Cochane Reviews that pertain to labor and birth-a quick summary

Antibiotic prophylaxis versus no prophylaxis for preventing infection after cesarean section.

AUTHORS' CONCLUSIONS:

Endometritis was reduced by two thirds to three quarters and a decrease in wound infection was also identified. However, there was incomplete information collected about potential adverse effects, including the effect of antibiotics on the baby, making the assessment of overall benefits and harms complicated. Prophylactic antibiotics given to all women undergoing elective or non-elective cesarean section is clearly beneficial for women but there is uncertainty about the consequences for the baby.

Cesarean delivery for the prevention of anal incontinence 

AUTHORS' CONCLUSIONS:

Without demonstrable benefit, preservation of anal continence should not be used as a criterion for choosing elective primary CD. The strength of this conclusion would be greatly strengthened if there were studies that randomised women with average risk pregnancies to CD versus VD.

Exercise for dysmenorrhoea.

MAIN RESULTS:

Four potential trials were identified of which one was included in the review. The available data could only be included as a narrative description. There appeared to be some evidence from the trial that exercise reduced the Moos' Menstrual Distress Questionnaire (MDQ) score during the menstrual phase (P < 0.05) and resulted in a sustained decrease in symptoms over the three observed cycles (P < 0.05).

AUTHORS' CONCLUSIONS:

The results of this review are limited to a single randomised trial of limited quality and with a small sample size. The data should be interpreted with caution and further research is required to investigate the hypothesis that exercise reduces the symptoms associated with dysmenorrhoea.

Fetal and umbilical Doppler ultrasound in high-risk pregnancies

MAIN RESULTS:

Eighteen completed studies involving just over 10,000 women were included. The trials were generally of unclear quality with some evidence of possible publication bias. The use of Doppler ultrasound in high-risk pregnancy was associated a reduction in perinatal deaths (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.52 to 0.98, 16 studies, 10,225 babies, 1.2% versus 1.7 %, numbers needed to treat = 203; 95%CI 103 to 4352). There were also fewer inductions of labour (average RR 0.89, 95% CI 0.80 to 0.99, 10 studies, 5633 women, random effects) and fewer caesarean sections (RR 0.90, 95% CI 0.84 to 0.97, 14 studies, 7918 women). No difference was found in operative vaginal births (RR 0.95, 95% CI 0.80 to 1.14, four studies, 2813 women) nor in Apgar scores less than seven at five minutes (RR 0.92, 95% CI 0.69 to 1.24, seven studies, 6321 babies).

AUTHORS' CONCLUSIONS:

Current evidence suggests that the use of Doppler ultrasound in high-risk pregnancies reduced the risk of perinatal deaths and resulted in less obstetric interventions. The quality of the current evidence was not of high quality, therefore, the results should be interpreted with some caution. Studies of high quality with follow-up studies on neurological development are needed.

Amnioinfusion for meconium-stained liquor in labour

MAIN RESULTS:

Thirteen studies of variable quality (4143 women) are included.Subgroup analysis was performed for studies from settings with limited facilities to monitor the baby's condition during labour and intervene effectively, and settings with standard peripartum surveillance.Settings with standard peripartum surveillance: there was considerable heterogeneity for several outcomes. There was no significant reduction in the primary outcomes meconium aspiration syndrome, perinatal death or severe morbidity, and maternal death or severe morbidity. There was a reduction in caesarean sections (CSs) for fetal distress but not overall. Meconium below the vocal cords diagnosed by laryngoscopy was reduced, as was neonatal ventilation or neonatal intensive care unit admission, but there was no significant reduction in perinatal deaths or other morbidity. Planned sensitivity analysis excluding trials with greater risk of bias resulted in an absence of benefits for any of the outcomes studied.Settings with limited peripartum surveillance: two studies (855 women) were included. In the amnioinfusion group there was a reduction in CS for fetal distress and overall; meconium aspiration syndrome (RR 0.25, 95% CI 0.13 to 0.47), and neonatal ventilation or neonatal intensive care unit admission; and a trend towards reduced perinatal mortality (RR 0.37, 95% CI 0.13 to 1.01). In one of the studies, meconium below the vocal cords was reduced and, in the other, neonatal encephalopathy was reduced.

AUTHORS' CONCLUSIONS:

Amnioinfusion is associated with substantive improvements in perinatal outcome only in settings where facilities for perinatal surveillance are limited. It is not clear whether the benefits are due to dilution of meconium or relief of oligohydramnios.In settings with standard peripartum surveillance, some non-substantive outcomes were improved in the initial analysis, but sensitivity analysis excluding trials with greater risk of bias eliminated these differences. Amnioinfusion is either ineffective in this setting, or its effects are masked by other strategies to optimise neonatal outcome.The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Bedrest with or without hospitalization for hypertension during pregnancy

Not enough evidence to say if bed rest in pregnancy helps women and their babies when women have high blood pressure.
High blood pressure in pregnant women can contribute to babies being small, being born too soon and having considerable health problems. Women with high blood pressure are often advised to rest in bed either at home or in hospital. It is suggested that this might help to reduce the mother's blood pressure and so provide benefits for the baby. However, there may be adverse effects; for example, some women may find it stressful, it may contribute to blood clots in the legs and can put a burden on the woman's family. Although one small trial suggested that there may be some possible benefits, there are insufficient data to be confident. Moreover, trials did not address possible adverse effects of bed rest. More women seemed to prefer normal activity at home rather than resting in hospital, if a choice were given. Further research is needed.

Interventions for varicose veins and leg oedema in pregnancy

Not enough evidence on treatments for varicose veins and leg oedema in pregnancy.
Varicose veins, sometimes called varicosity, occur when a valve in the blood vessel walls weakens and the blood stagnates. This in turn leads to problems with the circulation in the veins and to oedema or swelling. The vein then becomes distended, its walls stretch and sag, allowing the vein to swell into a tiny balloon near the surface of the skin. The veins in the legs are most commonly affected as they are working against gravity, but the vulva (vaginal opening) or rectum, resulting in haemorrhoids (piles), can be affected too. Pregnancy seems to increase the risk of varicose veins and they cause considerable pain, night cramps, numbness, tingling, the legs may feel heavy, achy, and they are rather ugly. Treatments for varicose veins are usually divided into three main groups: surgery, pharmacological treatments and non-pharmacological. The review identified three trials involving 159 women. Although the drug rutoside seemed to be effective in reducing symptoms, the study was too small to be able to say this with real confidence. Similarly, with compression stockings and reflexology, there were insufficient data to be able to assess benefits and harms, but they looked promising. More research is needed.

Maternal hydration for increasing amniotic fluid volume in oligohydramnios and normal amniotic fluid volume

Pregnant women with too little fluid surrounding their babies can increase this by consuming liquid, although it is not known whether this improves outcomes.
Oligohydramnios is where there is too little fluid surrounding the baby in the womb (uterus). This may occur because the baby is not thriving properly. It may cause the baby to be unable to turn into the head down position for the birth, or compression of the baby's umbilical cord. The review of four trials (122 women) found that women who drank extra water (usually two litres over two hours) or had fluid dripped directly into their bloodstream (both forms of maternal hydration) increased the volume of the fluid surrounding the baby. However, it is not clear whether this is better for the baby or not. More research is needed.

Rest during pregnancy for preventing pre-eclampsia and its complications in women with normal blood pressure

Not enough evidence to say if rest is helpful in preventing pre-eclampsia and its complications for women with normal blood pressure during pregnancy.
Pre-eclampsia is a serious complication of pregnancy occurring in about 2% to 8% of women. It is identified by increased blood pressure and protein in the urine, but women often suffer no symptoms initially. It can, through constriction of the blood vessels in the placenta, interfere with food and oxygen passing to the baby, thus inhibiting the baby's growth and causing the baby to be born too soon. Women can be affected through problems in their kidneys, liver, brain, and clotting system. Rest has been proposed as being beneficial for women at increased risk of pre-eclampsia, including those with normal blood pressure. There are also possible adverse effects such as the potential for increasing the risk of blood clots in the legs, and the impact considerable periods of rest on women's lives and that of their families. The review of trials found two small studies, of not very good quality, and there were insufficient data to say what the potential benefits and harms might be. Further studies are needed, and in the meantime women will be guided by their own beliefs and reasoning, as well as those of their caregivers.