Pregnancy complications and birth outcomes
Among medically recorded pregnancy complications the incidences of
threatened abortion (OR: 1.3, 95% CI: 1.2-1.5), threatened preterm
birth (OR: 1.4, 95% CI: 1.1-1.7) and anaemia (OR: 1.4, 95% CI:
1.3-1.6) were higher in the mothers of cases than in the mothers of
matched controls. On the contrary, the risk of gestational diabetes was
lower in the group of viral infections as compared to control mothers
(OR: 0.4, 95% CI: 0.23-0.9). Detailed data are shown in Table 2. In the
case of pregnancy complications, no differences have been found between
the specific virus groups and the viral infection group in general. The
only exception was a significantly higher risk of preeclampsia in the
influenza group as compared to control mothers (OR: 1.3, 95% CI:
1.0-1.8, p<0.05).
Data on pregnancy outcome measures are presented in Table 3. Events
during the 1st trimester may play a pivotal role in
the proceedings of the whole pregnancy, as it was mentioned before.
Therefore, pregnancy outcome results with a history of a viral infection
during the first three months are also given. No significant differences
have been detected in foetal birth weight or the prevalence of IUGR
between the infected and the control groups. Preterm birth measures
(birth before the completed 37th week or birth weight
under 2,500 grams) also did not differ significantly between the two
study groups. The only significant difference was the somewhat longer
gestational age detected among infected mothers as compared to the
control group (39.4±2.0 vs. 39.3±1.9 weeks). All pregnancy outcome
results in the group of 1st trimester virus infection
were congruent with results in the complete infected group. Among
specific viral infections a significantly lower birth weight
(2985.7±585.9 vs. 3297.4±521.0, p<0.05) and shorter
gestational age (38.1±1.4 vs. 39.3±1.9, p<0.05) have been
found in the case of mothers with hepatitis B as compared to the control
group. None of the other pathogens resulted in specific alterations in
pregnancy complications or birth outcomes different from virus
infections in general.