Social, biological and reproductive characteristics of mothers of twins: implications for breast cancer risk

Abstract

The biological, social and reproductive characteristics of women who have had twins were compared with those of other parous women using questionnaire data gathered for a prospective cohort study of women aged 35 and over on the island of Guernsey. Data for 97 mothers of twins and 4026 other parous women were available for analysis. The two groups were similar in height, first degree family history of breast cancer, use of hormone replacement therapy or other hormones, age at menarche, length of menstrual cycle and age at first and last birth. The mothers of twins were slightly heavier, more likely to smoke and consume more caffeine, less likely to have used oral contraceptives in the past, slightly younger when reaching the menopause and had a larger number of pregnancies. Adjustment for age did not alter these results. This study does not provide evidence that mothers of twins differ markedly from other parous women across a range of characteristics that might be associated with twinning or associated with breast cancer risk.

Initial and Cyclic Recruitment of Ovarian Follicles*

“…Assuming the increases in preovulatory follicles found in these individuals are due to elevated gonadotropins during the early follicular phase of their menstrual cycle (174 -176), this condition is likely due to enhanced cyclic recruitment of follicles and should not alter initial recruitment and menopausal age. However, some epidemiological studies have suggested that mothers of twins have an earlier menopause (177,178), although this may be related to other variables such as cigarette smoking which was not evaluated. Also, women who are carriers of the Fragile X syndrome show increased incidence of dizygotic twinning and an earlier onset of menopause (179).…”

Mid‐trimester ultrasound prediction of gestational age: advantages and systematic errors

“…The indicated increased risk for SGA among twins in pregnancies that were estimated to be more progressed according to the ultrasound measurement than the LMP date suggested is in contrast to this theory. Furthermore, Murphy et al 26 found no difference in the length of menstrual cycle between mothers of twins and other parous women. In addition, there is no reason to believe that twins are generally larger than singletons in early pregnancy.…”

Genetic versus Environmental Analysis of Reproductive Behavior of Female Twins

“…Data for 97 mothers of twins and 4026 other parous women were available for analysis. This study did not provide evidence that mothers of twins differ markedly from other parous women across a range of characteristics that might be associated with twinning or associated with breast cancer risk (Murphy et al, 1998). A more recent study investigated the genetic behavior of 4925 Finnish twins aged 23-27 years old (Mustanski et al, 2007).…”