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Management strategy in case of meconium stained amniotic fluid
Early Human Development 90 (2014) 341–342
Contents lists available at ScienceDirect
Early Human Development journal homepage: www.elsevier.com/locate/earlhumdev
Best practice guidelines
Management strategy in case of meconium stained amniotic fluid Victor J. Pop a,⁎, Simone M. Kuppens b a
Tilburg University, The Netherlands Department of Obstetrics and Gynaecology, Catharina Hospital Eindhoven, The Netherlands
b
Contents 1.
Preventive intervention . . . . . . . 1.1. Preventing post-term deliveries 1.2. Amnioinfusion . . . . . . . . 2. “Wait and watch” strategy . . . . . . Conflict of interest . . . . . . . . . . . . References . . . . . . . . . . . . . . .
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The management strategies can generally be divided in two categories: preventive intervention and “wait and watch” strategy. The first group again can be divided in two categories: the prevention of MSAF to occur and the prevention of any fetal or neonatal complication once MSAF is diagnosed. The possible benefit of the “wait and watch” strategy, in which neonatal complications when they occur after a MSAF delivery are vigorously monitored and treated, is largely dependent on the level of peripartum facilities. Interestingly, these facilities in turn have largely influenced the evidence of benefit of intervention within the first attitude, as very recently shown in the 2014 Cochrane review of the effect of amnio-infusion [1]. The corresponding author, Prof. G. Hofmeyr, kindly gave permission to describe these finding in details in this section of the BP issue. It is beyond the scope of this review to discuss interventions that are commonly used in obstetrics when – in the case of MSAF – during labor objective parameters are found of fetal distress. Moreover, evaluation of treatment strategies in case of a meconium aspiration syndrome (MAS) is also beyond the scope of this review. As in the introduction, we will evaluate the current concepts of treatment strategies also in the light of the recent paper of Hiersch et al., discriminating between primary MSAF and secondary MSAF [2].
⁎ Corresponding author. E-mail addresses: [email protected] (V.J. Pop), [email protected] (S.M. Kuppens).
http://dx.doi.org/10.1016/j.earlhumdev.2014.04.004 0378-3782/© 2014 Elsevier Ireland Ltd. All rights reserved.
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341 341 341 342 342 342
1. Preventive intervention 1.1. Preventing post-term deliveries As the incidence of MSAF increases with increasing gestational age, the most “simple” way of intervention reducing the risk of MSAF – and its possible serious consequences such as MAS – is to prevent prolonged pregnancy, generally defined as term over ≥41 weeks and occurring in 15–20% of all pregnancies. There is sufficient evidence that curtailing prolonged pregnancy reduces the incidence of MSAF and hence of MAS [3]. There is evidence that labor induction with prostaglandins, especially misoprostol, increases the risk of MSAF because placental crossing results in fetal bowel stimulation producing meconium. Amniotomy may increase the risk of MAS [3].
1.2. Amnioinfusion In the past, amnioinfusion has been advocated to prevent neonatal complications in case of MSAF. However, in the recent Cochrane review by Hofmeyr et al. [1], the authors conclude that in settings with standard peri-partum surveillance (the review included 3294 women) by amnioinfusion there “was no significant reduction in the primary outcomes meconium aspiration syndrome, perinatal death or severe morbidity, and maternal death or severe morbidity” [1]. In settings with limited peripartum surveillance (based on a review of three studies including 1141 women) the authors conclude that in the amnioinfusion group: “there was a reduction in CS for fetal distress and overall; meconium aspiration syndrome; perinatal mortality and neonatal ventilation or neonatal intensive care unit admission”. There was 6 times higher incidence of perinatal death and almost 3 times higher incidence of MAS in these
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V.J. Pop, S.M. Kuppens / Early Human Development 90 (2014) 341–342
under-resourced settings compared to standard peripartum surveillance [1]. 2. “Wait and watch” strategy The conservative therapy, carefully monitoring of the neonate born after MSAF followed by “aggressive” intervention when problems occur, seems to be the most appropriate attitude towards the management of MSAF. However, it is obvious that the level of peripartum surveillance dramatically will influence the figures of neonatal complications. For example, in the literature, the incidence of MAS in case of MSAF deliveries varies between 1 and 3% in standard peripartum surveillance center (and between 5 and 14% in under-resourced centers) but in the already mentioned study of Hiersch et al., performed in a tertiary medical center, MAS occurred in 2 out of 694 MSAF born babies, an incidence of 0.3% [2]. On the other hand, even in this highly skilled center, there were clear significant differences between primary and secondary meconium born neonates (a 2.5 higher rate of NICU admissions in secondary versus primary meconium born cases, an almost 2-fold increased occurrence of phototherapy in secondary meconium compared to primary meconium) suggesting again that a sub-group of MSAF neonates are definitely at risk for perinatal complications [2]. Interestingly, in their study, in secondary meconium the incidence of POP (persistent occiput posterior) was almost 3-times higher compared to primary meconium deliveries (which had similar figures as the clear meconium control group). Because POP – or abnormal cephalic position – has been related by our group to suboptimal maternal thyroid function (which has also been related to MSAF see this issue), it is a matter of speculation whether in this subgroup the incidence of MSAF is mediated by sub-optimal maternal thyroid function [4]. Also, the mean gestational age in secondary meconium as well as the number of women with term N 40 week gestation at delivery were significantly higher in secondary meconium compared to primary meconium [2]. As shown in this issue, sub-optimal maternal thyroid function was only related to MSAF occurring after 41 week
gestation, another argument suggesting that maternal thyroid function might be a mediator in secondary meconium. Intrapartum oro- and nasopharyngeal suction of the neonate born with MSAF is no longer recommended. It is obvious that, in case MSAF is related to fetal distress which in turn is caused by severe maternal complications such as infection, pre-eclampsia, HELPP or diabetes gravidarum, careful monitoring of the MSAF born neonate also include the mother. In summary, amnio-infusion might reduce perinatal complications in MSAF cases treated in a center with limited peripartum facilities while there is sufficient evidence that “wait and watch” in normal peripartum surveillance centers adequately meet the attitude towards adequate handling of MSAF, although even within these latter centers the incidence of for example MAS may differ with a factor ten. Future research will elucidate whether a special sub-category of MSAF (about 1/5 of all cases = secondary meconium) will benefit of even more rigorous surveillance with regard to neonatal outcome. Conflict of interest None declared. References [1] Hofmeyr GJ, Xu H, Eke AC. Amnioinfusion for meconium stained liquor in labour (review). Cochrane Library, Issue 1; 2014. [2] Hiersch L, Melamed N, Rosen H, Peled Y, Wiznitzer A, Yogev Y. New onset of meconium during labor versus primary meconium stained amniotic fluid — is there a difference in pregnancy outcome? J Matern Fetal Neonatal Med 2013:1–7 [early on line]. [3] Hofmeyr GJ. What (not) to do before delivery? Prevention of fetal meconium release and its consequences. Early Hum Dev 2009;85:611–5. [4] Wijnen HA, Kooistra L, Vader HL, Essed GG, Mol BW, Pop VJ. Maternal thyroid hormone concentration during late gestation is associated with foetal position at birth. Clin Endocrinol (Oxf) 2009;71(5):746–51.
Contents lists available at ScienceDirect
Early Human Development journal homepage: www.elsevier.com/locate/earlhumdev
Best practice guidelines
Management strategy in case of meconium stained amniotic fluid Victor J. Pop a,⁎, Simone M. Kuppens b a
Tilburg University, The Netherlands Department of Obstetrics and Gynaecology, Catharina Hospital Eindhoven, The Netherlands
b
Contents 1.
Preventive intervention . . . . . . . 1.1. Preventing post-term deliveries 1.2. Amnioinfusion . . . . . . . . 2. “Wait and watch” strategy . . . . . . Conflict of interest . . . . . . . . . . . . References . . . . . . . . . . . . . . .
. . . . . .
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. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
The management strategies can generally be divided in two categories: preventive intervention and “wait and watch” strategy. The first group again can be divided in two categories: the prevention of MSAF to occur and the prevention of any fetal or neonatal complication once MSAF is diagnosed. The possible benefit of the “wait and watch” strategy, in which neonatal complications when they occur after a MSAF delivery are vigorously monitored and treated, is largely dependent on the level of peripartum facilities. Interestingly, these facilities in turn have largely influenced the evidence of benefit of intervention within the first attitude, as very recently shown in the 2014 Cochrane review of the effect of amnio-infusion [1]. The corresponding author, Prof. G. Hofmeyr, kindly gave permission to describe these finding in details in this section of the BP issue. It is beyond the scope of this review to discuss interventions that are commonly used in obstetrics when – in the case of MSAF – during labor objective parameters are found of fetal distress. Moreover, evaluation of treatment strategies in case of a meconium aspiration syndrome (MAS) is also beyond the scope of this review. As in the introduction, we will evaluate the current concepts of treatment strategies also in the light of the recent paper of Hiersch et al., discriminating between primary MSAF and secondary MSAF [2].
⁎ Corresponding author. E-mail addresses: [email protected] (V.J. Pop), [email protected] (S.M. Kuppens).
http://dx.doi.org/10.1016/j.earlhumdev.2014.04.004 0378-3782/© 2014 Elsevier Ireland Ltd. All rights reserved.
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341 341 341 342 342 342
1. Preventive intervention 1.1. Preventing post-term deliveries As the incidence of MSAF increases with increasing gestational age, the most “simple” way of intervention reducing the risk of MSAF – and its possible serious consequences such as MAS – is to prevent prolonged pregnancy, generally defined as term over ≥41 weeks and occurring in 15–20% of all pregnancies. There is sufficient evidence that curtailing prolonged pregnancy reduces the incidence of MSAF and hence of MAS [3]. There is evidence that labor induction with prostaglandins, especially misoprostol, increases the risk of MSAF because placental crossing results in fetal bowel stimulation producing meconium. Amniotomy may increase the risk of MAS [3].
1.2. Amnioinfusion In the past, amnioinfusion has been advocated to prevent neonatal complications in case of MSAF. However, in the recent Cochrane review by Hofmeyr et al. [1], the authors conclude that in settings with standard peri-partum surveillance (the review included 3294 women) by amnioinfusion there “was no significant reduction in the primary outcomes meconium aspiration syndrome, perinatal death or severe morbidity, and maternal death or severe morbidity” [1]. In settings with limited peripartum surveillance (based on a review of three studies including 1141 women) the authors conclude that in the amnioinfusion group: “there was a reduction in CS for fetal distress and overall; meconium aspiration syndrome; perinatal mortality and neonatal ventilation or neonatal intensive care unit admission”. There was 6 times higher incidence of perinatal death and almost 3 times higher incidence of MAS in these
342
V.J. Pop, S.M. Kuppens / Early Human Development 90 (2014) 341–342
under-resourced settings compared to standard peripartum surveillance [1]. 2. “Wait and watch” strategy The conservative therapy, carefully monitoring of the neonate born after MSAF followed by “aggressive” intervention when problems occur, seems to be the most appropriate attitude towards the management of MSAF. However, it is obvious that the level of peripartum surveillance dramatically will influence the figures of neonatal complications. For example, in the literature, the incidence of MAS in case of MSAF deliveries varies between 1 and 3% in standard peripartum surveillance center (and between 5 and 14% in under-resourced centers) but in the already mentioned study of Hiersch et al., performed in a tertiary medical center, MAS occurred in 2 out of 694 MSAF born babies, an incidence of 0.3% [2]. On the other hand, even in this highly skilled center, there were clear significant differences between primary and secondary meconium born neonates (a 2.5 higher rate of NICU admissions in secondary versus primary meconium born cases, an almost 2-fold increased occurrence of phototherapy in secondary meconium compared to primary meconium) suggesting again that a sub-group of MSAF neonates are definitely at risk for perinatal complications [2]. Interestingly, in their study, in secondary meconium the incidence of POP (persistent occiput posterior) was almost 3-times higher compared to primary meconium deliveries (which had similar figures as the clear meconium control group). Because POP – or abnormal cephalic position – has been related by our group to suboptimal maternal thyroid function (which has also been related to MSAF see this issue), it is a matter of speculation whether in this subgroup the incidence of MSAF is mediated by sub-optimal maternal thyroid function [4]. Also, the mean gestational age in secondary meconium as well as the number of women with term N 40 week gestation at delivery were significantly higher in secondary meconium compared to primary meconium [2]. As shown in this issue, sub-optimal maternal thyroid function was only related to MSAF occurring after 41 week
gestation, another argument suggesting that maternal thyroid function might be a mediator in secondary meconium. Intrapartum oro- and nasopharyngeal suction of the neonate born with MSAF is no longer recommended. It is obvious that, in case MSAF is related to fetal distress which in turn is caused by severe maternal complications such as infection, pre-eclampsia, HELPP or diabetes gravidarum, careful monitoring of the MSAF born neonate also include the mother. In summary, amnio-infusion might reduce perinatal complications in MSAF cases treated in a center with limited peripartum facilities while there is sufficient evidence that “wait and watch” in normal peripartum surveillance centers adequately meet the attitude towards adequate handling of MSAF, although even within these latter centers the incidence of for example MAS may differ with a factor ten. Future research will elucidate whether a special sub-category of MSAF (about 1/5 of all cases = secondary meconium) will benefit of even more rigorous surveillance with regard to neonatal outcome. Conflict of interest None declared. References [1] Hofmeyr GJ, Xu H, Eke AC. Amnioinfusion for meconium stained liquor in labour (review). Cochrane Library, Issue 1; 2014. [2] Hiersch L, Melamed N, Rosen H, Peled Y, Wiznitzer A, Yogev Y. New onset of meconium during labor versus primary meconium stained amniotic fluid — is there a difference in pregnancy outcome? J Matern Fetal Neonatal Med 2013:1–7 [early on line]. [3] Hofmeyr GJ. What (not) to do before delivery? Prevention of fetal meconium release and its consequences. Early Hum Dev 2009;85:611–5. [4] Wijnen HA, Kooistra L, Vader HL, Essed GG, Mol BW, Pop VJ. Maternal thyroid hormone concentration during late gestation is associated with foetal position at birth. Clin Endocrinol (Oxf) 2009;71(5):746–51.