References
- Arey L B. The degree of normal menstrual irregularity. Am J Obstet Gynecol 1939; 37: 12–29
- Chiazze L, Brayer F T, Macisco J J, Parker M P, Duffy B J. The length and variability of the human menstural cycle. JAMA 1968; 203: 377–80
- Geirsson R T, Busby-Earle R M C. Certain dates may not provide a reliable estimate of gestational age. Brit J Obstet Gynaecol 1991; 98: 108–9
- Kramer M S, McLean F H, Boyd M, Usher R H. The validity of gestational age estimation by menstrual dating in term, preterm, and postterm pregnancies. JAMA 1988; 260: 3306–8
- Lindgren R, Selbing A, Leander E. Which fetal growth charts should be used?. Acta Obstet Gynecol Scand 1988; 67: 683–7
- Secher N J, Kern Hansen P, Lenstrup C, Pedersen-Bjergaard L, Sindberg Eriksen P, Thomsen B L, Keiding N. Birthweight for gestational age charts based on early ultrasound estimation of gestational age. Brit J Obstet Gynaecol 1986; 93: 128–34
- Campbell S, Warsof S L, Little D, Cooper D J. Routine ultrasound screening for the prediction of gestational age. Obstet Gynecol 1985; 65: 613–20
- Persson P-H, Weldner B M. Reliability of ultrasound fetometry in estimating gestational age in second trimester. Acta Obstet Gynecol Scand 1986; 65: 481–3