Raju Lakshmana1, 2 , Richard Hiscock1, 3, Megan Galbally3, Alison Fung3, Susan Walker1, 3, Gaynor Blankley3 and Anne Buist1
(1)
University of Melbourne, Melbourne, Australia
(2)
Northpark Private Hospital, Cnr Plenty and Greenhills Roads, Bundoora, Victoria, 3083, Australia
(3)
Mercy Hospital for Women, 163 Studley Rd, Heidelberg, VIC, 3084, Australia
Raju Lakshmana
Email: rraju@unimelb.edu.au
14.1 Introduction
14.2 Indications and Barriers for ECT in Pregnancy
14.2.1 Indications
14.2.2 Barriers
14.2.3 Risks of Untreated Psychiatric Illness (Fig. )
14.3 Risks Associated with ECT in Pregnancy
14.3.1 Risks Related to Electrical Stimulus and Seizure During ECT
14.3.2 Risks Associated with Anesthesia for ECT in Pregnancy and Strategies to Minimize them
14.3.3 Longer Term Effects in Children of Mothers Who Were Exposed to ECT During Pregnancy
14.3.4 Guiding Principles and Specific Recommendations for ECT in Pregnancy (Fig. )
14.4 Conclusion
References
Abstract
Modified Electroconvulsive Therapy (ECT) is a highly effective treatment in psychiatry despite variable community views. It is considered a first-line treatment option for severe depression (associated with high suicide risk, catatonic signs, and/or psychotic symptoms), functional catatonia, and severe psychotic agitation (acute mania or psychosis). It is also an effective treatment option for depression that is unresponsive to multiple trials of antidepressant medications with response rates close to 70 % in some studies. The current evidence suggests that pregnant women who present with the above indications for ECT should not per se be excluded from accessing ECT. There are specific considerations associated with ECT use in pregnancy and this chapter will summarize the principles of safety and effective use of ECT in pregnant patients to optimize perinatal outcomes. The chapter will not go into details of ECT electrophysiology and techniques that can be accessed from other texts and guidelines.
Keywords
Electroconvulsive therapy (ECT)Pregnancy
14.1 Introduction
Electroconvulsive Therapy (ECT) is an effective treatment for severe depression, with both rapid onset of action and high response rates compared to available pharmacological treatments (Pagnin et al. 2004). However, the evidence for safety and efficacy of ECT specifically in pregnancy is limited. There are no randomized controlled trials and the literature tends to be limited to case reports, case series, and review articles.
The stigma and concerns that limit the use of ECT in the general adult population also limit the numbers of pregnant patients receiving ECT, making it a relatively rare treatment. The infrequency with which it occurs necessitates that all possible precautions should be undertaken and that ideally women who require ECT in pregnancy should be managed in a setting that has adequate experience and resources to ensure safety for both the pregnant woman and the fetus.
There are specific concerns associated with the use of ECT in pregnant patients and these relate to the effects of general anesthesia and electrical induction of seizure on maternal, fetal, and obstetric outcomes. Clinicians undertaking ECT in pregnant women should also be cognizant of potential medico-legal issues.
This chapter will cover the key areas for administration of ECT in pregnancy, namely indications, barriers, and risks of ECT in pregnancy including longer term outcomes in children born to women who have received ECT during pregnancy. It will conclude with a discussion of guiding principles and specific recommendations for safe administration of ECT in pregnancy
14.2 Indications and Barriers for ECT in Pregnancy
14.2.1 Indications
Indications for ECT in pregnancy are similar to those in non-pregnant adult patients (Table 14.1). There is good evidence to support the consideration of ECT treatment in severe depression, particularly where there has been a failure to respond to medication (Prudic et al. 1990, 1996), or when the risks associated with the illness require a quicker treatment response than that usually occurs with pharmacological treatment (Pagnin et al. 2004). ECT is also one of the most effective treatment options for puerperal psychosis (Reed et al. 1999). When considering the place of ECT as a treatment for severely unwell pregnant women it must be compared to both pharmacological treatments that also carry a significant risk–benefit profile (see Chap. 6 for further discussion) and the risks of not treating the patient (Fig. 14.1). Three reviews (Saatcioglu and Tomruk 2011; Anderson and Reti 2009; Miller 1994) and a recent retrospective case series (Bulut et al. 2013) all conclude that ECT is relatively safe and effective as a treatment in pregnancy.
Table 14.1
Indications for ECT in pregnancy
|
Moderate to severe Major Depression (unipolar or bipolar): |
|
• Where there has been a failure of antidepressant medication or |
|
• If the severity of symptoms and the risk to life is such that there is a need for rapid improvement |
|
• Suicidal |
|
• Inadequate oral intake and is at risk of malnutrition or dehydration |
|
• Severe psychotic features |
|
• Agitation |
|
• Catatonia |
|
Catatonic states associated with any psychiatric condition |
|
Mania |
|
Mixed Affective states |
|
Schizophrenia with prominent affective symptoms |
|
Schizoaffective disorders |
|
Puerperal Psychosis |
Fig. 14.1
Balancing risks of treating depression in pregnancy
Anderson and Reti reviewed all published literature relating to ECT in pregnancy (2009). They described a total of 339 women receiving ECT during pregnancy; 25 adverse fetal effects were reported of which 11 were deaths. However, only one death seemed to be related to ECT (Anderson and Reti 2009) [see Sect. 14.3.1, point (4)]. In another review of all reported cases of ECT in pregnancy between 1942 and 1991, adverse events or complications were reported in 28 cases (9.3 %)—miscarriage was reported in 5 cases (1.6 %) which is comparable to the general population, and neonatal death or still birth was noted in 3 cases; however, factors other than ECT were considered responsible in these cases (Miller 1994). Another case report of miscarriage following ECT in the first trimester was published in 1998 (Echevarria Moreno et al. 1998): the patient developed profuse vaginal bleeding after the third ECT session and lost the fetus at 8 weeks gestation.
Collectively theses studies suggest an incidence of adverse events close to 10 %. With limited evidence to support biological plausibility and the virtual impossibility of demonstrating association by clinical studies, one has to exercise caution in utilizing ECT during all trimesters of pregnancy (Richards 2007). These clinical concerns over potential risks, as well as women’s treatment preferences, make this a rarely used treatment. Interestingly, Wheeldon et al. (1999) found over 80 % of patients receiving ECT were ‘satisfied’ with their treatment experience; however, these findings were not supported by a later systematic review (Rose et al. 2003).
14.2.2 Barriers
Barriers to ECT in pregnancy are not simply attitudinal, but also involve having adequate facilities and sufficiently experienced staff to ensure that it is carried out in a safe manner for the pregnant woman and fetus. This includes psychiatrists experienced in having administered ECT in pregnancy, obstetric and midwifery staff with mental health competencies and willingness to attend the ECT suite if required, access to fetal monitoring equipment and anesthetic staff who are familiar with protocols around administering anesthesia to pregnant women and for ECT. This inherently limits ECT to centers where maternity care and psychiatric care coincide. The geographical barriers and costs associated with this level of care may be prohibitive for both individuals and services. In some regions, there are legislative barriers for ECT treatment such as the requirement for clearance from a legislative body if the patient is unable to provide informed consent to the proposed treatment (e.g., Mental Health Act).
14.2.3 Risks of Untreated Psychiatric Illness (Fig. 14.1)
All treatments in pregnancy carry potential risks, not just for the expectant mother, but also for the fetus. Studies in the area of psychotropic medication exposure suggest that examination of risks should not just focus on those apparent at delivery, such as malformations, prematurity, and impaired fetal growth, but also on longer term outcomes for children. However, potential concerns must also be weighed against the increasing literature about risks to offspring born to women with untreated illness during pregnancy (Deave et al. 2008).
Adverse outcomes for the women with untreated mental illness during pregnancy include poor self-care and poor nutrition (Zuckerman et al. 1989), increased risk of substance abuse, poor antenatal clinic attendance, suboptimal monitoring of fetal growth and development (Leigh and Milgrom 2008; Bonari et al. 2004; Bansil et al. 2010), increased risk of hypertension and pre-eclampsia (Kurki et al. 2000), and increased risk of postpartum depression (Evans et al. 2001). Also, maternal mental illness has been one of the leading indirect causes of maternal deaths in the UK and Australia (Oates 2003). Adverse outcomes for the infants born to women with untreated mental illness during pregnancy include increased risk of preterm delivery (Wisner et al. 2009; Alder et al. 2007), low birth weight (Diego et al. 2009; Field et al. 2004, 2006), low APGAR scores (Alder et al. 2007), small head circumference (Lusskin et al. 2007), poor response to interactions with adults (Field et al. 2006), altered cortisol secretion and altered developmental outcomes at 18 months (Deave et al. 2008). In addition, prenatal depression has been associated with poor mother–infant bonding (Lusskin et al. 2007), family disharmony (Burke 2003), and long-term effects on offspring, with adolescents at increased risk of developing psychiatric disorders such as anxiety and depression (Halligan et al. 2009; Pawlby et al. 2009).
ECT is a faster and more effective treatment for severe depression than the available pharmacological treatments (Pagnin et al. 2004). These benefits need to be balanced against the potential maternal and fetal risks of ECT during pregnancy, these issues are discussed below.
14.3 Risks Associated with ECT in Pregnancy
14.3.1 Risks Related to Electrical Stimulus and Seizure During ECT
1.
2.
3.
4.
5.
14.3.2 Risks Associated with Anesthesia for ECT in Pregnancy and Strategies to Minimize them
The general principles of anesthesia for ECT in the non-pregnant patient apply in the pregnant woman. If the gestation is less than 14–16 weeks, these techniques can be safely used without modification. After this gestation, the physiological and anatomical changes associated with pregnancy require additional measures to maximize the safety of both mother and fetus.
1.
2.
3.
4.
5.
6.
14.3.3 Longer Term Effects in Children of Mothers Who Were Exposed to ECT During Pregnancy
Follow-up of children (up to 6 years after birth) born to women who received ECT during pregnancy did not show any significant abnormalities in children (Forssman 1955; Smith 1956). Impastato et al. (1964) in their follow-up of 79 children described two as “mentally deficient”; however, they conclude that these abnormalities are unlikely due to ECT and recommend ECT as a treatment of choice in psychotic unmanageable women (Impastato et al. 1964). None of these studies used any standardized tools to screen for developmental issues and relied only on clinical impression.
Table 14.2
Summary of risks
|
Anesthesia |
Electrical stimulus/induced seizure |
Other factors related to anesthesia |
||
|
Inducing Agent (propofol/methohexitone) |
Muscle relaxant (succinyl choline) |
|||
|
Mother |
No significant issues |
Duration of action increases after 30 weeks of gestation |
Status Epilepticus |
Aspiration |
|
Fetus |
Potential neuronal cell injury (under investigation). Neither drug is associated with teratogenicity. |
Passes placental barrier in negligible quantities |
Fetal distress from fluctuations in maternal blood pressure and uterine hypo-perfusion |
Bradyarrythmia due to hypoxemia during apnoeic phase |
|
Pregnancy |
Long history of use of propofol and methoxitone in pregnancy for caesarian section |
Induction of premature contractions or labor; abdominal pain; placental abruption |
Aortocaval compression and the supine hypotension syndrome after 18 weeks gestation |
|
14.3.4 Guiding Principles and Specific Recommendations for ECT in Pregnancy (Fig. 14.2)
Fig. 14.2
Principles guiding ECT in pregnancy
14.3.4.1 Principles to Guide Clinicians Prescribing and Providing ECT to Pregnant Women
Pre-ECT
1.
2.
3.
4.
During ECT
5.
6.
7.
Post-ECT
8.
9.
10.
11.
14.3.4.2 Recommended Practice (Table 14.3)
Table 14.3
Recommended practice whilst performing ECT during pregnancy
|
Anesthetic |
Obstetric |
Psychiatric |
|
Maintenance of uterine perfusion Avoidance of maternal hypoxaemia Maternal airway protection Minimal effective dosing of anesthetic agents Monitoring of vital signs until patient is stable. |
If gestational age is 14–25 weeks, monitor the fetal heart rate via handheld Doppler If gestational age is 26+ weeks, an obstetrician or senior obstetric trainee to be present (where possible) to continuously monitor the fetus using CTG before, during and post-ECT until the trace returns to normal |
Monitor and prevent prolonged seizure Avoid hyperventilation to lower seizure threshold Recommend bilateral ECT, avoids multiple stimulations Close monitoring of mental state to assess response to ECT |
· Specialized anesthetic requirements in patients after 14 weeks gestation include:
1.
2.
3.
4.
5.
6.
· Obstetric monitoring:
1.
2.
3.
· Psychiatric aspects:
1.
2.
3.
14.4 Conclusion
Pregnancy is a time of increased risk of depressive symptoms and these symptoms can range in severity. Untreated depression in pregnancy has been associated with perinatal and neonatal complications and may even have longer term implications on infant development. Maternal mental illness has been one of the leading indirect causes of maternal deaths in both the UK and Australia. While many women are successfully managed with either psychological and pharmacological treatments or both, for a small minority the severity of symptoms and the risks to mother and baby may require consideration of ECT as a treatment option. ECT can be safely utilized in pregnancy provided careful consideration is given to potential ethical, medico-legal, and clinical risk issues.
References
Alder J, Fink N, Bitzer J, Hösli I, Holzgreve W. Depression and anxiety during pregnancy: a risk factor for obstetric, fetal and neonatal outcome? A critical review of the literature. J Matern Fetal Neonatal Med. 2007;20(3):189–209.PubMedCrossRef
Anderson EL, Reti IM. ECT in pregnancy: a review of the literature from 1941 to 2007. Psychosom Med. 2009;71(2):235–42. doi:10.1097/PSY.0b013e318190d7ca.PubMedCrossRef
Balki M, Castro C, Ananthanarayan C. Status epilepticus after electroconvulsive therapy in a pregnant patient. Int J Obstet Anesth. 2006;15(4):325–8. doi:10.1016/j.ijoa.2006.01.005.PubMedCrossRef
Bansil P, Kuklina EV, Meikle SF, Posner SF, Kourtis AP, Ellington SR, et al. Maternal and fetal outcomes among women with depression. J Womens Health (Larchmt). 2010;19(2):329–34. doi:10.1089/jwh.2009.1387.CrossRef
Bonari L, Pinto N, Ahn E, Einarson A, Steiner M, Koren G. Perinatal risks of untreated depression during pregnancy. Can J Psychiatry. 2004;49(11):726–35.PubMed
Bozkurt A, Karlidere T, Isintas M, Ozmenler NK, Ozsahin A, Yanarates O. Acute and maintenance electroconvulsive therapy for treatment of psychotic depression in a pregnant patient. J ECT. 2007;23(3):185–7. doi:10.1097/YCT.0b013e31806db4dd.PubMedCrossRef
Bulut M, Bez Y, Kaya MC, Copoglu US, Bulbul F, Savas HA. Electroconvulsive therapy for mood disorders in pregnancy. J ECT. 2013;29(2):e19–20. doi:10.1097/YCT.0b013e318277cce2.PubMedCrossRef
Burke L. The impact of maternal depression on familial relationships. Int Rev Psychiatry. 2003;15(3):243–55.PubMedCrossRef
Davidson AJ. Anesthesia and neurotoxicity to the developing brain: the clinical relevance. Paediatr Anaesth. 2011;21(7):716–21. doi:10.1111/j.1460-9592.2010.03506.x.PubMedCrossRef
de Boer H, Driessen J, Marcus M, Kerkkamp H, Heeringa M, Klimek M. Reversal of rocuronium-induced (1.2 mg/kg) profound neuromuscular block by sugammadex. Anesthesiology. 2007;107(2):239–44.PubMedCrossRef
Deave T, Heron J, Evans J, Emond A. The impact of maternal depression in pregnancy on early child development. BJOG. 2008;115(8):1043–51.PubMedCrossRef
Diego MA, Field T, Hernandez-Reif M, Schanberg S, Kuhn C, Gonzalez-Quintero VH. Prenatal depression restricts fetal growth. Early Hum Dev. 2009;85(1):65–70.PubMedCentralPubMedCrossRef
Echevarria Moreno M, Martin Munoz J, Sanchez Valderrabanos J, Vazquez GT. Electroconvulsive therapy in the first trimester of pregnancy. J ECT. 1998;14(4):251–4.PubMed
Eckstein KL, Marx GF. Aortocaval compression and uterine displacement. Anesthesiology. 1974;40(1):92–6.PubMedCrossRef
Evans J, Heron J, Francomb H, Oke S, Golding J. Cohort study of depressed mood during pregnancy and after childbirth. BMJ. 2001;323(7307):257–60.PubMedCentralPubMedCrossRef
Field T, Diego M, Dieter J, Hernandez-Reif M, Schanberg S, Kuhn C et al. Prenatal depression effects on the fetus and the newborn. Infant Behav Dev 2004; 27 SRC - GoogleScholar:216–29.
Field T, Diego M, Hernandez-Reif M. Prenatal depression effects on the fetus and newborn: a review. Infant Behav Dev. 2006;29(3):445–55.PubMedCrossRef
Forssman H. Follow-up study of sixteen children whose mothers were given electric convulsive therapy during gestation. Acta Psychiatrica et Neurologica Scandinavica. 1955;30(3):437–41.PubMedCrossRef
Gin T, Mainland P, Chan M. Decreased thiopental requirements in early pregnancy. Anesthesiology. 1997;1997(86):73–8.CrossRef
Griffiths EJ, Lorenz RP, Baxter S, Talon NS. Acute neurohumoral response to electroconvulsive therapy during pregnancy. A case report. J Reprod Med. 1989;34(11):907–11.PubMed
Halligan SL, Murray L, Martins C, Cooper PJ. Maternal depression and psychiatric outcomes in adolescent offspring: a 13-year longitudinal study. J Affect Disord. 2009;97:145–54.CrossRef
Harris V. Electroconvulsive therapy: administrative codes, legislation, and professional recommendations. J Am Acad Psychiatry Law. 2006;34(3):406–11.PubMed
Impastato DJ, Gabriel AR, Lardaro HH. Electric and insulin shock therapy during pregnancy. Dis Nerv Syst. 1964;25:542–6.PubMed
Kadoi Y, Hoshi H, Nishida A, Saito S. Comparison of recovery times from rocuronium-induced muscle relaxation after reversal with three different doses of sugammadex and succinylcholine during electroconvulsive therapy. J Anesth. 2011;25(6):855–9.PubMedCrossRef
Kellner CH, Knapp R, Husain MM, Rasmussen K, Sampson S, Cullum M, et al. Bifrontal, bitemporal and right unilateral electrode placement in ECT: randomised trial. Br J Psychiatry. 2010a;196(3):226–34. doi:10.1192/bjp.bp.109.066183.PubMedCentralPubMedCrossRef
Kellner CH, Tobias KG, Wiegand J. Electrode placement in electroconvulsive therapy (ECT): a review of the literature. J ECT. 2010b;26(3):175–80. doi:10.1097/YCT.0b013e3181e48154.PubMedCrossRef
Kinsella SM, Lohmann G. Supine hypotensive syndrome. Obstet Gynecol. 1994;83(5 Pt 1):774–88.PubMed
Kurki T, Hiilesmaa V, Raitasalo R, Mattila H, Ylikorkala O. Depression and anxiety in early pregnancy and risk for preeclampsia. Obstet Gynecol. 2000;95(4):487–90.PubMedCrossRef
Lam CM, Chow KM. Electric shock during pregnancy. Can Fam Physician. 2003;49:737.PubMedCentralPubMed
Leigh B, Milgrom J. Risk factors for antenatal depression, postnatal depression and parenting stress. BMC Psychiatry. 2008;8:24.PubMedCentralPubMedCrossRef
Loo C, Trollor J, Alonzo A, Rendina N, Kavess R. Mental health legislation and psychiatric treatments in NSW: electroconvulsive therapy and deep brain stimulation. Australas Psychiatry. 2010;18(5):417–25. doi:10.3109/10398562.2010.508125.PubMedCrossRef
Lusskin SI, Pundiak TM, Habib SM. Perinatal depression: hiding in plain sight. Can J Psychiatry. 2007;52(8):479–88.PubMed
Miller LJ. Use of electroconvulsive therapy during pregnancy. Hosp Community Psychiatry. 1994;45(5):444–50.PubMed
Mongardon N, Servin F, Perrin M, Bedairia E, Retout S, Yazbeck C. Predicted propofol effect-site concentration for induction and emergence of anesthesia during early pregnancy. Anesth Analg. 2009;109(1):90–5.PubMedCrossRef
Moya F, Kvisselgaard N. The placental transmission of succinylcholine. Anesthesiology. 1961;22:1–6.PubMedCrossRef
Nguyen T, Chibber A, Lustik S, Kolano J, Dillon P, Guttmacher L. Effect of methohexitone and propofol with or without alfentanil on seizure duration and recovery in electroconvulsive therapy. Br J Anaesth. 1997;79(6):801–3.PubMedCrossRef
Oates M. Suicide: the leading cause of maternal death. Br J Psychiatry. 2003;183:279–81.PubMedCrossRef
O’Reardon JP, Cristancho MA, von Andreae CV, Cristancho P, Weiss D. Acute and maintenance electroconvulsive therapy for treatment of severe major depression during the second and third trimesters of pregnancy with infant follow-up to 18 months: case report and review of the literature. J ECT. 2011;27(1):e23–6. doi:10.1097/YCT.0b013e3181e63160.PubMedCrossRef
Pacifici GM, Nottoli R. Placental transfer of drugs administered to the mother. Clin Pharmacokinet. 1995;28(3):235–69.PubMedCrossRef
Pagnin D, de Queiroz V, Pini S, Cassano GB. Efficacy of ECT in depression: a meta-analytic review. J ECT. 2004;20(1):13–20.PubMedCrossRef
Pawlby S, Hay DF, Sharp D, Waters CS, O’Keane V. Antenatal depression predicts depression in adolescent offspring: prospective longitudinal community-based study. J Affect Disord. 2009;113(3):236–43.PubMedCrossRef
Pinette MG, Santarpio C, Wax JR, Blackstone J. Electroconvulsive therapy in pregnancy. Obstet Gynecol. 2007;110(2 Pt 2):465–6. doi:10.1097/01.AOG.0000265588.79929.98.PubMedCrossRef
Prudic J, Sackeim HA, Devanand DP. Medication resistance and clinical response to electroconvulsive therapy. Psychiatry Res. 1990;31(3):287–96.PubMedCrossRef
Prudic J, Haskett RF, Mulsant B, Malone KM, Pettinati HM, Stephens S, et al. Resistance to antidepressant medications and short-term clinical response to ECT. Am J Psychiatry. 1996;153(8):985–92.PubMed
Reed P, Sermin N, Appleby L, Faragher B. A comparison of clinical response to electroconvulsive therapy in puerperal and non-puerperal psychoses. J Affect Disord. 1999;54(3):255–60.PubMedCrossRef
Richards DS. Is electroconvulsive therapy in pregnancy safe? Obstet Gynecol. 2007;110(2 Pt 2):451–2. doi:10.1097/01.AOG.0000277540.63064.d3.PubMedCrossRef
Rose D, Fleischmann P, Wykes T, Leese M, Bindman J. Patients’ perspectives on electroconvulsive therapy: systematic review. BMJ. 2003;326(7403):1363. doi:10.1136/bmj.326.7403.1363.PubMedCentralPubMedCrossRef
Saatcioglu O, Tomruk NB. The use of electroconvulsive therapy in pregnancy: a review. Isr J Psychiatry Relat Sci. 2011;48(1):6–11.PubMed
Sherer DM, D’Amico ML, Warshal DP, Stern RA, Grunert HF, Abramowicz JS. Recurrent mild abruptio placentae occurring immediately after repeated electroconvulsive therapy in pregnancy. Am J Obstet Gynecol. 1991;165(3):652–3.PubMedCrossRef
Smith S. The use of electroplexy (E.C.T.) in psychiatric syndromes complicating pregnancy. J Ment Sci. 1956;102(429):796–800.PubMed
Smith D, Angst M, Brock-Unte J, DeBattista C. Seizure duration with remifentanil/methohexital vs. methohexital alone in middle -aged patients undergoing electroconvulsive therapy. Acta Anaesthesiol Scand. 2003;47(9):1064–6.PubMedCrossRef
UK ECT Review Group. Efficacy and safety of electroconvulsive therapy in depressive disorders: a systematic review and meta-analysis. Lancet. 2003;361(9360):799–808. doi:10.1016/S0140-6736(03)12705-5.CrossRef
Wheeldon TJ, Robertson C, Eagles JM, Reid IC. The views and outcomes of consenting and non-consenting patients receiving ECT. Psychol Med. 1999;29(1):221–3.PubMedCrossRef
Wisner KL, Sit DKY, Hanusa BH, Moses-Kolko EL, Bogen DL, Hunker DF, et al. Major depression and antidepressant treatment: impact on pregnancy and neonatal outcomes. Am J Psychiatry. 2009;166(5):557–66.PubMedCrossRef
Yau G, Kan AF, Gin T, Oh TE. A comparison of omeprazole and ranitidine for prophylaxis against aspiration pneumonitis in emergency caesarean section. Anaesthesia. 1992;47(2):101–4.PubMedCrossRef
Zuckerman B, Amaro H, Bauchner H, Cabral H. Depressive symptoms during pregnancy: relationship to poor health behaviors. Am J Obstet Gynecol. 1989;160(5 Pt 1):1107–11.PubMedCrossRef