Pregnancy and congenital heart disease--maternal and fetal outcome

Placental Adaptation to Hypoxia: The Case of High-Altitude Pregnancies

Even in the highest inhabited regions of the world, well above 2500 m altitude, women become pregnant and give birth to healthy children. The underlying adaptation to hypobaric hypoxia provides interesting insights into the physio(patho)logy of the human placenta. Although increasing altitude is regularly associated with fetal growth restriction (FGR), oxygen deficiency does not appear to be a direct cause. Rather, placental oxygen consumption is reduced to maintain the oxygen supply to the fetus. This comes at the expense of placental synthesis and transport functions, resulting in inappropriate nutrient supply. The hypoxia-inducible factor (HIF-1α), which modulates the mitochondrial electron transport chain to protect placental tissue from reactive oxygen species, plays a key role here. Reduced oxygen consumption also reflects decreased placental vascularization and perfusion, which is accompanied by an increased risk of maternal pre-eclampsia at high altitude. In native highlanders, the latter seems to be attenuated, partly due to a lower release of HIF-1α. In addition, metabolic peculiarities have been described in indigenous people that enhance glucose availability and thus reduce the extent of FGR. This review attempts to revisit the (albeit incomplete) knowledge in this area to draw the clinical reader's attention to the crucial role of the placenta in defending the fetus against hypoxia.

Maternal and perinatal outcomes of pregnant women with tetralogy of Fallot: a tertiary center experience from south-India

BACKGROUND

Women with tetralogy of Fallot especially uncorrected are at increased risk of adverse maternal and perinatal outcomes.

METHOD

We reviewed the maternal complications and pregnancy outcomes of women with tetralogy of Fallot (ToF), having corrected or uncorrected lesion during the period from 2011 to 2019 attending a south-Indian tertiary care center. Data regarding demographics, clinical course, and medications received and echocardiographic diagnosis regarding ToF, labor and delivery details, and postpartum follow-up was collected from the records. For each case, four women matched for age (±2 years), without a diagnosis of heart disease, were included as controls. We compared the outcomes in pregnant women with ToF and controls as well between those who have undergone repair with those without repair and also with the controls.

RESULTS

There were 27 pregnancies in 19 patients with ToF, including eight pregnancies in seven women with uncorrected lesions. There was no maternal death or occurrence of infective endocarditis. Women with uncorrected lesion had significantly higher rates of fetal growth restriction (37.5% vs 6.7%), preterm birth (50% vs. 13.3%) resulting in lower birth weight (1907.5 g vs. 2607.3 g)) compared to those with a corrected lesion. Women with corrected lesion had similar outcomes to the controls (p > .5).

CONCLUSION

Women with uncorrected ToF are at increased risk of perinatal complications compared to those with corrected lesion and require care under a multidisciplinary team, with an individualized plan for delivery to optimize the outcomes.

Oxygen and lack of oxygen in fetal and placental development, feto-placental coupling, and congenital heart defects

Low oxygen concentration (hypoxia) is part of normal embryonic development, yet the situation is complex. Oxygen (O₂ ) is a janus gas with low levels signaling through hypoxia-inducible transcription factor (HIF) that are required for development of fetal and placental vasculature and fetal red blood cells. This results in coupling of fetus and mother around midgestation as a functional feto-placental unit (FPU) for O₂ transport, which is required for continued growth and development of the fetus. Defects in these processes may leave the developing fetus vulnerable to O₂ deprivation or other stressors during this critical midgestational transition when common septal and conotruncal heart defects (CHDs) are likely to arise. Recent human epidemiological and case-control studies support an association between placental dysfunction, manifest as early onset pre-eclampsia (PE) and increased serum bio-markers, and CHD. Animal studies support this association, in particular those using gene inactivation in the mouse. Sophisticated methods for gene inactivation, cell fate mapping, and a quantitative bio-reporter of O₂ concentration support the premise that hypoxic stress at critical stages of development leads to CHD. The secondary heart field contributing to the cardiac outlet is a key target, with activation of the un-folded protein response and abrogation of FGF signaling or precocious activation of a cardiomyocyte transcriptional program for differentiation, suggested as mechanisms. These studies provide a strong foundation for further study of feto-placental coupling and hypoxic stress in the genesis of human CHD.

Maternal and fetal outcome in operated vs non-operated cases of congenital heart disease cases in pregnancy

OBJECTIVES

To study pregnancy outcomes in operated vs non-operated cases of congenital heart disease cases during pregnancy.

MATERIALS AND METHODS

A total of 55 patients of congenital heart disease who delivered in the authors unit in last 10 years were taken in this retrospective study. These were divided into two groups Group 1:29 (52.7%) patient who had no cardiac surgery and Group 2: 26(47.2%) who had cardiac surgery to correct their cardiac defect before pregnancy. All patients were evaluated for cardiac complications and outcome during pregnancy. Obstetric complications, mode of delivery and fetal outcome was compared in the two groups using statistical analysis.

RESULT

The commonest lesion was atrial septal defect (ASD) seen in 22(40%) patients followed by ventricular septal defect (VSD) in 16(29%) .Congenital valvular disease 8(14.5%) and patent ductus arteriosus in 4(7.2%) cases. The mean age was 25.9 ± 3.15 years in Group 1 and 26.3 ± 4.53 years in Group 2. The baseline characteristics were similar in the two groups. There was no difference in cardiac complications, NYHA deterioration and need of cardiac drugs in the two groups. Obstetric complications and mode of delivery were also similar in the two groups.Mean birth weight was 2516.65 ± 514.04 gm in Group 1 and 2683.00 ± 366.00 gm in Group 2 and was similar. APGAR < 8, stillbirth rate and other neonatal complications were also similar in two groups.

CONCLUSION

The maternal and fetal outcome was excellent in patients with congenital heart disease and was similar in unoperated and operated cases.

Congenital heart disease in pregnancy in a low-income country

OBJECTIVE

To assess maternal and perinatal outcomes among pregnant women with congenital heart disease (CHD) in a low-resource country.

METHODS

A prospective, observational study was conducted at a teaching hospital in Kolkata, India, between January 1, 2008, and December 31, 2010. All pregnant women with CHD were followed up from first prenatal visit to discharge. Both maternal and perinatal outcomes were analyzed.

RESULTS

Of 174 pregnant women with heart disease, 27 (16%) had CHD. Mean age was 23.5±3.6 years. Four (15%) patients were diagnosed with CHD during the index pregnancy. Nine (33%) women had undergone surgical correction before conception. Cesarean delivery was performed in 12 (44%) women. Fifteen (56%) neonates weighed less than 2500 g, and 4 (15%) were born preterm. Mean birth weight was slightly higher in women with corrected heart lesions than in those with uncorrected ones (2593±480 g vs 2294±620 g; P=0.22). Three (11%) neonates died, but no stillbirths occurred. One (4%) woman died after delivery owing to atonic postpartum hemorrhage.

CONCLUSION

Delayed diagnosis, lack of treatment, and unplanned pregnancy are major challenges for women with CHD, which need to be addressed to improve maternal and neonatal outcomes in low-resource countries.

Low-dose sequential combined-spinal epidural anesthesia for Cesarean section in patient with uncorrected tetrology of Fallot

Tetrology of Fallot (TOF) is the most commonly encountered congenital cardiac lesion in pregnancy. Although there are controversies regarding safe anesthetic technique for parturient with TOF, we use low-dose sequential combined-spinal epidural anesthesia in such a case posted for Cesarean section and found that low dose (0.5 ml of 0.5%) intrathecal bupivacaine and fentanyl with sequential epidural bupivacaine supplementation was adequate for the performance of an uncomplicated Cesarean section with minimal side effects and good fetal outcome. Thus, though the choice of anesthesia can vary in such patients, low-dose sequential combined-spinal epidural can be a safe alternate to achieve good anesthesia with impressive cardiovascular stability.

Fertility, Pregnancy and Delivery in Women after Biventricular Repair for Double Outlet Right Ventricle

OBJECTIVES

To investigate outcome of pregnancy and fertility in women with double outlet right ventricle (DORV).

METHODS

Using 2 congenital heart disease registries, 21 female patients with DORV (aged 18-39 years) were retrospectively identified. Detailed recordings of each patient and their completed (>20 weeks gestation) pregnancies were recorded.

RESULTS

Overall, 10 patients had 19 pregnancies, including 3 spontaneous miscarriages (16%). During the 16 live birth pregnancies, primarily (serious) noncardiac complications were observed, e.g. premature labor/delivery (n = 7 and n = 3, respectively), small for gestational age (n = 4), preeclampsia (n = 2) and recurrence of congenital heart disease (n = 2). Except for postpartum endocarditis and deterioration of subpulmonary obstruction, only mild cardiac complication pregnancies were recorded. Two women with children reported secondary female infertility. Several menstrual cycle disorders were reported: secondary amenorrhea (n = 4), primary amenorrhea (n = 3) and oligomenorrhea (n = 2).

CONCLUSION

Successful pregnancy in women with DORV is possible. Primarily noncardiac complications were observed and only few (minor) cardiac complications. Infertility and menstrual cycle disorders appear to be more prevalent.

Anaesthesia in parturients with heart disease: a five year review in an Australian tertiary hospital

At the Royal Women's Hospital, Queensland, between 1993 and 1997 there were 56 vaginal and 22 caesarean deliveries involving 68 women with heart disease. Over half of those women required anaesthetic input, in particular, the women who had the most serious cardiac compromise. There were two maternal deaths, four unbooked and five booked admissions to intensive or coronary care unit.

Cardiac disease and pregnancy

The pregnant state imposes a supraphysiologic strain on the pregnant woman's cardiac performance through complex biochemical, electric, and physiologic changes affecting the blood volume, myocardial contractility, and resistance of the vascular bed. In the presence of underlying heart disease, these changes can compromise the woman's hemodynamic balance, her life, and that of her unborn child. Cardiac pathology represents a heterogeneous group of disorders, each with its own hemodynamic, genetic, obstetric, and social implications. Physicians caring for these women should actively address the issue of reproduction. Ideally, pregnancy should be planned to occur after optimization of cardiac performance by medical or surgical means. Once pregnancy is achieved, the concerted effort of a multidisciplinary team of obstetricians, cardiologists, anesthesiologists, nursing, social, and other services provides the best opportunity to carry the pregnancy to a successful outcome.