Book Excerpt: What To Expect with Pregnancy and Delivery
The following is an excerpt From: Dawn A. Marcus, MD and Philip A. Bain, MD. The Woman’s Migraine Toolkit, 2011, DiaMedica (New York). You can purchase a copy of the book here.
What Is the Relationship of Hormones to Pregnancy, and How Does This Affect Headaches?
Pregnancy is another monumental milestone in a woman’s reproductive life and, not surprisingly, it has a huge impact on headaches. Once menses occur regularly, pregnancy is possible. When successful fertilization occurs, the fertilized egg is implanted in the uterus and a variety of hormones are produced, including human chorionic gonadotropin, or hCG, the substance that is measured by pregnancy tests.
This surge in hormones is thought to be responsible for early pregnancy symptoms such as morning sickness. HCG stimulates the lining of the uterus to begin producing progesterone, which helps to provide nourishment for the developing embryo. The placenta is formed and connects the developing fetus to the uterus. Although the ovaries continue to produce estrogen early on, as pregnancy develops the placenta begins to produce estrogen as well. As the pregnancy progresses, estrogen, progesterone, and hCG levels increase significantly.
Estrogen levels rise dramatically during pregnancy and drop precipitously after delivery. The figure below shows the expected changes in estrogen levels during each trimester and during the postpartum period after delivery. Compared to first-trimester levels, estrogen increases sixfold by the third trimester and then drops to almost undetectable levels after delivery.
Many women find that headaches improve as estrogen levels surge during pregnancy. Improvement usually begins at the end of the first trimester. This tends to continue throughout the remainder of pregnancy, while estrogen levels stay high. When the baby is born, estrogen levels drop and headache protection is lost, causing headaches to begin again.
Sixty to seventy percent of women with migraine will have significant improvement in their headache patterns during the second and third trimesters.
When was your last migraine check-up?