Fetal and post-natal growth in infants of mothers with multiple sclerosis: A case-control stud

Multiple sclerosis does not seem to adversely affect fetal and neonatal outcomes, although some studies reported a possible reduction in mean birth weight and length, and a higher incidence of preterm delivery, mainly in relation to the exposure to disease-modifying drugs (DMDs) during pregnancy. Few data are available on intrauterine fetal growth and postnatal somatic development of newborns from mothers with multiple sclerosis compared to those from healthy women. For these reasons, we decided to investigate fetal growth, neonatal anthropometric parameters, and postnatal somatic development up to 12 months of life in offsprings from MS mothers.

This retrospective cohort study included 211 women with multiple sclerosis, and 384 healthy women paired for maternal age and parity as controls. Fetal biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) measured during the third trimester of pregnancy (30-34 weeks' gestation) were retrieved from the computerized database of the Department (EcoPlus*) where the results of ultrasound exams performed in the hospital are stored. Newborn measurements (weight, length and head circumference) at birth were obtained from the hospital's computerized obstetric and neonatal database (Trackare* and Remote* data base); measurements at 6 and 12 months of life were obtained from the regional database (ECWMED*) of family pediatricians of our region.

No differences between the two groups were observed for all the fetal parameters considered, expressed as centiles of growth according to gestational age (biparietal diameter: p = 0.40; head circumference: p = 0.40; abdominal circumference: p = 0.32; femur length: p = 0.32). No differences in gestational age at delivery, birthweight, and in the incidence of low birthweight and small for gestational age newborns were observed between the two groups. In the multiple sclerosis group a significantly higher incidence of caesarean section (p = 0.01) and late preterm delivery (at less than 37 weeks'gestation, p = 0.001) were registered. The trends of postnatal growth in weight (F = 0.53; p-value = 0.590) and length (F = 0.44; p-value = 0.645) were superimposable between the two groups. The trends of growth for head circumference showed a slightly, not significantly greater head circumference of infants from mothers with multiple sclerosis at 6 months of life, but the values at twelve months of life in the two groups were similar (F = 0.85; p-value = 0.427) . Moreover, the trends of postnatal increase of weight (F = 1.016; p-value = 0.331), length (F = 2.001; p-value = 0.146) and head circumference (F = 1.591; p-value = 0.212) of newborns/infants (from birth to twelve months of life) born to mothers with multiple sclerosis who breastfed, mothers who did not, and in the control group were similar.

Multiple sclerosis in pregnancy does not seem to affect fetal growth and postnatal development during the first year of the offspring life. We think that these results represent an important and reassuring information to provide the patients with during preconception counseling.