The Effects of Renal Disease in Pregnancy
Published: 10 November 2021
Published: 10 November 2021
Caring for patients with renal disease in pregnancy is becoming an increasingly important aspect of midwifery care.
Current estimates suggest that chronic kidney disease affects about 3% of pregnant women in high-income countries, with predictions that this percentage is likely to rise in the future alongside increasing maternal age and obesity (Wiles et al. 2019).
Depending on the severity of the disease, routine antenatal care may need to be coordinated with specialist renal care. By taking an interprofessional approach, adequate and timely monitoring can be offered to ensure the safety of both the mother and the developing fetus. This usually includes:
(Gonzalez Suarez et al. 2019)
Despite offering combined care, Safi et al. (2019) suggest that the ability to provide optimal care for pregnant renal patients in Australia is often hindered by a lack of understanding around the prevalence, management and outcomes of women with serious kidney disease in pregnancy.
Typically, renal disease during pregnancy is related to either pre-existing disease, or develops secondary to diseases of pregnancy. Either way, it can present some heightened risks to the wellbeing of both the mother and fetus (Balofsky & Fedarau 2016). For example, the following outcomes are all more common in women with renal disease:
(Wiles et al. 2019; Fitzpatrick et al. 2019)
Proteinuria in the first trimester of pregnancy can indicate the presence of underlying kidney disease (DoH 2019).
The gold standard approach for testing for proteinuria is the 24-hour urine collection test. Other tests that can be used include:
Generally, a finding of 300 mg/24 hours or a protein:creatinine ratio of 30 mg/mmol of creatinine is indicative of proteinuria in pregnancy. Proteinuria that may be related to underlying kidney disease should be investigated further (DoH 2019).
Predicting specific outcomes for pregnant patients with renal disease can be difficult. In general, women with chronic renal disease adapt poorly to a gestational increase in renal blood flow, which may, in turn, heighten a decline in renal function and lead to a poor pregnancy outcome. In women with pre-existing kidney disease, pregnancy-related outcomes depend upon the degree of renal impairment, the amount of proteinuria and the severity of hypertension (Wiles et al. 2019).
The following factors have a large role to play in determining the well-being of both mother and baby:
(Kapoor, Makanjuola & Shehata 2019)
Chronic kidney disease often worsens during pregnancy due to the anatomical and physiological changes that occur from early gestation and increase the renal workload. For example, the glomerular filtration rate can increase by about 50%, with a commensurate fall in serum creatinine levels secondary to plasma volume expansion, renal vasodilation and hyperfiltration (Jesudason, Mohammadi & Fitzpatrick 2016).
In the first trimester of pregnancy, acute kidney injury can also be caused by hyperemesis gravidarum, ectopic pregnancy or miscarriage. In the second and third trimesters, however, the most common cause of acute kidney injury is severe pre-eclampsia (Jim & Garovic 2017).
Whatever the underlying cause, treatment of renal disease during pregnancy tends to be managed by an interprofessional team with a focus on supportive measures rather than on drug therapy, which could potentially harm fetal development. The goal, as Balofsky and Fedarau (2016) state, is always to prolong pregnancy until delivery is deemed safe.
To minimise any potential harms during pregnancy, specialist care should ideally begin with pre-pregnancy counselling, which has been described as a vital, yet largely underused tool for optimum management (Kapoor, Makanjuola and Shehata 2019).
As Wiles et al. (2019) point out, treatment and pre-pregnancy counselling are essential to help patients make informed decisions and allow time to ensure optimal renal function and stable blood pressure before conception.
During the pregnancy itself, additional challenges such as maintaining appropriate fluid balance often arise. For example, dehydration can cause acute kidney injury, especially for women with underlying chronic kidney disease, whereas fluid overload can cause pulmonary oedema, especially in women who have superimposed pre-eclampsia (NICE 2018).
Kapoor, Makanjuola and Shehata (2019) also highlight the need for more frequent scans throughout the pregnancy. These normally take place every 4 weeks from 28 weeks of gestation onwards to ensure adequate rates of fetal growth and amniotic fluid levels. Regular blood pressure monitoring is also essential, with a general recommendation that blood pressure should be maintained at no higher than 140/90 mmHg for the duration of the pregnancy.
Following delivery, interprofessional care should be maintained and patients should ideally be seen at a combined postnatal clinic before returning to continued care with their established nephrology team.
Taking an interprofessional approach is key to the successful management of renal disease in pregnancy, but there are relatively few studies exploring care from the patient’s perspective. This information could be of great value in guiding clinical approaches to pre-pregnancy counselling.
In order to address this knowledge gap, Jesudason, Mohammadi and Fitzpatrick (2016) performed a systematic review of 15 qualitative studies based on 257 women with renal disease. Common themes were identified, including:
A fundamental concern arising out of these studies was the patient’s distress at the focus on negative outcomes, and perceived discouragement and judgment by medical professionals, together with feelings of a lack of ownership in the decision-making process. In contrast, significant hope was reported when a positive attitude was shown by clinicians. In other words, these studies all flagged the importance of sensitive preconception counselling that embraces shared decision-making and acknowledges the patient’s goals and priorities.
As Safi et al. (2019) point out, there are currently no guidelines or policies to facilitate the delivery of specialised pregnancy care to women with renal disease in Australia, suggesting that further research studies are needed to help guide and inform current practice.
With preconception counselling and interprofessional care in place, patients with mild renal disease can do well in pregnancy. For those with moderate to severe kidney dysfunction, however, the outlook is less promising and many face the prospect of pregnancy-related complications as well as long-term renal deterioration (Kapoor, Makanjuola and Shehata 2019).
The challenging nature of these pregnancies underscores just how important pre-pregnancy planning can be. As Wiles et al. (2019) say, although chronic kidney disease is not a barrier to pregnancy in most women, the risk of adverse pregnancy outcomes can be increased significantly. Pre-eclampsia, restricted fetal growth, pre-term delivery and accelerated loss of maternal renal function are all common complications that must be considered when planning a pregnancy.
As Hewawasam et al. (2020) suggest, achieving parenthood can be difficult for these patients, especially those who are receiving some form of renal replacement therapy for end-stage kidney disease. The presence of pre-existing chronic renal disease of any stage can have an adverse effect on maternal and perinatal outcomes, and although it’s not a barrier to pregnancy, the risk of complications and adverse outcomes is significant. For midwives, awareness of these risks can help them to provide sensitive, well-coordinated care for the whole family, building on the understandings achieved during pre-pregnancy counselling.