Immune System Encourages Pregnancy When Sex Life is Lively

Fertility and Infertility News

Obie Editorial Team

  • 14 study participants were sexually active
  • 16 were sexually abstinent

None of the study participants were pregnant or taking medications that affect the hormonal or immune systems. Each one provided a saliva sample taken at four strategic phases of the menstrual cycle:

  • Menstrual
  • Follicular (between menstruation and ovulation)
  • Ovulatory
  • Luteal (between ovulation and menstruation)

When a foreign invader is detected in the bloodstream, helper T cells signal white blood cells to produce antibodies (immunoglobulins) to fend off illness. Of particular interest to the IU study were two types of helper T cells and two types of immunoglobulin antibodies:

  1. Type 1 helper T cells — defend the body against external threat.
  2. Type 2 helper T cells — alert the immune system that sperm, embryo, and fetus are desired foreign invaders that should not be destroyed.
  1. Immunoglobulin A antibodies — exist only in the mucus secretions of the female reproductive tract and respond to sperm and pregnancy.
  2. Immunoglobulin G antibodies — fight foreign DNA in the bloodstream for all the body except the uterus.

Examination of the saliva samples revealed immune system changes during the follicular and luteal phases of women who enjoy an active sex life:

Follicular (pre-ovulation phase during which follicles in the ovaries are maturing for release as an egg):

  • Type 1 helper T cells were found in high concentration.
  • Immunoglobulin A was also in high concentration.

Luteal (after ovulation when uterine lining thickens in anticipation of pregnancy):

  • Type 2 helper T cells were in significantly higher concentration.
  • Immunoglobulin G was also in highest concentration.

These immune-system fluctuations did not occur in the women who were abstaining from sexual intercourse.

The IU findings may prove beneficial to couples seeking treatment for infertility but may also prove helpful in treating sexually active women who have autoimmune disorders.


Sources:

  1. "Indiana University study: Sexual activity causes immune system changes that increase chances of conception." EurekAlert! Indiana University, 4 Oct. 2015. Web. 10 Nov. 2015.
  2. Lorenz, Tierney K., Julia R. Heiman, and Gregory E. Dumas. "Sexual activity modulates shifts in TH1/TH2 cytokine profile across the menstrual cycle: an observational study." Fertility and Sterility (2015). Elsevier Inc.. Web. 10 Nov. 2015.