Outcomes of 83 fetuses exposed to angiotensin receptor blockers during the second or third trimesters: a literature review

Overdose of angiotensin II receptor blocker in the third trimester of pregnancy: A case report

Angiotensin II receptor blockers (ARBs) are contraindicated during pregnancy because of fetal toxicity. All previous reports on adverse fetal outcomes involved women who continued to take low-dose ARBs for hypertension and were unaware of the adverse effects. Herein, we report the case of a 23-year-old pregnant woman in her third trimester who experienced an ARB overdose after an argument with her partner. Pregnancy was complicated by transient oligohydramnios, and fetal magnetic resonance imaging suggested renal failure. Despite these concerns, the newborn had no morphological abnormalities or abnormal neurological findings. Renal impairment improved over time, and the infant grew well. A single overdose of ARBs in the third trimester can lead to fetal renal failure, similar to long-term low-dose ARB administration; however, favorable outcomes are possible. An overdose of ARBs may transiently cause renal failure, which may improve. The study findings may inform counseling for women who are unexpectedly exposed to an overdose of ARBs.

Pathological AT1R-B2R Protein Aggregation and Preeclampsia

Preeclampsia is one of the most frequent and severe complications of pregnancy. Symptoms of preeclampsia usually occur after 20 weeks of pregnancy and include hypertension and kidney dysfunction with proteinuria. Up to now, delivery of the infant has been the most effective and life-saving treatment to alleviate symptoms of preeclampsia because a causative treatment does not exist, which could prolong a pregnancy complicated with preeclampsia. Preeclampsia is a complex medical condition, which is attributed to a variety of different risk factors and causes. Risk factors account for insufficient placentation and impaired vasculogenesis and finally culminate in this life-threatening condition of pregnancy. Despite progress, many pathomechanisms and causes of preeclampsia are still incompletely understood. In recent years, it was found that excessive protein complex formation between G-protein-coupled receptors is a common sign of preeclampsia. Specifically, the aberrant heteromerization of two vasoactive G-protein-coupled receptors (GPCRs), the angiotensin II AT1 receptor and the bradykinin B2 receptor, is a causative factor of preeclampsia symptoms. Based on this knowledge, inhibition of abnormal GPCR protein complex formation is an experimental treatment approach of preeclampsia. This review summarizes the impact of pathological GPCR protein aggregation on symptoms of preeclampsia and delineates potential new therapeutic targets.

Use of angiotensin II receptor blocker during pregnancy: A case report

BACKGROUND

Drugs that affect the renin-angiotensin system, such as angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors are not typically recommended for pregnant women because of their potential fetal toxicity.

CASE STUDY

A 32-year-old pregnant woman with nephrotic syndrome lasting more than 5 years became pregnant for the first time. She had been taking losartan tablets before and during pregnancy. Ultrasound at 24+2 weeks of pregnancy showed oligohydramnios, and the maximum vertical depth of amniotic fluid volume was 1.4 cm. Follow-up ultrasound examinations every 2 weeks showed persistent oligohydramnios [amniotic fluid volume: 1.1-3.4 cm, amniotic fluid index 1.9-6.9 cm]. B-ultrasound at 30+2 weeks showed slightly enhanced fetal renal cortex echo. The patient was treated at 32+2 weeks of pregnancy at our hospital.

DIAGNOSES

Nephrotic syndrome and oligohydramnios.

INTERVENTIONS

Losartan was discontinued and replaced by nifedipine controlled-release tablets to lower blood pressure. The amount of amniotic fluid gradually increased to normal levels within 8 days. The patient was discharged at 33+2 weeks of pregnancy for follow-up. At 34+4 weeks, blood pressure had increased to 177/113 mm Hg and the patient was re-hospitalized with nephrotic syndrome complicated by preeclampsia. Due to progression of severe preeclampsia, elective cesarean section was performed at 35+3 weeks. After delivery, losartan and nifedipine were prescribed to continue lowering blood pressure. The patient was discharged 4 days after surgery.

OUTCOMES

Losartan use was terminated at 32+2 weeks of pregnancy. Amniotic fluid returned to normal after 8 days and the baby was delivered after 22 days. At last follow-up, the infant was 24 months old and healthy.

CONCLUSION

Although ARBs are effective for treating hypertension, they should be replaced by other classes of anti-hypertensive drugs in pregnant women. Pregnant women who elect to continue using ARBs should be informed about risks, they should be carefully monitored during pregnancy, and their pregnancy should be allowed to proceed as long as clinically feasible in order to optimize maternal and infant outcomes.

Fetotoxic risk of AT1 blockers exceeds that of angiotensin-converting enzyme inhibitors: an observational study

OBJECTIVE

The fetotoxic potential of prenatal exposure to angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) has been known for many years. Symptoms range from transient oligohydramnios to neonatal anuria and permanent renal damage, joint contractures, hypocalvaria, lung hypoplasia and intrauterine or neonatal death. This study aims to investigate the critical gestational time for renin-angiotensin system inhibitor (RAS-I)-induced fetopathy, to quantify the fetopathy risk and to evaluate factors associated with the occurrence and severity of fetopathy.

METHODS

Prospectively and retrospectively ascertained RAS-I exposed pregnancies from the databases of six teratology information services were analyzed.

RESULTS

Eighty-nine pregnancies with ACE-I and 101 with ARB exposure beyond the first trimester were identified. Fifty-nine of these 190 pregnancies were classified as having evidence of RAS-I fetopathy. All pregnancies affected with fetopathy were exposed after 20 0/7 gestational weeks. Limited to prospectively enrolled cases with exposure at least 20 0/7 gestational weeks, the rate of fetopathy was 3.2% for ACE-I and 29.2% for ARB. The chance of recovery of amniotic fluid volume was higher with RAS-I discontinuation before 30 gestational weeks and with a longer exposure-free interval before delivery.

CONCLUSION

Exposure to ARBs is associated with a higher fetopathy risk than exposure to ACE-Is. RAS-I should ideally be discontinued prior to pregnancy or immediately after recognition of pregnancy. Because symptoms may improve in cases of RAS-I-induced oligohydramnios, pregnancy should be maintained as long as there is fetal well being. Physicians and patients need to be alerted to the fetotoxic risks of RAS-I.

Roles of angiotensin II type 2 receptor in mice with fetal growth restriction

Our previous report indicated that vascular injury enhances vascular remodeling in fetal growth restriction (FGR) mice. The angiotensin II type 2 receptor (AT₂R) is relatively highly expressed in fetal mice. Therefore, we investigated the roles of AT₂R in FGR-induced cardiovascular disease using AT₂R knockout (AT₂KO) mice. Dams (wild-type and AT₂KO mice) were fed an isocaloric diet containing 20% protein (NP) or 8% protein (LP) until delivery. Arterial blood pressure, body weight, and histological changes in organs were investigated in offspring. The birth weight of offspring from dams fed an LP diet (LPO) was significantly lower than that of offspring from dams fed an NP diet. The heart/body and kidney/body weight ratios in AT₂KO-LPO at 12 weeks of age were significantly higher than those in the other groups. Greater thickness of the left ventricular wall, larger cardiomyocyte size and enhancement of perivascular fibrosis were observed in AT₂KO-LPO. Interestingly, mRNA expression of collagen I and inflammatory cytokines was markedly higher in the AT₂KO-LPO heart at 6 weeks of age but not at 12 weeks of age. AT₂R signaling may be involved in cardiovascular disorders of adult offspring with FGR. Regulation of AT₂R could contribute to preventing future cardiovascular disease in FGR offspring.