Andrew J. Thomson

Nitric oxide donors induce ripening of the human uterine cervix: a randomised controlled trial

Objective To determine whether nitric oxide donors can induce cervical ripening before surgical termination of pregnancy in the first trimester.

Cell adhesion molecule expression in the cervix and myometrium during pregnancy and parturition

Objective To determine the expression and localization of cell adhesion molecules intercellular adhesion molecule-1 (ICAM-1), E-selectin, platelet–endothelial cell adhesion molecule (PECAM), and vascular cell adhesion molecule (VCAM) in the cervix and myometrium during pregnancy and labor. Methods Biopsies of myometrium and cervix were obtained from non-pregnant women and from pregnant women before and after onset of spontaneous labor at term. Cell adhesion molecule mRNA expression was quantified using Northern blotting and cell adhesion molecule protein was localized using immunohistochemistry. Results ICAM-1 mRNA was upregulated in the cervix (10-fold increase, P < .01) and myometrium (10.5-fold increase, P < .01) during labor. ICAM-1 was localized in the vascular endothelium and in leukocytes in the cervix and myometrium from all three groups of women. VCAM mRNA was upregulated in the cervix (2.5-fold increase, P < .01) during pregnancy and there was no further change during labor. VCAM localized weakly to the vascular endothelium in cervical and myometrial biopsies from pregnant and non-pregnant women. PECAM mRNA was significantly upregulated in myometrium during pregnancy (ninefold increase, P < .01) and did not change with the onset of labor. PECAM localized to the vascular endothelium in all cervical and myometrial biopsies and was identified on leukocytes. There were no significant changes in E-selectin mRNA expression in either tissue with pregnancy or parturition. Conclusion Cell adhesion molecule expression changes in human cervix and myometrium during pregnancy and parturition. At least part of these changes are attributable to expression by leukocytes infiltrating these tissues.

Randomised trial of nitric oxide donor versus prostaglandin for cervical ripening before first-trimester termination of pregnancy

BACKGROUND Vaginal administration of the nitric oxide donor isosorbide mononitrate can induce effective ripening of the human cervix. We investigated whether this drug is associated with fewer side-effects than prostaglandins when used to ripen the cervix before first-trimester surgical termination of pregnancy, and assessed whether the extent of cervical ripening it induces is clinically sufficient. METHODS 66 primigravid women scheduled for surgical termination were assigned to receive before surgery, per vaginam, isosorbide mononitrate 40 mg or 80 mg, or the prostaglandin analogue gemeprost 1 mg. The primary measured outcome was onset of new symptoms before termination of pregnancy. FINDINGS More women remained symptom-free after isosorbide mononitrate than after gemeprost (28/44 [64%] vs 3/22 [14%], p<0.005). Pretreatment with gemeprost resulted in abdominal pain in 73% of women and vaginal bleeding in 32% compared with 3% and 0%, respectively, after isosorbide mononitrate, whereas, more women developed headache after isosorbide mononitrate (27%) than after gemeprost (0%). Cervical resistance and measured intraoperative blood loss were lowest after pretreatment with gemeprost. The measured cervical resistance and intraoperative blood loss with either dose of isosorbide mononitrate did not differ from those in a comparison group of 22 parous women not in the randomised trial. INTERPRETATION Pretreatment with isosorbide mononitrate to ripen the cervix before first-trimester termination of pregnancy is associated with fewer side-effects than gemeprost treatment and adequately decreases cervical resistance. Isosorbide mononitrate could be used as an alternative to gemeprost for this indication.

Accidental out‐of‐hospital deliveries: an obstetric and neonatal case control study

Background. Accidental out‐of‐hospital (OHD) deliveries are associated with high rates of perinatal morbidity and mortality. The ability of health care workers to identify women at risk of out‐of‐hospital delivery is limited. The purpose of this study was to determine the prevalence of these deliveries in our population and to quantify the neonatal morbidity and mortality associated with such births. Further we aimed to determine whether women at risk of accidental out‐of‐hospital delivery in our population could be identified antenatally.

Use of enoxaparin in a pregnant woman with a mechanical heart valve prosthesis

A 28 year old parous woman with a mechanical aortic valve prosthesis conceived following an episode of vomiting while on the combined oral contraceptive pill. At 7 weeks of gestation, when her pregnancy was ®rst con®rmed, she was instructed to stop taking warfarin and started self-administered subcutaneous enoxaparin at a dose of 80 mg (1 mg/kg body weight) 12-hourly. Aspirin 75 mg once daily was taken as an additional thromboprophylactic precaution. Eight years previously she had been found to have congenital aortic valve disease and had undergone a Bjork-Shiley aortic valve replacement. She had been asymptomatic prior to surgery and had remained well since the operation. Two years following her operation she had a pregnancy which was cared for in another obstetric unit using intravenous dose-adjusted unfractionated heparin from 6±12 weeks of gestation, warfarin until 36 weeks, and then reverting to intravenous heparin for the peripartum period. Labour was induced at 36 completed weeks of gestation and she had a spontaneous vaginal delivery of a baby girl weighing 3800 g. The delivery was complicated by a postpartum haemorrhage, but she did not require a blood transfusion. Her baby remained well and showed no signs of warfarin embryopathy or intracranial haemorrhage. For the remainder of her current pregnancy she remained well on a dose of 80 mg of enoxaparin twice daily and low dose aspirin. Her peak (3-hour post-dose) anti-factor Xa levels were monitored regularly and ranged from 0.38±0.92 IU/mL. Her platelet counts remained within normal limits and no thrombotic or haemorrhagic complications occurred. Labour was induced at 38 weeks of gestation by amniotomy followed by an intravenous infusion of oxytocin. The dose of enoxaparin was reduced to 40 mg twice daily during labour and regional anaesthetic techniques were avoided. She received intravenous antibiotics during labour. She had a spontaneous vaginal delivery of a baby girl. Ten IU of oxytocin were administered intramuscularly in the third stage. The estimated blood loss was 150 mL. There were no maternal or neonatal complications and no fetal abnormality. Following delivery, she reverted to enoxaparin 80mg twice daily until satisfactory levels of anticoagulation were achieved with warfarin (international normalised ratio .3.0).