Mother-infant relationship and weight gain in the first month of life

Chronic stress in pregnant rats: effects on growth rate, anxiety and memory capabilities of the offspring

Female rats were repeatedly stressed for 10 periods of 15 min by the presence of a cat, at the 10th (S10) or the 19th (S19) gestational day. The litter from stressed females often contained a majority of males or a majority of females, especially in the S19 group. The death of pups was dramatically high in the S19 group and, compared with controls, growth of the surviving animals was slower. When adult, their long-term memory was altered and they exhibited an aversive behavior relative to wide areas. Moreover, cognitive alterations were revealed by the low level of exploration and the inability to rapidly process the relevant environmental cues. These deficits resemble those of psychiatric patients who had been submitted to pre-natal stress.

Effect of chronic intermittent stress on rat pregnancy and postnatal development

The present study evaluates the effect of chronic intermittent cold-swimming stress on body weight gain of pregnant rats and subsequent development of the offsprings after birth, till peripubertal stage. When stress was administered during the first half (1-11 days) of gestation, weight gain of pregnant rats was significantly lower at the 9th and 11th days (P < 0.05 vs. control, respectively). No differences of weight gain in comparison with control rats were found at term gestation in pregnant rats exposed to stress continuously. Similarly, stress administered, starting from 12th day till term gestation, had no effect on weight gain. Even though weight gain of pregnant rats during the second half of pregnancy in group stress 1-11 was restored to normal values, a high mortality rate of neonates 1, 2 and 3 weeks after birth was found in this group (P < 0.02, 0.01 and 0.001 vs. controls). There was no significant difference between stressed and control groups with respect to the number or body weight of litters, as well as weight gain of neonates during the first 21 days of life. In addition, in offsprings from all stressed groups, a high number of small for date animals was found after 14 days of life, and 74.4% of these small for date animals died during the peripubertal period. The present data demonstrate that the exposure to stress in utero may induce damaging effects on postnatal development.

Maternal Emotionality During Pregnancy and Reproductive Outcome: A Review of the Literature

Empirical studies dealing with the relationship between maternal emotionality during pregnancy and reproductive outcome are critically reviewed. In general, the results of the studies reviewed support the notion of a relationship between maternal emotionality and reproductive outcome. The most methodologically acceptable studies were those linking the emotional state of the expectant mother to habitual abortion, hyperemesis gravidarum, toxemia, deviant infant behavior, and a variety of pregnancy and birth complications. Anxiety is the emotional condition most often studied and implicated in reproductive complications. However, the available data do not permit any conclusions regarding the nature of the relationship between maternal emotionality and obstetric and reproductive outcome. Mediating factors and methodological difficulties are briefly discussed.

Maternal anxiety in pregnancy and fetal homeostasis

Although it is recognized that pregnant women may be extremely anxious and that anxiety is accompanied by sympathetic nervous system hyperactivity, little clinical consideration has been given to the potential harm to the fetus. A review of the literature, including research on both animal and human pregnancies, reveals what is known about this subject. A section on implications for maternity care follows, including a summary of the possible effects of anxiety during pregnancy, identification of women most at risk from anxiety, and intervention measures.

Early mother--infant interaction and somatic growth

This study tests the proposition that selected behaviors of both mother and infant during feeding are predictors of weight gain during the 1st mth of life. 40 normal mother--neonate pairs were studied, and the target behaviors were examined using an adaptation of the techniques developed by Brown and Bakeman [18]. Aggregate scores of 4 specific maternal and infant behaviors accounted for over 32% of the variance in total weight gain. These findings indicate that the availability of nutrients is not, in itself, a sufficient condition to meet the infant's nutritional needs. Implicit in these findings are the possibilities that infants at risk of failure-to-thrive can be identified, and measures to prevent this syndrome can be introduced.

Production of fetal asphyxia by maternal psychological stress

Several lines of evidence indicate that maternal psychological stress leads to adverse pregnancy outcome in rhesus monkey. Chronic anxiety causes an increased stillbirth rate, fetal growth retardation, and altered placental morphology. On another time scale, lightening of maternal anesthesia during surgery produces an impaired fetal oxygenation while re-institution of anesthesia ameliorates the fetal asphyxia. The present study, for the first time, demonstrates a relationship between specific episodes of meternal psychological stress and exacerbation of fetal asphyxia in utero. Eight term pregnant rhesus monkeys were anesthetized with sodium pentobarbital. Catheters were placed both into the maternal and the fetal femoral arteries for the continuous recording of blood pressure and heart rate and for the intermittent campling of maternal and fetal blood. An open-ended catheter recorded intrauterine pressures. Following a complete repair, the anesthesia of the mothers was allowed to lighten. As the mothers awakened, the fetuses invariably showed the developemnt of fetal asphyxia. A fetal acidosis developed and the fetal oxygenation and repair of acidosis. Studies while the mothers were fully awake showed the repeated and regular development of episodes of heightened fetal asphyxia produced by episodes of stressful stimulation of the mothers. Episodes of maternal psychological stress led to changes in both fetal vital signs and blood chemical findings. These alterations in fetal state regularly followed the onset of the episodes of psychological stress by 50 seconds. These changes also usually remitted 50 seconds following the termination of the periods of stress. These results demonstrated a direct and unequivocal relationship between meternal psychological stress and fetal asphyxia. It is assumed the maternal stress produces impairments in the circulation to the uterus through an increased sympathetic nervous system activity and a shunting of the maternal blood-flow from the abdominal viscera to other organs as occurs in the fight-orflight reaction.

Maternal psychological stress and fetal asphyxia: a study in the monkey

Fifteen pregnant rhesus monkeys near term were anesthetized with pentobarbital. Catheters were placed into the right femoral arteries of the mother and fetus, the fetuses being retained in utero. After repair of all incisions, the mothers were placed on their sides and allowed to recover from anesthesia. As they awakened, their fetuses regularly developed blood chemical and, frequently, vital signs changes indicative of deepening asphyxia. In eight cases, anesthesia was reinstated with intravenous pentobarbital, 30 mg. per kilogram. This caused an immediate and significant improvement in oxygenation of the fetus in all instances. The remaining animals were transferred to restraining chairs where the blood chemical and cardiovascular statuses of the mothers and fetuses were followed over the next 3 to 72 hours. During this time, the mothers, fully awake, were subjected to both "contrived" and "incidental" episodes of psychological stress stimulation. In the majority of instances, these periods of stress to the mothers caused episodes of bradycardia and hypotension in their fetuses. These induced vital signs changes of the fetuses appeared regularly about 50 seconds after the beginning of the periods of stress stimulation of the mother. Similarly, the vital signs changes frequently began returning toward more normal values with 1 to 2 minutes after the alleviation of maternal stress. Blood samples drawn in single cases before, during, and after recovery from bradycardia identified an associated increase in asphyxia of the fetuses. These episodic aggravations of the already existent fetal asphyxia of the fetuses. These episodic aggravations of the already existent fetal asphyxia brought about by stress stimulation of the mother are interpreted as resulting from activation of the maternal sympathetic nervous system causing vasoconstriction throughout the abdominal viscera and an accompanying retardation in intervillous space perfusion.