obstetric history, course of pregnancy and induction of labour and outcome of pregnancy. Findings were ... Since 1995, all pregnant women with documented car- ... repair/intervention, such as pulmonary oedema, pulmonary embolism ...
BJOG: an International Journal of Obstetrics and Gynaecology July 2004, Vol. 111, pp. 669 –675
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Pregnancy outcome in women with heart disease undergoing induction of labour Galia Oron,a,c Rafael Hirsch,b,c Avi Ben-Haroush,a,c Moshe Hod,a,c Yinon Gilboa,a,c Ofer Davidi,a,c Jacob Bara,c Objective To examine the safety and outcome of induction of labour in women with heart disease. Design Prospective single-centre comparative study. Setting Major university-based medical centre. Population/Sample One hundred and twenty-one pregnant women with heart disease. Methods The sample included all women with acquired or congenital heart disease who attended our HighRisk Pregnancy Outpatient Clinic from 1995 to 2001. The files were reviewed for baseline data, cardiac and obstetric history, course of pregnancy and induction of labour and outcome of pregnancy. Findings were compared between women who underwent induction of labour and those who did not. Forty-seven healthy women in whom labour was induced for obstetric reasons served as controls. Main outcome measures Pregnancy outcome. Results Of the 121 women with heart disease, 47 (39%) underwent induction of labour. There was no difference in the caesarean delivery rate after induction of labour between the women with heart disease (21%) and the healthy controls (19%). Although the women with heart disease had a higher rate of maternal and neonatal complications than controls (17% vs 2%, P ¼ 0.015), within the study group, there was no difference in complication rate between the patients who did and did not undergo induction of labour. Conclusion Induction of labour is a relatively safe procedure in women with cardiac disease. It is not associated with a higher rate of caesarean delivery than in healthy women undergoing induction of labour for obstetric indications, or with more maternal and neonatal complications than in women with a milder form of cardiac disease and spontaneous labour. INTRODUCTION Thanks to advances in medical care and surgical techniques, an increasing number of women with congenital and childhood heart diseases are surviving into adulthood and seeking to start families. Although pregnancy-related maternal and neonatal mortality are low in this population, maternal and neonatal morbidity may be significant.1 – 5 The reported incidence of maternal complications, cardiac as well as obstetric, in women with heart disease is 13% to 32%.4 – 7 Maternal mortality varies directly with functional class: 0.4% for New York Heart Association (NYHA)
a
Perinatal Division, Department of Obstetrics and Gynecology, Rabin Medical Center, Beilinson Campus, Petah Tiqva, Israel b Department of Cardiology, Rabin Medical Center, Beilinson Campus, Petah Tiqva, Israel c Sackler Faculty of Medicine, Tel Aviv University, Israel Correspondence: Dr G. Oron, Perinatal Division, Department of Obstetrics and Gynecology, Rabin Medical Center, Beilinson Campus, Petah Tiqva 49372, Israel. D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology
classes I and II, and 6.8% for classes III and IV. Fetal mortality is also greatly influenced by maternal functional class, varying from zero for class I to 30% for class IV.8,9 The increased maternal morbidity in women with heart disease is related to the physiologic circulatory changes that occur during pregnancy. The hormone-mediated increases in blood volume, red cell mass and heart rate result in an increased cardiac output.10 Circulating prostaglandins, gestational hormones and the low-resistance vascular bed in the placenta decrease peripheral vascular resistance. During labour and delivery, the supine position, uterine contractions, anxiety and pain increase the risk of maternal cardiovascular and haemodynamic decompensation.11,12 Vaginal delivery usually carries the lowest risk of complications in women with cardiac disease and is therefore recommended in most cases. Caesarean delivery should be reserved for obstetric indications such as cephalopelvic disproportion or placenta praevia.8,10 – 13 Caesarean section, even under the most vigilant conditions, is associated with an increased amount of blood loss (twice that during vaginal delivery) and an increased risk of wound/uterine infection and post-operative thrombophlebitis. The risk associated with vaginal delivery can be minimised by a lateral decubitus position, regional anaesthesia, reduction www.blackwellpublishing.com/bjog
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of patient anxiety and pain, strict monitoring of fluid input to prevent fluid overload and an assisted delivery to avoid maternal effort.10 – 13 There has been a considerable increase in the rate of labour induction in the general population, from 13% in 1980 to 26% in 1995.14,15 In pregnant women with underlying cardiac disease, labour induction is often offered to control the timing and setting of labour and to ensure the presence of a team of cardiologists, obstetricians and perinatologists.10,13 However, information on the outcome of induction of labour in this subgroup of patients remains limited. The aim of the present study was to examine the safety and outcome of induction of labour in women with heart disease.
METHODS Since 1995, all pregnant women with documented cardiac disease being treated at the Department of Cardiology of Rabin Medical Center have been routinely referred for surveillance to the High-Risk Pregnancy Outpatient Clinic. The present study included all women with congenital or acquired heart disease followed throughout their pregnancy at the clinic by the department’s counselling cardiologists and a team of perinatologists and neonatologists from 1995 to 2001. All women were medically stabilised and closely monitored during pregnancy. The decision to induce labour was based solely on medical indications, both cardiac and obstetric. Women who did not receive preconception counselling were excluded from the analysis. The women were enrolled in the study at the beginning of their pregnancy and information throughout pregnancy and delivery were collected prospectively. Medical records were reviewed for maternal age, parity, number of spontaneous abortions, nature of the cardiac lesion, cardiac medication(s) taken during pregnancy and prior surgical repair/intervention. NYHA functional class prior to and during pregnancy, findings on transthoracic echocardiographic assessment of ventricular systolic function, Doppler estimation of inflow or outflow obstructions, valvular regurgitation and systolic pulmonary artery pressure were recorded, as were cardiac events after the date of surgical repair/intervention, such as pulmonary oedema, pulmonary embolism, arrhythmia requiring medical treatment, myocardial infarction and haemoptysis. Complications were grouped into cardiac, obstetric and neonatal categories. Only complications occurring during delivery or the first 24 hours postpartum were included. The women with cardiac disease (study group) were divided into two subgroups: Group 1— those who underwent induction of labour; Group 2— those who did not undergo induction of labour because of spontaneous delivery or obstetric contraindications (malpresentation, twin pregnancy, known cephalopelvic disproportion or previous caesarean sections), or because of obstetric or medical
indications that warranted emergency caesarean section. In subgroup 1, induction of labour was planned between 37 and 40 weeks of gestation in those with stable cardiac disease, and after 34 weeks of gestation in those with signs of decompensation. In some cases, labour was induced for obstetric indications, such as postdate pregnancy, premature rupture of the membranes, oligohydramnios at term, large-for-gestational-age fetus in a diabetic patient, intrauterine growth restriction (defined as birthweight below the 10th centile) and pregnancy-induced hypertension. Induction of labour was performed according to our departmental protocol. All patients were hospitalised in the Perinatal Division. Blood was drawn for cross matching, and all women signed an informed consent form. Patients with a Bishop score of less than 7 underwent induction of labour with prostagladin E2 (PGE2). Following fetal heart rate monitoring and ultrasound to assess the fetal status, a 1.5 – 3.0 mg, commercially available tablet of Dinoprostone (Pharmacia Upjohn, Puurf, Belgium) was inserted into the posterior fornix. Fetal heart rate monitoring and tocography were performed routinely three times a day and at the first signs of contractions. An additional application of PGE2, if necessary, was given at least 8 hours later. Arrangements for possible emergency delivery were made: an operating room was made available, and a cardiologist, anesthesiologist, perinatologist and neonatologist were placed on standby. The Cardiac Intensive Care Unit was notified of the possible need for 24-hour observation after delivery. If uterine contractions were regular and the Bishop score rose to more than 7, the patient was transferred to the delivery room, where labour was further augmented with oxytocin, as necessary. Failed induction of labour was defined as performance of caesarean section. Instrumental delivery was not considered a failure because the recommended management of women with heart disease includes shortening the second stage of labour to avoid maternal effort.10 – 13 Healthy women who underwent induction of labour for obstetric indications according to the departmental protocol during the study period served as the control group (Group 3). The women were matched for age, gestational age at delivery and parity to the study group. Patient characteristics and the main outcome measures were compared between women with cardiac disease who did and did not have induction of labour, and between the cardiac patients and healthy controls. Main outcome measures were as follows: Bishop score before PGE2 application, number of PGE2 applications and duration from first PGE2 insertion to delivery (for women with induction of labour); mode and time of delivery, birthweight, rate of intrauterine growth restriction, maternal and neonatal complications during labour or the first 24 hours postpartum. Statistical analysis was performed with the Student’s t test for continuous data and m2 test for categorical data; P < 0.05 was considered significant. Enrolment to the study was done at the beginning of pregnancy, and information D RCOG 2004 Br J Obstet Gynaecol 111, pp. 669 – 675
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throughout pregnancy and after delivery was collected prospectively. Therefore, for purposes of comparison between the study and control group, most recent pregnancy was used. Moreover, the statistical methods we used are based on the assumption of independent observations, and more than one pregnancy for each patient contradicts this assumption. Logistic regression analysis was used to identify risk factors affecting the outcome of induction and maternal and neonatal complications. The factors entered into the analysis were those known to have an impact on failed induction and maternal or neonatal complications:
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maternal age, parity, number of miscarriages, medical treatment during pregnancy, maternal functional class (NYHA), number of PGE2 applications, week of delivery and birthweight.
RESULTS The study group included 121 women (total all pregnancies 283; current pregnancies 121) with documented cardiac disease, of whom 47 had induction of labour (Group 1)
Table 1. Medical and obstetric history prior to the index pregnancy for women who had induction of labour (Group 1) and those who did not (Group 2). Values are n (%), n/n (%) or as otherwise indicated. Background parameters Underlying cardiac disease Congenital heart disease Acquired heart disease Valvular heart disease Obstructive lesions (aortic stenosis, mitral stenosis, pulmonic stenosis, coarctation of aorta) Regurgitation lesions (aortic, mitral, pulmonic and tricuspid regurgitation, Ebstein’s anomaly) Prosthetic valves Atrial septal defect Shunt lesions (ventricular septal defect, patent ductus arteriosus) Complex and cyanotic lesions (tetralogy of Fallot, transposition of great arteries — corrected and uncorrected, double-outlet of right ventricle, single ventricle, Eisenmenger syndrome) Myocardial dysfunction (cardiomyopathy — dilated/myocardial infarction, arrhythmia causing myocardial dysfunction)
Group 1 (n ¼ 47)
Group 2 (n ¼ 74)
27 (57) 20 (43)
60 (81) 14 (19)
9 5 3 3 3 10
20 11 2 11 13 8
