Does oral carbohydrate supplementation improve labour outcome? A systematic review and individual patient data meta-analysis.

BACKGROUND: Labour is a period of significant physical activity. The importance of carbohydrate intake to improve outcome has been recognised in sports medicine and general surgery. OBJECTIVES: To assess the effect of oral carbohydrate supplementation on labour outcomes. SEARCH STRATEGY: MEDLINE (1966-2014), Embase, the Cochrane Library and clinical trial registries. SELECTION CRITERIA: Randomised controlled trials (RCT) of women randomised to receive oral carbohydrate in labour (<6 cm dilated), versus placebo or standard care. DATA COLLECTION AND ANALYSIS: Authors were contacted to provide data. Individual patient data meta-analyses were performed to calculate pooled risk ratios (RR) and 95% confidence intervals (CI). MAIN RESULTS: Eight RCTs met the inclusion criteria. Six authors responded, four supplied data (n = 691). Three studies used isotonic drinks (one placebo-controlled, two compared with standard care), and one an advice booklet regarding carbohydrate intake. The mean difference in energy intake between the intervention and control groups was small [three studies, 195 kilocalories (kcal), 95% CI 118-273]. There was no difference in the risk of caesarean section (RR 1.15, 95% CI 0.83- 1.61), instrumental birth (RR 1.26, 95% CI 0.96-1.66) or syntocinon augmentation (RR 0.99, 95% CI 0.86-1.13). Length of labour was similar (mean difference -3.15 minutes, 95% CI -35.14 to 41.95). Restricting the analysis to primigravid women did not affect the result. Oral carbohydrates did not increase the risk of vomiting (RR 1.09, 95% CI 0.78-1.52) or 1-minute Apgar score <7 (RR 1.23, 95% CI 0.82-1.83). AUTHORS' CONCLUSION: Oral carbohydrate supplements in small quantities did not alter labour outcome. TWEETABLE ABSTRACT: Oral carbohydrate does not affect labour. But the difference between intervention and control equals 10 teaspoons sugar.

Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis.

BACKGROUND: Fetal macrosomia is associated with an increased risk of adverse maternal and neonatal outcomes. OBJECTIVES: To compare the accuracy of antenatal two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, and magnetic resonance imaging (MRI) in predicting fetal macrosomia at birth. SEARCH STRATEGY: Medline (1966-2013), Embase, the Cochrane Library and Web of Knowledge. SELECTION CRITERIA: Cohort or diagnostic accuracy studies of women with a singleton pregnancy, who had third-trimester imaging to predict macrosomia (>4000 g, >4500 g or >90th or >95th centile). DATA COLLECTION AND ANALYSIS: Two reviewers screened studies, performed data extraction and assessed methodological quality. The bivariate model was used to obtain summary sensitivities, specificities and likelihood ratios. MAIN RESULTS: Fifty-eight studies (34 367 pregnant women) were included. Most were poorly reported. Only one study assessed 3D ultrasound volumetry. For predicting birthweight >4000 g or >90th centile, the summary sensitivity for 2D ultrasound (Hadlock) estimated fetal weight (EFW) >90th centile or >4000 g (29 studies) was 0.56 (95% CI 0.49-0.61), 2D ultrasound abdominal circumference (AC) >35 cm (four studies) was 0.80 (95% confidence interval [95% CI] 0.69-0.87) and MRI EFW (three studies) was 0.93 (95% CI 0.76-0.98). The summary specificities were 0.92 (95% CI 0.90-0.94), 0.86 (95% CI 0.74-0.93) and 0.95 (95% CI 0.92-0.97), respectively. CONCLUSION: There is insufficient evidence to conclude that MRI EFW is more sensitive than 2D ultrasound AC (which is more sensitive than 2D EFW); although it was more specific. Further primary research is required before recommending MRI EFW for use in clinical practice. TWEETABLE ABSTRACT: Systematic review of antenatal imaging to predict macrosomia. MRI EFW is more sensitive than ultrasound EFW.

Evaluation of offline analysis of archived three-dimensional volume datasets in the diagnosis of fetal brain abnormalities.

OBJECTIVE: To retrospectively evaluate the reliability of offline manipulation of archived three-dimensional (3D) ultrasound volumes in the assessment of the normal fetal brain and the diagnosis of fetal brain abnormalities. METHODS: Seventy-nine 3D volume datasets, archived at the time of scanning, from women attending a tertiary center, were analyzed. They comprised 52 cases with brain abnormalities and 27 normal controls. Postnatal magnetic resonance imaging or postmortem examination confirmed the final diagnosis in all cases with brain anomalies. Offline analysis of the 79 anonymized 3D volume datasets was carried out by three fetal medicine experts, examiner one (E1), examiner two (E2) and examiner three (E3), using 4D View software. The experts were blinded to any prior diagnosis or history. Data were collected on a specially designed data sheet and entered into a specialized database for analysis. Results were compared between examiners, with the initial two-dimensional (2D) diagnosis and with the final definitive diagnosis by calculation of percentage agreement and kappa coefficients. RESULTS: Of the 52 cases with brain anomalies, the correct diagnosis was reached in 88.5% (46/52), 98.1% (51/52) and 92.3% (48/52) of cases on analysis of the 3D volumes by E1, E2 and E3, respectively, whereas only 82.7% (43/52) of cases were correctly diagnosed on the initial 2D examination when compared with the definitive diagnosis. Fetuses without brain anomalies were identified as such by the three experts with 100% agreement. There was good agreement between the initial 2D examination and the analysis of 3D volumes by each of the experts: 86.1% for E1 (κ = 0.7), 89.9% for E2 (κ = 0.79) and 88.6% for E3 (κ = 0.76). CONCLUSIONS: 3D volume datasets are an appropriate and reliable format for storing data from examination of the fetal brain. Offline analysis of 3D datasets is a reliable method that can be used to help in the assessment of brain anomalies and could be a useful adjunct to realtime 2D ultrasonography.

Changes in myometrial 'perfusion' during normal labor as visualized by three-dimensional power Doppler angiography.

OBJECTIVES: Myometrial contractions are one of the most important aspects of effective labor. For cells within the myometrium to work efficiently they need to be well oxygenated and this requires an adequate blood supply. This study used quantitative three-dimensional (3D) power Doppler angiography to calculate the percentage change in myometrial blood flow during a relaxation-contraction-relaxation cycle of active labor. METHODS: Transabdominal 3D power Doppler ultrasound imaging was used to acquire volumetric data during the first stage of spontaneous labor in 20 term, nulliparous women. 3D datasets were acquired during a single cycle of uterine relaxation, contraction and subsequent relaxation for each subject. The resultant datasets were analyzed independently by two investigators on two occasions using Virtual Organ Computer-aided AnaLysis to define a volume of interest within the myometrium; the power Doppler signal within this volume was quantified to provide 3D indices of vascularity: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). The percentage change in these indices, during a uterine contraction, was calculated from the baseline value during the initial uterine relaxation phase (taken as a maximum of 100%). RESULTS: Myometrial blood flow fell significantly during the uterine contraction and returned during the subsequent relaxation phase of the cycle (P < 0.001 for VI and VFI, P = 0.002 for FI). From the initial baseline relaxation value, VI dropped to 43.9%, FI to 85.5% and VFI to 40.8% during uterine contraction, and returned to 86.7%, 98.1% and 89.1%, respectively, during the subsequent relaxation. The intraclass correlation coefficients in blood flow measurements of 0.982-0.999 between the two investigators were indicative of good interobserver reliability. CONCLUSIONS: This study confirms that myometrial perfusion, as measured by quantitative 3D power Doppler angiography, significantly falls during uterine contractions, returns during the subsequent relaxation phase, and can be quantified reliably from stored datasets. Further work is now required to establish clinical applicability for this non-invasive investigation.

In vitro dual perfusion of human placental lobules as a flow phantom to investigate the relationship between fetoplacental flow and quantitative 3D power doppler angiography.

Flow phantoms have been used to investigate and quantify three-dimensional power Doppler data but this is the first study to use the in vitro, dual perfused, placental perfusion model. We used this model to investigate and quantify the effect of variation in fetal-side flow rates and attenuation on 3D power Doppler angiography. Perfusion of a placental lobule was commenced within 30 min of delivery and experimentation was successful in 8 of the 18 placenta obtained. Fetal and maternal perfusate was modified Earle's bicarbonate buffer which, following equilibration, was supplemented on the fetal side with whole heparinised cord blood. Imaging was performed with a Voluson-i ultrasound machine. A 'vascular biopsy' the thickness of the placental lobule was defined and signal quantified within using VOCAL (GE Medical Systems, Zipf, Austria). Three vascular indices are generated: vascularisation index (VI) defined as the percentage of power Doppler data within a volume of interest; flow index (FI), the mean signal intensity of the power Doppler information; and vascularisation flow index (VFI), a combination of both factors derived through their multiplication. Attenuation was investigated in this model with the addition of tissue mimic blocks. Our results showed a predictable relationship between flow rates and the vascular indices VI and VFI. However the FI was a less reliable predictor of flow; thus it should be interpreted with caution. The power Doppler signal was markedly affected by attenuation leading to a complete loss of information at a depth of 6 cm in the model used. In conclusion this model can be adapted to provide a phantom to analyse and quantify 3D power Doppler signals and demonstrates that vascular indices within a tissue remain related to volume flow. This model provides further evidence that depth dependent attenuation of signal needs to be accounted for in any in vivo work where the probe is not in direct contact with the tissue of interest.

Hypoxic inhibition of human myometrial contractions in vitro: implications for the regulation of parturition.

BACKGROUND: Insufficient tissue oxygenation is a likely contribution to weak, inco-ordinate human uterine contractile activity characteristic of prolonged, dysfunctional labour. However, the direct effects of hypoxia on human myometrial contractility has, surprisingly, not yet been detailed. Therefore, we report the influence of hypoxia on spontaneous and agonist-induced carbachol, prostaglandin (PGF2alpha), and oxytocin contractions of myometria from nonpregnant and pregnant women. MATERIALS AND METHODS: Uterine biopsies were obtained from pregnant women at term undergoing elective Caesarean section and nonpregnant women undergoing hysterectomy. Myometrial strips were equilibrated at 37 degrees C in normoxic physiological salt solution (95% air/5% CO(2)) and the influence of hypoxia (95% N(2)/5% CO(2)) on contractility was investigated. RESULTS: Hypoxia resulted in a significant reduction in spontaneous contractile function; nonpregnant tissue was less resistant to the deleterious effects of hypoxia. Agonist-induced contractions, while being more resistant to hypoxia than spontaneous contractions, were also significantly inhibited. In myometria of pregnant women the PGF2alpha- or oxytocin-induced contractility was more resistant to hypoxia than carbachol. Finally, the inhibitory actions of hypoxia were exacerbated with repeated oxytocin administration with a more severe effect on contractile integral than on initial phasic contraction amplitude. CONCLUSIONS: We detail, for the first time, the effects of hypoxia on contractility of human myometria from nonpregnant and pregnant women. Physiologically important uterotonic agents are more resistant to the effects of hypoxia than spontaneous contractions although repeated stimulation with oxytocin during hypoxia results in progressively less force. The results indicate that if significant hypoxia occurs in vivo then it is a likely contributory factor to the pathways underlying prolonged dysfunctional labour.

Chorionic plate artery function and Doppler indices in normal pregnancy and intrauterine growth restriction.

BACKGROUND: In fetal growth restriction (FGR) abnormal umbilical artery (UA) Doppler waveform indices suggest increased vascular resistance and impaired placental blood flow. This study aimed to determine whether UA Doppler waveform indices were related to the vasoreactivity of placental chorionic plate small arteries in normal and FGR pregnancies. MATERIALS AND METHODS: UA Doppler waveform analysis was performed 24 h before delivery in 23 normal term and 15 FGR pregnancies. Post-delivery responses of chorionic plate arteries to vasoactive agents were examined using the technique of wire myography. RESULTS: Altered vascular reactivity to agonists was demonstrated in chorionic plate arteries in FGR pregnancy. Constriction to U46619 (thromboxane mimetic) and relaxation to sodium nitroprusside (nitric oxide donor) were significantly increased in the arteries of FGR pregnancies compared with normal pregnancies. No relationship existed between Doppler indices and chorionic plate responses in normal or FGR pregnancies. CONCLUSIONS: Fetoplacental vascular reactivity is altered in FGR pregnancy independently of UA Doppler waveform indices. Altered function may be additive to the pathophysiology underlying abnormal Doppler waveforms and could contribute to the inappropriate control of vascular tone in FGR.

Routine symptom screening for postnatal urinary and anal incontinence in new mothers from a district.

Parous middle-aged women present with urinary and faecal incontinence and childbirth trauma is thought to be a causal factor. Both symptoms are common after childbirth but usually go under-reported. It has been suggested that new mothers are likely to benefit from routine symptom screening because by actively identifying symptomatic women they could then be helped to access continence services. The main objective of this study was to pilot a programme of routine symptom screening for postnatal urinary and anal incontinence in new mothers from a district general hospital. Self-completion questionnaires for both urinary and anal incontinence were sent by post to 442 primiparous women who had delivered consecutively 10 months previously in a district general hospital. Two hundred and seventy-five new mothers responded to the survey. Ninety-two women had new symptoms of incontinence at 10 months, 82 had urinary incontinence and 25 had anal incontinence. However, only six new mothers had discussed the problem with a health professional. Although nine women requested a hospital appointment none of the women attended the appointment arranged for them. The domain scores on both questionnaires were significantly less for symptomatic new mothers when compared to women with established symptoms of incontinence. The programme of screening successfully identified women with symptoms of incontinence. However, all of the symptomatic women declined a follow-up appointment at hospital which questions the benefits of routine screening 10 months after childbirth.

Grandmultiparae in a modern setting.

OBJECTIVE: To compare the incidence of antenatal and intrapartum complications and neonatal outcomes among women who had previously delivered five or more times (grandmultiparous) with that of age-matched control women who had previously delivered two or three times (multiparous). DESIGN: A matched cohort study. SETTING: An inner city university maternity hospital in the United Kingdom. SAMPLE: Three hundred and ninety-seven grandmultiparous women were compared with three hundred and ninety-seven age-matched multiparous women. METHODS: Data on the subjects were obtained from a computerised maternity information system (SMMIS). Characteristics and complications occurring in the two groups were compared. Data validation was performed with a 10% randomised sample of the casenotes in both groups. Nineteen relevant data fields were abstracted and compared with the matched SMMIS record. Results The overall incidence of intrapartum complications for grandmultiparous women was 16% compared with 18% in the control multiparous women (odds ratio 0.9, 95% CI 0.6-1.3). Grand multiparity was associated with a significantly higher body mass index at booking (P < 0.01) and the last antenatal clinic (P < 0.05), an increased incidence of antenatal anaemia (22% vs 16%, odds ratio 1.8, 95% CI 1.2-2.8) and a decreased incidence of elective caesarean section (6% vs 11%, odds ratio 0.5, 95% CI 0.3-0.9). Agreement was greater than 95% in all the data fields reviewed except three. In the 14 categorical variables reviewed the Cohen's kappa results were in excess of 0.6. CONCLUSION: This study suggests that in a developed country with satisfactory health care conditions, grandmultiparity should not be considered dangerous,and risk assessment should be based on past and present history and not simply on the basis of parity.