Techniques for chorionic villus sampling and amniocentesis: a survey of practice in specialist UK centres.

OBJECTIVES: Guidelines exist for amniocentesis and chorionic villous sampling (CVS) practice, but there is no consensus regarding individual techniques. Our survey sought to review current practice within specialist centres in the United Kingdom. METHODS: RCOG sub-specialist training centres were invited to complete a postal questionnaire, seeking their consultants' primary choices for amniocentesis and CVS techniques. Information sought included needle choice, local anaesthetic (LA), suction methods, quantity of samples obtained; and with regard to CVS, preferred approach [transcervical (TC) or transabdominal (TA)]. RESULTS: Response rate was 96% providing information on 111 consultants (111 amniocentesis/90 CVS). During amniocentesis, 86% use 22G needles and 70% are helped by an assistant who aspirates a set liquor volume (69%). For CVS, 98% use a TA approach, 89% use LA, and 29% an 18G single needle with 38% preferring a 17/19G double needle but no clear consensus regarding the use of assistants. CONCLUSIONS: There is some agreement among specialists in the United Kingdom regarding techniques for invasive prenatal diagnosis. For amniocentesis, most operators use 22G needles, with an assistant to aspirate a set volume of fluid regardless of gestation. For CVS, there is considerable variation in needle choice, although most operators use a TA approach with LA.

Prospective observational study of bone mineral density during pregnancy: low molecular weight heparin versus control.

BACKGROUND: The aim of this study was to assess the effect of long-term low molecular weight heparin (LMWH) on bone mineral density (BMD) during pregnancy. METHODS: Fifty-five patients with recurrent miscarriage and known thrombophilia (antiphospholipid syndrome) were followed through pregnancy in an ethically approved prospective observational study. All women had dual energy X-ray absorptiometry (DEXA) scans at the lumbar spine (L1-L4) performed within 6 months prior to conception and in the immediate post-natal period, within 6 weeks of delivery. LMWH (5000 U/day) plus low-dose aspirin was commenced after a positive urine pregnancy test and continued throughout pregnancy and after delivery until 6 weeks post-partum. A group of 20 volunteers with recurrent miscarriage, not requiring any treatment intervention, acted as controls and were monitored in an identical fashion. RESULTS: Characteristics were not significantly different between treated patients and controls. Both groups showed a similar loss in lumbar spine (L1-L4) BMD by the end of the pregnancy [LMWH 4.17% or 0.045 g/cm(3), 95% confidence interval (CI) 0.036-0.062 versus control 3.56% or 0.043 g/cm(3), 95% CI 0.027-0.059]. However, the difference in bone loss between the groups was not statistically significant (0.002 g/cm(3), CI -0.0124 to 0.00865; P = 0.88). No patient suffered vertebral fracture. CONCLUSIONS: Bone loss associated with the use of long-term LMWH is not significantly different from physiological losses during pregnancy.