Foley catheter or vaginal prostaglandin gel for labour induction
Induction of labour using a Foley catheter in women with an unfavourable cervix at term is similar to using vaginal prostaglandin E2 gel — but with fewer adverse effects in mother and baby. This is the conclusion of an open-label randomized controlled trial that included 824 women scheduled for induction of labour at term with a singleton pregnancy in cephalic presentation, intact membranes and an unfavourable cervix. Participants were randomized to one of two induction protocols: insertion of either a 16F or 18F Foley catheter into the cervix or of prostaglandin E2 into the posterior vaginal fornix. Over two-thirds of the women delivered spontaneously after induction, but oxytocin augmentation was required more often in the group receiving the Foley catheter (86% v. 59%; relative risk [RR] 1.66, 95% confidence interval [CI] 1.34–1.61). Rates of cesarean section (the primary outcome) were similar in both groups (23% v. 20%; RR 1.13, 95% CI 0.87–1.47), as were vaginal instrumental deliveries. Operative deliveries for fetal distress were less common in the catheter group (12% v. 18%, RR 0.68, 95% CI 0.49–0.95). Two serious adverse effects were reported: one uterine perforation and one uterine rupture, both in the prostaglandin group. See Lancet 2011; DOI:10.1016/S0140-6736(11)61484-0.
Oral contraceptives and risk of venous thromboembolism
Users of oral contraceptives containing desogestrel, gestodene or drospirenone are at least at twice the risk of venous thromboembolism than users of those containing levonorgestrel. Using data from four Danish national registries, the authors of this retrospective cohort study assessed the risk of venous thromboembolism from use of oral contraceptive agents, according to type of progestogen and dose of estrogen. The study period between 2001 and 2009 included over 1.4 million women between the ages of 15 and 49 years. There were 4307 first-time episodes of venous thromboembolism recorded, including deep venous thrombosis only (63.6% of episodes) and pulmonary embolism (26.2%). Compared with women who had never used oral contraceptives, the relative risk of venous thromboembolism in current users of oral contraceptives with levonorgestrel and 30 μg ethinylestradiol was 2.19 (95% confidence interval [CI] 1.74–2.75.) The relative risk in those using oral contraceptives with the same estrogen dose but combined with desogestrel was 4.21 (95% CI 3.63–4.87), with gestodene 4.23 (3.87–4.63) and with drospirenone 4.47 (3.91–5.11). The risk decreased with decreasing estrogen dose in some combined oral contraceptive agents. Contraceptive devices (e.g., hormone-releasing intrauterine devices) or pills containing only progestogens were not associated with an increased risk of venous thromboembolism. See BMJ 2011;343:d6423 doi: 10.1136/bmj.d6423.
Excision margins for primary cutaneous melanoma
For patients with cutaneous melanoma thicker than 2 mm, excision with a 2-cm resection margin appears to be sufficient and safe when compared with a 4-cm margin, say the authors of a multicentre randomized controlled trial. Over 930 patients aged 75 years or younger with clinically localized lesions on the trunk or upper or lower extremities were included. Overall survival rates at 5 years (65%) and 10 years (50%) were similar in both groups, with a hazard ratio of 1.11 (95% confidence interval 0.90–1.37), comparing the 2-cm group to the 4-cm group. Although isolated local recurrence was uncommon, melanoma usually recurred as regional lymph node metastases. In both groups, the most common cause of death was melanoma (about three of four deaths.) Male sex, location on the trunk, ulceration and tumour thickness more than 3 mm were independent negative prognostic factors for overall survival and risk of recurrence. The authors point out that with a surgical margin of 2 cm, the skin can usually be closed without skin grafting or flaps. See Lancet 2011; DOI:10.1016/S0140-6736(11)61546-8.
Screening strategies for cervical cancer
Either liquid-based cytology or conventional cytology can be used for cervical cancer screening in women aged 30 years or older; however, more evidence is needed before widely adopting enhanced screening that includes testing for human papilloma virus (HPV). In this systematic review for the US Preventive Services Task Force, the authors searched for studies comparing conventional cytology with liquid-based cytology or enhanced screening that included HPV testing. On the basis of four studies involving over 140 000 participants, liquid-based cytology had equivalent sensitivity and specificity to conventional cytology. Although six studies on diagnostic accuracy suggested that one-time HPV screening was more sensitive than conventional cytology (63%–98% v. 38%–65% for carcinoma-in-situ stage 2 or higher), this HPV screening strategy was consistently less specific (around 3%–5% lower.) In addition, there were mixed results for studies that looked at HPV testing plus conventional cytology compared with cytology alone. The authors raise concerns about increased false–positive results, unnecessary colposcopies and overdiagnosis with use of HPV testing either alone or with conventional cytology for screening for cervical cancer. See Ann Intern Med 2011; Oct. 17 [Epub ahead of print].