Evaluation of the sensitivity of a rapid polymerase chain reaction for detection of group B streptococcus.

The objective of this study was to compare detection of group B streptococcal (GBS) carriage using 'real-time' polymerase chain reaction (PCR) and microbiological standard culture. The study design was a test accuracy study comparing a novel molecular technique against the standard microbiological cultural technique in normal pregnant women. The setting and population consisted of 143 pregnant women with pre-labour rupture of the membranes, recruited from two large teaching hospitals in the UK. The study examined the efficacy of a polymerase chain reaction (PCR) assay for screening pregnant women who presented with term rupture of the membranes. Low vaginal specimens were obtained from the women. The specimens were tested for GBS by conventional culture and with a GBS-specific real-time PCR assay. The main outcome measure was the sensitivity and specificity of the PCR assay with 95% confidence intervals (CI) compared with the standard culture. The length of time to obtain a result was also reported for both methods. Among the 143 women, the results of the culture were positive (at least one colony) for GBS in 20 women (14%). The PCR assay detected GBS carriage in 10 women (7%). As compared with the culture method, the sensitivity and specificity of the PCR assay were 45% and 99%, respectively. The positive and negative predictive values of the PCR assay were 90% and 92%, respectively. The length of time required to obtain results for the majority of women (94%) was <2.5 h for the PCR assay and at least 24 h for culture. While a rapid result (within 3 h) of carriage of GBS can be obtained by the PCR assay, at present, it cannot replace conventional culture without further optimisation of the DNA extraction method. The sensitivity may further be improved by testing both low vaginal and rectal specimens.

A comparison of fetal behaviour in term fetuses exposed to anticonvulsant medication with unexposed controls.

OBJECTIVE: To compare behaviour in term fetuses exposed to anticonvulsants with unexposed controls. DESIGN: An observational study. SETTING: Pregnancy Assessment Centre, University Hospital, Nottingham, UK. SAMPLE: Seventeen fetuses whose mothers were taking anticonvulsants and 94 fetuses whose mothers were on no medication between 28 and 41 weeks. METHODS: Behaviour (fetal heart rate and activity) was recorded with the use of Doppler ultrasound. The duration of recording was 60 minutes or more in all but four recordings (minimum 49 minutes). MAIN OUTCOME MEASURES: Behavioural criteria studied were: 1. the relative percentage time spent in low and high variation fetal heart rate patterns; 2. the duration and recurrence of fetal activity; 3. the number of accelerations in low and high fetal heart rate variation; and 4. the number of fetal behavioural state transitions. RESULTS: The two groups were comparable in terms of maternal age, parity. birthweight, Apgar scores and absence of neonatal problems. There was less fetal activity in the anticonvulsant group, but this was only statistically significant at 33-36 weeks in fetal heart rate pattern B (equivalent to state 2F). CONCLUSIONS: This study showed that fetuses exposed to anticonvulsant medication exhibited a trend of being less active. There were no other significant differences in behaviour. The data do not support the hypothesis of substantial differences in behaviour in fetuses exposed to anticonvulsants.

A comparison of fetal behaviour in breech and cephalic presentations at term.

OBJECTIVE: To evaluate fetal behaviour in breech and cephalic fetuses at term, using a computerised fetal behaviour program. DESIGN: An observational study. SETTING: Pregnancy Assessment Centre, University Hospital, Nottingham. SAMPLE: Twenty-six breech and 58 cephalic fetuses between 36 and 41 weeks. METHODS: Behaviour (fetal heart rate and activity) was recorded with the use of Doppler ultrasound. The duration of recording was 60 minutes or more in all but four recordings (minimum 49 minutes). MAIN OUTCOME MEASURES: Behavioural criteria studied were 1. the relative percentage time spent in low and high variation fetal heart rate patterns; 2. the duration and recurrence of fetal activity; 3. the number of accelerations in low and high fetal heart rate variation; and 4. the number of fetal behavioural state transitions. RESULTS: Breech fetuses differed from the cephalic group in that they were lighter than the cephalic fetuses (median 3105 g vs 3400 g; P < 0.01) and were born to older mothers (median maternal age 30 years vs 28 years; P < 0.01). No significant differences were found in rates of movement, numbers of accelerations and time exhibiting low and high fetal heart rate variation. However, breech fetuses exhibited significantly more state transitions (median 5.2/h vs 3.69/h; P = 0.01). CONCLUSIONS: This study shows that breech fetuses are neurologically different from their cephalic counterparts in otherwise healthy pregnancies, and that subtle behavioural differences can be demonstrated in utero using this computerised method.

Pregnancy care of the low risk woman: the community-hospital interface.

Aims to determine the extent to which women suitable for community-based antenatal and intrapartum care will require hospital contact. Reports on an historical cohort study of low risk women who underwent standard shared care and for whom the records for both pregnancy and delivery were complete at The City Hospital and University Hospital, Nottingham. Concludes that the shift to community-based care aims to bring many improvements to the overall care and satisfaction of pregnant women. However, it may not reduce the workload of hospital-based services to a great extent as the majority of women, even if low risk at booking, will require some hospital input at some time during pregnancy or labour.