Levels of cord blood thyroid stimulating hormone after external cephalic version.

Abstract

OBJECTIVE:

To investigate the relationship between breech presentation, external cephalic version and levels of cord blood thyroid stimulating hormone.

DESIGN:

Case-control study.

SETTING:

University teaching hospital.

POPULATION:

The study group consisted of 289 consecutive singleton deliveries at term over a four-year period, all of whom had an attempt at external cephalic version performed near term for breech presentation. The control group included 23,001 singleton term deliveries during the same four-year period.

METHODS:

Between group differences were compared with the Mann-Whitney U test or chi2 test when appropriate.

MAIN OUTCOME MEASURES:

Levels of cord blood thyroid stimulating hormone and the incidence of false positive screening results for congenital hypothyroidism.

RESULTS:

Babies who were born vaginally after prior successful external cephalic version had significantly higher median levels of cord blood thyroid stimulating hormone (6.4 vs 6.0 mlU/L, P = 0.034) and the incidence of false positive screening for thyroid stimulating hormone (12.9% vs 7.2%, P = 0.016, OR 1.9) compared with babies with spontaneous cephalic presentation. In babies with a breech presentation born by elective caesarean section, previous attempts at external cephalic version had no effect on cord blood thyroid stimulating hormone levels. There was also no difference in the levels of cord blood thyroid stimulating hormone between cephalic and breech-presenting fetuses born by elective caesarean section. However, breech-presenting babies born by emergency caesarean section after onset of labour had higher median levels of cord thyroid stimulating hormone than those with cephalic presentation (5.1 vs 4.5 mIU/L, P= 0.008).

CONCLUSION:

Levels of cord blood thyroid stimulating hormone are elevated in babies born vaginally after a successful external cephalic version. This finding may represent a biological difference in fetal response to the stress of labour in breech-presenting fetuses, which is not correctable by a successful external cephalic version.

• Authors: Cha LYS, T K Lau, P Y Chiu, G Wing-KinWong, T N Leung
• Journal: BJOG : an international journal of obstetrics and gynaecology (BJOG) Vol. 108 Issue 10 Pg. 1076-80 (Oct 2001) ISSN: 1470-0328 [Print] England
• PMID: 11702840 (Publication Type: Journal Article)

Chemical References

• Thyrotropin

Topics

• Adult
• Breech Presentation
• Case-Control Studies
• Congenital Hypothyroidism
• Female
• Fetal Blood (chemistry)
• Fetal Diseases (blood, etiology)
• Humans
• Hypothyroidism (blood, diagnosis)
• Obstetric Labor Complications (blood)
• Pregnancy
• Retrospective Studies
• Stress, Physiological (blood, etiology)
• Thyrotropin (blood)
• Version, Fetal (adverse effects)