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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
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Preventive measures against pre-eclampsia have been heavily studied. Because the pathogenesis of pre-eclampsia is not completely understood, prevention remains a complex issue. Below are some of the currently accepted recommendations.
Supplementation with a balanced protein and energy diet does not appear to reduce the risk of pre-eclampsia. Further, there is no evidence that changing salt intake has an effect.
Supplementation with antioxidants such as vitamin C, D and E has no effect on pre-eclampsia incidence; therefore, supplementation with vitamins C, E, and D is not recommended for reducing the risk of pre-eclampsia.
Calcium supplementation of at least 1 gram per day is recommended during pregnancy as it prevents preeclampsia where dietary calcium intake is low, especially for those at high risk. Low selenium status is associated with higher incidence of pre-eclampsia.
Fetal mortality refers to stillbirths or fetal death. It encompasses any death of a fetus after 20 weeks of gestation or 500 gm. In some definitions of the PNM early fetal mortality (week 20-27 gestation) is not included, and the PNM may only include late fetal death and neonatal death. Fetal death can also be divided into death prior to labor, antenatal (antepartum) death, and death during labor, intranatal (intrapartum) death.
Early neonatal mortality refers to a death of a live-born baby within the first seven days of life, while late neonatal mortality covers the time after 7 days until before 28 days. The sum of these two represents the neonatal mortality. Some definitions of the PNM include only the early neonatal mortality. Neonatal mortality is affected by the quality of in-hospital care for the neonate. Neonatal mortality and postneonatal mortality (covering the remaining 11 months of the first year of life) are reflected in the Infant Mortality Rate.
Treatment of infants suffering birth asphyxia by lowering the core body temperature is now known to be an effective therapy to reduce mortality and improve neurological outcome in survivors, and hypothermia therapy for neonatal encephalopathy begun within 6 hours of birth significantly increases the chance of normal survival in affected infants.
There has long been a debate over whether newborn infants with birth asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
Some doctors recommend complete bed-rest for the mother coupled with massive intakes of protein as a therapy to try to counteract the syndrome. Research completed shows these nutritional supplements do work. Diet supplementation was associated with lower overall incidence of TTTS (20/52 versus 8/51, P = 0.02) and with lower prevalence of TTTS at delivery (18/52 versus 6/51, P = 0.012) when compared with no supplementation. Nutritional intervention also significantly prolonged the time between the diagnosis of TTTS and delivery (9.4 ± 3.7 weeks versus 4.6 ± 6.5 weeks; P = 0.014). The earlier nutritional regimen was introduced, the lesser chance of detecting TTTS ( P = 0.001). Although not statistically significant, dietary intervention was also associated with lower Quintero stage, fewer invasive treatments, and lower twin birth weight discordance. Diet supplementation appears to counter maternal metabolic abnormalities in monochorionic twin pregnancies and improve perinatal outcomes in TTTS when combined with the standard therapeutic options. Nutritional therapy appears to be most effective in mitigating cases that are caught in Quintero Stage I, little effect has been observed in those that are beyond Stage I.
Bed rest has not been found to improve outcomes and therefore is not typically recommended.
Mothers whose fetus is diagnosed with intrauterine growth restriction by ultrasound can use management strategies based on monitoring and delivery methods. One of these monitoring techniques is an umbilical artery Doppler. This method has been shown to decrease risk of morbidity and mortality before and after parturition among IUGR patients.
Time of delivery is also a management strategy and is based on parameters collected from the umbilical artery doppler. Some of these include: pulsatility index, resistance index, and end-diastolic velocities, which are measurements of the fetal circulation.
IH/BA is also a causitive factor in cardiac and circulatory birth defects the sixth most expensive condition, as well as premature birth and low birth weight the second most expensive and it is one of the contributing factors to infant respiratory distress syndrome (RDS) also known as hyaline membrane disease, the most expensive medical condition to treat and the number one cause of infant mortality.
This procedure involves removal of amniotic fluid periodically throughout the pregnancy under the assumption that the extra fluid in the recipient twin can cause preterm labor, perinatal mortality, or tissue damage. In the case that the fluid does not reaccumulate, the reduction of amniotic fluid stabilizes the pregnancy. Otherwise the treatment is repeated as necessary. There is no standard procedure for how much fluid is removed each time. There is a danger that if too much fluid is removed, the recipient twin could die. This procedure is associated with a 66% survival rate of at least one fetus, with a 15% risk of cerebral palsy and average delivery occurring at 29 weeks gestation.
Low birthweight, pre-term birth and pre-eclampsia have been associated with maternal periodontitis exposure. But the strength of the observed associations is inconsistent and vary according to the population studied, the means of periodontal assessment and the periodontal disease classification employed. However the best is that the risk of low birth weight can be reduced with very simple therapy. Treatment of periodontal disease during gestation period is safe and reduction in inflammatory burden reduces the risk of preterm birth as well as low birth weight.
While active maternal tobacco smoking has well established adverse perinatal outcomes such as LBW, that mothers who smoke during pregnancy are twice as likely to give birth to low-birth weight infants. Review on the effects of passive maternal smoking, also called environmental tobacco exposure (ETS), demonstrated that increased risks of infants with LBW were more likely to be expected in ETS-exposed mothers.
Regarding environmental toxins in pregnancy, elevated blood lead levels in pregnant women, even those well below 10 ug/dL can cause miscarriage, premature birth, and LBW in the offspring. With 10 ug/dL as the Centers for Disease Control and Prevention's “level of concern”, this cut-off value really needs to arise more attentions and implementations in the future.
The combustion products of solid fuel in developing countries can cause many adverse health issues in people. Because a majority of pregnant women in developing countries, where rate of LBW is high, are heavily exposed to indoor air pollution, increased relative risk translates into substantial population attributable risk of 21% of LBW.
One environmental exposure which has been found to increase the risk of low birth weight is particulate matter, a component of ambient air pollution. Because particulate matter is composed of extremely small particles, even nonvisible levels can be inhaled and present harm to the fetus. Particulate matter exposure can cause inflammation, oxidative stress, endocrine disruption, and impaired oxygen transport access to the placenta, all of which are mechanisms for heightening the risk of low birth weight. To reduce exposure to particulate matter, pregnant women can monitor the EPA’s Air Quality Index and take personal precautionary measures such as reducing outdoor activity on low quality days, avoiding high-traffic roads/intersections, and/or wearing personal protective equipment (i.e., facial mask of industrial design). Indoor exposure to particulate matter can also be reduced through adequate ventilation, as well as use of clean heating and cooking methods.
A correlation between maternal exposure to CO and low birth weight has been reported that the effect on birth weight of increased ambient CO was as large as the effect of the mother smoking a pack of cigarettes per day during pregnancy.
It has been revealed that adverse reproductive effects (e.g., risk for LBW) were correlated with maternal exposure to air pollution combustion emissions in Eastern Europe and North America.
Mercury is a known toxic heavy metal that can harm fetal growth and health, and there has been evidence showing that exposure to mercury (via consumption of large oily fish) during pregnancy may be related to higher risks of LBW in the offspring.
It was revealed that, exposure of pregnant women to airplane noise was found to be associated with low birth weight. Aircraft noise exposure caused adverse effects on fetal growth leading to low birth weight and preterm infants.
In sheep, intrauterine growth restriction can be caused by heat stress in early to mid pregnancy. The effect is attributed to reduced placental development causing reduced fetal growth. Hormonal effects appear implicated in the reduced placental development. Although early reduction of placental development is not accompanied by concurrent reduction of fetal growth; it tends to limit fetal growth later in gestation. Normally, ovine placental mass increases until about day 70 of gestation, but high demand on the placenta for fetal growth occurs later. (For example, research results suggest that a normal average singleton Suffolk x Targhee sheep fetus has a mass of about 0.15 kg at day 70, and growth rates of about 31 g/day at day 80, 129 g/day at day 120 and 199 g/day at day 140 of gestation, reaching a mass of about 6.21 kg at day 140, a few days before parturition.)
In adolescent ewes (i.e. ewe hoggets), overfeeding during pregnancy can also cause intrauterine growth restriction, by altering nutrient partitioning between dam and conceptus. Fetal growth restriction in adolescent ewes overnourished during early to mid pregnancy is not avoided by switching to lower nutrient intake after day 90 of gestation; whereas such switching at day 50 does result in greater placental growth and enhanced pregnancy outcome. Practical implications include the importance of estimating a threshold for "overnutrition" in management of pregnant ewe hoggets. In a study of Romney and Coopworth ewe hoggets bred to Perendale rams, feeding to approximate a conceptus-free live mass gain of 0.15 kg/day (i.e. in addition to conceptus mass), commencing 13 days after the midpoint of a synchronized breeding period, yielded no reduction in lamb birth mass, where compared with feeding treatments yielding conceptus-free live mass gains of about 0 and 0.075 kg/day.
In both of the above models of IUGR in sheep, the absolute magnitude of uterine blood flow is reduced. Evidence of substantial reduction of placental glucose transport capacity has been observed in pregnant ewes that had been heat-stressed during placental development.
Some disorders and conditions can mean that pregnancy is considered high-risk (about 6-8% of pregnancies in the USA) and in extreme cases may be contraindicated. High-risk pregnancies are the main focus of doctors specialising in maternal-fetal medicine.
Serious pre-existing disorders which can reduce a woman's physical ability to survive pregnancy include a range of congenital defects (that is, conditions with which the woman herself was born, for example, those of the heart or , some of which are listed above) and diseases acquired at any time during the woman's life.
A Dutch 2010 research showed that "low-risk" pregnancy in the Netherlands may actually carry a higher risk of perinatal death than a "high-risk" pregnancy.
Perinatal asphyxia, neonatal asphyxia or birth asphyxia is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain. Hypoxic damage can occur to most of the infant's organs (heart, lungs, liver, gut, kidneys), but brain damage is of most concern and perhaps the least likely to quickly or completely heal. In more pronounced cases, an infant will survive, but with damage to the brain manifested as either mental, such as developmental delay or intellectual disability, or physical, such as spasticity.
It results most commonly from a drop in maternal blood pressure or some other substantial interference with blood flow to the infant's brain during delivery. This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term, and more for those that are born prematurely. WHO estimates that 4 million neonatal deaths occur yearly due to birth asphyxia, representing 38% of deaths of children under 5 years of age.
Perinatal asphyxia can be the cause of hypoxic ischemic encephalopathy or intraventricular hemorrhage, especially in preterm births. An infant suffering severe perinatal asphyxia usually has poor color (cyanosis), perfusion, responsiveness, muscle tone, and respiratory effort, as reflected in a low 5 minute Apgar score. Extreme degrees of asphyxia can cause cardiac arrest and death. If resuscitation is successful, the infant is usually transferred to a neonatal intensive care unit.
There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
There is considerable controversy over the diagnosis of birth asphyxia due to medicolegal reasons. Because of its lack of precision, the term is eschewed in modern obstetrics.
A 2008 bulletin from the World Health Organization estimates that 900,000 total infants die each year from birth asphyxia, making it a leading cause of death for newborns.
In the United States, intrauterine hypoxia and birth asphyxia was listed as the tenth leading cause of neonatal death.
With treatment, maternal mortality is about 1 percent, although complications such as placental abruption, acute renal failure, subcapsular liver hematoma, permanent liver damage, and retinal detachment occur in about 25% of women. Perinatal mortality (stillbirths plus death in infancy) is between 73 and 119 per 1000 babies of woman with HELLP, while up to 40% are small for gestational age. In general, however, factors such as gestational age are more important than the severity of HELLP in determining the outcome in the baby.
The World Health Organization defines a maternal near-miss case as "a woman who nearly died but survived a complication that occurred during pregnancy, childbirth or within 42 days of termination of pregnancy."
Maternal mortality is a sentinel event to assess the quality of a health care system. The standard indicator is the Maternal Mortality Ratio, defined as the ratio of the number of maternal deaths per 100,000 live births. Due to improved health care the ratio has been declining steadily in developed countries. For example, in the UK 1952-1982 the ratio was halving every 10 years. In the European Union the ratio has now stabilized at around 10 to 20.
The small number of cases makes the evaluation of maternal mortality practically impossible Historically, the study of negative outcomes have been highly successful in preventing their causes, this strategy of prevention therefore faces difficulties when if the number of negative outcome drop to low levels. In the UK, for example, the most dramatic decline in maternal death was achieved in Rochdale, an industrial town in the poorest area of England. In 1928 the town had a Maternal Mortality Ratio of over 900 per 100,000 live births, more than double the national average of the time. An enquiry into the causes of the deaths reduced the ratio to 280 per 100,000 pregnancies by 1934, only six years later, then the lowest in the country.
The very low figures of maternal mortality have therefore stimulated an interest in investigating cases of life-threatening obstetric morbidity or maternal near miss. There are several advantages of investigating near miss events over events with fatal outcome
- near miss are more common than maternal deaths
- their review is likely to yield useful information on the same pathways that lead to severe morbidity and death,
- investigating the care received may be less threatening to providers because the woman survived
- one can learn from the women themselves since they can be interviewed about the care they received.
- all near misses should be interpreted as free lessons and opportunities to improve the quality of service provision
- it is also clear that maternal deaths merely are the tip of the iceberg of maternal disability. For every woman who dies, many more will survive but often suffer from lifelong disabilities.
The growing interest is reflected in an increasing number of systematic reviews on the prevalence of near miss. The studies and reviews span
- analytic attempts to define the concept more strictly,
- descriptive efforts to measure and quantify new indicators (prevalence) of near-miss for different geographical regions etc.
- explanatory efforts of the leading cause for morbidity
Genetics plays a role in having a baby born with LGA. Taller, heavier parents tend to have larger babies. Babies born to an obese mother have greatly increased chances of LGA.
In the past, treatment options were limited to supportive medical therapy. Nowadays neonatal encephalopathy is treated using hypothermia therapy.
Common risks in LGA babies include shoulder dystocia, hypoglycemia, metatarsus adductus, hip subluxation and talipes calcaneovalgus due to intrauterine deformation.
Shoulder dystocia can result from the anterior shoulder becoming impacted on the maternal symphysis pubis. The doctor or midwife will try to push the baby's anterior shoulder downward to pass through the birth canal and clear the woman's symphysis pubis. This can be difficult if the child is LGA, since the birth canal is 10 cm when fully dilated for most women and there may not be much room to move the baby. If shoulder dystocia occurs, there are various manoeuvres which can be performed by the birth attendant to try to deliver the shoulders. These generally involve trying to turn the shoulders into the oblique, using suprapubic pressure to disimpact the anterior shoulder from above the symphysis pubis, or delivering the posterior arm first. If these do not resolve the situation, the provider may intentionally snap the baby's clavicle (bone that holds shoulder in place) in order to displace the shoulder and allow the child to be delivered. The bone should heal spontaneously, and most babies will make a full recovery from this birth injury.. There is still a risk of temporary or permanent nerve damage to the baby's arm, or other injuries such as humeral fracture.
Although big babies are at higher risk for shoulder dystocia, most cases of shoulder dystocia happen in smaller babies because there are many more small and normal-size babies being born than big babies. Researchers have found that it is impossible to predict who will have shoulder dystocia and who will not.
In non-diabetic women, shoulder dystocia happens 0.65% of the time in babies that weigh less than , 6.7% of the time in babies that weigh to , and 14.5% of the time in babies that weigh more than .
Big babies are at higher risk of hypoglycemia in the neonatal period, independent of whether the mother has diabetes.
Fetuses with polyhydramnios are at risk for a number of other problems including cord prolapse, placental abruption, premature birth and perinatal death. At delivery the baby should be checked for congenital abnormalities.
The only effective treatment is prompt delivery of the baby. Several medications have been investigated for the treatment of HELLP syndrome, but evidence is conflicting as to whether magnesium sulfate decreases the risk of seizures and progress to eclampsia. The disseminated intravascular coagulation is treated with fresh frozen plasma to replenish the coagulation proteins, and the anemia may require blood transfusion. In mild cases, corticosteroids and antihypertensives (labetalol, hydralazine, nifedipine) may be sufficient. Intravenous fluids are generally required. Hepatic hemorrhage can be treated with embolization, as well, if life-threatening bleeding ensues.
The University of Mississippi standard protocol for HELLP includes corticosteroids. However, a 2009 review found "no conclusive evidence" supporting corticosteroid therapy, and a 2010 systematic review by the Cochrane Collaboration also found "no clear evidence of any effect of corticosteroids on substantive clinical outcomes" either for the mothers or for the newborns,
An initial assessment to determine the status of the mother and fetus is required. Although mothers used to be treated in the hospital from the first bleeding episode until birth, it is now considered safe to treat placenta previa on an outpatient basis if the fetus is at less than 30 weeks of gestation, and neither the mother nor the fetus are in distress. Immediate delivery of the fetus may be indicated if the fetus is mature or if the fetus or mother are in distress. Blood volume replacement (to maintain blood pressure) and blood plasma replacement (to maintain fibrinogen levels) may be necessary.
Corticosteroids are indicated at 24–34 weeks gestation, given the higher risk of premature birth.