Milk transfer and neonatal safety of tacrolimus

Preparing the Heart for a New Baby: Management of Pregnancy in Heart Transplant Recipients

Heart transplant (HT) recipients are more frequently reaching childbearing age given improvement in median survival and outcomes after HT. Although most pregnancies in HT recipients have favorable outcomes, poor fetal outcomes and maternal complications such as hypertensive disorders of pregnancy are more common in HT recipients than in the general population. In this review, we summarize the current evidence to guide the management of pregnancy in HT recipients. Preconception counseling, focused on risk stratification and optimal timing of conception, is the first important step to optimize pregnancy outcomes. During pregnancy and in the postpartum period, frequent monitoring of graft function and immunosuppressive levels is recommended. Calcineurin inhibitors and corticosteroids should be the mainstay of treatment for both prevention and treatment of graft rejection. Delivery planning should follow usual obstetric indications, preferably with vaginal delivery at term using regional anesthesia. A multidisciplinary care team should be involved in management through all stages of pregnancy to ensure success.

Infertility, pregnancy and breastfeeding in kidney transplantation recipients: Key issues

Chronic kidney disease (CKD), especially in advanced stages, is an important cause of infertility. In CKD patients, infertility has been linked to multiple factors. The pathophysiology of infertility related to CKD is complex and forked. Correction of modifiable factors can improve fertility in both genders. In males as well as females, successful kidney transplantation offers good chances of restoration of reproductive function. In female renal allograft recipients, recovery of reproductive functions in the post-transplant period will manifest as restoration of normal menses and ovulation. Owing to this improvement, there is a significant risk of unplanned pregnancy, hence the need to discuss methods of contraception before transplantation. In kidney transplant recipients, different contraceptive options for pregnancy planning, have been used. The selection of one contraception over another is based on preference and tolerability. Pregnancy, in renal transplanted females, is associated with physiologic changes that occur in pregnant women with native kidneys. Immunosuppressive medications during pregnancy, in a recipient with a single functioning kidney, expose the mother and fetus to unwanted complications. Some immunosuppressive drugs are contraindicated during pregnancy. Immunosuppressive medications should be discussed with renal transplant recipients who are planning to breastfeed their babies. In addition to antirejection drugs, other medications should be managed accordingly, whenever pregnancy is planned.

Reproductive health after thoracic transplantation: An ISHLT expert consensus statement

Pregnancy after thoracic organ transplantation is feasible for select individuals but requires multidisciplinary subspecialty care. Key components for a successful pregnancy after lung or heart transplantation include preconception and contraceptive planning, thorough risk stratification, optimization of maternal comorbidities and fetal health through careful monitoring, and open communication with shared decision-making. The goal of this consensus statement is to summarize the current evidence and provide guidance surrounding preconception counseling, patient risk assessment, medical management, maternal and fetal outcomes, obstetric management, and pharmacologic considerations.

Outcomes of Children with Fetal and Lactation Immunosuppression Exposure Born to Female Transplant Recipients

Solid organ transplantation (SOT) is a lifesaving procedure for those with end-stage kidney, liver, heart, lung, and intestinal diseases, including females of childbearing age who wish to proceed with pregnancy following transplantation. While there is clear risk associated with use of mycophenolate during pregnancy, the risks associated with use of other immunosuppressant agents are less well understood, and the timing of use in pregnancy may be pertinent when considering the risk versus benefit for individual patients. In addition to overall fetal outcomes, including gestational age, birth weight, and mortality, this review summarizes published literature on additional complications that have been examined in association with maternal use during pregnancy and postpartum while breastfeeding. Compared with non-transplant pregnancies, pregnancies in transplant recipients are associated with lower birth weight and earlier gestational age. Effects associated with particular immunosuppressant agents in the infant include renal dysfunction from calcineurin inhibitors, myelosuppression from azathioprine, and decreased circulating immune cells with several agents. However, these effects are noted to primarily be transient, though the decrease in immune cells may predispose the infant to increased infectious complications in the first year of life. Utilizing relative infant dose estimations, nearly all commonly utilized immunosuppressants are likely safe during breastfeeding given the limited exposure to the infant.

A Comprehensive Review of Calcineurin Inhibitors Used for Immunosuppression in Cardiac Transplantation

Calcineurin inhibitors (CNIs) have been the foundation of immunosuppression in solid organ transplantation since the 1980s. Cyclosporine A (CSA), the first in class, was identified as the metabolite of the soil fungus Tolypocladium inflatum Gams as part of a larger program of screening for naturally occurring fungal metabolites with biologic activity in the 1970s. Significant immunosuppressive effects were discovered and consequently CSA was trialed as an immunosuppressant in renal transplantation. This initial success led to its widespread study and adoption in solid organ transplantation. This novel agent yielded significant improvements in both 1 year and longer-term allograft and patient survival. Subsequently, a similar and more potent CNI, tacrolimus was developed. Today, it is the principal CNI used for prevention of allograft rejection. Like all other immunosuppressives, the benefits of CNIs are counterbalanced by side effects and complications resulting from drug toxicity. This chapter comprehensively reviews the clinical use of CNIs in cardiac transplantation.

Usage of Tacrolimus and Mycophenolic Acid During Conception, Pregnancy, and Lactation, and Its Implications for Therapeutic Drug Monitoring: A Systematic Critical Review

BACKGROUND

Conception, pregnancy, and lactation following solid organ transplantation require appropriate management. The most frequently used immunosuppressive drug combination after solid organ transplantation consists of tacrolimus (Tac) plus mycophenolic acid (MPA). Here, the effects of Tac and MPA on fertility, pregnancy, and lactation are systematically reviewed, and their implications for therapeutic drug monitoring (TDM) are discussed.

METHODS

A systematic literature search was performed (August 19, 2019) using Ovid MEDLINE, EMBASE, the Cochrane Central Register of controlled trials, Google Scholar, and Web of Science, and 102 studies were included. Another 60 were included from the reference list of the published articles.

RESULTS

As MPA is teratogenic, women who are trying to conceive are strongly recommended to switch from MPA to azathioprine. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes. Nevertheless, in 2015, the drug label was updated with additional risk minimization measures in a pregnancy prevention program. Data on MPA pharmacokinetics during pregnancy and lactation are limited. Tac treatment during conception, pregnancy, and lactation seems to be safe in terms of the health of the mother, (unborn) child, and allograft. However, Tac may increase the risk of hypertension, preeclampsia, preterm birth, and low birth weight. Infants will ingest very small amounts of Tac via breast milk from mothers treated with Tac. However, no adverse outcomes have been reported in children exposed to Tac during lactation. During pregnancy, changes in Tac pharmacokinetics result in increased unbound to whole-blood Tac concentration ratio. To maintain Tac concentrations within the target range, increased Tac dose and intensified TDM may be required. However, it is unclear if dose adjustments during pregnancy are necessary, considering the higher concentration of (active) unbound Tac.

CONCLUSIONS

Tac treatment during conception, pregnancy and lactation seems to be relatively safe. Due to pharmacokinetic changes during pregnancy, a higher Tac dose might be indicated to maintain target concentrations. However, more evidence is needed to make recommendations on both Tac dose adjustments and alternative matrices than whole-blood for TDM of Tac during pregnancy. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes, whereas MPA use in women during conception and pregnancy is strongly discouraged.

Tacrolimus concentrations after renal transplantation in a mother-neonate dyad: Maternal, neonatal and breast milk measurements

WHAT IS KNOWN AND OBJECTIVE

We aim to add to the few reports on tacrolimus concentrations in breast milk and in maternal, umbilical vein and neonatal blood after maternal renal transplantation.

CASE SUMMARY

In a 30-year-old pregnant woman, the tacrolimus concentration at delivery was the same in maternal, umbilical vein and neonatal blood. The breast milk/maternal blood tacrolimus ratio ranged from 0.40 to 0.64.

WHAT IS NEW AND CONCLUSION

The maternal and neonatal blood tacrolimus concentrations at birth are equivalent; thus, one must assume that maternal tacrolimus concentrations directly affect the foetus and/or neonate. Tacrolimus is not detectable in the neonate 3 weeks after birth, suggesting that there is minimal transfer through breast milk.

Susac syndrome and pregnancy: a review of published cases and considerations for patient management

Susac syndrome (SuS) is a rare autoimmune endotheliopathy leading to hearing loss, branch retinal artery occlusions and encephalopathy. Young females are more frequently affected than males, making counselling for family planning an important issue. We reviewed published cases on SuS during pregnancy or in the postpartum period, and selected 27 reports describing the details of 33 patients with SuS. Treatment options and implications for pregnancy and breastfeeding are discussed. We propose new areas for research and suggest a management strategy.

Pregnancy after Heart Transplantation

As post-transplant survival improves, many heart transplant (HT) recipients are of, or are surviving to, childbearing age. Solid-organ transplant recipients who become pregnant should be managed by a multidisciplinary cardio-obstetrics team, including specialists in maternal and fetal medicine, cardiology and transplant medicine, as well as anesthesia, neonatology, psychology, genetics, and social services. With careful patient selection, pregnancy after HT can been managed safely. The purpose of this comprehensive review was to summarize the current evidence and recommendations surrounding preconception counseling, medical management and surveillance, maternal outcomes, breastfeeding, and remaining gaps in knowledge.

Management of reproductive health after cardiac transplantation

Pregnancy after cardiac transplantation poses immense challenges. Maternal risks include hypertensive disorders of pregnancy, rejection, and failure of the cardiac allograft that may lead to death. Fetal risks include potential teratogenic effects of immunosuppression and prematurity. Because of the high-risk nature of pregnancy in a heart transplant patient, management of reproductive health after cardiac transplantation should include preconception counseling to all women in the reproductive age group before and after cardiac transplantation. Reliable contraception is vital as nearly half of the pregnancies in this population are unintended. Despite the associated risks, successful pregnancies after cardiac transplantation have been reported. A multidisciplinary approach proposed in this review is essential for successful outcomes. A checklist for providers to guide management is provided.

Renal disease in pregnancy: Fetal, neonatal and long-term outcomes

Renal disease in women of childbearing age is estimated to be approximately 3%; consequently, renal disease is not an uncommon comorbidity in pregnancy. There has been considerable evidence published over the last 20 years to suggest that renal disease in pregnancy is associated with higher maternal, fetal, and offspring morbidity. Studies published are largely heterogeneous; include unmatched cohort studies; and focus on early neonatal outcomes such as prematurity, small for gestational age, and neonatal unit admission. There appears to be an inverse relationship between maternal renal function and likelihood of neonatal morbidity using these outcome measures. Overall though, data regarding medium-to long-term outcomes for children born to mothers with renal disease are scarce. However, in view of emerging epidemiological evidence regarding cardiovascular programming in intrauterine life in those born premature or small for gestational age, it is likely that this population of children remain at high risk of cardiovascular disease as adults. The scope of this review is to amalgamate and summarize existing evidence regarding the outcomes of infants born to mothers with renal disease. Focus will be given to pregnancy-related acute kidney injury, chronic kidney disease, dialysis, and transplantation.

Changes in the blood level, efficacy, and safety of tacrolimus in pregnancy and the lactation period in patients with systemic lupus erythematosus

OBJECTIVES

We investigated the efficacy and safety of tacrolimus (TAC) by monitoring its serum concentration for mothers and infants in pregnant patients with systemic lupus erythematosus (SLE).

METHODS

We measured trough concentrations of TAC in 25 pregnant patients with SLE to assess influence of TAC on the disease activity. Additionally, we measured the concentrations of TAC in umbilical arterial blood, breast milk, and breastfed infants to investigate the safety of TAC for the mothers and infants.

RESULTS

The trough concentrations of TAC in the mothers significantly decreased in the second trimester as compared with those before pregnancy. However, the decrease in the trough concentrations of TAC did not lead to the deterioration of SLE. When examined, the doses of TAC were significantly lower in the second trimester and postpartum in the deteriorating group than those in the non-deteriorating group. There were no adverse events by TAC in mothers and fetuses. The concentrations of TAC in the umbilical cord blood were lower than those in the maternal blood. The relative infant dose in breastfed infants of TAC was < 1%. The level of TAC in infant bloods was below detectable limits.

CONCLUSION

These findings suggest that TAC is one of the most effective and safest immunosuppressive drugs for use in pregnant patients with SLE.

Low Transfer of Tacrolimus and Its Metabolites into Colostrum of Graft Recipient Mothers

Currently, the majority of neonates born to organ recipient mothers on chronic immunosuppressive therapy are formula fed. However, over the past few years, evidence has grown, suggesting that breastfeeding might be possible and beneficial. We designed a study assessing the transfer of tacrolimus into the colostrum of posttransplant mothers. We assessed the amount of tacrolimus and its metabolites, M-1 and M-3, that would be ingested by the breastfed neonates. Concentrations of tacrolimus and its metabolites were measured in colostrum from 14 posttransplant mothers as well as in venous cord blood and venous blood of the neonates. Test material analysis was performed by liquid chromatography coupled with mass spectrometry (LC/MS). The amount of ingested formula was registered, which allowed for estimation of the amount of tacrolimus and its metabolites that would be ingested by breastfed infants. The mean amount of tacrolimus that would be ingested by the neonates in maternal milk was 151.4 ng/kg/24 h (standard deviation SD ± 74.39); metabolite M-1: 23.80 ng/kg/24 h (SD ± 14.53); and metabolite M-3: 13.25 ng/kg/24 h (SD ± 9.05). The peak level of tacrolimus and metabolite M-1 in colostrum was noted 8 h after an oral dose (3.219 ng/mL SD ± 2.22 and 0.56 ng/mL SD ± 0.60, respectively) and metabolite M-3 after 6 h (0.29 ng/mL SD ± 0.22). Low concentrations of tacrolimus and its metabolites, M-1 and M-3, in colostrum show that neonates will ingest trace amounts of the drug. Further studies are required to fully assess the safety of breastfeeding by posttransplant mothers.

Tacrolimus in the prevention of adverse pregnancy outcomes and diabetes-associated embryopathies in obese and diabetic mice

BACKGROUND

T2DM is a high-risk pregnancy with adverse fetal and maternal outcomes including repeated miscarriages and fetal malformations. Despite the established association between placental insufficiency and poor maternal Th1-adaptability to the development of pregnancy complications in T2DM, there have been no established data to assess benefits of pre-pregnancy immunosuppression relative to gestational outcomes in T2DM. We hypothesized that pre-pregnancy macrolide immune suppression can re-establish normal placental development and uterine vascular adaptation in a mouse model of obesity-associated T2DM.

METHODS

Fetal live birth rate, postnatal variability, mid-gestational uterine and umbilical flow dynamics and certain morphological features of spiral artery modification were examined in the New Zealand Obese (NONcNZO10/Ltj) female mice (n = 56) weaned to ages of 32 weeks on a 60% calories/g high-fat diet (also referred to as HFD-dNONcNZO), and which received either tacrolimus (0.1 mg/kg s.c. q2d) , its vehicle (castor oil and ethanol) or metformin (in drinking water 200 mg/dL p.o. ad libitum). HFD-BALBc-Rag2/IL2-gc female mice (n = 24) were used as HFD-immunodeficient controls.

RESULTS

Treatment of the HFD-dNONcNZO female mice with tacrolimus improved live birth rates and postnatal viability scores (p < 0.01), normalized OGTT (p < 0.001), inhibited fetal malformation rates, restored morphology of spiral arterial modification; and improved uterine arterial and umbilical blood flow (p < 0.01). Placental production of TNFαand IL16 in the tacrolimus-treated HFD-dNONcNZO dams were restored to non-diabetic levels and the treatment resulted in the inhibition of aberrant monocyte/macrophage activation during pregnancy in the HFD-dNONcNZO dams.

CONCLUSIONS

Our present data suggest a casual association between chronic maternal overnutrition and aberrancy in the maternal Th1-immune maladaptation to pregnancy and defective spiral artery modification, placental insufficiency and adverse fetal outcomes in the T2DM subjects. Further safety studies into the use of tacrolimus in the pre-pregnancy glycemic control may be beneficial.

Nutrition, Pregnancy, and Transplantation

One benefit of transplantation, along with the restoration of health, is the opportunity for successful pregnancies. A growing number of pregnancies have been reported among all types of solid-organ recipients. There is an increasing need for practice guidelines that include nutrition information in order to assist practitioners caring for and counseling these high-risk patients. In the transplant community, guidelines for managing pregnancies in transplant recipients have been evolving but lack specific nutrition recommendations. As for all pregnancies, there is a need to optimize nutrition for the mother and her infant, with additional consideration given to the transplant recipient's graft. This article reviews outcomes of posttransplant pregnancies and management guidelines, with special emphasis on nutrition in this unique population.

A Review of the Course and Treatment of Non-Infectious Uveitis during Pregnancy

Inflammatory conditions such as autoimmune uveitis often occur in women of childbearing age. During pregnancy, women may experience exacerbations of their disease in the first trimester. In the later stages of pregnancy, however, the uveitis tends to remain less active. The management of uveitis during pregnancy is a challenging task, forcing the physician to re-evaluate the patient's current therapy and offer alternative options that pose the least risk to the patient and fetus. This article will review treatments widely used for uveitis, including corticosteroid therapy, anti-metabolites, calcineurin inhibitors, and biologic therapy. It will evaluate the use of these medications in pregnancy and the postpartum state.

Safety of Drugs during Pregnancy and Breastfeeding in Cystic Fibrosis Patients

Health management of cystic fibrosis (CF) patients should be maximized during pregnancy and breastfeeding because of its significant impact on the maternal and newborn outcomes. Thus, numerous drugs will have to be continued during pregnancy and lactation. Most of the drugs representing CF treatment lines cross the placenta or are excreted into human milk. Research addressing the risks and benefits of drugs used in CF patients during pregnancy and lactation is often incomplete or challenged by limited methodology, which often leads to conflicting or inconclusive results. Yet, potential treatment benefits for CF pregnant patients most often outbalance potential risks for the unborn child.

Treating Inflammatory Bowel Disease in Pregnancy: The Issues We Face Today

Many women of childbearing age are living with inflammatory bowel disease [IBD], yet there are limited studies on the use of IBD medications in pregnancy. In this review, we provide a comprehensive update on the safety of these medications during pregnancy, particularly thiopurines and biologicals. Antibiotics, steroids, and aminosalicylates are relatively low risk for use in pregnancy, and growing evidence supports the safety of immunomodulators and anti-tumour necrosis factor agents as well. Available studies on infliximab, adalimumab, and certolizumab pegol show no increase in adverse events during pregnancy or perinatally. Similarly, studies on lactation demonstrate that concentrations of subcutaneous anti-tumour necrosis factor biologicals are undetectable, and levels of thiopurines and infliximab are negligible in breast milk. Less is known about anti-integrins in pregnancy [eg natalizumab and vedolizumab] but currently available data suggest they may be safe as well. Although more studies are needed to examine the long-term effects of these medications on offspring, the available data provide reassuring information for providers caring for women of childbearing age.

Immunophenotypic profile and increased risk of hospital admission for infection in infants born to female kidney transplant recipients

Children born to female kidney recipients are exposed to immunosuppressive drugs during gestation. Little is known about their immune system at birth or in the long term. Twenty-eight children born to female kidney recipients and 40 full-term children born to healthy mothers were evaluated. T, B, NK, NKT, γδT cells were assessed by flow cytometry and functional evaluation of T and dendritic cells after in vitro activation was performed at birth and at 8 months of age. At birth, infants born to female kidney recipients showed lower numbers of CD4+ T, NKT and intense reduction of B cells (median cells/mm(3) , transplant: 153.7 X control: 512.4; p < 0.001). There was also a reduced percentage of activated CD8+ T and of CD4+ regulatory T cells. Activated memory and exhausted memory B cells showed higher percentages among children exposed to immunosuppressors when compared to control group. At 8 months, most immune alterations were no longer observed, but four children still had low numbers of some lymphocyte subsets at this age. Children born to female kidney recipients had 4.351 (95% CI: 1.026-15.225; p = 0.046) higher risk of hospital admission in the first months of life-some, with severe clinical manifestations-than those born to healthy women.

Successful term pregnancy in an intestine-pancreas transplant recipient with chronic graft dysfunction and parenteral nutrition dependence: a case report

Pregnancy after solid organ transplantation is becoming more common, with the largest recorded numbers in renal and liver transplant recipients. Intestinal transplantation is relatively new compared to other solid organs, and reports of successful pregnancy are far less frequent. All pregnancies reported to date in intestinal transplant recipients have been in women with stable graft function. The case reported here involves the first reported successful term pregnancy in an intestine-pancreas transplant recipient with chronic graft dysfunction and dependence on both transplant immunosuppression and parenteral nutrition (PN) at the time of conception. Pregnancy was unplanned and unexpected in the setting of chronic illness and menstrual irregularities, discovered incidentally on abdominal ultrasound at approximately 18 weeks' gestation. Rapamune was held, tacrolimus continued, and PN adjusted to maintain consistent weight gain. A healthy female infant was delivered vaginally at term. Medical complications during pregnancy included anemia and need for tunneled catheter replacements. Ascites and edema were improved from baseline, with recurrence of large volume ascites shortly after delivery. Successful pregnancy is possible in the setting of transplant immunosuppression, chronic intestinal graft dysfunction, and long-term PN requirement, but close monitoring is required to ensure the health of mother and child.

Review article: the management of Crohn's disease and ulcerative colitis during pregnancy and lactation

BACKGROUND

Inflammatory bowel diseases (IBD) commonly affect young patients in the reproductive phase of their lives. The chronic and relapsing nature of IBD and the potential need for medical or surgical interventions raise concerns about family planning issues.

AIM

To review the current knowledge on IBD management in pregnant and nursing IBD patients.

METHODS

A PubMed literature search was performed using the search terms 'reproduction' and 'inflammatory bowel disease' and using the headers and main subjects of each section of this article as search terms.

RESULTS

Male and female fertility are not impaired in the majority of IBD patients. In IBD patients with quiescent disease pregnancy outcomes are not impaired in comparison to the general population, however, an increased incidence of pregnancy complications is observed in active IBD patients. As methotrexate (MTX) has been demonstrated to be teratogenic, the use of MTX is contraindicated in patients, who wish to conceive, throughout pregnancy and when nursing. However, normal pregnancies following MTX treatment at conception and later have been reported. Most of the other currently approved IBD medications are not associated with adverse pregnancy outcomes and may be used to maintain quiescent disease or to induce a rapid remission in patients with flares and active disease. Breast-feeding in IBD patients is possible and recommended.

CONCLUSIONS

The overall outcome of pregnancies in IBD patients is favourable and not different to healthy controls, thus patients with IBD should not be discouraged from having children.

Breast-feeding after transplantation

Transplantation affords recipients the potential for a full life and, for some, parenthood. Female transplant recipients must continue to take immunosuppression during pregnancy and breast-feeding. This article reviews case and series reports regarding breast-feeding in those taking transplant medications. Avoidance of breast-feeding has been the customary advice because of the potential adverse effects of immunosuppressive exposure on the infant. Subsequent studies have demonstrated that not all medication exposure translates to risk for the infant, that the exposure in utero is greater than via breast milk and that no lingering effects due to breast-feeding have been found to date in infants who were breast-fed while their mothers were taking prednisone, azathioprine, cyclosporine, and/or tacrolimus. Thus, except for those medications where clinical information is inadequate (mycophenolic acid products, sirolimus, everolimus, and belatacept), the recommendation for transplant recipients regarding breast-feeding has evolved into one that is cautiously optimistic.

Tacrolimus placental transfer at delivery and neonatal exposure through breast milk

AIM(S)

The current investigation aims to provide new insights into fetal exposure to tacrolimus in utero by evaluating maternal and umbilical cord blood (venous and arterial), plasma and unbound concentrations at delivery. This study also presents a case report of tacrolimus excretion via breast milk.

METHODS

Maternal and umbilical cord (venous and arterial) samples were obtained at delivery from eight solid organ allograft recipients to measure tacrolimus and metabolite bound and unbound concentrations in blood and plasma. Tacrolimus pharmacokinetics in breast milk were assessed in one subject.

RESULTS

Mean (±SD) tacrolimus concentrations at the time of delivery in umbilical cord venous blood (6.6 ± 1.8 ng ml(-1)) were 71 ± 18% (range 45-99%) of maternal concentrations (9.0 ± 3.4 ng ml(-1)). The mean umbilical cord venous plasma (0.09 ± 0.04 ng ml(-1)) and unbound drug concentrations (0.003 ± 0.001 ng ml(-1)) were approximately one fifth of the respective maternal concentrations. Arterial umbilical cord blood concentrations of tacrolimus were 100 ± 12% of umbilical venous concentrations. In addition, infant exposure to tacrolimus through the breast milk was less than 0.3% of the mother's weight-adjusted dose.

CONCLUSIONS

Differences between maternal and umbilical cord tacrolimus concentrations may be explained in part by placental P-gp function, greater red blood cell partitioning and higher haematocrit levels in venous cord blood. The neonatal drug exposure to tacrolimus via breast milk is very low and likely does not represent a health risk to the breastfeeding infant.

Inflammatory bowel disease in women of reproductive age

Management of inflammatory bowel disease in women of reproductive age requires special attention. Even though fertility in women without previous pelvis surgery is similar to the general population, active disease at conception and during pregnancy can lead to unfavorable pregnancy and fetal outcomes. In general, most medications needed to treat inflammatory bowel disease are low risk during pregnancy and breastfeeding. Achieving and maintaining disease remission, patient education, and a multidisciplinary team approach is the key to a successful pregnancy.

Breastfeeding and tacrolimus: is it a reasonable approach?

Successful pregnancy after transplantation has become more common and more recipients are choosing to breastfeed their infants, despite the controversy surrounding the safety of breastfeeding while the mother is taking immunosuppressive medications, such as tacrolimus. Data collected to date by the National Transplantation Pregnancy Registry have not revealed specific problems related to breastfeeding; however, individual circumstances must be considered when counseling transplant recipients regarding breastfeeding. Bramham et al. reported on a series of transplant recipients who were maintained on tacrolimus during pregnancy and lactation and concluded that women should not be discouraged from breastfeeding while on tacrolimus. Recently, other authors have also supported the option of breastfeeding while recipients are maintained on tacrolimus. Herein, we review the Bramham article and discuss the key issues to be considered regarding the compatibility of breastfeeding and immunosuppression.

Neonatal immune-tolerance in mice does not prevent xenograft rejection

Assessing the efficacy of human stem cell transplantation in rodent models is complicated by the significant immune rejection that occurs. Two recent reports have shown conflicting results using neonatal tolerance to xenografts in rats. Here we extend this approach to mice and assess whether neonatal tolerance can prevent the rapid rejection of xenografts. In three strains of neonatal immune-intact mice, using two different brain transplant regimes and three independent stem cell types, we conclusively show that there is rapid rejection of the implanted cells. We also address specific challenges associated with the generation of humanized mouse models of disease.

Safety considerations: breastfeeding after transplant

Organ transplant is an effective treatment for end-stage organ failure. For women, restoration of organ function can restore fertility and the ability to successfully carry a pregnancy. Posttransplant pregnancies have been reported among recipients of all types of solid organ transplants via case and center reports plus registry data. Stable graft function is dependent on prevention of rejection, currently accomplished by using maintenance immunosuppressant medications, to which the fetus is exposed in utero. Common among neonatal outcomes in transplant recipients are preterm and low-birth-weight infants. Emotional, nutritional, and immunologic benefits of breastfeeding have been well-documented and could be valuable for these newborns. Concern must be directed at the effects of the child's exposure to immunosuppressive agents excreted into the breast milk. Breastfeeding could be considered in transplant recipients if it can be shown that the level of exposure does not result in risks to the newborn, immediately and throughout childhood. Despite concerns of health care professionals, some recipients have chosen to breastfeed. Breastfeeding after transplant must be approached with consideration of many issues, and the potential risks require further study. This review focuses on benefits of breastfeeding, common immunosuppressive agents used in organ transplant recipients, a summary of the reports of women who have breastfed their infants while on immunosuppressive therapy and the published studies on breastfeeding and immunosuppressive agents. Recommendations are provided to guide health care professionals to help mothers receiving immunosuppressive agents to make informed choices about breastfeeding their infants.

Update on pregnancy and breastfeeding in the era of biologics

Inflammatory bowel diseases are chronic conditions that frequently affect patients during their childbearing years. Considering the characteristics of disease and the medications used to treat it, several issues arise in the care of these patients when they attempt or achieve conception. We review the most current evidence concerning fertility and pregnancy outcomes in patients with inflammatory bowel diseases. With the exception of those women who undergo pelvic surgery, patients with inflammatory bowel diseases have no decreased fertility. Sulfasalazine decreases fertility in men. When looking at obstetrical outcomes, active disease at conception is associated with an increased risk of preterm delivery and low birth weight. While most medications used to treat inflammatory bowel diseases are low risk, some precautions need to be taken and the risk-to-benefit ratio needs to be considered on an individualized basis. In general, aminosalicylates and thiopurines should be continued, but methotrexate is contraindicated. Anti-tumour necrosis factor agents are considered safe to continue but full monoclonal antibodies do cross the placenta. As a general rule, the it is important to counsel women that conception is optimal when disease is in remission, as adverse obstetrical outcomes are directly associated with disease activity. Clinicians need to educate patients before, during and after conception, emphasizing treatment compliance.

Interpreting tacrolimus concentrations during pregnancy and postpartum

Pregnancy after solid organ transplantation, although considered high risk for maternal, fetal, and neonatal complications, has been quite successful. Tacrolimus pharmacokinetic changes during pregnancy make interpretation of whole blood trough concentrations particularly challenging. There are multiple factors that can increase the fraction of unbound tacrolimus, including but not limited to low albumin concentration and low red blood cell count. The clinical titration of dosage to maintain whole blood tacrolimus trough concentrations in the usual therapeutic range can lead to elevated unbound concentrations and possibly toxicity in pregnant women with anemia and hypoalbuminemia. Measurement of plasma or unbound tacrolimus concentrations for pregnant women might better reflect the active form of the drug, although these are technically challenging and often unavailable in usual clinical practice. Tacrolimus crosses the placenta with in utero exposure being approximately 71% of maternal blood concentrations. The lower fetal blood concentrations are likely due to active efflux transport of tacrolimus from the fetus toward the mother by placental P-glycoprotein. To date, tacrolimus has not been linked to congenital malformations but can cause reversible nephrotoxicity and hyperkalemia in the newborn. In contrast, very small amounts of tacrolimus are excreted in the breast milk and are unlikely to elicit adverse effects in the nursing infant.

Pharmacokinetics of tacrolimus during pregnancy

BACKGROUND

Information on the pharmacokinetics of tacrolimus during pregnancy is limited to case reports despite the increasing number of pregnant women being prescribed tacrolimus for immunosuppression.

METHODS

Blood, plasma, and urine samples were collected over 1 steady-state dosing interval from women treated with oral tacrolimus during early to late pregnancy (n = 10) and postpartum (n = 5). Total and unbound tacrolimus as well as metabolite concentrations in blood and plasma were assayed by a validated liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) method. A mixed-effect linear model was used for comparison across gestational age and using postpartum as the reference group.

RESULTS

The mean oral clearance (CL/F) based on whole-blood tacrolimus concentration was 39% higher during mid-pregnancy and late pregnancy compared with postpartum (47.4 ± 12.6 vs. 34.2 ± 14.8 L/h, P < 0.03). Tacrolimus-free fraction increased by 91% in plasma (f(P)) and by 100% in blood (f(B)) during pregnancy (P = 0.0007 and 0.002, respectively). Increased fP was inversely associated with serum albumin concentration (r = -0.7, P = 0.003), which decreased by 27% during pregnancy. Pregnancy-related changes in f(P) and f(B) contributed significantly to the observed gestational increase in tacrolimus whole-blood CL/F (r² = 0.36 and 0.47, respectively, P < 0.01). In addition, tacrolimus whole-blood CL/F was inversely correlated with both hematocrit and red blood cell counts, suggesting that binding of tacrolimus to erythrocytes restricts its availability for metabolism. Treating physicians increased tacrolimus dosages in study participants during pregnancy by an average of 45% to maintain tacrolimus whole-blood trough concentrations in the therapeutic range. This led to striking increases in unbound tacrolimus trough concentrations and unbound area under the concentration-time curve, by 112% and 173%, respectively, during pregnancy (P = 0.02 and 0.03, respectively).

CONCLUSIONS

Tacrolimus pharmacokinetics are altered during pregnancy. Dose adjustment to maintain whole-blood tacrolimus concentration in the usual therapeutic range during pregnancy increases circulating free drug concentrations, which may impact clinical outcomes.

Breastfeeding and tacrolimus: serial monitoring in breast-fed and bottle-fed infants

BACKGROUND AND OBJECTIVES

Women have traditionally been advised not to breastfeed while taking tacrolimus, based on theoretical risks of neonatal immunosuppression and assumed secretion into breast milk, rather than clinical data suggesting neonatal absorption. The aim of this study was to assess tacrolimus levels in breast milk and neonatal exposure during breastfeeding.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An observational cohort study was performed in two tertiary referral high-risk obstetric medicine clinics. Fourteen women taking tacrolimus during pregnancy and lactation, and their 15 infants, 11 of whom were exclusively breast-fed, were assessed. Tacrolimus levels were analyzed by liquid chromatography-tandem mass spectrometry. Samples from mothers and cord blood were collected at delivery and from mothers, infants, and breast milk postnatally where possible.

RESULTS

All infants with serial sampling had a decline in tacrolimus level, which was approximately 15% per day (ratio of geometric mean concentrations 0.85; 95% confidence interval, 0.82-0.88; P<0.001). Breast-fed infants did not have higher tacrolimus levels compared with bottle-fed infants (median 1.3 μg/L [range, 0.0-4.0] versus 1.0 μg/L [range, 0.0-2.3], respectively; P=0.91). Maximum estimated absorption from breast milk is 0.23% of maternal dose (weight-adjusted).

CONCLUSIONS

Ingestion of tacrolimus by infants via breast milk is negligible. Breastfeeding does not appear to slow the decline of infant tacrolimus levels from higher levels present at birth. Women taking tacrolimus should not be discouraged from breastfeeding if monitoring of infant levels is available.

Pregnancy after solid organ transplantation: a guide for obstetric management

Successful pregnancy outcomes are possible among all solid organ transplant recipients. Patients should be fully counseled regarding the potential adverse fetal outcomes, including prematurity and low birth weight. Transplant recipients are at an increased risk for both maternal and neonatal complications and should be seen by a high-risk obstetrician in conjunction with their transplant teams. Ideally, preconception counseling begins during the pretransplantation evaluation process. Initiating contraception early after transplantation is ideal, and long-acting reversible methods such as intrauterine devices and subdermal implants may be preferred. Pregnancy should be avoided for at least 1 year after transplantation to limit the potential risks of early pregnancy that may adversely affect both allograft function and fetal well-being. Hypertension, diabetes, and infection should be monitored and treated to minimize fetal risks during pregnancy. Maintenance of current immunosuppression is usually recommended, with the exception of mycophenolic acid products, which (when possible) should be discontinued before conception and replaced with an alternative medication. Throughout pregnancy, immunosuppression must be maintained at appropriate dosing to avoid graft rejection. During labor and delivery, cesarean delivery should be performed for obstetric reasons only. A multidisciplinary team should manage pregnant transplant recipients before, during, and following pregnancy. Breastfeeding and long-term in utero exposure to immunosuppressants for offspring of transplant recipients continue to require further investigation but have been encouraged by recent reports. Continued reporting of post-transplantation pregnancy outcomes to the National Transplantation Pregnancy Registry is highly encouraged.

Pregnancy after cardiac transplantation

More women are reporting pregnancy following heart transplantation. Although successful outcomes have been reported for the mother, transplanted heart, and newborn, such pregnancies should be considered high risk. Hypertension, preeclampsia, and infection should be treated. Vaginal delivery is recommended unless cesarean section is obstetrically necessary. Most outcomes are live births, and long-term follow-up of children show most are healthy and developing well. Maternal survival, independent of pregnancy-related events, should be part of prepregnancy counseling.

Safety and efficacy of immunomodulators and biologics during pregnancy and lactation for the treatment of inflammatory bowel disease

INTRODUCTION

The inflammatory bowel diseases (IBD) are chronic, idiopathic, inflammatory conditions of the gastrointestinal tract, that peak in incidence during the reproductive years. Therefore, the safety of IBD medications during pregnancy and lactation is of significant interest to patients. Unfortunately, the current pregnancy labeling used by the United States Food and Drug Association (FDA) is often misinterpreted and may mislead healthcare providers and their patients to believe that risk increases from Category A to B to C to D to X, which in fact, is not the case. In addition, the FDA categories do not always distinguish between risks based on human versus animal data, or between differences in frequency, severity, and type of fetal developmental toxicities.

AREAS COVERED

This article provides an in-depth review of the available safety data during pregnancy and lactation for the more potent immunosuppressants used to treat IBD: the immunomodulators and biologics. It also includes the authors' expert opinions on the use of these medications during these critical periods.

EXPERT OPINION

The benefit-to-risk ratio for most immunomodulators and biologics used in the treatment of IBD favors medication continuation during pregnancy. Certain immunomodulators, however, can cause extreme fetal harm and should be used with caution. While human safety data regarding teratogenesis and some data on pregnancy outcomes exist for most IBD medications, long-term follow-up studies of children and young adults exposed to these drugs in utero are lacking. These studies are needed to determine if these drugs are of sufficiently low risk to be considered safe.

[Liver transplantation and pregnancy]

Patients with liver failure have menstrual cycle irregularities or amenorrhea. Liver transplantation restores menstrual pattern among women with cirrhosis in childbearing years. It is now accepted that a planned pregnancy is possible among liver transplant recipients at least 1 year after liver transplantation, with stable allograft function and under immunosuppressive regimens, to minimize the risks of preterm delivery and pregnancy-induced hypertension. After 1 year, the risk of graft loss decreases and is not related to pregnancy. It is a high-risk pregnancy which requires a specific and regular multidisciplinary joint follow-up (obstetrician, hepatologist, and anaesthesiologist), which leads in most cases to successful outcome for mother and child. But, early prevention and multidisciplinary management of the most common complications (pregnancy-induced hypertension, preeclampsia, and fetal growth restriction) is essential. The prematurity rate, maternal morbidity and mortality are higher than in the general population. Usual immunosuppressive treatments (corticoids, cyclosporine, tacrolimus, azathioprine or mycophenolate mofetil) may require dose adaptation during pregnancy. Immunosuppressive drugs are not teratogenic, but breast feeding is not allowed.

Pregnancy and liver transplantation

Since the first pregnancy in a transplant recipient in 1958, pregnancy in recipients of solid organ transplants has become increasingly common. Although previously considered a hazardous event, data collected over the last 50 years demonstrate that despite an increased risk of maternal and fetal complications, pregnancy in transplant recipients can have a successful outcome. As of 2006, there were over 3000 female liver transplant recipients of childbearing age in the USA. Two hundred and two pregnancies and 205 outcomes were reported in 121 liver transplant recipients in the National Transplantation Pregnancy Registry. Children born to female liver recipients have a greater risk of prematurity and low birth weight than the general population, but no malformation patterns have been observed. Mothers are more likely to experience pregnancy-induced hypertension, pre-eclampsia and caesarian section, but overall mortality is not worse. Rates of acute rejection and graft loss are similar to nonpregnant liver recipients. The optimal timing of conception post-transplant is controversial, but current recommendations suggest waiting for at least 1 year after transplantation. Choice of contraception is also debatable, although barrier methods have traditionally been preferred. Many medications used for post-transplant immunosuppression have potential effects during pregnancy and breast-feeding. The risks and benefits of each medication should be reviewed with patients contemplating pregnancy, and regimens should be tailored accordingly.

Pregnancy after transplantation

The National Transplantation Pregnancy Registry (NTPR) was established in 1991 to study the outcomes of pregnancies in female transplant recipients and pregnancies fathered by male transplant recipients. Data from the NTPR have helped to endorse the reassurances from publications of smaller experiences that successful pregnancies are possible in the transplant population. In our last review for this journal (2000), we noted that important future issues would include the reassessment of prepregnancy guidelines, gestational and organ-specific problems, the role of new immunosuppressive drugs, and the long-term effects of pregnancy on both graft and child. Data collected by the NTPR over the last 7 years have addressed these issues, thus providing additional information for health care providers of transplant recipients of childbearing age. There has been some refinement of prepregnancy guidelines, but there is a need for additional data collection so that organ-specific outcomes and risks can further be identified. To date, the outcomes of the children followed have been encouraging, and specific remote effects have not been identified, but continued surveillance is still vital. Of special concern are the new immunosuppressive drugs, specifically for mycophenolate mofetil (CellCept, Roche Laboratories Inc., Nutley, New Jersey), where data reported to the NTPR and through postmarketing surveillance have shown an increased incidence of nonviable outcomes and a specific pattern and increased incidence of malformation in the newborn, which has resulted in a pregnancy category change. Newer information points to an increased need for vigilance among centers and continued monitoring of pregnancy outcomes in this population. As the first reported pregnancy after transplantation occurred in a kidney recipient 50 years ago, in March 1958, this review also highlights the first reported pregnancies in other solid organ recipients.

Immunosuppressant therapy in pregnant organ transplant recipients

Transplant recipients are becoming pregnant with increasing frequency, and successful pregnancy outcomes have now been reported for women with all types of solid organ transplants. To prevent rejection of the transplanted organ, these patients are maintained on a life-long immunosuppressive regimen that must also be continued through pregnancy. Controlled human studies of the safety of these drugs have not been conducted, and knowledge regarding the pharmacokinetics of these medications in pregnancy is limited. Significant experience and safety data regarding the use of some of the more common immunosuppressants in pregnancy have, however, been accumulated from large case series and national registries. These observational studies suggest that successful pregnancy outcomes are possible in female organ transplant recipients, although sporadic adverse outcomes have been reported after immunosuppressant use in pregnancy. In this chapter, we will outline the information available regarding the use of immunosuppressive medications in pregnant transplant recipients as well as general concepts regarding fetal exposure to immunosuppressants.

The use of tacrolimus in the treatment of inflammatory bowel disease

Tacrolimus is a calcineurin inhibitor that suppresses pro-inflammatory cytokine production and T-cell activation. These immunosuppressant effects have been used to treat inflammatory bowel disease, especially fistulising Crohn's disease and refractory ulcerative colitis. The more predictable oral bioavailability and better side-effect profile makes tacrolimus a more favourable choice as compared with ciclosporin. Dose-dependent side effects, such as nephrotoxicity, are reported but are mostly reversible with dose reduction or cessation of therapy. Topical tacrolimus has also been used to treat pyoderma gangrenosum, an extra-intestinal manifestation of inflammatory bowel disease. Tacrolimus is well-tolerated and should be considered as an alternative agent in the treatment of inflammatory bowel disease, especially those intolerant or refractory to the more conventional immunomodulators.