Consenso colombiano de diagnóstico, prevención y manejo de la enfermedad Rh

Objective: To train healthcare professionals involved
in the care of Rh-D negative pregnant women,
with the aim of standardizing the management of
Rh isoimmunization prevention, timely antenatal
diagnosis of Rh disease, fetal assessment, and
treatment of fetuses with Rh disease, in order to
prevent adverse perinatal outcomes.
Materials and Methods: A group of 23 expert
panelists participated in the development of the
consensus through three rounds, answering a
questionnaire consisting of 8 domains and 22
questions. A modified Delphi method was used
until the consensus threshold among participants
was reached, defined as 80% or greater agreement
in responses. In the third round of the expert
panel, a twenty-third question emerged, which was
answered by one of the thematic leaders. The eight
domains of antenatal management for Rh-D negative pregnant women were: 1) Rh-D determination, 2)
initial prenatal care for Rh-D negative patients, 3)
titration and periodicity of the indirect Coombs test,
4) sensitizing events, 5) administration of anti-D
immunoglobulin (IgG), 6) Doppler velocimetry
of the middle cerebral artery (MCA), 7) antenatal
management of isoimmunized patients and anemic
fetuses, and 8) timing for pregnancy termination
based on different clinical scenarios. Based on these
responses, and a review of international clinical
practice guidelines, consensus statements were
formulated, including recommendations, their
justification, and adaptation to the local context.
Results: The following recommendations were
issued:
1. It is suggested that Rh-D negative women
of childbearing age attend a preconception
consultation.
2. It is recommended to determine maternal Rh-D
status at the first contact with health services,
either during the preconception consultation or
at the first prenatal check-up.
3. For Rh-D negative patients, it is recommended
to determine the Rh-D status of the child's father
during prenatal care as early as possible, preferably
before the 28th week of gestation.
4. For Rh-D negative primigravidas, where the father
is Rh-D positive, it is suggested to: a) determine and
quantify Rh-D antibodies (indirect Coombs test)
during the first consultation and then quarterly,
b) expand the obstetric history, with an emphasis
on identifying sensitizing events, and c) provide
parental counseling regarding potential risks, the
need for additional tests, and the possibility of
immunization during pregnancy.
5. During prenatal care for Rh-D negative multiparous
patients with previous Rh-D positive offspring, the
initial approach should include: a) determining
and titrating Rh-D antibodies (indirect Coombs
test); b) expanding the obstetric history, focusing
on sensitizing events; and c) providing parental
counseling about potential risks and additional
tests.
6. After a sensitizing event, it is recommended to
administer anti-D IgG within the first 72 hours at
a dose of 1500 IU (300 μg). If not feasible, it can be administered up to 4 weeks after the event if it
was not given initially.
7.1. For non-isoimmunized pregnant women (with a
negative Coombs test and Rh-positive newborn), it
is recommended to administer anti-D IgG between
weeks 28 and 32, and within the first 72 hours
postpartum if the newborn is Rh-positive. The
dose is 300 μg IM or IV.
7.2. In the case of a cesarean section in an Rh-D
negative patient with a Rh-D positive child, the
consensus does not recommend doubling the dose
of anti-D IgG. The dose remains the same as after
a vaginal delivery: 300 μg IM or IV.
7.3. In a twin delivery involving an Rh-D negative
patient with two or more Rh-D positive live-born
infants, the consensus recommends not doubling
the dose of anti-D IgG. The dose remains 300 μg
IM or IV, the same as after a vaginal delivery.
7.4. For a non-isoimmunized Rh-D negative patient
in the puerperium with immediate postpartum
surgical tubal sterilization and an Rh-D positive
neonate, anti-D IgG is recommended, assuming
no prior sensitization, given the potential for
reproductive decision changes or failure of the
procedure.
8. An Rh-D negative patient is considered
isoimmunized if: a) the indirect Coombs test is
positive at any titer, provided anti-D IgG was not
received in the previous month, or b) there is a
history of adverse perinatal outcomes associated
with Rh disease in prior pregnancies, such as
hydrops.
9.1. If Rh-D negative women are isoimmunized, it is
necessary to determine the anti-D antibody titer, as
this titer correlates with the severity of the disease
and determines the need for fetal anemia studies
with Doppler velocimetry of the MCA.
9.2. For isoimmunized Rh-D negative patients, it
is recommended to follow up with monthly
quantitative indirect Coombs tests until week 24,
then bi-weekly, or until reaching a critical titer (≥
1:16).
10.1. Doppler ultrasound of the MCA is suggested for
Rh-D negative patients with a positive indirect
Coombs test and titers ≥ 1:16. 10.2. In non-isoimmunized Rh-D negative patients,
the consensus does not recommend MCA Doppler
velocimetry.
10.3. Weekly MCA Doppler ultrasounds are
recommended for isoimmunized patients with
indirect Coombs titers ≥ 1:16.
10.4. The consensus suggests adopting a cut-off value
of ≥ 1.5 multiples of the median (MoM) of the
peak systolic velocity for gestational age on MCA
Doppler, as this value best correlates with fetal
anemia.
11. The consensus suggests Cordocentesis when
fetal anemia is suspected, and intrauterine fetal
transfusion when cordocentesis shows severe fetal
anemia. This procedure should be performed by
trained personnel.
12. It is recommended to prolong pregnancy until
the fetus has achieved sufficient lung and tissue
maturation to improve perinatal survival, according
to the indirect Coombs test titer threshold.
Conclusions: It is essential to address Rh-D negative
pregnant women, isoimmunized women, and
fetuses with Rh disease in an appropriate and
standardized manner, according to the Colombian
context, across all levels of prenatal care. The
recommendations issued in this consensus are
expected to improve clinical care, as well as
enhance perinatal health and neonatal quality of
life in cases of Rh disease.