Low birth weight is a major global health issue, particularly in low- and middle-income countries, often resulting from preterm birth or being small for gestational age. Low birth weight increases the risk of neonatal mortality, childhood morbidity, growth faltering, and reduced cognitive development.
Public health strategies have focused on early childhood nutrition and infection control, but since growth restriction often begins during the fetal period, these may be insufficient. Maternal and fetal infections are identified as key contributors to preterm birth and fetal growth faltering, yet there is limited data on how pregnancy interventions affect long-term child health.
A randomized controlled trial in Malawi tested earlier whether intermittent preventive treatment for malaria (IPTp) and reproductive tract infections during pregnancy could reduce preterm birth and low birth weight. Women receiving monthly sulfadoxine-pyrimethamine (SP) and two doses of azithromycin had infants with lower risks of preterm birth, low birth weight, and stunting at four weeks, compared to those receiving standard Malawian antenatal care.
The aim of Lotta Hallamaa’s doctoral dissertation was to assess if the gains in child size soon after birth were sustained and reflected in childhood growth, development, and mortality, among infants born to mothers who received intensified infection treatment during pregnancy. The study also assessed the impact of monthly SP with or without two doses of azithromycin on maternal PCR-diagnosed malaria positivity during pregnancy and on the fetal growth velocity.
The results suggest that preventive maternal treatment with monthly SP with or without azithromycin reduced malaria positivity during pregnancy. The findings do not support the hypothesis that the intervention would increase the fetal head or thigh growth velocity. IPTp with azithromycin and monthly SP during pregnancy reduced the incidence of stunting in childhood and had a positive effect on child development at five years of age and may have reduced postneonatal mortality.
“The results of this study were encouraging in terms of sustained benefit of antenatal infection control on child growth and development. However, these results should not be interpreted to promote widespread use of broad-spectrum antibiotics as routine antenatal treatment, because of the increasing antimicrobial resistance,” Hallamaa says.
“Instead, the results should mainly be considered indicative of a causal role of maternal infections and inflammation in fetal growth restriction and its sustained impact on child growth and development, and to be taken into account when planning new interventions to improve birth outcomes and child health in low- and middle-income settings,” Hallamaa adds.
Public defence on Friday 27 June
The doctoral dissertation of MSc Lotta Hallamaa in the field of global health titled The Impact of Antenatal Azithromycin and Monthly Sulfadoxine-Pyrimethamine on Maternal Malaria during Pregnancy, Fetal Growth, and Child Health Outcomes will be publicly examined in the Faculty of Medicine and Health Technology at Tampere University at 12 o’clock on Friday 27 June 2025 at Kauppi campus, Arvo building, auditorium F115 (Arvo Ylpön katu 34, Tampere). The opponent will be Professor Terhi Ruuska-Loewald from University of Oulu. The custos will be Professor Per Ashorn from Tampere University.