Maternal and Umbilical Cord Hormone Concentrations in Twin and Singleton Pregnancies
Condition: Normal Pregnancy
Study type: Observational

Summary: 
      This study will examine levels of hormones, such as estrogen and testosterone, in maternal
      and umbilical cord blood to compare hormones between mothers who are having twins and mothers
      who are having one baby. It will investigate whether hormone levels in twin versus singleton
      pregnancies influence the babies' risk of developing breast, prostate, and testicular cancers
      later in life.

      Pregnant women 18 years of age and older who do not have preeclampsia, chronic hypertension,
      pre-pregnancy or gestational diabetes, thyroid disease, or other major pregnancy
      complications are eligible for this study. Participants will be recruited from the obstetrics
      and gynecology practice at the Dartmouth Hitchcock Medical Center in Lebanon, New Hampshire.

      Participants will have a blood sample drawn from their arm during their third trimester
      prenatal visit and again when they are admitted to the hospital for delivery. After the baby
      is born, a blood sample will be collected from the cut umbilical cord. Information about the
      pregnancy and delivery will be collected from the mother's medical chart, and information
      about the baby's size will be obtained from the baby's medical chart.
    

Detailed description: 
      Epidemiologic data are few but suggest that effects during the prenatal and early life
      periods may be important in influencing risk of breast, prostate and testicular cancers later
      in life. In particular, evidence is accumulating for associations with several maternal,
      perinatal and pregnancy characteristics, including twining. The effect of these factors may
      be mediated through alterations in hormone levels such as the estrogens and other steroid
      hormones, to which the embryo and fetus are exposed during pregnancy. Differences in maternal
      hormone concentrations by maternal and perinatal factors have been noted, though data for
      most factors are sparse. Furthermore, less is known about the relationships of pregnancy
      factors to hormones in cord blood, the proximal exposure to the fetus, since most work thus
      far has been based on hormones in the maternal circulation. In collaboration with
      investigators at Dartmouth Hitchcock Medical Center, we are collecting maternal and cord
      blood samples from monochorionic twin, dichorionic twin and singleton pregnancies of similar
      gestational age to quantify differences in concentrations of several hormones and other
      pregnancy products. The purpose of the study is to assess the consistency of these data with
      hypotheses regarding the altered cancer risk daughters of twin pregnancies experience. All
      data collection is completed. We are currently analyzing the data for development of
      manuscripts to be submitted for publication.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Mothers and children treated at Dartmouth Hitchcock Medical Center and Medical School.
      
Keywords: Twins; Clinical Research; Endocrinology; Breast Cancer; Biochemical Epidemiology