OP03.03: Factors influencing transplacental transmission of IgG antibodies providing newborns with maternal passive immunity after COVID-19 in pregnancy

TY - JOUR

T1 - OP03.03: Factors influencing transplacental transmission of IgG antibodies providing newborns with maternal passive immunity after COVID-19 in pregnancy

AU - Tallarek, Ann-Christin

AU - Hollwitz, Bettina

AU - Lütgehetmann, Marc

AU - Arck, Petra

AU - Diemert, Anke

AU - Hecher, Kurt

PY - 2022/10/14

Y1 - 2022/10/14

N2 - ObjectivesMothers convey passive immunity to their newborns through the transplacental transfer of IgG antibodies. We aimed to evaluate the influence of specific factors modulating the transplacental IgG transfer rate (TPTR) in 57 mother/neonate dyads with maternal COVID-19 infection in pregnancy.Methods57 women with a COVID-19 infection in pregnancy proven by positive RT-PCR in a nasopharyngeal swab were included in this prospective cohort study. At birth, a venous blood sample was obtained from the mother. Cord blood was taken from the umbilical cord at childbirth after cord clamping. Commercially available high-throughput COVID-19 immunoassays were used for quantitative detection of IgG antibody against COVID-19 spike protein (Liasion Xl, Diasorine).Results21 women showed seroconversion at delivery, 36 women had no COVID-19 IgG antibodies in maternal or cord blood at delivery. A lack of antibodies was associated with a short infection-to-delivery interval (<21 days) or asymptomatic or mild infection. Median gestational age at delivery was 39.1 (range 33.4-42.0) weeks, median infection-to-delivery interval was 131 (range 33-261) days, including women in all trimesters. The transplacental transfer ratio of IgG was 139% (range 56-200%). There was positive correlation between the infection-to-delivery interval and the TPTR. The pulsatility index in the uterine arteries (PI) and the maternal body-mass-index (BMI) were negatively correlated with the TPTR.ConclusionsCOVID-19 IgG antibodies after COVID-19 infection in pregnancy seem to wane rather rapidly. Asymptomatic or mild infection is often associated with a lack of maternal antibodies at delivery leading to a missing passive immunity of the newborn. Several factors (e.g. PI in the uterine arteries, maternal BMI and the infection-to-delivery interval) might influence the transplacental transfer of COVID-19 specific antibodies but need to be evaluated in further larger cohort studies.

AB - ObjectivesMothers convey passive immunity to their newborns through the transplacental transfer of IgG antibodies. We aimed to evaluate the influence of specific factors modulating the transplacental IgG transfer rate (TPTR) in 57 mother/neonate dyads with maternal COVID-19 infection in pregnancy.Methods57 women with a COVID-19 infection in pregnancy proven by positive RT-PCR in a nasopharyngeal swab were included in this prospective cohort study. At birth, a venous blood sample was obtained from the mother. Cord blood was taken from the umbilical cord at childbirth after cord clamping. Commercially available high-throughput COVID-19 immunoassays were used for quantitative detection of IgG antibody against COVID-19 spike protein (Liasion Xl, Diasorine).Results21 women showed seroconversion at delivery, 36 women had no COVID-19 IgG antibodies in maternal or cord blood at delivery. A lack of antibodies was associated with a short infection-to-delivery interval (<21 days) or asymptomatic or mild infection. Median gestational age at delivery was 39.1 (range 33.4-42.0) weeks, median infection-to-delivery interval was 131 (range 33-261) days, including women in all trimesters. The transplacental transfer ratio of IgG was 139% (range 56-200%). There was positive correlation between the infection-to-delivery interval and the TPTR. The pulsatility index in the uterine arteries (PI) and the maternal body-mass-index (BMI) were negatively correlated with the TPTR.ConclusionsCOVID-19 IgG antibodies after COVID-19 infection in pregnancy seem to wane rather rapidly. Asymptomatic or mild infection is often associated with a lack of maternal antibodies at delivery leading to a missing passive immunity of the newborn. Several factors (e.g. PI in the uterine arteries, maternal BMI and the infection-to-delivery interval) might influence the transplacental transfer of COVID-19 specific antibodies but need to be evaluated in further larger cohort studies.

U2 - 10.1002/uog.23940

DO - 10.1002/uog.23940

M3 - Conference abstract in journal

VL - 58

SP - 65

EP - 66

JO - ULTRASOUND OBST GYN

JF - ULTRASOUND OBST GYN

SN - 0960-7692

IS - S1

ER -