Sports Obstetrics: Implications of Pregnancy in Elite Sportswomen, a Narrative Review.

Increasing numbers of females are participating in elite sports, with a record number having competed at the Tokyo Olympic Games. Importantly, the ages of peak performance and fertility are very likely to coincide; as such, it is inevitable that pregnancy will occur during training and competition. Whilst there is considerable evidence to promote regular exercise in pregnancy, with benefits including a reduction in hypertensive disorders, gestational diabetes, and reduced rates of post-natal depression, few studies have been conducted which include elite athletes. Indeed, there are concerns that high-intensity exercise may lead to increased rates of miscarriage and preterm labour, amongst other pregnancy-related complications. There is minimal guidance on the obstetric management of athletes, and consequently, healthcare professionals frequently adopt a very conservative approach to managing such people. This narrative review summarises the evidence on the antenatal, intrapartum, and postpartum outcomes in elite athletes and provides recommendations for healthcare providers, demonstrating that generally, pregnant athletes can continue their training, with a few notable exceptions. It also summarises the physiological changes that occur in pregnancy and reviews the literature base regarding how these changes may impact performance, with benefits arising from pregnancy-associated cardiovascular adaptations at earlier gestations but later changes causing an increased risk of injury and fatigue.

Contemporary experience of polyhydramnios: A single-centre experience.

INTRODUCTION: Polyhydramnios is common; the majority of cases are idiopathic, but maybe associated with fetal abnormality. Literature suggests the volume of amniotic fluid discriminates idiopathic from pathological polyhydramnios but is not unanimous. We assessed fetal anomaly incidence amongst women with polyhydramnios and the role of discriminatory variables in identifying pathological cases. METHODS: Retrospective observational cohort study at an inner-city London fetal medicine centre. Records for patients referred and/or diagnosed with polyhydramnios were reviewed as well as maternal/fetal demographics, amongst singleton pregnancies using the Astraia™ database from January 2015-2016. Estimated fetal weight was calculated using the Hadlock model (biometry undertaken at diagnosis). Student's t-test/one-way ANOVA compared means; chi-squared tests compared proportions. RESULTS: 120 cases were identified. 36 (30%) had fetal abnormality. There was no difference in AFI between fetuses with an abnormality and without (26.7 vs 25.2 cm, P = 0.22). AFI was normalised for weight (AFI (cm)/estimated fetal weight (kg)): AFI/kg was significantly different between cases with fetal abnormality and without (24.4 vs 16.7 cm/kg, P < 0.001) - incidence of abnormality increased with increasing AFI/kg (P = 0.007). Early gestational diagnosis was associated with higher rates of anomaly (P = 0.004). Differences in AFI/kg between those with and without abnormality were not significant when adjusted for gestation. AFI was significantly higher in cases of abnormality diagnosed at later gestation (P = 0.005). CONCLUSION: Excess volume of amniotic fluid alone does not denote abnormality. Earlier gestations and higher AFI/kg corresponded with significantly increased rates of anomaly. However, the latter is a result of confounding by gestation, which is closely correlated with fetal weight.

The impact of maternal hyper-oxygenation on foeto-placental blood flow.

OBJECTIVE: Maternal hyperoxygenation has been reported to increase foetal oxygen saturation, and is frequently employed during intra-partum episodes of foetal compromise as a component of in utero resuscitation. However, there has been little investigation of its influence on foetal haemodynamics, particularly in appropriately grown foetuses. METHODS: This cohort study was undertaken between July 2013 and November 2013. All participants underwent an ultrasound scan prior to active labour (<4 cm dilated), during which foetal biometry, umbilical and middle cerebral artery Dopplers were recorded. Doppler measurements were then repeated after a 20-min period (to act as a control for subsequent measurements after oxygen therapy). Women were then asked to breathe 60% oxygen through Venturi valve masks for 20 min, after which the Doppler measurements were repeated. RESULTS: Twenty women were recruited to the study. No significant change in the foetal cerebro-umbilical (CU) ratio was observed following maternal oxygen therapy. The degree of change in Doppler parameters after oxygen therapy was not related to the baseline value of the Doppler parameter. CONCLUSION: Maternal hyperoxygenation using 60% oxygen concentration over a 20-min period does not influence foetal umbilical or middle cerebral artery Doppler in appropriately grown foetuses. No adverse effects of maternal oxygen therapy were observed.

Expert review--identification of intra-partum fetal compromise.

Whilst most cases of cerebral palsy occur as a consequence of an ante-natal insult, a significant proportion, particularly in the term fetus, are attributable to intra-partum hypoxia. Intra-partum monitoring using continuous fetal heart rate assessment has led to an increased incidence of operative delivery without a concurrent reduction in the incidence of cerebral palsy. Despite this, birth asphyxia remains the strongest and most consistent risk factor for cerebral palsy in term infants. This review evaluates current intra-partum monitoring techniques as well as alternative approaches aimed at better identification of the fetus at risk of compromise in labour.

Gender specific intrapartum and neonatal outcomes for term babies.

OBJECTIVE: The purpose of this study is to document the gender specific intrapartum and neonatal outcomes in term, singleton, appropriately grown babies. STUDY DESIGN: De-identified, routinely collected data of all women meeting inclusion criteria between 2001 and 2011 were examined (n=9223). Inclusion criteria were public (non-insured), primiparous women who had delivered singleton, appropriately grown babies at term. In this retrospective cohort study, we estimated 95% confidence intervals. Outcomes measured were maternal demographics, mode of delivery, birthweight, APGAR score, cord blood acidemia, respiratory distress, any resuscitation requirement, nursery admission and stillbirth rates. RESULTS: The sex ratio of male babies was 1.05:1 (4718 males; 4505 females, p=0.85). Male babies were more likely to be delivered by instrumental (p=0.004) or caesarean (p<0.001). Birthweight was found to be a significant influencing factor on mode of delivery. Even after adjusting for birthweight, male babies were more likely to be delivered by instrumental delivery (OR 1.24, p<0.001), as well as by emergency caesarean for failure to progress (OR 1.24, p=0.04) and fetal distress (OR 1.38, p<0.001). Male babies, despite having greater birthweights than female babies (p<0.001), were more likely to have lower APGAR scores at 5 min (p=0.004), require neonatal resuscitation (p<0.001), develop respiratory distress (p=0.005) and require nursery admission (p<0.001). No statistical difference between male and female babies was found for cord blood acidemia (p=0.58) or stillbirth (p=0.49). CONCLUSION: This large cohort study demonstrates that term, appropriately grown male babies in primiparous pregnancies fare more poorly in the intrapartum and neonatal periods than female babies. Even when birthweight was accounted for, male babies still required higher rates of intervention in the intrapartum and neonatal periods. This suggests gender may play an independent role in influencing pregnancy outcomes, although the underlying contributing physiology is not definitively established. The gender of the baby perhaps should be considered when counselling parents in the antepartum period.

Mode of delivery has an independent impact on neonatal condition at birth.

OBJECTIVE: Current intra-partum monitoring techniques are often criticized for their poor specificity, with their performance frequently evaluated using measures of the neonatal condition at birth as a surrogate marker for intra-partum fetal compromise. However, these measures may potentially be influenced by a multitude of other factors, including the mode of delivery itself. This study aimed to investigate the impact of mode of delivery on neonatal condition at birth. STUDY DESIGN: This prospective observational study, undertaken at a tertiary referral maternity unit in London, UK, included 604 'low risk' women recruited prior to delivery. Commonly assessed neonatal outcome variables (Apgar score at 1 and 5min, umbilical artery pH and base excess, neonatal unit admission, and a composite neonatal outcome score) were used to compare the condition at birth between babies born by different modes of delivery, using one-way ANOVA and chi-squared testing. RESULTS: Infants born by instrumental delivery for presumed fetal compromise had the poorest condition at birth (mean composite score=1.20), whereas those born by Cesarean section for presumed fetal compromise had a better condition at birth (mean composite score=0.64) (p=<0.001). No difference in composite neonatal outcome scores was observed between babies born by instrumental delivery for a prolonged second stage (no evidence of compromise), and those born by Cesarean delivery for presumed fetal compromise. CONCLUSIONS: Mode of delivery represents a potential confounding factor when using condition at birth as a surrogate marker of intra-partum fetal compromise. When evaluating the efficacy of intra-partum monitoring techniques, the isolated use of Apgar scores, umbilical artery acidosis and neonatal unit admission should be discouraged.

Prediction of fetal compromise in labor.

OBJECTIVE: The majority of intrapartum fetal hypoxia occurs in uncomplicated pregnancies. Current intrapartum monitoring techniques have not resulted in a reduction in the incidence of cerebral palsy in term neonates. We report the development of a composite risk score to allow risk stratification of normal pregnancies before labor. METHODS: Six hundred one women were recruited to this prospective observational study. All women underwent an ultrasound examination before active labor, during which fetal biometry and fetal Doppler flow resistance indices were measured. A composite risk score, amalgamating data from the umbilical artery, middle cerebral artery, and umbilical vein, was then developed and correlated with intrapartum outcomes. RESULTS: In cases with the highest composite risk scores, the incidence of fetal compromise (the primary outcome) was 80.0% compared with just 15.3% in cases with the lowest risk scores (relative risk 5.2, 95% confidence interval 2.7-10.1). These cases were also at increased risk of cesarean delivery (53.3% compared with 3.4%, P<.001) and of developing a fetal heart rate pattern considered pathologic by National Institute for Health and Clinical Excellence criteria (P=.003). No significant variation in Apgar scores or umbilical artery pH was observed. CONCLUSION: Intrapartum fetal compromise remains a significant global health issue. The composite risk score reported here can identify fetuses at both high risk and low risk of a subsequent diagnosis of intrapartum fetal compromise. This may enable more judicious use of current intrapartum fetal monitoring techniques, which are hampered by low specificity. LEVEL OF EVIDENCE: II.

Are 1st-trimester ß-human chorionic gonadotrophin and pregnancy-associated plasma protein A levels predictive of intrapartum fetal compromise in a selected normal population?

BACKGROUND: The incidence of cerebral palsy in term infants has not changed over the last 30 years. Current intrapartum monitoring techniques are limited by their inherent poor specificity. Changes in fetal haemodynamics in the term fetus, similar to those seen in fetal growth restriction, have been associated with an increased risk of subsequent intrapartum fetal compromise. Alterations in first-trimester ß-hCG and PAPP-A levels are predictive of fetal growth restriction. AIMS: In this study, we aimed to establish whether first-trimester ß-hCG and PAPP-A levels were predictive of fetal compromise in labour and whether these first-trimester markers could be correlated with fetal haemodynamics at term in a low-risk population. MATERIALS AND METHODS: Over a two-year period, 427 women with low risk, uncomplicated pregnancies were recruited to this study. All participants underwent a prelabour ultrasound examination during which fetal biometry and haemodynamics were assessed. First-trimester ß-hCG and PAPP-A levels were recorded from the case notes. All cases were followed up within 48 hours of delivery, and first-trimester ß-hCG and PAPP-A levels correlated with intrapartum outcomes and fetal haemodynamics. RESULTS: No significant relationship between first-trimester ß-hCG and PAPP-A levels and subsequent intrapartum fetal compromise was observed. Weak but significant correlations were observed between ß-hCG levels and umbilical venous flow rate, as well as PAPP-A levels and uterine artery pulsatility index. CONCLUSIONS: ß-hCG and PAPP-A levels measured during the first trimester are not predictive of subsequent intrapartum fetal compromise within a low-risk population.

Umbilical venous flow rate in term fetuses: can variations in flow predict intrapartum compromise?

OBJECTIVE: The objective of the study was to investigate the distribution of umbilical venous flow rates, measured in early labor, in a cohort of normal term pregnancies and to establish the relationship between umbilical venous flow and subsequent intrapartum outcome. STUDY DESIGN: Five hundred eighty-nine women with uncomplicated, term, singleton pregnancies were recruited to this prospective observational study prior to active labor (dilation of 4 cm or less) at Queen Charlotte's and Chelsea Hospital (London, UK). All participants underwent an ultrasound examination, during which fetal biometry, umbilical venous flow velocity, and umbilical vein diameter were recorded. Umbilical venous flow rate was then calculated. Following delivery, intrapartum and neonatal outcomes were correlated with the ultrasound findings. Cases were subdivided according to mode of delivery, and mean umbilical venous flow rates were compared between the groups. Cases were also subdivided according to umbilical venous flow rate (less than the 20th centile, 20th-80th centile, and greater than the 80th centile), and the incidence of diagnoses of fetal compromise was compared. RESULTS: Fetuses delivered by emergency cesarean for presumed fetal compromise had the lowest umbilical venous flow rates (both corrected for and uncorrected for birthweight) (P = .02 and P = .001, respectively). Fetuses with the lowest umbilical venous flow rates were significantly more likely to require emergency cesarean for presumed fetal compromise than those with the highest flow rates (15.7% vs 5.6%, relative risk, 2.83; 95% confidence interval, 1.16-6.91). CONCLUSION: Fetuses with the lowest umbilical venous flow rates are at increased risk of a subsequent diagnosis of intrapartum fetal compromise. Measurement of umbilical venous flow could contribute to the risk stratification of pregnancies prior to labor.

Perinatal- and procedure-related outcomes following radiofrequency ablation in monochorionic pregnancy.

OBJECTIVE: We sought to assess the efficacy, complication rates, and outcomes for complex monochorionic pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA). STUDY DESIGN: In this prospective observational study, 100 consecutive cases of selective fetal reduction using RFA were analyzed. All cases were managed at the Centre for Fetal Care at Queen Charlotte's and Chelsea Hospital in London. Indications for offering RFA, details of the procedure, and pregnancy outcomes were collected and analyzed. RESULTS: The main indications for RFA were discordant fetal anomaly and twin-twin transfusion syndrome. Overall live birth rate was 78% and the median gestation at delivery was 35.15 weeks. Delivery <32 weeks' gestation occurred in 17.9% of cases. Postprocedure abnormal antenatal magnetic resonance imaging occurred in 3% of cases. There was no statistical difference in outcomes with regard to gestation when the procedure was performed or the indication for the RFA. CONCLUSION: RFA appears to be a reasonable option for selective fetal reduction in complex monochorionic pregnancies with an overall survival rate of 78%.

Maternal and perinatal outcomes following peripartum hysterectomy from a single tertiary centre.

BACKGROUND: We investigated the indications for and maternal and perinatal outcomes following peripartum hysterectomy in a single large tertiary centre. MATERIALS AND METHODS: All cases of peripartum hysterectomy between 2000 and 2011 were investigated. Data regarding maternal demographics, previous obstetric and gynaecological history, indications for hysterectomy, and details of haemorrhage, surgical complications and neonatal outcomes were collected. RESULTS: There were 47 cases of peripartum hysterectomy of 55 262 births giving an incidence of 0.85 per 1000 births. Forty-one cases were total hysterectomies, while six were subtotal procedures. A total of 70.2% of cases were performed because of a morbidly adherent placenta, 27.7% for uterine atony and 2.1% for uterine rupture. The median estimated blood loss was 7290 mL. The overall surgical complication rate was 44.6% with bladder injury (19.1%) and sepsis (12.8%) commonest. Intensive care admission was required in 57.4% of women. CONCLUSIONS: Peripartum hysterectomy is a major procedure carrying a high morbidity rate. In this series, maternal survival was 100%.

Sex specific differences in fetal middle cerebral artery and umbilical venous Doppler.

BACKGROUND: The incidence of several adverse pregnancy outcomes including fetal growth restriction are higher in pregnancies where the fetus is male, leading to suggestions that placental insufficiency is more common in these fetuses. Placental insufficiency associated with fetal growth restriction may be identified by multi-vessel Doppler assessment, but little evidence exists regarding sex specific differences in these Doppler indices or placental function. This study aims to investigate sex specific differences in fetal and placental perfusion and to correlate these changes with intra-partum outcome. METHODS AND FINDINGS: This is a prospective cohort study. We measured Doppler indices of 388 term pregnancies immediately prior to the onset of active labour (≤3 cm dilatation). Fetal sex was unknown at the time of the ultrasound assessment. Information from the ultrasound scan was not made available to clinical staff. Case notes and electronic records were reviewed following delivery. We report significantly lower Middle Cerebral artery pulsatility index (1.34 vs. 1.43, p = 0.004), Middle Cerebral artery peak velocity (53.47 cm/s vs. 58.10 cm/s, p = <0.001), and Umbilical venous flow/kg (56 ml/min/kg vs. 61 ml/min/kg, p = 0.02) in male fetuses. These differences however, were not associated with significant differences in intra-partum outcome. CONCLUSION: Sex specific differences in feto-placental perfusion indices exist. Whilst the physiological relevance of these is currently unknown, the identification of these differences adds to our knowledge of the physiology of male and female fetuses in utero. A number of disease processes have now been shown to have an association with changes in fetal haemodynamics in-utero, as well as having a sex bias, making further investigation of the sex specific differences present during fetal life important. Whilst the clinical application of these findings is currently limited, the results from this study do provide further insight into the gender specific circulatory differences present in the fetal period.

Changes in the fetal and neonatal cytokine profile in pregnancies complicated by fetal growth restriction.

Fetal growth restriction (FGR) is a major complication of pregnancy with unknown etiology which results in marked fetal, neonatal and long-term morbidity, and mortality. FGR is likely to result from suboptimal placental implantation and perturbed immunological interactions. The diagnostic criteria for FGR vary between studies and the condition often occurs with pre-eclampsia. Here, we review published studies of fetal and neonatal cytokines in FGR and compare these with studies of small for gestational age, pre-eclampsia and pregnancies delivering pre-term.

Prediction of intrapartum fetal compromise using the cerebroumbilical ratio: a prospective observational study.

OBJECTIVE: To investigate the use of the fetal cerebroumbilical ratio to predict intrapartum compromise in appropriately grown fetuses. STUDY DESIGN: A prospective observational study set at Queen Charlotte's and Chelsea hospital, London, UK. Fetal biometry and Doppler resistance indices were measured in 400 women immediately before established labor. Labor was then managed according to local protocols and guidelines, and intrapartum and neonatal outcome details recorded. RESULTS: Infants delivered by cesarean section for fetal compromise had significantly lower cerebroumbilical ratios than those born by spontaneous vaginal delivery (1.52 vs 1.82, P ≤ .001). Infants with a cerebroumbilical ratio <10th percentile were 6 times more likely to be delivered by cesarean section for fetal compromise than those with a cerebroumbilical ratio ≥10th percentile (odds ratio, 6.1; 95% confidence interval, 3.03-12.75). A cerebroumbilical ratio >90th percentile appears protective of cesarean section for fetal compromise (negative predictive value 100%). CONCLUSION: The fetal cerebroumbilical ratio can identify fetuses at high and low risk of a subsequent diagnosis of intrapartum compromise, and may be used to risk stratify pregnancies before labor.

Changes in the maternal cytokine profile in pregnancies complicated by fetal growth restriction.

Fetal growth restriction (FGR) is an important and poorly understood condition of pregnancy, which results in significant fetal, neonatal and long-term morbidity and mortality. The aetiology of FGR is unknown and is likely to result from sub-optimal placental implantation and feto-maternal immunological interaction. The diagnostic criteria for FGR vary between studies, and the condition often occurs with preeclampsia (PET). We present a review of studies of maternal cytokines in FGR and compare these with studies of Small for Gestational Age and PET pregnancies.

Early procedure-related complications of fetal blood sampling and intrauterine transfusion for fetal anemia.

OBJECTIVE: To review the procedure-related complication rates following fetal blood sampling and intrauterine red cell transfusion for anaemic fetuses at a single tertiary center. DESIGN: A retrospective study of 114 intrauterine transfusions. SETTING: A single tertiary referral fetal medicine center at Queen Charlotte's and Chelsea Hospital, Imperial College London, London, UK. SAMPLE: All cases (114) undergoing fetal blood sampling and intrauterine transfusion between January 2003 and May 2010. METHODS: Early procedure-related complications (severe fetal bradycardia requiring either abandonment of the procedure or emergency delivery, fetal death, preterm labor or rupture of membranes) were investigated by review of computerized records and individual chart review. MAIN OUTCOME MEASURES: Live birth rate, perinatal mortality, procedure-related fetal bradycardia, preterm labor and procedure-related spontaneous rupture of membranes. RESULTS: The majority of cases (77.8%) were due to red cell alloimmunization, with anti-D being the commonest cause. The live birth rate was 93.5%, with a procedure-related fetal death rate of 0.9%. The preterm labor rate (<37 weeks' gestation) was 3.5% only occurring in patients undergoing multiple (>3) fetal transfusions. Complications in this series did not appear to be increased the earlier the gestation at which the first transfusion took place. CONCLUSIONS: Despite a reduction in the number of cases requiring intrauterine therapy for fetal anemia, contemporary outcomes appear to be good if not improving. It is important that the experience required to manage these cases should be concentrated in fewer centers to maximize good perinatal outcome.