Beatrix Mita Sadipun studies History of Accounting Thought and Kesehatan. Abstract. Background: Intrauterine growth restriction (IUGR) is an obstetrical IUGR are reviewed, and a management strategy is suggested. Prolonged rupture of membranes. Familial predisposition. Maternal hypertension or toxemia. Cesarean section without labor. IUGR/SGA. Perinatal asphyxia.
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NK conceived and designed the study, interpreted the data, and prepared the manuscript. JTC helped devise the analytic plan, conducted the analyses, and assisted with interpreting the data and preparing the manuscript.
BAC advised on the analytic plan, and assisted with analyzing and interpreting the data and with preparing the manuscript. Postterm pregnancy is a pregnancy that extends to 42 weeks of gestation or beyond. Fetal, neonatal and maternal complications associated with this condition have always been underestimated. It is not well understood why some women become postterm although in obesity, hormonal and genetic factors have been implicated.
The management of postterm pregnancy constitutes a challenge to clinicians; knowing who to induce, who will respond to induction and who will require a caesarean section CS.
The current definition and management of postterm pregnancy have been challenged in several studies as the emerging evidence demonstrates that the incidence of complications associated with postterm pregnancy also increase prior mkaalah 42 weeks of gestation. For example the incidence of stillbirth increases from 39 weeks onwards with a ,akalah rise after 40 weeks of gestation.
Induction of labour before 42 weeks of gestation has the potential to prevent these complications; however, both patients and clinicians alike are concerned about risks associated with induction of labour such as failure of induction and increases in CS rates. It seems therefore that a policy of induction of labour at 41 weeks in postterm women could be beneficial with potential improvement in perinatal outcome and a reduction in maternal complications.
Post term pregnancy makalzh associated with an increased risk of fetal and neonatal mortality and morbidity Olesen et al.
Antepartum stillbirth at and beyond term weeks gestation is a major public health problem accounting for a iugt contribution to perinatal mortality than either deaths from complications of prematurity or the lugr infant death syndrome Cotzias et al. Increased fetal mortality from postterm pregnancy could therefore be prevented by induction of labour IOL at term, however, both clinicians and patients alike are concerned about the risks of induction of labour including uterine hyper-stimulation, failed induction and increased Caesarean section rates.
Postterm pregnancy is also associated with increased costs related to antenatal fetal monitoring and induction of labour Allen et al. Optimisation of these conflicting pressures is a clinical challenge. The terms prolonged pregnancy, postdates and postdatism are synonymously mamalah to describe the same condition. The terms postdate and prolonged pregnancy are ill-defined and best avoided ACOG, Postmaturity, postmaturity syndrome and dysmaturity are not synonymous makalxh to postterm pregnancy.
They are often used to describe the features of a neonate who appears to have been in utero longer than 42 weeks of gestation. They describe the effects of intrauterine growth restriction IUGR secondary to utero-placental insufficiency encountered in iufr postterm pregnancy Shime et al. The prevalence varies depending on population characteristics and local management practices.
Population characteristics that affect the prevalence include: The proportion of women with pregnancy complications and the frequency of spontaneous preterm labour also influence the rate of postterm pregnancy.
The link between ethnicity and iigr duration of pregnancy is not well established Collins et al. Local management practices such as scheduled IOL, differences in the use of early ultrasound US for pregnancy dating, and elective Caesarean section CS rates will affect the overall prevalence of postterm pregnancy.
The most common cause of prolonged pregnancies is inaccurate dating Neilson, ; Crowley, The use of standard clinical criteria to determine the estimated delivery date EDD tends to overestimate gestational age and consequently increases the incidence of postterm pregnancy Gardosi et al. Iugd criteria which are commonly majalah to confirm gestational age include last menstrual period LMPthe size of the uterus as estimated by bimanual examination in the first trimester, the perception of fetal movements, auscultation of fetal heart tones, and fundal height in a singleton pregnancy.
When postterm pregnancy truly exists the cause is usually unknown. Common risk factors include primiparity, previous postterm pregnancy Alfirevic and Walkinshaw, ; Mogren et al. It is not known how body mass index BMI affects the duration of pregnancy and timing of delivery, but interestingly obese women have a higher incidence makkalah postterm pregnancy Usha Kiran et al.
Because adipose tissue is hormonally active Baranova et al. Perhaps amongst all the factors which could influence the incidence of postterm pregnancy obesity is the one modifiable risk factor which could theoretically improve by dietary and exercise behavioural modifications before or during pregnancy.
Such modifications would have an impact on other health outcomes as well, mzkalah because postterm pregnancy is associated with a number of perinatal makalwh, its prevention would be clearly beneficial Ingemarsson and Kallen, Using a number needed to treat calculation, it was found that for approximately every 20 women who successfully decreased BMI below the obesity range, one fewer woman would go past 41 weeks of gestation adjusted odds ratio of 1.
Altered levels of circulating hormones that are thought to play a role in spontaneous labour may also play a role in the causation of postterm pregnancy. Placental sulphatase deficiency for example, is a rare X-linked recessive disorder that can prevent spontaneous labour due to a defect in placental sulphatase activity and the resulting decreased oestriol levels E3.
Genetic factors may be involved with prolongation of pregnancy. Women who makalxh themselves amkalah of a prolonged pregnancy are at higher risk of postterm pregnancy relative risk is 1. Twin studies also support a genetic predisposition. Rates of prolonged pregnancy are increased in women whose twin sister has had a previous postterm birth.
This association is greater in monozygotic than in dizygotic twins Laursen et al. There also appears to be makalh paternal role in the recurrence risk of prolonged pregnancy. The risk of recurrence of postterm pregnancy was reduced from The pathogenesis of postterm pregnancy is not clearly understood. As demonstrated above some risk factors associated with postterm pregnancy were identified with some possible explanations, however, the pathogenesis of the condition is not yet clear.
Despite improved understanding of parturition in recent years, we still lack clarity about the exact mechanisms which initiate labour and allow its progression. To have a better understanding of the pathogenesis of postterm pregnancy it is essential to shed some lights on the pathophysiology of parturition and try to understand why these mechanisms fail to be triggered in postterm pregnancies or conversely are triggered earlier in preterm labour. It seems logical that a common ground or a link does exist between these three conditions.
The mechanisms of parturition include interactions between hormonal, mechanical and inflammatory processes, in which placenta, mother and fetus each play a vital role. Placental production of the peptide corticotrophin releasing hormone CRH has been related to the length of gestation McLean et al.
Synthesis of CRH mskalah the placenta increases exponentially as pregnancy advances and peaks at the time of labour. In women who deliver prematurely the exponential rise is more rapid than those delivering at term, while in women who deliver postterm the rate of rise is slower Ellis et al.
This data suggests that postterm delivery is due to a change in the biological mechanisms regulating the length of gestation.
This may be due to an inherited predisposition due to polymorphisms in the genes on the physiological pathway linking CRH to birth.
It is also possible that the maternal phenotype may change the response of maternal tissues to the usual hormonal signals to birth as may occur in the obese woman.
Maternal plasma CRH concentrations correlate with oestriol concentrations Smith et al.
The rising oestriol driven by CRH increases at the end of gestation more rapidly than oestradiol levels leading to an increase in the oestriol to oestradiol ratio which has been postulated to produce an estrogenic environment in the last weeks of pregnancy.
Concurrently the rise in maternal plasma progesterone concentrations that occurs across gestation slows at the end of pregnancy or even falls. This may be due to CRH inhibition of placental progesterone synthesis Yang et al.
Thus the pro-pregnancy effect of progesterone promoting relaxation is declining as the pro-labour actions of oestriol promoting contraction are increasing. These changes in ratios have been observed in preterm births, singletons delivering at term and in twin gestations Smith et al. The situation in postterm pregnancies is unknown.
It is likely to be similar in postterm women who go into spontaneous labour or those who respond to IOL, based on one study of postterm women Torricelli et al. Postterm pregnancies are associated with increased fetal and neonatal motality and morbidity as well as maternal morbidity. These risks are greater than it was originally thought. Risks have been underestimated in the past for two reasons.
First, earlier studies on postterm pregnancy were published before the routine iuugr of ultrasound for pregnancy dating. As a result many pregnancies included in the studies were not actually postterm. The second reason rests within the definition of stillbirth itself.
Stillbirth rates were traditionally calculated using pregnancies delivered at a given gestational age rather than ongoing undelivered pregnancies. This would lower the stillbirth rates in postterm pregnancies as once the fetus is delivered it is no longer at risk of intra-uterine fetal death IUFD.
The appropriate denominator is therefore not all malalah at a given gestational age but ongoing undelivered pregnancies Rand et al. One retrospective study mskalah oversingleton births, using the appropriate denominator demonstrated a 6-fold increase in stillbirth rates in postterm pregnancies from 0.
The perinatal mortality rate, defined as stillbirths plus early neonatal deaths, at 42 weeks of gestation is twice as high as that at term versus per deliveries, respectively. It increases 4-fold at 43 weeks makkalah fold at 44 weeks Bakketeig and Bergsjo, ; Feldman, ; Hilder et al.
These data also demonstrate that when calculated per ongoing pregnancies, fetal and neonatal mortality rates increase sharply after 40 weeks Hilder et al. It is believed that utero-placental insufficiency, mxkalah aspiration and intrauterine infection are the underlying causes of the increased perinatal mortality rates in these cases Hannah, Fetal morbidity is also increased in postterm pregnancies and pregnancies that progress beyond 41 weeks gestation.
This includes passage of meconium, meconium aspiration syndrome, macrosomia and dysmaturity. Post term pregnancy also is an independent risk factor for low umbilical cord pH levels neonatal acidaemialow 5-minute Apgar scores Kitlinski et al. Although some of these infant deaths clearly result from peripartum complications such as meconium aspiration syndrome, most have no known cause.
Meconium aspiration syndrome refers to respiratory compromise with tachypnea, cyanosis, and reduced pulmonary compliance in newborn infants exposed to meconium in utero. It is seen in higher rates in postterm neonates Kabbur et al. In the United States the incidence of meconium aspiration syndrome has shown a 4-fold reduction between and from 5. This has been attributed primarily to a reduction in postterm pregnancy rates Yoder et al. Conventional interventions such as amnio-infusion Hofmeyr, ; Fraser et al.
Makallah infants are larger than term infants and have a higher incidence of fetal macrosomia 2. Shoulder dystocia is associated with risk of orthopaedic injury e. However, there is no evidence that IOL as a preventative measure in these cases is associated with a reduction in complication rates or improvement in iuhr outcome ACOG, This includes thin wrinkled peeling skin excessive desquamationthin body malnourishmentlong hair and nails, oligohydramnios and frequently passage of meconium.
These pregnancies are at increased risk of umbilical cord compression from oligohydramnios, meconium aspiration, and short-term neonatal complications such as hypoglycemia, seizures, and respiratory insufficiency. They also have an increased incidence of non-reassuring antepartum and intrapartum fetal testing Knox et al. Whether such infants are at increased risk of long-term neurologic sequelae is not clear.
In a large, prospective, follow-up study of children at ages 1 and 2 years, the general intelligence quotient, physical milestones, and frequency of intercurrent illnesses were not significantly different between normal infants born at term and those born postterm Shime et al.
A study from Scotland published in demonstrated increased risk of stillbirth both overall and unexplained stillbirth as pregnancy advances especially after 39 weeks of gestation Sutan et al. The rates of mmakalah aspiration and neonatal acidaemia both increase as term pregnancies progress beyond 38 weeks Bruckner et al. Neonatal morbidity including birth injuries seems to nadir at around 38 weeks and increase in a continuous fashion thereafter Nicholson et al.