, a decreasing proportion of circulating fetal haemoglobin and a decreasing mean fetal red corpuscular volume. All infants were born alive at an average of 5.5 weeks after the first transfusion; 3 infants died, including the hydropic twins and another with lethal congenital anomalies. All 5 survivors required simple transfusions for up to 54 days after birth because of prolonged bone marrow suppression. In severe erythroblastosis in the second trimester, direct intravascular transfusion using ultrasound guidance promises to improve fetal outcome.

Amniocentesis: a comparison of 'monitored' versus 'blind' needle insertion technique.

The incidence of complications following 382 'blind' amniocenteses, in which ultrasound was used prior to but not during the procedures, was compared with those following 482 'continuously monitored' amniocenteses. The monitored technique was associated with a reduction in the incidence of blood-stained amniotic fluid, the number of attempts required to obtain fluid and with a fall in the number of spontaneous abortions from 9 (2.4%) to 4 (0.8%).

Mortality and two year outcome of infants of birthweight 500-1500 g: relationship with neonatal cerebral ultrasound data.

Cranial ultrasounds were performed on 218 (96%) of 227 liveborn infants of birthweight 500-1500 g delivered in the Royal Women's Hospital, Melbourne, Australia, in an 18-month period concluding in March 1982. Seventy-two (31.7%) of the children died; 28 children (38.9%) had cerebroventricular haemorrhage, 35 (48.6%) showed no bleeding and there were nine (12.5%) with no data. Paired necropsy and ultrasound data were congruent in 22 (88%) of 25 children. One hundred and forty-eight (95.5%) of 155 survivors were seen at 2 years of age. Forty-one (28%) had cerebroventricular haemorrhage; nine children (6%) had both ventricular dilatation and haemorrhage and two had ventricular dilatation alone. Apart from a marginal advance in gestation and higher number of immigrant and less educated mothers in children without cerebroventricular haemorrhage, all other perinatal, biographical and social variables between those with haemorrhage and those without were similar. The major handicap rate overall was 14.2% (21 patients). The children with cerebroventricular haemorrhage had a trend for greater prevalence of handicap and lower mean Bayley psychological scores. This was even more evident with ventricular dilatation being present. Of children with major handicap 57.1% (12/21) had normal serial ultrasound findings during their primary hospitalization. Major handicap occurred in 15% (3/20) of children with grade 1 haemorrhage, 23.5% (4/17) with grade 2 or 3 bleeds and 25% (1/4) of those with grade 4 haemorrhage. Laterality of cerebral palsy did not correlate with ultrasound findings. Ultrasound findings did not improve statistical prediction of deaths or major handicap.

Ultrasound-guided fetal blood transfusion for severe rhesus isoimmunization.

Four fetuses with severe rhesus isoimmunization were transfused with packed red blood cells directly into the umbilical vein. The outcome was successful in three. In one infant, this ultrasound-guided technique resulted in resolution of severe fetal hydrops at 27 weeks, allowing delivery of a healthy nonhydropic infant at 33 weeks, and in the other three infants in prolongation of the pregnancy. The last four transfusions were performed after fetal neuromuscular blockade with curare. The procedure would appear to be associated with a low risk of complication and to provide an excellent chance of a successful outcome of a fetus with severe rhesus isoimmunization even when fetal hydrops is present.

Ventricular size in newborn infants.

Cranial ultrasound examinations were performed on 533 infants of between 48 and 96 hours of age to establish the range of ventricular size in neonates of different gestational ages in whom there was no evidence of intraventricular hemorrhage or neural tube defects. It was found that ventricular size did not vary in infants with gestational age of 26 weeks or more. Only 15 (2.8 per cent) neonates had a ventricular width of greater than 3 mm. Of these 15 infants, 13 were re-examined within the first year of life and found to be neurologically and developmentally normal.

Gestation sac size in in-vitro fertilization pregnancies.

The gestation sac size in pregnancies resulting from in-vitro fertilization (IVF) and embryo transfer have been compared with those in spontaneous pregnancies. Small-for-dates gestational sac sizes were found in 36% of the IVF pregnancies. This proportion held for both singleton and multiple pregnancies. With increasing gestation beyond 8 weeks the gestation sac volume increasingly approached normal. In contrast to spontaneous conceptions, IVF pregnancies had a low rate of pregnancy loss once fetal heart movements were demonstrated, when the gestation sac size was small-for-dates. Small sac size in an IVF pregnancy may lead to the misdiagnosis of a failed pregnancy.