09 June, 2011

Predicting pre-eclampsia

Pre-eclampsia remains unpredictable, despite numerous biochemical and biophysical efforts to provide pointers. Working on history taking may prove of some value so North et al (BMJ 2011;342:d1875) embarked on an international study of over 3000 healthy nulliparous women which screened for pregnancy endpoints (the SCOPE study).

The women were interviewed at the start of the second trimester, routine biometry and Doppler studies were carried out around 20 weeks and the later development of pre-eclampsia tracked. It turned out that 5% did show signs and symptoms of pre-eclampsia with the following points on history indicating an increased risk: young maternal age, higher mean arterial blood pressure, raised BMI, family history of pre-eclampsia, family history of coronary heart disease, the woman having a low birth weight, vaginal bleeding for at least 5 days during early pregnancy or a duration of the sexual relationship of six months or less. The only protective predictor was a previous miscarriage of at least 10 weeks gestation with the same partner.

Adding the ultrasonic data did not improve the SCOPE prediction tool which raises the predictability of history taking to about 10%. Maybe adding the biochemical markers will increase the value of this interesting but inconclusive line of investigation.

04 April, 2011

Nifedipine & preterm labour

The management of preterm labour involves the acute suppression of uterine contractions. By inhibiting the end-organ response it is presumed the initial stimulus will not remain operative or the incident producing it has passed. It is a conveniently uninvestigated aspect of preterm labour research – so are randomized trials using placebo controls which are scarce and nifedipine has never been subjected to this gold-standard form of investigation (Caritis AJOG 2011;204:95-6).

Most trials of uterine activity suppression test one drug against another and look at relative efficacy and side-effects rather than neonatal outcomes. However in the present ethical climate it may be that comparative efficiency is the best that can be hoped for and the best evidence comes from a meta-analysis by Conde-Anudelo et al (AJOG 2011;204:134 e 1-20).

Their work shows nifedipine to be superior to beta-adrenergics and magnesium sulphate for tocolysis of women in preterm labour, so if a decision is made on clinical grounds to suppress the myometrium then there is guidance in favour of nifedipine for the person in charge of the case.

Hot flush treatment

There are limited non-hormonal treatments for women seeking relief from hot flushes. Peri- and postmenopausal women may not wish to take estrogens and selective serotonin reuptake inhibitors (SSRIs) offer a reasonably good option for decreasing the frequency, severity or bothersome effects of hot flushes.

A report by Freeman et al (JAMA 2011;305:267-74) indicates that the SSRI escitalopram is effective in controlling flushes in healthy menopausal women.
As usual in controlled trials for flushes about one third of volunteers had a 50% reduction in symptoms on the placebo but more than half had a similar beneficial effect from 10 – 20 mg per day of escitalopram over 8 weeks. The active substance had few side effects and it was convincing that 3 weeks after the trial ended those who took the escitalopram had the return of more hot flushes than those “coming off” the placebo.

For the record the participants had at least 4 flushes or night sweats a day before treatment and there were no racial differences between African-American and white women who were equally represented in the sample population. Estrogens are the treatment of choice for menopausal symptoms but escitalopram appears to be an option in reducing the frequency, severity and bother of menopausal vasomotor symptoms.