Objective To assess the effect on the human sex ratio at birth by assisted reproductive technology (ART) procedures.Design Retrospective population-based study.Setting Fertility clinics in Australia and New Zealand.Population The study included 13 368 babies by 13 165 women who had a single embryo transfer (SET) between 2002 and 2006.Methods Logistic regression was used to model the effect on the sex ratio at birth of ART characteristics [in vitro fertilisation (IVF) or intracytoplasmic sperm insemination (ICSI) SET, cleavage-stage or blastocyst SET, and fresh or thawed SET] and biological characteristics (woman's and partner's age and cause of infertility).Main outcome measures Proportion of male births.
ResultsThe crude sex ratio at birth was 51.3%. Individual ART procedures had a significant effect on the sex ratio at birth. More males were born following IVF SET (53.0%) than ICSI SET (50.0%), and following blastocyst SET (54.1%) than cleavage-stage SET (49.9%). For a specific ART regimen, IVF blastocyst SET produced more males (56.1%) and ICSI cleavage-stage SET produced fewer males (48.7%).Conclusions The change in the sex ratio at birth of SET babies is associated with the ART regimen. The mechanism of these effects remains unclear. Fertility clinics and patients should be aware of the bias in the sex ratio at birth when using ART procedures.Keywords ART births, blastocyst, cleavage-stage embryo, ICSI, IVF, logistic regression, sex ratio at birth, single embryo transfer.Please cite this paper as: Dean J, Chapman M, Sullivan E. The effect on human sex ratio at birth by assisted reproductive technology (ART) procedures -an assessment of babies born following single embryo
The metabolic and cardiovascular side‐effects of intravenous infusions of therapeutic doses of beta 2‐adrenoceptor agonists salbutamol and rimiterol have been determined in four healthy male subjects. There were dose‐related increases in plasma glucose, renin activity, serum insulin and heart rate, and significant hyperlactataemia and ketonaemia. There were dose‐related decreases in plasma potassium, phosphate and corticosteroids and significant hypocalcaemia and hypomagnesaemia. The effects of equivalent molar amounts of salbutamol and rimiterol were similar. Whichever drug is used, special care is required with patients who may have abnormal glucose tolerance, potassium depletion, or be predisposed to lactic acidosis. Rimiterol may be preferable for infusion because of its short plasma half‐life.
The outcomes of 129 pregnancies in which the fetus was found to have a structural cardiac abnormality are reviewed. Over a 30month period from January 1985 to June 1987June , 1924 patients were refcrred to the Britich Heart Foundation Research Centre for Perinatal Cardiology at Guy's Hospital for fetal cardiac scanning. A total of 129 structural cardiac abnormalities was diagnosed; 53% of these patients were referred because of an abnormal 'four-chamber view' on ultrasound at thc referring hospital; 47 of the pregnancieh (69% of the 68 patients referred before 28 weeks) were terminated, and in the remaining 82 pregnancies outcome was poor with only 20 infants (16%) surviving longer than 11 months. The prenatal diagnosis was fully or partly correct in 96% of the 111 cases where it was possible to verify the diagnosis by post-mortem or postnatal diagnosis. In the 82 pregnancies not terminated, 13 of the 22 cases given a moderate or good prognosis survived more than 11 months (59Y0 survival), but only seven of the 60 (12% survival) given a fatal, poor or uncertain prognosis. The benefits of a multidisciplinary approach are discussed. Structural cardiac defccts account for 20% of the perinatal deaths due to congenital malformations (Young &L Clarke 1987) and murc than half the deaths in childhood from lcthal malformations (Kcith et al. 1978). The overall frequency
L~t t o~l n a unlfasc~ata 1s a small llttorin~d s n a~l found at ~m dto hlgh-shore levels on rocky shores In Australia Much has been published on patterns of dlstnbutlon and abundance of L un~fascl-ata on dlfferent shores, at d~fferent helghts on the shole and In dlfferent microhab~tats but there IS httle ~nformatlon on patterns of aggregatlon of t h~s specles Nevertheless, thls specles tends to form very distlnct clusters when emersed dunng low tlde Thls study IS a quantlflcatlon of aggregat~on by L unlfasc~ata on d~fferent shores, levels on the shore and In dlfferent mlcrohabltats The use of patches of habltat of d~fferent size durlng low tlde and hlgh tlde IS also examlned Aggregation was vallable from tlme to tlme and place to place and lndlvldual snalls dld not show a consistent tendency to aggregate on d~fferent occasions S n a~l s were less aggregated when they spread out to feed dunng hlgh tlde than when emersed durlng low t~d e , but thls was only found at very small spatlal scales because s n a~l s do not move far to feed Therefore, the cues that operate to cause the s n a~l s to aggregate In some patches and not others appear to be operating at the scale of centimetres rather than metres Thls suggests that many of the tradltlonal explanations for patterns of aggregatlon In ~n t e r t~d a l anlmals, such as those havlng to do wlth desiccation or temperature may not be Important In thls specles This phenomenon may be more widespread among lntertldal anlmals than IS currently recognised but ~t w~l l be necessary to examine patterns and test models about ecolog~cal processes at small spatlal scales wlthln shores, in addltlon to among shores, before thls can be deterlnlned
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