Ultrasound assessment of cervical length at 18-21 weeks' gestation in an Australian obstetric population: comparison of transabdominal and transvaginal approaches.

BACKGROUND: Using a fixed cut-off of ≤25 mm, ultrasound assessment of cervical length during the 18-23 week anomaly scan has been shown to identify approximately 50% of pregnancies that would deliver prior to 34 weeks. AIM: To determine whether a policy of reverting to transvaginal cervical assessment only if the cervix appears short (≤25 mm) on transabdominal assessment affects the efficiency of screening. METHODS: Women with a singleton pregnancy that presented for a routine anomaly scan had their cervical length assessed transabdominally, initially with the maternal bladder full (TABF) and then empty (TABE). Cervical length was then assessed transvaginally (TV). RESULTS: One hundred and ninety-eight women agreed to participate in the study. Identification of the internal and external cervical os was possible during TABF, TABE and TV sonography in 97.0, 82.8 and 100%, respectively. Compared with TV sonography, TABF overestimates cervical length (6.1 mm difference in median values; P < 0.01). There was no significant difference between TV and TABE. However, TABE assessment was not possible in one in six women. If TABF sonography was to be used as a screening tool and using ≤25 mm as the critical cut-off, the sensitivity and specificity was 15.4 and 93.2%, respectively. CONCLUSION: This study has shown that assessment of cervical length using a TA approach is only routinely possible when the bladder is full. However, measurements are significantly overestimated. Therefore, we feel that TV assessment of cervical length is the preferred method of reliable cervical assessment. As such, all women should be offered a TV assessment of cervical length at the time of the fetal anomaly ultrasound as a screening test for preterm birth.

Role of proteinuria in defining pre-eclampsia: clinical outcomes for women and babies.

1. The presence of proteinuria is not essential to the diagnosis of pre-eclampsia under many diagnostic consensus statements. The aim of the present study was to assess maternal and perinatal outcomes after proteinuric pre-eclampsia compared with other non-proteinuric disease presentations. 2. An individual patient data review (n = 670) was undertaken for 2003-2006 at a tertiary referral centre in Sydney (NSW, Australia). Women were diagnosed in accordance with the Australasian Society for the Study of Hypertension in Pregnancy Consensus Statement. Data were analysed with the Chi-squared test, t-tests and non-parametric tests. Statistical significance was set at P < 0.05. 3. The proteinuric cohort had higher systolic and diastolic blood pressure recordings than the non-proteinuric cohort (160/102 and 149/94 mmHg, respectively; P < 0.001), and were also administered magnesium sulphate more frequently (44 vs 22%, respectively; P < 0.001), delivered at earlier gestation (37 vs 38 weeks, respectively; P < 0.001), required operative delivery more frequently (63 vs 48%, respectively; P < 0.001) and received more antihypertensive medications during the antenatal period (72 vs 57%, respectively; P < 0.001). Acute renal failure and acute pulmonary oedema were rare. Four cases of eclampsia all occurred in non-proteinuric women. The perinatal mortality rate was lower for the offspring of women with proteinuric pre-eclampsia compared with offspring of non-proteinuric women (13/1000 and 31/1000, respectively; P = 0.006). 4. The results of the present study indicate that the presence of proteinuria denotes a group of women who have higher antenatal blood pressure, who deliver at earlier gestation and require operative delivery more commonly, although it is not an indicator of other markers of maternal morbidity or perinatal mortality.

Does the anti-hypertensive drug clonidine affect the short-term variation in CTG recordings?

BACKGROUND: Cardiotocographic (CTG) recordings of the fetal heart remain standard obstetric practice among hypertensive women. Changes in the short-term variation (STV) in the fetal heart are often attributed to the effect of anti-hypertensive medications, regardless of the fact that this principle has never been validated. AIM: To assess the STV of CTG recordings pre- and post- the anti-hypertensive medication, clonidine. METHODS: Forty hypertensive pregnant women, already receiving the anti-hypertensive clonidine, were recruited. The CTGs were conducted pre- and post-dose administration. The CTGs were assessed by the Sonicaid Team® automated CTG analysis (Oxford Instruments, UK) to avoid CTG assessor bias. Baseline fetal heart rate (FHR) (delta change from pre- and post-dose) and STV were compared using spss v.14® utilising Student t-tests. RESULTS: No statistical difference was found in the pre- and post-baseline FHRs (P = 0.48). The mean delta baseline heart rate before and after drug administration was -0.54 bpm. The STV of the CTGs recorded pre- and post-clonidine dose was also not affected by administration of the drug (P = 0.34). The mean delta STV before and after drug administration was 0.39 ms. Two women received betamethasone 12 mg intramuscularly within the 12-h period prior to CTG recordings to enhance fetal lung maturity. The mean STV for the fetuses of these women pre-drug was 4.8 ms and 13.2 ms post-administration. This was the largest delta seen in all STVs recorded in this dataset. CONCLUSION: The anti-hypertensive drug clonidine does not alter baseline FHRs or affect the STV of the FHR in hypertensive pregnant women.

A prospective cross-sectional study to define racial variation in fetal nasal bone length through ultrasound assessment at 18-20 weeks' gestation.

OBJECTIVE: An absent or short nasal bone is highly predictive of Down syndrome in Caucasian populations, but Asians may have shorter nasal bones - increasing the false positive rate of screening. We examine differences in nasal bone length (NBL) in Caucasian and Asian populations. METHODS: This prospective cohort study involved pregnant women attending for their routine anomaly scan at 18-20 weeks' gestation. Ethnicity of the patient and their partner was recorded, and the nasal bone was measured three times. Mean NBL was calculated and used to investigate the effect of ethnicity first with a simple linear regression model and second with a mixed-effects regression model that accounted for variability of measurement between sonographers. RESULTS: A total of 1087 families were involved in the study, including 592 (54%) Caucasians, 214 (20%) East Asians, 110 (10%) South Asians and 171 (16%) West Asians. Twenty-three sonographers performed the scans with an average of 19 scans each. There is no significant difference in NBL between Caucasian and Asian populations. The mixed-effects model shows that accounting for sonographer variation is important, with 6.7% of the total variance in measurement being related to this random effect. CONCLUSIONS: There is no significant difference in NBL between Caucasian and Asian populations. It is reasonable to use criteria established in a Caucasian population to define the characteristics of an absent/short nasal bone in Asian fetuses. This finding also removes difficulties in counselling mixed race couples.

Placental Growth Factor Reduces Blood Pressure in a Uteroplacental Ischemia Model of Preeclampsia in Nonhuman Primates.

An imbalance in the angiogenesis axis during pregnancy manifests as clinical preeclampsia because of endothelial dysfunction. Circulating soluble fms-like tyrosine kinase 1 (sFLT-1) increases and placental growth factor (PlGF) reduces before and during disease. We investigated the clinical and biochemical effects of replenishing the reduced circulating PlGF with recombinant human PlGF (rhPlGF) and thus restoring the angiogenic balance. Hypertensive proteinuria was induced in a nonhuman primate (Papio hamadryas) by uterine artery ligation at 136 days gestation (of a 182-day pregnancy). Two weeks after uteroplacental ischemia, rhPlGF (rhPlGF, n=3) or normal saline (control, n=4) was administered by subcutaneous injection (100 µg/kg per day) for 5 days. Blood pressure was monitored by intra-arterial radiotelemetry and sFLT-1 and PlGF by ELISA. Uteroplacental ischemia resulted in experimental preeclampsia evidenced by increased blood pressure, proteinuria, and endotheliosis on renal biopsy and elevated sFLT-1. PlGF significantly reduced after uteroplacental ischemia. rhPlGF reduced systolic blood pressure in the treated group (-5.2±0.8 mm Hg; from 132.6±6.6 mm Hg to 124.1±7.6 mm Hg) compared with an increase in systolic blood pressure in controls (6.5±3 mm Hg; from 131.3±1.5 mm Hg to 138.6±1.5 mm Hg). Proteinuria reduced in the treated group (-72.7±55.7 mg/mmol) but increased in the control group. Circulating levels of total sFLT-1 were not affected by the administration of PlGF; however, a reduction in placental sFLT-1 mRNA expression was demonstrated. There was no significant difference between the weights or lengths of the neonates in the rhPlGF or control group; however, this study was not designed to assess fetal safety or outcomes. Increasing circulating PlGF by the administration of rhPlGF improves clinical parameters in a primate animal model of experimental preeclampsia.

Acute pulmonary oedema as a complication of hypertension during pregnancy.

OBJECTIVE: To determine rates of and potential causative factors for acute pulmonary oedema (APO) in hypertensive women. METHODS: Statistical analysis, including logistic regression, was applied to the individual patient data (IPD) of all hypertensive women who delivered in 2005 at two comparable units. RESULTS: Of 880 cases analysed, there were no women with APO in unit one and 19 women in unit two. The women with APO received larger quantities of intravenous fluids, delivered at earlier gestations, via Caesarean section, following failed induction of labour and had a longer hospital stay. CONCLUSION: The development of APO in women with hypertension during pregnancy is associated with high levels of intravenous fluid administration.

A randomised comparison of hydralazine and mini-bolus diazoxide for hypertensive emergencies in pregnancy: the PIVOT trial.

AIMS: Diazoxide is one of few available agents for treatment of hypertensive emergencies in pregnancy. From previous studies, there is a question concerning safety after moderate-dose administration caused episodes of hypotension. Rapid control of severe hypertension is necessary to reduce maternal morbidity, for example, stroke and placental abruption. This study was designed to compare the efficacy of mini-bolus diazoxide with intravenous (i.v.) hydralazine. DESIGN: A randomised controlled trial. SETTING: Tertiary referral maternity hospital, Royal Prince Alfred Women and Babies, Sydney Australia. POPULATION: Antenatal and postnatal women with severe hypertension. METHODS: One hundred and twenty-four hypertensive women were randomised to either i.v. hydralazine (5 mg doses) or mini-bolus diazoxide (15 mg doses). PRIMARY OUTCOME MEASURE: Achievement of target blood pressure reduction; secondary measures included requirement for Caesarean section because of fetal deterioration as determined by non-reassuring cardiotocograph (CTG). RESULTS: Reduction in systolic and diastolic blood pressure was 34 min for hydralazine and 19 min for diazoxide (P < 0.001). There were no episodes of hypotension after diazoxide and one after hydralazine (after epidural). Episodes of persistent severe hypertension were more common with hydralazine (38%) than with diazoxide (16%), P < 0.01. The Caesarean section rate for no-reassuring CTG was no different between the two groups. Neonatal outcomes were similar. CONCLUSION: Diazoxide and hydralazine are safe and effective antihypertensives, showing a controlled and comparable blood pressure reduction in women with hypertensive emergencies in pregnancy. The mini-bolus doses of 15 mg of diazoxide did not precipitate maternal hypotension as previously described and reduces episodes of persistent severe hypertension.