[Occiput posterior presentation at delivery: Materno-foetal outcomes and predictive factors of rotation]. / Accouchement en variété occipito-postérieure : issues materno-fœtales et facteurs prédictifs de la rotation.

OBJECTIVES: To describe the maternal and foetal outcomes of an occiput posterior foetal position at delivery; to evaluate predictive factors of anterior rotation during labour. METHODS: Descriptive retrospective analysis of a cohort of 439 women with foetuses in occiput posterior position during labour. Logistic regression analysis to quantify the effect of factors that may favour anterior rotation. RESULTS: Most of foetuses (64%) do an anterior rotation during labour and 13% during the expulsive phase. The consequences of a persistent foetal occiput posterior position during delivery are a significantly increased average time of second stage labour compared to others positions (65.19minutes vs. 43.29, P=0.001, respectively); a higher percentage of caesarean sections (72.0% versus 4.7%, P<0.001) and instrumental delivery (among low-birth deliveries, 60.7% versus 25.2%, P<0.001); more frequent third-degree perineal tears (14.3% vs. 0.6%, P<0.001) and more abundant blood loss (560mL versus 344mL, P<0.001). In a multi-variable model including nulliparity, station of the presenting part and degree of flexion of the foetal head at complete dilatation, the only predictive factor independent of rotation at delivery is a good flexion of the foetal head at complete dilatation, which multiplies the anterior rotation probability by six. CONCLUSION: A good flexion of the foetal head is significantly associated with anterior rotation. Other studies exploring ways to increase anterior rotation during labour are needed to reduce the very high risk of caesarean section and instrumentation associated with the foetal occiput posterior position.

Maternal positioning to correct occiput posterior fetal position during the first stage of labour: a randomised controlled trial.

OBJECTIVE: To evaluate the efficacy of the hands and knees position during the first stage of labour to facilitate the rotation of the fetal head to the occiput anterior position. DESIGN: Randomised controlled trial. SETTING: Geneva University Hospitals, Switzerland. POPULATION: A total of 439 women with a fetus in the occiput posterior position during the first stage of labour. METHODS: The women in the intervention group were invited to take a hands and knees position for at least for 10 minutes. Women allocated to the control group received the usual care. For both groups, 15 minutes after randomisation, women completed a short questionnaire to report their perceived pain and the comfort of their position. MAIN OUTCOME MEASURES: The rotation of the fetal head in occiput anterior position confirmed by ultrasonography 1 hour after randomisation. RESULTS: One hour after the randomisation, 35 of 203 (17%) fetuses were diagnosed as being in the occiput anterior position in the intervention group compared with 24 of 209 (12%) in the control group. This difference was not statistically significant (relative risk 1.50; 95% CI 0.93-2.43; P = 0.13). The change in the evaluation of comfort between the randomisation and 15 minutes after showed an improvement in 70 and 39 women, no change in 82 and 78 women and a decrease in 56 and 86 women in the intervention and control groups, respectively (P = 0.02). CONCLUSIONS: This study could not demonstrate a benefit of the hands and knees position to correct the occiput posterior position of the fetus during the first stage of labour, but the women reported an increase in their comfort level. TWEETABLE ABSTRACT: Hands and knees position does not facilitate rotation into occiput anterior but increases the comfort level of women.

[Prevention of preterm birth with vaginal progesterone in women with preterm labor: which are the evidences?]. / Progestérone par voie vaginale chez les femmes avec une menace d'accouchement prématuré: quelles évidences?

The presence of uterine contractions and a short cervix at less than 37 weeks of gestation (preterm labor) is an important risk factor for a preterm birth. Currently, there is not treatment able to reduce the risk of preterm birth in this high risk group of women. Vaginal progesterone has been shown to be effective in reducing the risk of preterm birth in asymptomatic women with a prior preterm birth and in women with a short cervix, measured by vaginal ultrasound before 24 weeks of gestation. Unfortunately, vaginal progesterone has not been shown to be efficacious in women with preterm labor. A recent clinical trial has shown that it can even be deleterious in this group of women.

Prevention of preterm delivery with vaginal progesterone in women with preterm labour (4P): randomised double-blind placebo-controlled trial.

OBJECTIVE: To evaluate the effectiveness of 200 mg of daily vaginal natural progesterone to prevent preterm birth in women with preterm labour. DESIGN: Multicentre, randomised, double-blind, placebo-controlled trial. SETTING: Twenty-nine centres in Switzerland and Argentina. POPULATION: A total of 385 women with preterm labour (24(0/7) to 33(6/7) weeks of gestation) treated with acute tocolysis. METHODS: Participants were randomly allocated to either 200 mg daily of self-administered vaginal progesterone or placebo within 48 hours of starting acute tocolysis. MAIN OUTCOME MEASURES: Primary outcome was delivery before 37 weeks of gestation. Secondary outcomes were delivery before 32 and 34 weeks, adverse effects, duration of tocolysis, re-admissions for preterm labour, length of hospital stay, and neonatal morbidity and mortality. The study was ended prematurely based on results of the intermediate analysis. RESULTS: Preterm birth occurred in 42.5% of women in the progesterone group versus 35.5% in the placebo group (relative risk [RR] 1.2; 95% confidence interval [95% CI] 0.93-1.5). Delivery at <32 and <34 weeks did not differ between the two groups (12.9 versus 9.7%; [RR 1.3; 95% CI 0.7-2.5] and 19.7 versus 12.9% [RR 1.5; 95% CI 0.9-2.4], respectively). The duration of tocolysis, hospitalisation, and recurrence of preterm labour were comparable between groups. Neonatal morbidity occurred in 44 (22.8%) cases on progesterone versus 35 (18.8%) cases on placebo (RR: 1.2; 95% CI 0.82-1.8), whereas there were 4 (2%) neonatal deaths in each study group. CONCLUSION: There is no evidence that the daily administration of 200 mg vaginal progesterone decreases preterm birth or improves neonatal outcome in women with preterm labour.

[Correcting occiput posterior position during labor: the role of maternal positions]. / Correction des variétés occipito-postérieures durant la phase de dilatation de l'accouchement: intérêt des postures maternelles.

Occipito-posterior presentation represents 10 to 34% of cephalic presentations in early labor. Spontaneous rotation during labor to occipito-anterior mode occurs in most cases, but 5 to 8% of fetuses will persist in posterior position for the expulsive phase of delivery. Previous research has shown that this presentation carries an increased risk of unusually long labor, maternal and fetal exhaustion, instrument-assisted delivery, severe perineal injury, and cesarean section. The diagnosis of posterior variety is usually made quite late at the end of dilation. Several researchers have reported the benefits of determining presentation during labor by transabdominal ultrasonography. Some obstetrical techniques to correct these presentations at complete dilation have also been described. In the case of diagnosis of posterior variety, the usual attitude is expectant management. Postural techniques to promote physiological labor and delivery have been documented in the literature. De Gasquet has described a very precise technique to facilitate fetal rotation, but its effectiveness has never been assessed scientifically. A Cochrane review on the topic has shown that similar positions are well accepted by women and reduce back pain. On the other hand, the sample size of included studies appeared inadequate to assess their interest for use in childbirth, in general, and for adverse outcomes associated with posterior presentation varieties in particular. Attempts to correct the fetal malposition during the expansion phase would allow to reduce adverse outcomes during the expulsive phase of delivery. Further research is necessary to assess the efficacity of specific maternal positions during labor for the correction of fetal posterior presentation.

OS108. Preeclamptic women display salt sensitivity and cardiovascular damage before their menopause.

INTRODUCTION: Salt sensitivity is an important cardiovascular risk factor. It has been shown that preeclamptic (PEC) women may not be totally cured after the delivery and keep a higher cardiovascular risk than nonPEC women. OBJECTIVES: We aimed to study the salt sensitivity of the blood pressure in women with a history of severe preeclamspia and women with no history of hypertensive complications.The design was a case control study with intervention, including 42 women recruited 5 to 17 years following delivery. METHODS: 21 women having suffered from a severe preeclampsia before 34 weeks of pregnancy and 19 age, race matched controls women,were randomized to follow for one week a low salt (LS) diet and a high salt (HS) diet (adding 6g NACL/d to usual diet). On day seven of each dietary period, 24h ambulatory blood pressure was recorded, and 24h urine collected in order to measure sodium excretion.Salt sensitivity was assigned if the mean 24h blood pressure increased by ⩾ 3mmHg on a high- compared with a low-salt diet. RESULTS: Preeclamptic women were aged 39.1(24-49) and controls 40.1(29-49), p=NS.Two of the PEC women already suffered from a cardiovascular event (2coronary events). The PEC women showed a significant increase of the BP and standard deviation (SD) of the BP compared to the controls.10 (47.6%) preeclamptic women showed salt sensitivity (odd ratio 5.4, 95% CI 0.972-30.601;P=0.042).Recurrent preeclampsia was associated with a significantly high risk to salt sensitivity status (OR 5; 95% confidence interval 1.1-31.6). CONCLUSION: Severe PEC women display already salt sensitivity of the blood pressure before their menopause and increased variability of the BP. Recurrent preeclampsia is a high risk factor for salt sensitivity and could allow to target this high-risk group at an early stage for preventive measures for cardiovascular disease.

Maternal heart rate changes during labour.

OBJECTIVES: Labour and delivery represent a considerable effort for pregnant women. Lack of aerobic fitness may limit pushing efforts during childbirth and represents increased cardiovascular strain and risk. Increasing prevalence of sedentary behaviour and lack of aerobic fitness may reduce heart rate reserve during labour. STUDY DESIGN: We quantified maternal heart rate reserve (maximum heart rate minus resting heart rate) of 30 healthy pregnant women during labour and delivery and related it to habitual daily physical activity levels quantified during the third pregnancy trimester by the Pregnancy Physical Activity Questionnaire. RESULTS: Heart rates during labour reached values similar to those observed during moderate to heavy physical exercise. During active pushing one out of five women reached heart rates more than 90% of their heart rate reserve (188 ± 7 beats per min). Half of the women reached more than 70% of heart rate reserve (172 ± 14 beats per min). Physically inactive women used more of their heart rate reserve as physically more active women (87 ± 20% vs. 65 ± 12%, upper and lower tertile respectively, p<0.05). CONCLUSIONS: Use of heart rate reserve for the effort of labour is increased in physically inactive women and may potentially limit the intensity and duration of pushing efforts. Such higher cardiovascular strain in physically less active women may represent increased cardiovascular risk during labour.