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Objective To determine whether nitric oxide donors can induce cervical ripening before surgical Design Prospective, randomised controlled trial.Setting Department of Obstetrics and Gynaecology, Royal Infirmary, Glasgow.Participants Forty-eight primigravid women undergoing surgical termination of pregnancy before 12 weeks of gestation. MethodsThe women were randomised to receive per vaginam before surgery either the nitric oxide donor isosorbide mononitrate, the nitric oxide donor glyceryl trinitrate, the prostaglandin analogue gemeprost, or no treatment. Main outcome measuresThe cumulative force required to dilate the cervix to 8 mm was measured objectively and the cervical diameter before surgical dilatation was recorded.Results Following isosorbide mononitrate or gemeprost, a lower cumulative force was required to dilate the cervix to 8 mm and a higher cervical diameter before dilatation was recorded. Pretreatment with glyceryl trinitrate reduced the cumulative force required to dilate the cervix but had no effect on cervical diameter. ConclusionsLike the prostaglandin analogue gemeprost, the nitric oxide donors isosorbide mononitrate and glyceryl trinitrate can effect cervical ripening. Nitric oxide donors may provide an alternative to prostaglandins for cervical ripening before surgical procedures in the first trimester.termination of pregnancy in the first trimester. INTRODUCTIONThe control of cervical ripening is crucial to the process of human parturition. Animal studies have shown that nitric oxide, a free radical with a short half-life', is a fundamental mediator of the ripening process. The nitric oxide generating system is present in the rat cervix and is up-regulated during labour both at term and preterm2s. In pregnant guinea pigs the local application of the nitric oxide donor, sodium nitroprusside, effectively produces cervical ripening without inducing labour". Cervical ripening is an active process involving remodelling of the cervical tissue. This process can be induced pharmacologically in the first trimester to facilitate procedures such as surgical termination. Preoperative cervical ripening reduces the morbidity of surgical termination, including haemorrhage, incomplete uterine evacuation, uterine perforation and cervical trauma5-'. The role of nitric oxide in human cervical ripening has not been investigated. We hypothesise that nitric oxide donors can effect cervical ripening in humans. We therefore performed a randomised controlled trial to determine whether the nitric oxide donors, isosorbide mononitrate, and glyceryl trinitrate, can induce effective cervical ripening before surgical termination of pregnancy. In addition, we compared their ripening effects with those of the prostaglandin analogue gemeprost, the cervical priming agent currently used in our hospital. METHODSA prospective randomised controlled trial was performed involving 48 primigravid women referred for surgical termination of pregnancy by vacuum aspiration in the first trimester. The study was approved by the local res...

We assessed the factors influencing the birth weight of infants born to 83 women with insulin-dependent diabetes mellitus (IDDM) over a 5-yr period. Maternal glycosylated hemoglobin (HbA1) concentrations at delivery correlated with the percentile birth-weight ratios (r = .43, P less than .001) and indicated that approximately 18% of variance in the birth weight could be ascribed to glycemic control in the third trimester. Fetal macrosomia occurred in 22 (27%) pregnancies. When 20 of these pregnancies were compared closely with 20 nonmacrosomic pregnancies in diabetic women, the mothers of macrosomic infants were found to be more obese, have a history of previous macrosomic birth, and have higher concentrations of serum human placental lactogen and urinary estriols in the third trimester. Macrosomic pregnancy was further distinguished by accelerated fetal growth (judged by serial ultrasonography) from the 32nd wk of gestation and by biochemical (but asymptomatic) hypoglycemia in the neonate. In our study, no serious neonatal morbidity could be attributed to macrosomic pregnancy. Good glycemic control was attained in both groups, and no significant differences between the groups in overall glycemic control throughout pregnancy were noted. Thus, despite good glycemic control, macrosomia remains comparatively common in modern pregnancy complicated by IDDM, and factors other than maternal hyperglycemia must contribute to its etiology.

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