Key words
delivery - obstetrics - metabolic defects
Schlüsselwörter
Geburt - Geburtshilfe - Stoffwechselprobleme
Introduction
Chylomicronemia syndrome is a rare familial genetic disorder characterized by an abnormal
high level of triglycerides (> 11.3 mmol/L) and a massive accumulation of chylomicrons.
This condition can lead to the development of hepatosplenomegaly, occasionally lipemia
retinalis, eruptive xanthoma or/and abdominal symptoms [1], [2]. The incidence of this disorder is one in one million and it is caused by a gene
mutation of an enzyme called lipoprotein lipase or apoprotein C-II. The deficiency
of this enzyme, normally found in fat and muscle, determines the inability to reduce
fatty acids [2], [3]. In these cases one of the most feared potentially life threatening complications
is a severe acute pancreatitis (AP). The incidence of AP is approximately 5 % and
the mortality, in severe cases, can reach 39 % [4], [5]. During a pregnancy the woman undergoes profound and reversible anatomical and physiological
change which also involves the lipid metabolism.
We present a very rare case of a pregnant woman with a severe AP affected by a chylomicronemia
syndrome characterized by massive high levels of triglycerides in blood.
Case
A 38-year-old gravida 2, para 0 with an uneventful course of pregnancy and a history
of a hypertriglyceridemia (HTG) of unknown origin for over 20 years was referred at
37 0/7 weeks of gestation to a nearby hospital with sudden and persistent abdominal
pain. The chemical analysis excluded a HELLP syndrome but showed elevated pancreatic
enzymes (lipase 1690 U/l, amylase 1533 U/l) with significant HTG (triglyceride 155 mmol/l).
A diagnosis of acute pancreatitis was made and because of decreased coagulation values
the patient was transferred to our hospital. At admission, a pathological fetal heart
tracing associated with a breech presentation was detected and a caesarean delivery
was performed immediately. The Apgar score of the female newborn was 5/8/8 at 1, 5
and 10 minutes, with a birth weight of 2720 g. The pH from the umbilical cord were
7.26 (artery) and 7.59 (vein). Once transferred to our intensive care unit a computer
tomography scan confirmed an onset of an AP associated with a massive abdominal fluid
collection ([Fig. 1]). An acute pancreatitis secondary to HTG was considered. A conservative treatment
with systemic antibiotics (imipenem), fluid replacement and parenteral nutrition was
tried without success. For this reason a surgical debridement was performed and an
infected necrosis of the pancreas was detected. The operation was performed via an
upper midline access. Once localized the debridement was begun by a blunt dissection
of the necrotic tissue. During the hospitalization the severe hypertriglyceridemia-induced
pancreatitis was caused by a chylomicronemia syndrome (not known by the patient) associated
by oestrogen exposure due to the pregnancy. After a long-lasting hospitalisation with
cessation of oral intake and a continuous postoperative lavage the patient could be
discharged home after 2.5 months in good general condition.
Fig. 1 Computer tomography scan showing the onset of acute pancreatitis.
Discussion
During pregnancy the lipid metabolism changes, characterized by an elevation of total
plasma cholesterol and triglyceride levels. This is normally caused by an increased
liver synthesis of triglycerides in response to elevated estrogen levels. These changes
are important for the fetal-maternal needs. This high level of triglyceride concentration
in the serum permits the mother to spare glucose for the fetus and allows, thanks
to elevated LDL cholesterol levels, the placental stereodogenesis [6].
Acute pancreatitis is a life-threatening condition caused by different agents [7]. HTG, after alcohol and gallstones, is considered the third most common cause of
AP ([Table 1]). The identification of risk factors, like HTG, plays an important role in preventing
AP. This disease has not yet not occurred in patients with triglyceride levels under
5.6 mmol/L, but the risk of AP increases above this value and markedly over 11.3 mmol/L
[8].
Table 1 Common causes of acute pancreatitis.
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Pregnancy-induced HTG has been found to be responsible for up to 56 % of cases of
AP. In an uncomplicated pregnancy the serum triglycerides rarely exceed 3.3 mmol/L
but if they do so, like in our case, the cause can be an unrecognized genetic disorder
that elevates the concentration of triglycerides, predisposing the pregnant woman
for AP [9].
Our patient had a history of undiagnosed cause of HTG for over 20 years. In this case
the pregnancy had probably acted as triggering factor that determined an exacerbation
of a pre-existing lipid abnormality determining a markedly elevation of triglycerides
in blood up to 155 mmol/L. The result was severe onset of AP with an increased risk
of mortality for both mother and fetus.
Preventive measures in patients affected by a chylomicronemia syndrome, especially
before pregnancy occurs, play an important role to avoid an AP. When triglyceride
levels are above 5.6 mmol/L a nonpharmacological treatment with weight loss, aerobic
exercise, avoidance of sugars and strict glycemic control is considered sufficient
to minimize the risk of AP [10], [11]. On the contrary when the triglyceride level exceeds 11.3 mmol/L, a pharmacological
treatment for example with gemfibrozil must be started as soon as possible. This therapy
is often required during the third trimester of pregnancy, a period during which the
serum levels of triglycerides are normally at their highest [12], [13].
When an AP caused by HTG is detected, the therapy resembles that of pancreatitis of
other origin, but differs in terms of the severity of the disease. In a mild AP, supportive
care including pain control, intravenous fluids, correction of electrolyte and metabolic
abnormalities is suggested. Intravenous insulin is a low-cost and effective good alternative
treatment in HTG-induced pancreatitis during pregnancy [9]. This differs from cases of a severe AP where the mortality rate is around 39 %
and monitoring in an intensive care unit with support of renal, circulatory, pulmonary
and hepatobiliary function with cessation of oral intake is strictly recommended.
Fluid replacement and antibiotics like imipenem are usually administered to avoid
a vascular leak syndrome in case of a necrotizing pancreatitis [14].
Conclusion
Early diagnosis of chylomicronemia syndrome is the key component to avoid severe complications
and improve pregnancy outcome. Practitioners have an important role in evaluating
chylomicronemic patients and implementing therapeutic lifestyle and pharmacologic
interventions aimed to reduce the risk of AP.
