209
Thompson et al, Fetal breathing activity
J. Perinat. Med. 20 (1992) 209-213
Fetal breathing movements and prostaglandin levels in pregnancies complicated by premature rupture of the membranes Peter J. Thompson, Anne Greenough, and Kypros H. Nicolaides
Department of Child Health and the Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, U. K.
1 Introduction
We previously demonstrated that the level of bicyclo-PGEM, the major stable metabolite of prostaglandin E2, was elevated in nine patients with pregnancies complicated by premature rupture of the membranes (PROM) compared to levels in control fetuses from pregnancies with intact membranes [15]. In the fetal lamb infusion of prostaglandin E2 has been shown to abolish fetal breathing movemelnts (FBM) [10]. Fetal breathing activity is important for normal antenatal lung growth [17]. In pregnancies in which the outcome has been fatal neonatal pulmonary hypoplasia, fetal breathing activity is absent [4]. It is thus tempting to speculate that in such pregnancies fetal breathing activity may have been affected by elevated prostaglandin levels. The aim of this study was to test this hypothesis by measuring breathing activity in those fetuses in whom cordocentesis was performed and prostaglandin levels assessed.
2 Methods
nation was recorded onto videotape which, at a later date, was analysed for the number of FBM and the proportion of the observation period that the fetus was breathing. FBM were defined as regular downward movements of the diaphragm with paradoxical movements of the fetal chest and abdomen. An episode of FBM continued until the fetus became apnoeic, defined as a breath-to-breath interval of six seconds or greater [12]. The duration of each of these episodes was then added together to give the total time the fetus spent breathing and this was expressed as a percentage of the one-hour observation period. These data were then related to reference ranges for fetal breathing activity related to gestational age [7]. Reference ranges for fetal breathing activity both in the fasting and post-prandial state were used. Following completion of the ultrasound examination the patients underwent cordocentesis, ultrasound-guided pucture of the umbilical cord. Fetal blood was thus obtained for rapid fetal karyotyping and estimation of 11 deoxy-13, 14 dihydro-15-keto-ll beta, 16-cyclo PGE2 (bicyclo PGEM), as has previously been described [15]. All patients subsequently underwent our routine policy of conservative management of PPROM [3]. The gestational age at delivery and the neonatal outcome was recorded.
Nine patients with pregnancies complicated by membrane rupture at a median gestational age of 28 weeks (range 22-31) were recruited. These patients were studied at a median of four days post membrane rupture (range 1 — 38) at a time when no mother had clinical signs of infection or premature labour. A real time ultrasound examination was performed for 60 minutes using 3 Results a 3.5 MHz curvilinear transducer. All examina- All fetuses made some breathing movements durtions were made approximately two hours after ing the ultrasound examination but the number breakfast, mothers having been requested not to of FBM ranged from 1 to 181, with a median of smoke on that morning. The ultrasound exami-Brought 21. The median percentage time spent breathing to you by | University of California 1992 by Walter de Gruyter & Co. Berlin · New York
Authenticated Download Date | 6/9/15 7:01 AM
210
Thompson et al, Fetal breathing activity
Table I. Fetal breathing activity Patient
1 2 3 4 5 6 7 8 9
Gestational age Fetal (weeks) breathing movements (n) 27 32 28 30 32 28 31 26 27
1 4 7 12 21 21 31 99 181
Time spent breathing [%] (expressed as a % of observation period)
Amount of time spent breathing (expressed as a % of the reference value, corrected for gestational age [%]) Fasting
Postprandial
Thompson et al, Fetal breathing activity
J. Perinat. Med. 20 (1992) 209-213
Fetal breathing movements and prostaglandin levels in pregnancies complicated by premature rupture of the membranes Peter J. Thompson, Anne Greenough, and Kypros H. Nicolaides
Department of Child Health and the Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, U. K.
1 Introduction
We previously demonstrated that the level of bicyclo-PGEM, the major stable metabolite of prostaglandin E2, was elevated in nine patients with pregnancies complicated by premature rupture of the membranes (PROM) compared to levels in control fetuses from pregnancies with intact membranes [15]. In the fetal lamb infusion of prostaglandin E2 has been shown to abolish fetal breathing movemelnts (FBM) [10]. Fetal breathing activity is important for normal antenatal lung growth [17]. In pregnancies in which the outcome has been fatal neonatal pulmonary hypoplasia, fetal breathing activity is absent [4]. It is thus tempting to speculate that in such pregnancies fetal breathing activity may have been affected by elevated prostaglandin levels. The aim of this study was to test this hypothesis by measuring breathing activity in those fetuses in whom cordocentesis was performed and prostaglandin levels assessed.
2 Methods
nation was recorded onto videotape which, at a later date, was analysed for the number of FBM and the proportion of the observation period that the fetus was breathing. FBM were defined as regular downward movements of the diaphragm with paradoxical movements of the fetal chest and abdomen. An episode of FBM continued until the fetus became apnoeic, defined as a breath-to-breath interval of six seconds or greater [12]. The duration of each of these episodes was then added together to give the total time the fetus spent breathing and this was expressed as a percentage of the one-hour observation period. These data were then related to reference ranges for fetal breathing activity related to gestational age [7]. Reference ranges for fetal breathing activity both in the fasting and post-prandial state were used. Following completion of the ultrasound examination the patients underwent cordocentesis, ultrasound-guided pucture of the umbilical cord. Fetal blood was thus obtained for rapid fetal karyotyping and estimation of 11 deoxy-13, 14 dihydro-15-keto-ll beta, 16-cyclo PGE2 (bicyclo PGEM), as has previously been described [15]. All patients subsequently underwent our routine policy of conservative management of PPROM [3]. The gestational age at delivery and the neonatal outcome was recorded.
Nine patients with pregnancies complicated by membrane rupture at a median gestational age of 28 weeks (range 22-31) were recruited. These patients were studied at a median of four days post membrane rupture (range 1 — 38) at a time when no mother had clinical signs of infection or premature labour. A real time ultrasound examination was performed for 60 minutes using 3 Results a 3.5 MHz curvilinear transducer. All examina- All fetuses made some breathing movements durtions were made approximately two hours after ing the ultrasound examination but the number breakfast, mothers having been requested not to of FBM ranged from 1 to 181, with a median of smoke on that morning. The ultrasound exami-Brought 21. The median percentage time spent breathing to you by | University of California 1992 by Walter de Gruyter & Co. Berlin · New York
Authenticated Download Date | 6/9/15 7:01 AM
210
Thompson et al, Fetal breathing activity
Table I. Fetal breathing activity Patient
1 2 3 4 5 6 7 8 9
Gestational age Fetal (weeks) breathing movements (n) 27 32 28 30 32 28 31 26 27
1 4 7 12 21 21 31 99 181
Time spent breathing [%] (expressed as a % of observation period)
Amount of time spent breathing (expressed as a % of the reference value, corrected for gestational age [%]) Fasting
Postprandial
