(Mini-commentary on BJOG-20-0468.R1)
Rossana Orabona
Consultant, Division of Obstetrics and Gynaecology, Spedali Civili di
Brescia, Italy
Federico Prefumo
Associate Professor, Department of Clinical and Experimental Sciences,
University of Brescia, Italy
BJOG Scientific Editor
Correspondence: Federico Prefumo, Division of Obstetrics and Gynecology,
ASST Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, Italy
(e-mail
federico.prefumo@unibs.it)
The paper by Mulder et al. addresses the effect of pregnancy
prolongation on maternal and fetal outcomes in women with early-onset
pre-eclampsia diagnosed after 24 weeks of gestation (Mulder et al., BJOG
2020 xxxx). They report that pregnancy prolongation - from the time of
pre-eclampsia diagnosis to delivery - is associated with improved
offspring outcome and survival, without adverse consequences on
short-term maternal cardiovascular and metabolic function. The maternal
findings are apparently at odds with another recent study from New York
(Rosenbloom et al. Obstet Gynecol 2020;135:27-35) which observed an
increased risk of maternal cardiovascular events after pregnancy, in
case of an interval of more than 7 days between the diagnosis of any
hypertensive disorders of pregnancy and delivery.
Some issues should be pointed out in order to avoid misunderstandings
about these findings. Being Mulder et al.’s an observational study,
readers cannot infer causality because women were not randomized to the
length of pregnancy prolongation. Data are spread over a significant
time period (from 1996 to 2017), and this aspect could be another
confounder. Pre-eclampsia is a multi-organ syndrome based on chronic
inflammation, oxidative stress and endothelial dysfunction leading to a
persistent subclinical cardiovascular impairment and an increased risk
of adverse events later in life (Sciatti et al., Eur J Prev Cardiol 2020
doi: 10.1177/2047487320925646), similarly to what happens in cases with
heart failure with preserved ejection fraction. Myocardial geometry and
ejection fraction are not sensitive enough to be altered by just a few
days of pregnancy prolongation, and to forecast cardiovascular
consequences. Only innovative techniques such as speckle-tracking
imaging may document an impairment in myocardial contractility and
relaxation in former pre-eclamptics, even if ejection fraction is
normal.
Pre-eclampsia is currently defined as new-onset hypertension combined
with de-novo proteinuria and/or “adverse conditions” or “severe
maternal/fetal complications” (Magee et al., Pregnancy Hypertens
2014;4:105-145). International guidelines recommend that women with
severe forms of pre-eclampsia should be delivered immediately regardless
of gestational age, while an expectant management should be considered
for women with non-severe pre-eclampsia before term (Magee et al.,
Pregnancy Hypertens 2014;4:105-145; NICE guideline no. 133, 2019).
Delaying delivery is expected to benefit newborn’s health, which is well
exemplified by Mulder et al.’s findings. However, the fetus is often the
protagonist of adverse conditions, and severe complications such as
fetal growth restriction, often co-exist with early-onset pre-eclampsia,
requiring longitudinal monitoring with Doppler ultrasound and
cardiotocography. The timing of delivery depends on both maternal and
fetal conditions. The lack of data about fetal growth and Doppler and
cardiotocography findings (in cases with growth restricted babies)
limits the generalisability of the results by Mulder et al. One would
expect that a longer delay before delivery can be attained only in
fetuses and mothers with milder clinical manifestations of disease.
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