Comparison of diurnal variations, gestational age and gender related differences in fetal heart rate (FHR) parameters between appropriate-for-gestational-age (AGA) and small-for-gestational-age (SGA) fetuses in the home environment

Objective To assess the influence of gender, time of the day and gestational age on fetal heart rate (FHR) parameters between appropriate-for-gestational-age (AGA) and small-for-gestational age (SGA) fetuses using a portable fetal ECG monitor employed in the home setting. Methods We analysed and compared the antenatal FHR data collected in the home setting on 61 healthy pregnant women with singleton pregnancies from 24 weeks gestation. Of the 61 women, 31 had SGA fetuses (estimated fetal weight below the tenth gestational centile) and 30 were pregnant with AGA fetuses. FHR recordings were collected for up to 20 h. Two 90 min intervals were deliberately chosen retrospectively with respect to signal recording quality, one during day-time and one at night-time for comparison. Results Overall, success rate of the fetal abdominal ECG in the AGA fetuses was 75.7% compared to 48.6% in the SGA group. Based on randomly selected episodes of heart rate traces where recording quality exceeded 80% we were able to show a marginal difference between day and night-time recordings in AGA vs. SGA fetuses beyond 32 weeks of gestation. A selection bias in terms of covering different representation periods of fetal behavioural states cannot be excluded. In contrast to previous studies, we neither controlled maternal diet and activity nor measured maternal blood hormone and heart rate as all mothers were monitored in the home environment. Conclusion Based on clinically unremarkable, but statistically significant differences in the FHR parameters between the AGA and SGA group we suggest that further studies with large sample size are required to assess the clinical value of antenatal fetal ECG monitoring

Prophylaxis and Treatment of Fetal Growth Restriction

Foetal growth restriction (FGR) and associated placental pathologies such as pre-eclampsia and stillbirth arise in early pregnancy when inadequate remodelling of maternal spiral arteries leads to persistent high-resistance low-flow uteroplacental circulation. Current interventions concentrate on targeting the placental ischaemia-reperfusion injury and oxidative stress associated with an imbalance in angiogenic/anti-angiogenic factors. Recent meta-analyses confirm that aspirin modestly reduces the risk for small-for-gestational-age pregnancy in high-risk women. A dose of ≥100 mg starting by 16 weeks of gestation is recommended. In vitro and in vivo studies suggest that low-molecular-weight heparin may prevent FGR; further research is needed to confirm efficacy. Once FGR is diagnosed, no treatment will improve foetal growth. Potential FGR therapies such as phosphodiesterase type-5 inhibitors or maternal VEGF gene therapy aim to improve poor placentation and/or uterine blood flow. Melatonin, creatine and N-acetyl cysteine have potential as novel neuroprotective and cardioprotective agents in FGR

Early onset fetal growth restriction

Fetal growth restriction remains a challenging entity with significant variations in clinical practice around the world. The different etiopathogenesis of early and late fetal growth restriction with their distinct progression of fetal severity and outcomes, compounded by doctors and patient anxiety adds to the quandary involving its management. This review summarises the literature around diagnosing and monitoring early onset fetal growth restriction (early onset FGR) with special emphasis on optimal timing of delivery as guided by recent research advances