Pregnancy Promotes Maternal Hippocampal Neurogenesis in Guinea Pigs

Adult neurogenesis in the hippocampal dentate gyrus (DG) modulates cognition and behavior in mammals, while motherhood is associated with cognitive and behavioral changes essential for the care of the young. In mice and rats, hippocampal neurogenesis is reported to be reduced or unchanged during pregnancy, with few data available from other species. In guinea pigs, pregnancy lasts ~9 weeks; we set to explore if hippocampal neurogenesis is altered in these animals, relative to gestational stages. Time-pregnant primigravidas (3-5 months old) and age-matched nonpregnant females were examined, with neurogenic potential evaluated via immunolabeling of Ki67, Sp8, doublecortin (DCX), and neuron-specific nuclear antigen (NeuN) combined with bromodeoxyuridine (BrdU) birth-dating. Relative to control, subgranular Ki67, Sp8, and DCX-immunoreactive (+) cells tended to increase from early gestation to postpartum and peaked at the late gestational stage. In BrdU pulse-chasing experiments in nonpregnant females surviving for different time points (2-120 days), BrdU+ cells in the DG colocalized with DCX partially from 2 to 42 days (most frequently at 14-30 days) and with NeuN increasingly from 14 to 120 days. In pregnant females that received BrdU at early, middle, and late gestational stages and survived for 42 days, the density of BrdU+ cells in the DG was mostly high in the late gestational group. The rates of BrdU/DCX and BrdU/NeuN colocalization were similar among these groups and comparable to those among the corresponding control group. Together, the findings suggest that pregnancy promotes maternal hippocampal neurogenesis in guinea pigs, at least among primigravidas.

Prediction of school outcome after preterm birth: a cohort study

ObjectiveTo identify if the educational trajectories of preterm infants differ from those of their term peers.DesignThis work is based on the Avon Longitudinal Study of Parents and Children (ALSPAC). Educational measures were categorised into 10 deciles to allow comparison of measures across time periods. Gestational age was categorised as preterm (23–36 weeks) or term (37–42 weeks). Multilevel mixed-effects linear regression models were derived to examine the trajectories of decile scores across the study period. Gestational group was added as an interaction term to assess if the trajectory between educational measures varied between preterm and term infants. Adjustment for possible confounders was performed.SubjectsThe final dataset contained information on 12 586 infants born alive at between 23 weeks and 42 weeks of gestation.Main outcome measuresUK mandatory educational assessments (SATs) scores throughout educational journal (including final GCSE results at 16 years of age).ResultsPreterm infants had on average lower Key Stage (KS) scores than term children (−0.46 (−0.84 to −0.07)). However, on average, they gained on their term peers in each progressive measure (0.10 (0.01 to 0.19)), suggesting ‘catch up’ during the first few years at school. Preterm infants appeared to exhibit the increase in decile scores mostly between KS1 and KS2 (p=0.005) and little between KS2 and KS3 (p=0.182) or KS3 and KS4 (p=0.149).ConclusionsThis work further emphasises the importance of early schooling and environment in these infants and suggests that support, long after the premature birth, may have additional benefits.

Gestational group B streptococcal infection in two twin pregnancies

Twin pregnancies represent an interesting pattern in which selective infection of one gestational sac over the other can occur. Despite the ubiquity of Group B streptococcus (GBS), only a few cases documenting twin gestational GBS infections have been reported. We describe two cases of gestational GBS infection in twin pregnancies (a monochorionic/diamniotic pregnancy and a dichorionic/diamniotic pregnancy) both resulting in the death of one twin.

N-terminal pro-C-type natriuretic peptide, but not C-type natriuretic peptide, is greatly elevated in the fetal circulation

We have identified recently a new peptide, NT-proCNP(1–50) (N-terminal pro-C-type natriuretic peptide), in the circulation of humans and sheep. A previous report of an elevated fetal–maternal gradient in immunoreactive CNP raised the possibility that processing and metabolism of proCNP may differ in maternal and fetal tissues. We therefore collected matching peripheral maternal and umbilical cord plasma samples at delivery from women with normotensive and pre-eclamptic pregnancies to investigate the presence and concentrations of CNP and NT-proCNP using HPLC and RIA. Plasma concentrations of NT-proCNP in normotensive umbilical cord plasma were 10-fold higher than maternal venous levels (246±17 compared with 24.3±1.8 pmol/l; P<0.001) and much higher than corresponding levels of CNP (3.6±0.4 compared with 1.8±0.3 pmol/l in the fetal and maternal plasma respectively; P<0.001). Although there was no significant difference between normotensive and pre-eclamptic plasma CNP concentrations in either maternal or umbilical cord blood, NT-proCNP showed a significant statistical interaction (F=5.8, P=0.025) between the source (maternal or fetal) and gestational group (normotensive or pre-eclamptic). Maternal NT-proCNP levels were raised in the pre-eclampsia group, whereas the converse was observed in umbilical cord blood. In conclusion, the greatly elevated ratio of NT-proCNP/CNP in fetal compared with maternal plasma suggests that synthesis, as well as clearance, of CNP (but not NT-proCNP clearance) are markedly increased in fetal tissues.

Age-dependent changes in the response of the lamb ductus arteriosus to oxygen and ibuprofen

Circular strips of ductus arteriosus from lambs of gestational age between 90 and 144 days (term 147 days) were studied in vitro at low (8–16 torr (1 torr = 133.322 Pa)) and high (426–622 torr) [Formula: see text]. Potassium- and oxygen-induced contractions increased with the gestational age and attained a maximum at term. At low [Formula: see text], ibuprofen, a blocker of prostaglandin synthesis, produced a dose-dependent contraction of the ductus at all ages and enhanced the potassium-induced contraction of the immature ductus (90–124 days). Both effects were relatively greater in the 103- to 107-day gestational group. At that age, ibuprofen also potentiated the oxygen-induced contraction. These findings, while confirming that a prostaglandin is involved in ductus patency, indicate that the prostaglandin-relaxing mechanism becomes functional at an early stage of gestation and reaches maximal activity before term. The existence of an active, prostaglandin-mediated relaxation in the preterm ductus may account, in part, for the reduced responsiveness of the vessel to oxygen. It is confirmed that ibuprofen and other nonsteroidal antiinflammatory drugs are well suited for the management of the premature infant with patent ductus arteriosus.