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Table 43.5 Perinatal outcome in 13 reported cases of maternal brain death during pregnancy [ NA - Not Available; SVD - spontaneous vaginal delivery].. Obstetric management should focus o

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Nutritional support, usually in the form of enteral or paren-teral hyperalimentation, is required for maternal maintenance and fetal growth and development (see Chapter 12 ) Because of poor maternal gastric motility, parenteral rather than enteral hyperalimentation is often preferred [117] to maintain a positive nitrogen balance The use of hyperalimentation during preg-nancy does not appear to have deleterious effects on the fetus [147] As a rule, the amount of hyperalimentation should be

in keeping with the caloric requirements for that gestational age

hyperglycemia

In such patients, panhypopituitarism frequently occurs As a result, a variety of hypoendocrinopathies, such as diabetes insipi-dus, secondary adrenal insuffi ciency, and hypothyroidism, may develop, each mandating therapy to maintain the pregnancy Treatment of these conditions requires the use of vasopressin, corticosteroids, and thyroid replacement, respectively

Because of the hypercoagulable state of pregnancy and the immobility of the brain - dead gravida, these patients also are at

fl ow Along with vasopressors to support the maternal blood

pressure and organ perfusion, the patient should be kept, when

possible, in the lateral recumbent position to maintain

uteropla-cental blood fl ow At the same time, care should be exercised to

avoid decubitus ulcers

With maternal brain death, the thermoregulatory center

located in the ventromedian nucleus of the hypothalamus does

not function, and maternal body temperature cannot be

main-tained normally As a result, maternal hypothermia is the rule

Maintenance of maternal euthermia is important and usually can

be accomplished through the use of warming blankets and the

administration of warm, inspired, humidifi ed air

Maternal pyrexia suggests an infectious process and the need

for a thorough septic work - up Thus, infection surveillance for,

and the treatment of, infectious complications is helpful to

prolong maternal somatic survival [142] If the maternal

tem-perature remains elevated for a protracted period, cooling

blan-kets may be necessary to avoid potentially deleterious effects on

the fetus [146]

Table 43.5 Perinatal outcome in 13 reported cases of maternal brain death during pregnancy [ NA - Not Available; SVD - spontaneous vaginal delivery]

Gestation age (weeks)

Reference Year Brain death Delivery Indication for delivery Mode of delivery Apgar score at 5min Birth Weight (grams)

Terminated

Maternal Sepsis

FHR decelerations

Maternal Hypotension

Growth Impaired

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34 weeks gestation to enhance fetal lung maturation [117,149] For stimulation of fetal lung maturity, betamethasone or dexa-methasone is recommended Repeat steroid injections in subse-quent weeks are not recommended due to the concern over the effect of repeated steroid injections on fetal brain growth, and the absence of proven additive benefi t [142]

Another obstetric concern is the development of premature labor Here, tocolytic therapy has been used successfully [122,150] Catanzarite et al [122] described the use of a magnesium sulfate infusion and indomethacin to control uterine contractions, allowing prolongation of the pregnancy for 25 days Other agents

an increased risk for thromboembolism Therefore, to minimize

the potential for deep venous thrombosis or pulmonary embolus,

heparin prophylaxis (5000 – 7500 units twice or three times a day)

and/or intermittent pneumatic calf compression are

recom-mended [148]

By artifi cially supporting the maternal physiologic system, the

intrauterine environment can be theoretically maintained to

allow for adequate fetal growth and development (Table 43.7 )

Obstetric management should focus on monitoring fetal growth

with frequent ultrasound evaluations, antepartum FHR

assess-ment, and the administration of corticosteroids between 24 and

Table 43.6 Perinatal outcome in 17 reported cases of persistent vegetative state during pregnancy

Gestation age (weeks)

Reference Year PVS Delivery Indication for delivery Mode of delivery Apgar score at 5min Birth Weight (grams)

BenAderet (129) 1984 17 35 Premature Rupture

Of Membranes

Of Membranes

Chiossi - 1 (141) 2006 10 34 Hypotension

Fetal Lung Maturity

Chiossi - 2 (141) 2006 19 31 Abnormal FHR Pattern

Biophysical Profi le 6/10

NA - Not Available; SVD - Spontaneous Vaginal Delivery; FHR – Fetal Heart Rate; mo - Months; PVS - Persistent Vegetative State

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months To date, there have been 307 cases of perimortem cesar-ean delivery reported in the English literature [152,153] Of these cesareans, there have been 222 surviving infants [152,153] Since Weber ’ s monumental review of the subject in 1971, the causes of maternal death leading to a perimortem cesarean deliv-ery have not changed substantially [152,153] but are more refl ec-tive of contemporary obstetric care [130,131] These include traumatic events, pulmonary embolism from amniotic fl uid, clot

or air, acute respiratory or cardiac failure, and sepsis In the case

of a sudden, unanticipated maternal arrest, the timing of cesarean delivery becomes the quintessential element [152,153]

If a pregnant woman does sustain a cardiopulmonary arrest, cardiopulmonary resuscitation (CPR) should be initiated immediately (Chapter 7 ) Optimal performance of CPR in the non pregnant patient results in a cardiac output less than a third of

optimal circumstances, produces a cardiac output around 10%

of normal To optimize maternal cardiac output, the patient should be placed in the supine position Dextrorotation of the uterus and compression of the major vessels of the uterus may impede venous return and may further compromise this effort Lateral uterine displacement may help to remedy this problem; but CPR in this position is extremely awkward Ultimately, a cesarean may be necessary to alleviate this impedance to CPR

If maternal and fetal outcomes are to be optimized, the timing

of the cesarean delivery is critical According to Katz and associ-ates [152] in 1986 and reaffi rmed in 2005 [153] , the theory behind a perimortem cesarean is that if CPR fails to produce a pulse within 4 minutes, a cesarean delivery should be begun and the baby delivered within 5 minutes of maternal cardiac arrest Once the baby is delivered, maternal CPR should continue because many women will have “ sudden and profound improve-ment ” [153] after evacuation of the uterus Hence, the “ 4 - minute rule ” came into effect and has been adopted by the American Heart Association when maternal CPR has been ineffective [153,154] Thus, the standard ABCs of cardiopulmonary resusci-tation (airway, breathing, circulation) should be expanded to include D (delivery)

As demonstrated in Table 43.8 , fetal survival is linked consis-tently with the interval between maternal arrest and delivery It

is clear from the available data [152,153] that the longer the time interval from maternal death to the delivery of the fetus, the greater is the likelihood of permanent neurologic impairment of the fetus Ideally, the fetus should be delivered within 5 minutes

of maternal arrest Within that 5 - minute window rests the great-est likelihood of delivering a child who will be neurologically normal (Table 43.8 ) However, the potential exists for a favorable fetal outcome beyond 15 minutes of maternal cardiac arrest, and therefore, delivery should not be withheld even if beyond 5 minutes, if the fetus is still alive [152,153]

While the timing of cesarean delivery is a major determinant

of subsequent fetal outcome, the gestational age of the fetus also

is an important consideration The probability of survival is related directly to the neonatal birth weight and gestational age

available for tocolysis include betamimetics, calcium - channel

blockers, and oxytocin antagonists The hemodynamic effects of

betamimetics and calcium channel - blocking agents may make

these drugs less than ideal choices in these settings, in which

maternal hemodynamic instability is common [122]

The timing of delivery is based on the deterioration of maternal

or fetal status or the presence of fetal lung maturity Classical

cesarean is the procedure of choice [117,142] and is the least

traumatic procedure for the fetus To assure immediate cesarean

capability, a cesarean pack and neonatal resuscitation equipment

should be immediately available in the intensive care unit

Perimortem c esarean d elivery

For centuries, perimortem cesarean delivery has been described

as an attempt to preserve the life of the unborn child when the

pregnant woman dies [151] The fi rst description of a

perimor-tem cesarean was by Pliny the Elder in 237 AD This delivery

related to that of Scipio Africanus Over a thousand years later in

1280, the Catholic Church at the Council of Cologne decreed that

a perimortem cesarean delivery must be performed to permit the

unborn child to be baptized and to undergo a proper burial

Failure to perform the delivery constituted a punishable offense

Moreover, perimortem cesarean was mandated specifi cally in

those women whose pregnancies were advanced beyond 6

Table 43.7 Medical and obstetric considerations in providing artifi cial life

support to the brain - dead gravida

Maternal considerations

Mechanical ventilation

Cardiovascular support

Temperature lability

Hyperalimentation

Panhypopituitarism

Infection surveillance

Prophylactic anticoagulation

Fetal considerations

Fetal surveillance

Ultrasonography

Steroids

Timing of delivery

Table 43.8 Perimortem cesarean delivery with the outcome of surviving infants

from the time of maternal death until delivery [152,153]

Time interval (min) Surviving infants (no.) Intact neurologic

status of survivors (%)

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12 Phelan JP , Kim JO Fetal heart rate observations in the brain -

dam-aged infant Semin Perinatol 2000 ; 24 : 221 – 229

13 Phelan JP Perinatal risk management: obstetric methods to prevent

birth asphyxia Clin Perinatol 2005 ; 32 : 1 – 17

14 Phelan JP , Korst LM , Martin GI Causation – fetal brain injury and

uterine rupture Clin Perinatol 2007 ; 34 ( 3 ): 409 – 438

15 Lockshin MD , Bonfa E , Elkon D , Druzin ML Neonatal lupus risk

to newborns of mother with systemic lupus erythematosus Arthritis

Rheum 1988 ; 31 : 697 – 701

16 Manning FA , Platt LD , Sipos L Antepartum fetal evaluation:

devel-opment of a fetal biophysical profi le Am J Obstet Gynecol 1980 ; 136 :

787 – 795

17 Sibai BM Diagnosis, prevention, and management of eclampsia

Obstet Gynecol 2005 ; 105 : 402 – 410

18 Clark SL , Hankins GD , Dudley DA , et al Amniotic fl uid embolism:

analysis of the National Registry Am J Obstet Gynecol 1995 ; 172 :

1158 – 1167

19 Paul RH , Koh KS , Bernstein SG Change in fetal heart rate: uterine

contraction patterns associated with eclampsia Am J Obstet Gynecol

1978 ; 130 : 165 – 169

20 Koh KD , Friesen RM , Livingstone RA , et al Fetal monitoring during

maternal cardiac surgery with cardiopulmonary bypass Can Med

Assoc J 1975 ; 112 : 1102 – 1106

21 Korsten HHM , van Zundert AAJ , Moou PNM , et al Emergency aortic valve replacement in the 24th week of pregnancy Acta Anaestesiol Belg 1989 ; 40 : 201 – 205

22 Strange K , Halldin M Hypothermia in pregnancy Anesthesiology

1983 ; 58 : 460 – 465

23 Bates B Hon fetal heart rate pattern fl ags brain damage Ob Gyn

News 2005 ; 40 ( 10 ): 1 – 2

24 Kim JO , Martin G , Kirkendall C , Phelan JP Intrapartum fetal heart rate variability and subsequent neonatal cerebral edema Obstet Gynecol 2000 ; 95 : 75S

25 National Institute of Child Health and Human Development Research Planning Workshop Electronic fetal heart rate

monitor-ing: research guidelines for interpretation Am J Obstet Gynecol 1997 ;

177 : 1385 – 1390

26 Smith CV Vibroacoustic stimulation for risk assessment Clin

Perinatol 1994 ; 21 : 797 – 808

27 Petrie RH , Yeh SY , Maurata Y , et al Effect of drugs on fetal heart

rate variability Am J Obstet Gynecol 1978 ; 130 : 294 – 299

28 Babakania A , Niebyl R The effect of magnesium sulfate on fetal

heart rate variability Obstet Gynecol 1978 ; 51 (Suppl): 2S – 4S

29 Clark SL , Miller FC Sinusoidal fetal heart rate pattern associated

with massive fetomaternal transfusion Am J Obstet Gynecol 1984 ;

149 : 97 – 99

30 Katz M , Meizner I , Shani N , et al Clinical signifi cance of sinusoidal

fetal heart rate pattern Br J Obstet Gynaecol 1984 ; 149 : 97 – 100

31 Modanlou HD , Freeman RK Sinusoidal fetal heart rate pattern: its

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1033 – 1038

32 Theard FC , Penny LL , Otterson WN Sinusoidal fetal heart rate:

ominous or benign? J Reprod Med 1984 ; 29 : 265 – 268

33 Kirkendall C , Romo M , Phelan JP Fetomaternal hemorrhage in fetal

brain injury Am J Obstet Gynecol 2001 ; 185 ( 6 ): S153

34 Heise RH , van Winter JT , Ogburn PL Jr Identifi cation of acute transplacental hemorrhage in a low - risk patient as a result of daily counting of fetal movements Mayo Clin Proc 1993 ; 68 :

892 – 894

[155 – 158] At what gestational age should a perimortem cesarean

delivery be considered? Is there a lower limit? It becomes obvious

immediately that there are no clear answers to these questions

As a general rule, intervention appears prudent whenever the

fetus is potentially viable or is “ capable of a meaningful existence

outside the mother ’ s womb ” [159] According to Gdansky and

Schenker [143] , the gray zone rests between 23 and 26 weeks ’

gestation But, this threshold is continually pushed to earlier

ges-tational ages in keeping with the advances in neonatal care

Ideally, criteria for intervention in such circumstances should be

formulated with the aid of an institution ’ s current neonatal

sur-vival statistics and guidance from its bioethics committee In light

of the continual technologic advances in neonatology, care must

be taken to periodically review these criteria because the

gesta-tional age and weight criteria may be lowered in the future

[155 – 159]

When maternal death is an anticipated event, is informed

consent necessary? For instance, patients hospitalized with

termi-nal cancer, class IV cardiac disease, pulmonary hypertension, or

previous myocardial infarction are at an increased risk of death

during pregnancy Although these cases are infrequent, it seems

reasonable to prepare for such an eventuality Decisions

regard-ing intervention should be made in advance with the patient and

family When intervention has been agreed to, one consideration

is to have a cesarean delivery pack and neonatal resuscitation

equipment immediately available in the ICU

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Critical Care Obstetrics, 5th edition Edited by M Belfort, G Saade,

M Foley, J Phelan and G Dildy © 2010 Blackwell Publishing Ltd

Critical Care

Mark Santillan & Jerome Yankowitz

Department of Obstetrics and Gynecology, University of Iowa College of Medicine, Iowa City, IA, USA

Introduction

Rarely must a physician in an intensive care unit (ICU) consider

the fetal effects of drugs commonly used in this setting The

incidence of ICU admissions during pregnancy is 0.17 – 1.1% [1]

This infrequent occurrence coupled with the lack of drug data in

parturients complicates treatment of the pregnant ICU patient

A brief review of the physiologic changes in pregnancy that affect

pharmacodynamics reveals some of this complexity

The four aspects of pharmacokinetics affected by pregnancy

are absorption, distribution, metabolism and excretion Overall,

absorption increases during pregnancy Gastric pH, small bowel

motility, and the rate of gastric emptying are decreased [2] The

increased cardiac output during pregnancy also helps increase the

delivery of medications to tissues to increase absorption [3] An

increase in plasma volume, total body water, some plasma

pro-teins, and body fat has been shown to increase the volume of

distribution for some drugs Increased cardiac output also

con-tributes to increased distribution [4] Various metabolic enzymes,

such as cytochrome P - 450, CYP1A2, and cholinesterase have

dif-ferent activity levels in the face of pregnancy Cytochrome P - 450

is upregulated In contrast, CYP2C19 and cholinesterase are

downregulated These activities attenuate how drugs are

metabo-lized in pregnancy Ten to twenty per cent of the population has

lower metabolic enzyme activity This further causes variation in

how pregnant women metabolize drugs [4] An increase in drug

elimination is driven by the increased glomerular fi ltration rate

[5] Of note, renal secretion and reabsorption of drugs increase

in pregnancy Drug processing also occurs through respiration

The changes in pulmonary function during pregnancy make

res-piration a more important factor in drug elimination [4] These

physiologic changes during pregnancy make predicting

pharma-cokinetics diffi cult

The fetal effects of medications provide an additional challenge

in treating the pregnant patient Particularly in preterm fetuses, the poorly developed blood – brain barrier can lead to a higher concentration of drugs in the fetal CNS The preterm fetus also has fewer protein binding sites Consequently, more unbound drug is in the fetal circulation In addition, preterm hyperbiliru-binemia further increases the effects of drugs as bilirubin com-petes with drugs for protein binding sites [6] Overall, preterm physiology increases the effects of most drugs The challenge of treating two patients colors all therapeutic decisions of those caring for pregnant patients A summary of the drugs that may commonly be encountered in the critical care unit are shown in Table 44.1

Maternal a nalgesia and s edation

Analgesia and sedation are essential components of critical care medicine Although there are many drugs to use for sedation, analgesia, and neuromuscular blockade, multiple practice surveys point to a pattern of commonly used medications in the ICU [7 – 9] The most commonly used sedatives are midazolam, loraz-epam, propofol, and haldol The most common pain medications are morphine and fentanyl The most frequently used neuromus-cular blocking agents are pancuronium and vecuronium

Midazolam

Midazolam is a water - soluble benzodiazepine As a sedative/ hypnotic, it is often used in combination with other anesthetic protocols It has a rapid onset and a short duration of action The elimination half - life is 1 hour in pregnant women [10] , and 6.3 hours in neonates [11] Placental transfer of the drug is very rapid Rapid drug clearance makes midazolam a more acceptable seda-tive for use in pregnancy Although cases of infant respiratory depression requiring resuscitation have occurred if midazolam is given before a cesarean section [12] , there are no controlled trials investigating the embryotoxic effect of midazolam or cases of con-genital anomalies in newborns of midazolam - exposed mothers

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use of fi rst - trimester benzodiazepines When the data were ana-lyzed specifi cally for lorazepam there was a signifi cant association

of lorazepam with anal atresia (OR 6.2, 95% CI 2.4 – 15.7, P = 0.01) [16] Of note, only 262 of the 13 703 infants were exposed to a benzodiazepine Six cases of anal atresia were identifi ed in this subgroup, 5 of which were exposed to lorazepam Although there was a statistically signifi cant correlation between lorazepam and anal atresia, the clinical signifi cance of this fi nding is in question Given the study design and the small number of cases of anal atresia, one should not use these data to restrict the use of loraz-epam in pregnancy, particularly in the acute setting after the tera-togenic period

In terms of breastfeeding, only small amounts of lorazepam have been detected in breast milk [17] and it is considered likely safe for breastfeeding

Propofol

Propofol is a widely used intravenous anesthetic It is used in many general anesthesia protocols Propofol has a rapid onset of action with a short duration of action In pregnant women under-going a cesarean section, onset of action is reported at 75 s after administration with a half - life of 4.7 min [18] Placental transfer

is also rapid, with rapid uptake by fetal tissues In multiple studies, the fetal levels of the drug are lower than maternal levels One case report describes a prolonged exposure to propofol greater than 48 hours in a pregnant woman with no adverse neonatal outcome except for prolonged neonatal sedation [19] There is little written on adverse neonatal outcomes associated with pro-pofol One study suggests that there is a decrease in the Early

In doses greater than 30 mg, diazepam, a similar

benzodiaze-pine, has been linked to fetal hypothermia, hypotonia, poor

feeding, and increased risk of jaundice [6] Even though the

man-ufacturer suggests caution in use of midazolam in pregnancy

based on these adverse neonatal effects of diazepam at high doses,

midazolam ’ s rapid onset of action and rapid clearing coupled

with medical needs in the ICU, makes use of midazolam in an

ICU setting during pregnancy acceptable

Midazolam is excreted in small amounts in breast milk and

considered likely safe for breastfeeding [31]

Lorazepam

Lorazepam, like midazolam, is a water - soluble benzodiazepine

with a longer duration of action Lorazepam is more often used

as an acute anxiolytic It has a rapid onset and a short duration

of action relative to diazepam Its elimination half - life in adults

is approximately 12 hours [13] Lorazepam does cross the

pla-centa, but fetal levels of the drug are uniformly lower than

mater-nal levels [14] In addition, neonatal rate of metabolism of the

drug is less than maternal rates [13] A “ fl oppy infant syndrome ”

characterized by muscular hypotonia, hypothermia, low Apgar

scores, and neurologic depression has been associated with this

drug [14]

The question of embryotoxicity of lorazepam has not been

adequately answered Previous studies investigating this question

showed no correlation with congenital malformations [15] A

large French retrospective review of 13 703 congenital

malforma-tions documented in the French Central East registry

demon-strates that overall there is no increase of malformations with the

Table 44.1 Summary of drugs

Haloperidol Vecuronium

Morphine Amiodarone

Adenosine Atropine

Calcium channel blockers Epinephrine

Lidocaine Ibutilide

Digoxin Procainamide

Furosemide Dopamine

Hydralazine Dobutamine

Labetalol Isoproterinol

Heparins Hydrochlorothiazide

Insulin Nitroglycerin

Thyroxine Nitroprusside

Propylthiouracil Warfarin

Thrombolytics

Corticosteroids

Methimazole

Mannitol

Trang 10

neurobehavior and development are unknown but the use of morphine is considered compatible with pregnancy

The American Academy of Pediatrics noted that morphine is compatible with breastfeeding [34] Even in a case of chronic maternal use of morphine for severe pain, the infant was esti-mated to receive 0.8 – 12% of the maternal dose with no adverse side effects observed in the infant [35]

Fentanyl

Fentanyl is a synthetic narcotic agonist It is often used in trans-dermal form for chronic pain indications In obstetrics, it is a common component of epidural analgesia The half - life has been reported from 3 to 12 hours with an average of 7 hours [36] Placental transfer of fentanyl is well documented in all three tri-mesters with a mean cord to maternal venous fentanyl concentra-tion ratio of 0.94 [37] There are no reports linking congenital

defects conclusively to in utero fentanyl exposure [31] As a labor

analgesic, IV fentanyl demonstrated no statistical difference versus matched controls not requiring analgesia in terms of dif-ferent neonatal outcomes including Apgar scores, incidence of respiratory depression, and use of naloxone [38] The same study does link morphine with the loss of fetal heart rate variability with

no evidence of fetal hypoxia There is a case report of fentanyl -linked fetal respiratory muscle rigidity which made neonatal resuscitation more diffi cult [39] This is noteworthy since respira-tory muscle rigidity is a common adult side effect The use of fentanyl is considered compatible with pregnancy given the overall favorable neonatal outcomes

Fentanyl is transferred to human milk in small proportions It has been reported that 0.033% of the maternal dose of fentanyl

is transferred to breast milk Fentanyl has also been found in low doses in colostrum In this study, the colostrum concentrations were higher than serum concentrations The authors state that given the low oral bioavailability of fentanyl that it is still safe in breastfeeding Given the above data, the AAP agrees and consid-ers it compatible with breastfeeding [31]

Pancuronium

Pancuronium is a non - depolarizing curaremimetic neuromuscu-lar blockade agent It is a competitive inhibitor of acetylcholine

at the neuromuscular junction level It is commonly used to aid ventilation and intubation for general anesthesia for surgical cases including cesarean sections In obstetrics, it is also used for

acute, in utero neuromuscular blockade of a fetus for fetal therapy

procedures such as intrauterine blood transfusions [40,41] In term pregnant women, the half - life of pancuronium is reported between 72 and 114 minutes [42] Term placental transfer of pancuronium has been well documented In comparison to other

has a higher mean cord to maternal venous concentration ratio

at varying maternal doses [40] This is supported by the fi nding that a 1 - min Apgar score greater than 7 occurs as low as 20% of the time in term cesarean sections using pancuronium To date, there have been no cases of human teratogenesis linked to

Neonatal Neurobehavioral Scale score at 1 hour of life in infants

exposed to propofol in utero during a cesarean section This

change in the ENNS score resolved at the fourth hour of life [20]

This same study also states that these infants have satisfactory

arterial pH and Apgar scores at delivery There are multiple

studies showing that fetuses exposed in utero to propofol show

no signifi cant neonatal depression as assessed by Apgar scores,

arterial pH, and neurologic and adaptive capacity scores (NACS)

[21 – 23] No fetal structural abnormalities have been reported

with propofol Therefore, propofol is a safe induction agent in

pregnancy

Propofol is present only in very small amounts in breast milk

Breastfeeding is considered safe after propofol exposure [24]

Haloperidol

Haloperidol is often used as an acute tranquilizer, or in chronic

Haloperidol has a relatively rapid onset of action with a time to

peak plasma concentration of 20 min The average half - life of

haloperidol of both intravenous and intramuscular

administra-tions is 20 min [25] The lipophilic nature of haloperidol makes

it available to the fetal circulation very rapidly [26] The side

effect profi le of haloperidol includes the side effects of other

neuroleptic drugs including akathisia and tardive dyskinesia

There are some case reports discussing the occurrence of these

side effects in the fetus post delivery In particular, one case report

describes a subtype of tardive dyskinesia in an infant exposed to

2 – 5 mg/day of haloperidol throughout pregnancy [27] Human

fetal structural abnormalities have not been conclusively linked

to haloperidol In a review of 100 pregnancies exposed to

halo-peridol, no association with structural anomalies was noted [28]

Consequently, the use of haloperidol is considered safe in

preg-nancy, particularly in the acute setting

Haloperidol is excreted in the breast milk It is estimated

that the infant will ingest 3% of the maternal dose through breast

milk [29] This small exposure to haloperidol has not been linked

to any adverse neonatal outcomes [30] Despite these fi ndings,

given the case reports of infant side effects, the American Academy

of Pediatrics has classifi ed haloperidol as a drug “ for which the

effect on nursing infants is unknown but may be of concern ”

[31]

Morphine

Morphine was widely used for pain control during labor in the

1940s It has long since been replaced by newer narcotics

second-ary to its delayed onset of action, prolonged duration of action,

and adverse side effects to mother and fetus [6] One of the most

concerning of these side effects is maternal and fetal respiratory

depression Intrathecal morphine has proved to be safe analgesia

without fetal toxicity [32] The placental transfer of morphine is

rapid Morphine, like other opioids, has a corresponding fetal

withdrawal syndrome in opioid - addicted mothers There have

been no conclusive studies linking congenital malformations to

morphine [33] As with most agents, the long - term effects of

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