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Notes: Objective The aim of this study was to investigate the efficacy and safety of recombinant human relaxin (rhRIx) as a cervical ripening agent in women with an unfavourable cervix before induction of labour at term.Design A multi-centre, double-blind, placebo-controlled trial performed in Edinburgh, Glasgow and Oxford. Women were treated with 0, 1, 2 or 4 mg of rhRIx in a gel vehicle administered intravaginally. Analysis of variance tests were performed on all continuous variables, and Cochran Mantel-Haenszel tests employed for all discrete variables.Participants Ninety-six women at 37 to 42 weeks of gestation with a singleton pregnancy and a modified Bishop score of 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:14700328:BJO775:les" location="les.gif"/〉 4 were recruited.Results There was no significant difference in the change in modified Bishop score between the four treatment groups. The lengths of the first and second stages of labour were similar in all 4 groups. PGE2 and oxytocin requirements were similar in all groups, as was the mode of delivery. There was no evidence that relaxin was absorbed systemically when given in this way.Conclusion Recombinant human relaxin 1 to 4 mg, administered as an intravaginal gel, has no effect as a cervical ripening agent before induction of labour at term.

Notes: Objective To determine the concentrations of the metabolites of prostaglandin E2 (PGEM) and of prosta-glandin F2α (PGFM) prior to the onset of labour and during spontaneous labour, and to correlate the changes in concentrations of these metabolites with labour outcome.Design Longitudinal study throughout labour.Setting Labour ward of a large maternity unit.Subjects Seven primigravid and 11 parous women in the late third trimester with no signs of labour, and 17 primigravid and 11 parous women in spontaneous labour.Interventions Six of the primigravid women required augmentation with oxytocin because of dysfunctional labour.Results Before labour, parous women had significantly higher concentrations of both PGEM (P〈0.007) and PGFM (P〈0.006) compared with primigravid women. During labour, PGFM concentrations were significantly higher in both primigravid (P〈0.0002) and parous (P〈0.0001) women compared with the concentrations of these metabolites in women not in labour; the same was true for PGEM in primigravid (P〈0.003) but not in parous (P= 0.1) women. There was a small but significant increase (P〈0.02) in PGEM as labour progressed in both the normal groups. Amniotomy was associated with a significant increase in PGFM in primigravid and parous women (P〈0.002 and P〈0.009, respectively). The concentration of PGFM one hour following amniotomy correlated inversely with the amniotomy to delivery interval in both the normal primigravid (r=−0.624; P= 0.04) and the parous (r= 0.745; P= 0.021) groups. Women with dysfunctional labour showed no significant rise in PGEM or PGFM. Their PGFM concentrations were significantly lower than those seen in normal labour (P〈0.05). The concentration of PGFM in cord blood was significantly higher (P〈0.0001) in the parous women who laboured than in women delivered by elective caesarean section. There was no difference in the corresponding concentrations of PGEM (P= 0.9).Conclusions These data show that spontaneous labour is associated with increased concentrations of prostaglandin metabolites in the maternal plasma, and are consistent with PGF2α being an important stimulator of uterine contractility, with a relative deficiency of PGF2α being associated with dysfunctional labour.

Notes: Concentrations of prostaglandins Fα (PGF2α plus PGF1α) have been measured in terms of PGF2α equivalents by specific radioimmunossay in serial samples of amniotic fluid and peripheral plasma from five patients with spontaneous onset of labour, five induced by amniotomy followed by intravenous oxytocin and six by amniotomy followed by intravenous prostaglandin E2. The mean PGFα concentration in amniotic fluid at amniotomy in patients not in labour was 0.68±0.2 (S.D.) ng./ml. After three to four hours stimulation with oxytocin or PGE2, the concentration was 0.76±0.7 ng./ml. This value is significantly lower (p〈0.05) than the concentration in the first amniotic fluid sample taken from patients in spontaneous labour (2.34±l.7) ng./ml., despite uterine activity being tocographically greater in the former patients. In patients labouring spontaneously a transient decline was noted in amniotic fluid PGFα from 2.5±l.6 at amniotomy to 0.79±0.6 ng./ml. in the subsequent sample. A rise in amniotic fluid PGFα concentrations was noted in all patients during the course of labour but the extent of the increase was variable reaching 0.8 to 30 ng./ml.; in four of six patients in whom amniotic fluid sampling was continued during the second stage a further rise in PGFα occurred.Peripheral plasma levels of PGFα did not increase during labour.