British journal of obstetrics and gynaecology最新文献

Objective To investigate in vivo the function of the microcirculation of the skin in pregnancy and pregnancy complicated with pre-eclampsia.

Design Case–control study.

Setting Academic Medical Centre.

Participants A group of 10 women with pre-eclampsia and a healthy control group of 10 pregnant women.

Methods The microcirculation of the skin of the finger at rest and during venous occlusion was studied with laser Doppler fluxmetry and orthogonal polarisation spectral imaging. By inflating a cuff around the upper arm to a pressure of 50mmHg, causing venous occlusion, the local sympathetic veno-arteriolar reflex was provoked. With laser Doppler fluxmetry the blood flow of the skin at a depth of 1–2mm was measured at rest and during venous occlusion. Orthogonal polarisation spectral imaging was used to assess red blood cell velocity at rest and during venous occlusion of the nutritive capillaries of the skin.

Results Laser Doppler fluxmetry showed no significant difference between the normotensive group and the group with pre-eclampsia. Using orthogonal polarisation spectral imaging, venous occlusion produced a significantly greater decrease in red blood cell velocity in the control group than in the women with pre-eclampsia: (84% (81–88)(median and interquartile range) vs 58% (45–88), P=0.0029). No differences in absolute red blood cell velocities were observed between groups either at rest or during venous occlusion.

Conclusion This study shows an impaired local veno-arteriolar reflex in pre-eclampsia at the nutritive, but not at the thermoregulatory, level of the microcirculation of the skin.

Obstetric cholestasis is a liver disorder unique to pregnancy, which typically presents with pruritus. However, pruritus is common in pregnancy and the diagnosis of obstetric cholestasis is confirmed by finding abnormal liver function. We report 10 cases in which pruritus occurred before any abnormality in liver function tests (including total serum bile acids) and discuss the implications of this for clinical practice.

Objective To evaluate whether the fetus loses weight in utero following fetal death, looking specifically at weight differences according to whether the death occurred during labour or before labour.

Design Record linkage of maternity data and perinatal mortality data.

Setting Scotland, UK.

Population A group of 8069 singleton live and stillbirths without obvious congenital abnormalities delivered at 24–32 weeks.

Main outcome measure Birthweight.

Results Stillborn infants weighed less than liveborns of equivalent gestational age at delivery. Stillborn infants in whom the death occurred during labour weighed more than those in whom the death occurred before labour; this applied to both vaginal deliveries and those by caesarean section.

Conclusions These findings could be attributed to the hypothesis that the low birthweight of stillborn infants is due to weight loss following the death, in addition to any process of growth restriction before the death. The analysis described here contains no data which would negate this hypothesis.

Objective To examine the association between maternal HIV infection and pregnancy outcomes controlling for potential confounding factors among a cohort of HIV-uninfected and HIV-infected pregnant women in Dar es Salaam, Tanzania.

Design Prospective cohort study.

Methods A cohort of 1078 HIV-infected and 502 HIV-uninfected pregnant women between 12 and 27 weeks of gestation were enrolled and followed up until delivery. Multiple regression models were used to compare the risk of adverse pregnancy outcomes among HIV-uninfected women with those among HIV-infected women overall, and separately among asymptomatic or symptomatic HIV-infected women.

Results No significant differences between HIV-uninfected women and HIV-infected women were observed in risks of fetal loss or low birthweight or in the weight, head circumference and gestational age of infants at birth. HIV-infected women were more likely to have severe immature infants (<34 weeks) than HIV-uninfected women (multivariate RR 1.54 [95% CI 0.90–2.48]; P=0.05). There was a significantly higher risk of low birthweight (RR 2.29, 95% CI 1.34–3.92; P=0.03) and prematurity (<37 weeks) (RR 1.93, 95% CI 1.35–2.77; P=0.0003) among symptomatic HIV-infected women when compared with HIV-uninfected women.

Conclusion HIV-infected women, particularly those who are symptomatic, are at a higher risk of adverse pregnancy outcomes.

Objective To examine the differences in multiples of the median (MoM) of total alpha-fetoprotein, and the proportion of Lens culinaris agglutinin reactive alpha-fetoprotein (% alpha-fetoprotein-L2+L3) in the maternal serum and amniotic fluid of pregnant women whose fetuses were diagnosed with autosomal or sex chromosomal abnormalities.

Design Prospective consecutive series.

Setting University hospital.

Sample Maternal sera and amniotic fluids from 46 pregnant women with trisomy 21 fetuses, 10 pregnant women with trisomy 18 fetuses, one pregnant woman with a trisomy 13 fetus, six pregnant women with fetal sex chromosomal abnormalities, and 100 pregnant women for whom the fetal karyotype was diagnosed as normal following a genetic amniocentesis.

Results The proportion of alpha-fetoprotein-L2+L3 in maternal serum for trisomy 21 (40.3%, P<0.0001) and trisomy 18 (39.8%, P<0.05) showed a significantly higher value compared with normal (32.6%). The proportion of alpha-fetoprotein-L2+L3 in amniotic fluid was significantly higher (P<0.0001) for trisomy 21 (46.6%) than for a normal karyotype (41.5%). Only for the trisomy 21 group was there a strong correlation in the % alpha-fetoprotein-L2+L3 between maternal serum and amniotic fluid (r=0.840, P<0.0001). For all groups, there was no correlation between alpha-fetoprotein MoM and % alpha-fetoprotein-L2+L3 in maternal serum and amniotic fluid.

Conclusion The proportion of alpha-fetoprotein-L2+L3 in maternal serum is an appropriate choice for a trisomy 21 biochemical marker, and it is possible that combining alpha-fetoprotein-L2+L3 analysis with assays of alpha-fetoprotein in maternal serum could further improve the sensitivity and specificity of multiple marker screening.

Objective To examine the relationship between the cervical dilatation at which women present in labour and the subsequent likelihood of caesarean section.

Design Retrospective cohort study.

Setting University teaching hospital.

Population 3220 women met the entry criteria from 14,050 deliveries between January 1995 and December 1999.

Methods Women meeting the following criteria were identified: those in spontaneous labour with a singleton pregnancy and a cephalic presentation at 37–42 weeks of gestation; all women delivering within 36 hours of first presentation were included. Women who had spontaneous rupture of the membranes before first attendance were excluded.

Main outcome measures The primary outcome was the rate of caesarean section. Secondary outcomes were operative vaginal delivery, fetal weight, cord pH, five minute Apgar score, length of labour, labour augmentation with oxytocin and epidural analgesia.

Results The risk of caesarean section decreased with increasing cervical dilatation at presentation. This was true for nulliparous (n=1168) and parous women (n=2052). The caesarean section rate of nulliparous women presenting at 0–3cm (n=812) was 10.3%, compared with 4.2% for those presenting at 4cm–10cm (n=356), and the mean duration of labour before presentation was 2.0 hours versus 4.5 hours, respectively (P=0.0001). For parous women the caesarean section rates were 5.7% and 1.3%, respectively (P=0.0001). There were significantly greater frequencies of use of oxytocin and epidural analgesia by women presenting earlier in labour. The caesarean section rate of 185 nulliparae (15.8%) who were initially allowed home was no different from those admitted immediately (9.2% vs 8.2%, P=0.67). Similarly, 196 (9.5%) of multiparae went home and had a caesarean section rate of 3.6%, compared with 3.1% if admitted immediately (P=0.76).

Conclusions Women who present to hospital at 0–3cm spend less time in labour before presentation and are more likely to have obstetric intervention than those presenting in more advanced labour. Outcomes were similar whether or not the woman was initially allowed home.

Four hundred and eighty-three consecutive women referred for videocystourethrography completed a structured questionnaire about their menstrual status and urinary symptoms. Women were included in the study if they were premenopausal, had a regular menstrual cycle and were not taking hormonal therapy. One hundred and thirty-three women satisfied the inclusion criteria of whom 55 (41%) complained that their urinary symptoms were cyclical. The times at which symptoms were said to be at their worst were reported by the women as follows: during a period (n=20; 36%); just after a period (n=4; 7%); middle of the month (n=8; 15%); just before a period (n=23; 42%). The prevalence of abnormal detrusor activity on videocystourethrography increased significantly with time from the last menstrual period (χ² for trend=6.56, P=0.01) and might reflect increases in the circulating level of progesterone following ovulation. This study provides further indirect evidence that progesterone could have an adverse effect on female lower urinary tract function. In addition, it might be necessary to consider the stage within the menstrual cycle when interpreting the results of urodynamic investigation.

Objective To determine any differences in cerebral perfusion pressure in patients with chronic hypertension compared with those with chronic hypertension and superimposed pre-eclampsia.

Design A prospective observational study.

Setting University hospital clinic and labour and delivery suite.

Participants Fifteen women with chronic hypertension and 15 with superimposed pre-eclampsia.

Methods Transcranial Doppler ultrasound was used to measure blood velocity in the middle cerebral arteries of the patients. Systemic blood pressure in the brachial artery was measured simultaneously. Middle cerebral artery, resistance index, pulsatility index, and cerebral perfusion pressure were calculated and plotted on the same axes as data from normal pregnant women. Cerebral perfusion pressure values outside of the 5th and 95th centiles were regarded as abnormal. Cerebral perfusion pressure data from the chronic hypertension and superimposed pre-eclampsia groups were also expressed in terms of the number of normative standard deviations from the mean value for normal pregnancy (Multiples of the Standard Deviation: MOS). All studies were conducted before labour, under similar conditions, and before volume expansion or treatment. Statistical analysis was by Student's t test and Fisher's exact test as appropriate with significance set at a two-tailed P<0.05.

Results Patient demographics and blood pressure were not significantly different between the two groups. The resistance index and pulsatility index were not significantly different (neither absolute nor multiples of the standard deviation values). The absolute cerebral perfusion pressure was significantly higher in the patients with superimposed pre-eclampsia. The group of women with superimposed pre-eclampsia had a significantly higher mean value of cerebral perfusion pressure measured as multiples of the standard deviation from the mean value for normal pregnancy, despite there being no blood pressure difference.

Conclusions Superimposed pre-eclampsia is associated with significantly higher cerebral perfusion pressure measurements compared with women with uncomplicated chronic hypertension. This is not directly related to a higher blood pressure. The difference in cerebral perfusion pressure may be used to speculate upon the pathophysiology of the increased risk for eclampsia seen in patients with superimposed pre-eclampsia.

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.