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The physiologic reactions of pregnant women and their fetuses were studied during routine commercial flights. Ten healthy pregnant women (32 to 38 weeks of gestation) each undertook two flights. Maternal respiratory and heart rates, transcutaneous PO2 and PCO2, blood pressure, uterine activity, and fetal beat-to-beat heart rate variability were continuously monitored. During these flights, maternal heart rate and blood pressure increased, and PO2 decreased significantly while PCO2 remained unchanged. Respiratory rate showed a short increase during takeoff and landing but remained unchanged during the rest of the flight. Mean fetal heart rate was within normal limits during the whole flight. No bradycardia, prolonged tachycardia, or significant loss of heart rate variability was observed. This study indicates no hazards of commercial flights to the mother and the fetus in uncomplicated pregnancies.

The objective of the study reported here was to investigate the reactions of mother and fetus to high-altitude hypoxia combined with physical exercise. The climb was passive, by means of scheduled journeys of the Grap Sogn Gion AG aerial cableway in Laax (Switzerland). The valley station is at an altitude of 1100 m, the mountain station at 2200 m. The mother exercised on a bicycle ergometer set to 25 watts for 3 minutes. The following were measured continuously and noninvasively: heart rate, respiratory rate, systolic and diastolic blood pressure, Po2 and Co2, uterus activity, and fetal heart rate. Twelve pregnant women with an average gestational age of 36 weeks (30th-39th week) took part in the study. Ten of the women were primiparae and two multiparae. During the trip up the mountain the barometric pressure dropped on average from 668 to 583 mmHg. This resulted in a maximum difference in Po2 between the valley and mountain stations of 18 mmHg. There were no systematic changes in Po2. Respiratory rate, heart rate, systolic and diastolic blood pressure remained unchanged during the trip up the mountain. The physical exercise at the mountain station led to an increase in respiratory rate from 12 to 20 min-1, while heart rate rose from 103 to 128 min-1, systolic blood pressure from 117 to 144 mmHg, and diastolic blood pressure from 70 to 90 mmHg. Six of the 12 women had regular contractions even during the trip up the mountain; these either remained unchanged or became less frequent in the course of the study. The mean fetal heart rate only changed slightly.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of Class II compression stockings on maternal and fetal circulation was studied in left lateral position and standing in 21 patients with uterovascular syndrome in late pregnancy. The effect of different compression pressures was analyzed in further seven women also suffering from uterovascular syndrome in late pregnancy. It was shown that the use of compression stockings causes a measurable improvement in maternal and fetal circulation. The most favourable compression pressure for the maternal circulation parameters measured is 40 mm Hg.

In 58 newborn infants a new iridium oxide sensor was evaluated for transcutaneous carbon dioxide (tcPCO2) monitoring at 42 degrees C with a prolonged fixation time of 24 hours. The correlation of tcPCO2 (y; mm Hg) v PaCO2 (x; mm Hg) for 586 paired values was: y = 4.6 + 1.45x; r = .89; syx = 6.1 mm Hg. The correlation was not influenced by the duration of fixation. The transcutaneous sensor detected hypocapnia (PaCO2 less than 35 mm Hg) in 74% and hypercapnia (PCO2 greater than 45 mm Hg) in 74% of all cases. After 24 hours, calibration shifts were less than 4 mm Hg in 90% of the measuring periods. In 86% of the infants, no skin changes were observed; in 12% of infants, there were transitional skin erythemas and in 2% a blister which disappeared without scarring. In newborn infants with normal BPs, continuous tcPCO2 monitoring at 42 degrees C can be extended for as many as 24 hours without loss of reliability or increased risk for skin burns.

The treatment of premature labor with beta-adrenergic substances is complicated by side effects. Although most human control mechanisms are pulsatile, therapy is usually administered continuously. We designed a microprocessor-controlled pump to allow pulsatile tocolytic infusion, hoping to reduce the total dose and thus the side effects. In 33 patients pulsatile bolus tocolysis was compared with continuous tocolysis in a control group of 38 patients. Bolus tocolysis required considerably less beta-sympathomimetic agent for comparable therapeutic success (median dosage 3.0 versus 15.9 mg, p less than 0.001). Duration of therapy under bolus tocolysis was also significantly shorter (p less than 0.05). Birth weight was higher after bolus tocolysis (median 3070 versus 2580 gm, p = 0.05). Additional indicators favored bolus tocolysis but were not statistically significant: a longer gestational period, fewer infants weighing less than 2500 gm, and a lower incidence of respiratory distress syndrome. Pulmonary edema occurred in one patient during continuous tocolysis.

The efficacy of low and high dose caffeine on idiopathic bradycardia and hypoxaemia was tested in premature infants. Among 41 infants admitted to the study 21 fulfilled the criterion for treatment, e.g. greater than 3 bradycardia or greater than 3 hypoxaemia during 6 h, and received a low dose of caffeine citrate (loading dose 10 mg/kg, maintenance dose 5 mg/kg/24 h) resulting in serum concentrations of 42 +/- 19 mumol/l (M +/- SD). Four infants had to be excluded later because a possible cause for the increased frequency of bradycardia and hypoxaemia was found. Ten infants met the treatment criterion once more and got a double dose of caffeine resulting in serum concentrations of 90 +/- 35 mumol/l. The efficacy of caffeine was evaluated by comparing for each infant the 12-h period preceding the treatment with three 12-h periods during treatment. Low dose caffeine reduced significantly the frequency of bradycardia (less than 0.01), but not the frequency of hypoxaemia. In those infants with insufficient response, who consequently got high dose caffeine, the frequency of bradycardia decreased significantly (p less than 0.01), whereas the frequency of hypoxaemia did not. These results have to be confirmed in a randomized placebo controlled trial.