You are currently browsing the Dr Licciardi blog archives for November, 2006.

What’s a Hormone?

And how do they help us ovulate? Hormones are chemicals that are made in one part of the body and act in another part of the body. For example, estrogen, our favorite hormone, is made in the ovaries and acts in the uterus, bones and other areas of the body. The hormone estrogen is stimulated by a different hormone, follicle stimulating hormone (FSH), which is made in the pituitary gland, a gland at the base of the brain. So the FSH hormone travels from the pituitary, through the bloodstream, to the ovaries and makes the follicle grow. It’s the follicle that makes estrogen. And there’s more. There’s another hormone that starts the whole thing off, and it’s called GnRH. This stands for gonadotropin releasing hormone. This is made in the brain (the hypothalamus to be precise). Just to review: The hormone GnRH comes from the brain to the pituitary through the blood stream. In the pituitary gland, GnRH stimulates FSH, which in turn travels to the ovary to stimulate the follicle to grow, and this produces estrogen.
We can use the thyroid system as another example. The hypothalamus makes TRH, which goes through the bloodstream to the pituitary gland to stimulate Thyroid Stimulating Hormone (TSH). TSH goes to the thyroid gland to make the thyroid hormone.

References:

  • Crowley WF Jr, Filicori M, Spratt DI, Santoro NF. The physiology of gonadotropin-releasing hormone (GnRH) secretion in men and women. Recent Prog Horm Res 1985; 41:473.
  • Conn PM, Crowley WF Jr. Gonadotropin-releasing hormone and its analogues. N Engl J Med 1991; 324:93.
  • Licciardi FL, Liu HC, Rosenwaks Z. Day 3 estradiol serum concentrations as prognosticators of ovarian stimulation response and pregnancy outcome in patients undergoing in vitro fertilization. Fertil Steril. 1995 Nov; 64(5):991-4.

How Can the Pregnancy be Bad But Still Growing?

This is a common unfortunate situation. There are a few typical scenarios. One is when a woman has a normal or lowish first beta. Then she has a second beta a week later that is not perfect but close enough. Another scenario is betas that go up slowly but are never in the normal range. Another scenario is when the betas are very nice and all is well until an ultrasound shows a problem.
All of these cases sometimes have a sad ending, as an ultrasound that shows a normal sac, without an embryo. So how can this be? How can you hear from your doctor that the beta is rising but the pregnancy is abnormal?
The early embryo is composed of 2 types of cells: the cells that go on to form the embryo and the cells that go on to form the placenta. Most of the cells are for the placenta, only a few are for the embryo. It’s the placental cells that make the hCG and this is the hormone of the pregnancy test. It is possible for the placental cells to continue grow even if the embryo is growing poorly or not at all. Some of you have heard a term for this problem, an “empty sac”. Except in rare cases, the placental cells will eventually stop growing after a few weeks, and an early miscarriage will occur. Sometimes a D and C is recommended.

References:

  • Regan L, Braude PR, Trembath PL. Influence of past reproductive performance on risk of spontaneous abortion. BMJ 1989; 299:541-5.
  • Chen BA, Creinin MD. Contemporary management of early pregnancy failure. Clin Obstet Gynecol. 2007 Mar; 50(1):67-88.
  • Barnhart KT. Early pregnancy failure: beware of the pitfalls of modern management. Fertil Steril. 2012 Nov; 98(5):1061-5.

How Many Embryos are You Putting Back?

Consider fewer.
Women under 35 and egg recipients should at least entertain the idea of a one-embryo transfer. Over the past few years there have been abstracts and papers (some of my own) written showing that in selected cases, a one-embryo transfer has an excellent pregnancy rate. The best candidates are women who are in their first try with excellent embryos. Many women who elect 1 embryo have at least 1 child at home. In these cases, the uterus is “proven” and this may increase their odds of getting pregnant with IVF or DE. In a small study here at NYU we showed that in good prognosis patients, the pregnancy rate with 1 embryo was the same as with 2. Once we do more cases we can update these results. I do believe that overall, the pregnancy rate with 1 will be lower than with 2, but I don’t think the difference is very big. One reason is that when we put in 1, we put in the best one, and that is the one with the highest chance of making a baby.
Why consider 1 when 2 can give you twins? A twin pregnancy is a complicated pregnancy. The idea of twins in not foreign because twins occur naturally. We all have friends or family members who are healthy twins. The problem is we may not know about the twins that delivered early, suffered early death, or are surviving with long term disability. The number one issue with twins is early delivery. We say twins deliver about a month earlier than singletons, bringing the gestation to about 36 weeks, no big deal. Delivery at 24-30 weeks is a very big deal. And yes it’s true even singletons can deliver early, but the odds are lower.
All this being said, almost all women still prefer to get at least 2 embryos back, which is fine. People are surprised to hear they have the option of requesting 1.
And again, please see disclaimer 5/17/06

References:

  • Jain T, Missmer SA, Hornstein MD. Trends in embryo-transfer practice and in outcomes of the use of assisted reproductive technology in the United States. N Engl J Med. 2004 Apr 15; 350(16):1639-45.
  • Mullin CM, Fino ME, Talebian S, Krey LC, Licciardi F, Grifo JA. Comparison of pregnancy outcomes in elective single blastocyst transfer versus double blastocyst transfer stratified by age. Fertil Steril. 2010 Apr; 93(6):1837-43.
  • The Practice Committee of the American Society for Reproductive Medicine and the Practice Committee of the Society for Assisted Reproductive Technology. Criteria for number of embryos to transfer: a committee opinion. Fertil Steril. 2012 Oct 22.
  • Niinimäki M, Suikkari AM, Mäkinen S, Söderström-Anttila V, Martikainen H. Elective single-embryo transfer in women aged 40-44 years. Hum Reprod. 2012 Nov 22.