Alan G. Monheit

Knowing is believing: information and attitudes towards physical activity during pregnancy

Physical activity is safe for most pregnant women and improves maternal fitness and birth outcomes. Yet, despite evidence of benefit, prevalence rates are low. Research in other populations suggests that attitudes and information are associated with physical activity. We examined the sources and types of information that women receive about physical activity during pregnancy and their association with attitudes towards prenatal physical activity. We also investigated whether particular groups of women are more likely to receive physical activity information. Questionnaires were completed by 179 ethnically and socio-economically diverse pregnant women. Women who were younger, unpartnered, less educated and had less income were less likely to report receiving information about prenatal physical activity. Receipt of information concerning benefits and risks of activity, risks of inactivity and specific techniques was associated with more favourable attitudes towards physical activity. Women who perceived low risk of birth complications also held more favourable attitudes. Some viewed all forms of physical activity as dangerous. Results suggest that providing information about benefits and risks of prenatal physical activity may motivate pregnant women to practice better health behaviours.

Intravenous gammaglobulin therapy in the management of a patient with idiopathic thrombocytopenic purpura and a warm autoimmune erythrocyte panagglutinin during pregnancy.

Intravenous gammaglobulin (IVIgG) was recently introduced for the treatment of idiopathic thrombocytopenic purpura (ITP). Reported is a previously splenectomized patient who had a severe exacerbation of her ITP during pregnancy and was managed with large doses of IVIgG throughout the second half of her pregnancy. She also had an autoimmune IgG erythrocyte panagglutinin on her red blood cells and in her serum, but only minimal evidence of hemolysis. There was little or no transplacental passage of her autoimmune antibodies since she delivered a normal fetus after 34 weeks of gestation who had a normal platelet count and no evidence of an antierythrocyte antibody. Interestingly, at the time of delivery the mothers serum IgG was dramatically elevated, but the cord serum IgG was normal for the length of gestation, indicating the presence of a dramatic and abnormal difference in IgG between maternal and fetal blood. This raises the possibility that the IVIgG therapy may have actually prevented transplacental passage of the pathological antibodies.

Fetal Heart Rate and Transcutaneous Monitoring during Experimentally Induced Hypoxia in the Fetal Dog

ABSTRACT: A model of impaired oxygen delivery, using an acute surgical preparation in the fetal dog, is described. Fetal heart rate, transcutaneous pO2 and pCO2, and tissue pH were simultaneously recorded during hypoxic episodes produced by a series of successive occlusions of the maternal abdominal aorta. Corresponding values were also determined in the arterial blood of the fetus. The following pathophysiologic sequence of events was observed: 1) a latency period with no changes; 2) a drop in pO2 which stabilized later at a lower pressure; 3) late fetal heart rate deceleration, the pattern of which was not related to the progressively deteriorating fetal condition; 4) a progressive increase in pCO2; 5) a progressive decrease in pH. Abnormal tissue values consistently preceded and were more adversely affected than corresponding blood values. This experimental model demonstrates first that late decelerations of the fetal heart rate are an early sign of fetal hypoxia and second that a fall in fetal blood pH, beyond that level normally seen during labor, occurs relatively late in this pathophysiologic sequence. Between these two, there are intermediary stages that could be continuously monitored in order to identify worsening fetal condition. Continuous tissue pH and transcutaneous pO2 and pCO2 recording may potentially be of significant clinical value.

The use of a rapid in situ technique for third-trimester diagnosis of trisomy 18

A rapid in situ coverslip technique was used to diagnose trisomy 18 within 1 week of amniocentesis in the third trimester. Two cases are presented. The clinical significance and advantages over umbilical vein aspiration are discussed.

The use of an indwelling Doppler probe to study acute changes in umbilical artery waveforms in the fetal sheep

A chronic sheep model for Doppler umbilical vascular analysis was developed, in which indwelling Doppler probes were used. These were designed with a fixed angle of insonation and implanted directly on the umbilical cord to register umbilical artery velocity waveforms. The fetuses in eight pregnant ewes underwent maternal aortic and umbilical cord constrictions producing serial blood flow reductions. Occlusion of the umbilical cord and maternal aorta caused distinctly different waveforms. Cord occlusion produced an immediate response with an elevated systolic/diastolic ratio and disappearance of diastolic velocity. Maternal aortic occlusion produced a delayed response with drops in both systolic and diastolic velocity; diastolic velocity never reached zero. Although systolic/diastolic ratios are believed to reflect placental resistance, the maintenance of the systolic/diastolic ratio with diminution of systolic velocity suggests declining fetal cardiac output as an additional factor. It is possible to differentiate uteroplacental from umbilicoplacental insufficiency by Doppler methods. With technologic improvements Doppler ultrasonography may allow better analysis of acute stressful conditions during human labor.

Failure of ibuprofen in treatment of herpes genitalis

Motrin (ibuprofen), a potent inhibitor of prostaglandin synthetase, was tested in women and men for treatment of recurrences of genital herpes. In a double-blind trial, no statistically significant differences were observed between treated and placebo groups in any of the measured parameters.

Arterial Po2, Pco2, and pH versus transcutaneous Po2 and Pco2 and tissue pH in the fetal dog

In the fetal dog, simultaneous recording by transcutaneous PO2 and PCO2 and tissue pH electrodes were compared to corresponding arterial values during hypoxic episodes produced by occlusion of the maternal abdominal aorta. Before occlusion, the differences between the paired values were minimal. Under anoxic conditions, expected changes in the peripheral circulation were observed. However, the transcutaneous PO2 was lower, the transcutaneous PCO2 much higher, and the tissue pH much lower than in blood. Continuous electrodes demonstrate changes resulting from gas and hydrogen ion coming from cells more readily than blood because they are closer to the former. Additionally, carbon dioxide and hydrogen ion are buffered to a greater degree in blood than in cells. Consequently, under conditions of stress and active metabolism, PCO2 is higher while PO2 and pH are lower in cells than in blood. When compared with monitoring of gases and acid-base balance through blood sampling, continuous transcutaneous and intracutaneous monitoring would seem to be more representative of the environment at the cellular level.

Use of an indwelling Doppler probe to study acute changes in umbilical vein waveforms in the fetal sheep

A chronic sheep model for Doppler umbilical vascular analysis with indwelling probes was used for the investigation of umbilical vein velocity waveforms. Maternal aortic occlusions produced a delayed drop but never eliminated umbilical vein velocity. With umbilical cord occlusion, there was immediate umbilical vein waveform response. Sudden cord occlusion and release showed reactive venous overflow velocity at the beginning and end of occlusion. Total cord occlusion produced zero velocity, but within seconds, the flow velocity was seen despite persistent occlusion in 65% of the cases. A characteristic undulating venous waveform pattern synchronous with fetal heart rate in over half of the cases was often observed. Reduction of blood flow by uteroplacental insufficiency may be differentiated from umbilical cord occlusion.

Intrauterine Resuscitation in the Severely Distressed Fetal Dog

Severe fetal distress was produced in 16 fetal dogs by successive and/or prolonged occlusion of the maternal abdominal aorta in an acute surgical preparation, and was characterized in fetal arterial blood of 7.06 for pH, 10 mm Hg for O2, 127 mm Hg for CO2, and fetal heart rate decelerations. Five fetuses recovered spontaneously in utero and delivered normally; 3 needed maternal oxygenation before delivery; 3 suddenly died in utero; 5 fetuses were delivered while still alive in utero when the tpH reached 6.85, and eventually expired. Intrauterine recovery and resuscitation was effective in some fetuses.