Study of DDT and Loss of Clinically-Recognized Pregnancies in South Africa
Condition: Spontaneous Abortion; Malaria; Pregnancy Outcome; Stillbirth; HIV Infections
MeSH terms: Malaria; Stillbirth; Abortion, Spontaneous
Study type: Observational

Summary: 
      Background:

        -  In some countries, such as South Africa, the pesticide DDT is an important chemical for
           control of malaria-carrying mosquitoes. However, there is little evidence about the
           effects that it might have on human health.

        -  DDT has been associated with miscarriage and fetal loss in areas with high levels of
           exposure, but more research is needed to determine what levels of exposure are
           associated with loss of pregnancies.

      Objectives:

        -  To examine the relationship between pre-pregnancy levels of DDT in the blood and the
           loss of clinically recognized pregnancies.

        -  To conduct a pilot study to evaluate data collection procedures for future research.

      Eligibility:

        -  Women between 20 and 30 years of age who are not currently pregnant and who reside in
           villages in the Vhembe District in the northeastern part of South Africa.

      Design:

        -  Evaluation of eligibility:

             1. Short physical examination, with questionnaire about medical history, current
                living conditions, and daily life.

             2. Several blood samples will be taken for study and to test for anemia, elevated lead
                levels, malaria, syphilis, and human immunodeficiency virus (HIV).

        -  Half of the women will come from villages that are currently being sprayed with DDT, and
           half will come from villages that are not being sprayed.

        -  Evaluation before and during pregnancy for subjects who become pregnant:

             1. Blood and urine test, including urine pregnancy test.

             2. Questions about recent menstrual history and sexual activity.

             3. Questions about medical history, including treatment for malaria.

        -  Pregnancy follow-up study, including blood draws, will be conducted regardless of
           whether the pregnancy is carried to term.

        -  Researchers will assess and adjust study parameters as needed.
    

Detailed description: 
      In this study, the primary goal is to examine the relationship between DDT
      (dichlorodiphenyltrichloroethane) levels and the odds of loss of clinically-recognized
      pregnancies amongst women in Limpopo, South Africa. The initial protocol (which will be
      referred to as Part 1) planned to enroll 2,400 non-pregnant women, draw blood for measurement
      of DDT exposure, and follow 1,200 pregnant participants to ascertain occurrence of
      miscarriage. An initial two-year pilot of 850 non-pregnant women was proposed to evaluate
      field procedures, recruitment strategies and the reproducibility of DDT levels. Of the 444
      women enrolled in the first 10 months of the pilot of Part 1, only 27 have become pregnant.
      Although the field procedures have been well executed, the number of pregnancies has been
      low. Based upon the experience to date, the approach taken so far is unlikely to generate
      enough pregnancies to monitor the occurrence of miscarriages. Therefore, the revised protocol
      (referred to as Part 2) will modify enrollment criteria to include only pregnant women who
      are in the early stages of pregnancy, confirmed by rising human chorionic gonadotropin (hCG)
      blood levels taken 1 week apart or pregnant women who have a pregnancy loss within 4 weeks of
      enrollment. Participants who were enrolled in Part 1 of the pilot, who are still not pregnant
      at implementation of Part 2 will be withdrawn from the study, while pregnant participants
      from Part 1 will continue to be followed. In Part 2, a total of 2,400 pregnant women will be
      enrolled. Only those who meet the follow-up criteria (n=1,200) will be followed to determine
      the outcome of pregnancy. The reproducibility study of DDT levels amongst a subset of 200
      women will also be dropped and replaced with an analysis using specimens that were collected
      in Part 1.
    

Time perspective: Prospective
Keywords: DDT; Malaria; Pregnancy Outcome; Spontaneous Abortion; HIV; Pregnancy