May 2010 Archives

Becoming pregnant after successful breast cancer treatment not only appears to be safe, it may also be protective against a recurrence of breast cancer.

Over the years, I have done consultations with a number of women with a new diagnosis of breast cancer whose concern is fertility preservation, preserving the ability to have a baby after completing therapy. Although there are other options, this usually involves doing an expedited ("emergency") in vitro fertilization (IVF) cycle to minimize the delay before the initiation of treatment for the breast cancer. The eggs (oocytes) we retrieve are frozen, either unfertilized if the patient does not have a partner or as fertilized eggs (embryos) if she does.

Treatment for breast cancer is difficult emotionally and physically, and thus it's not surprising that breast cancer survivors are genuinely very concerned about doing anything that might trigger a recurrence. Inevitably, one of the first questions I am asked by women when they return to begin the process of building (or completing) their family is whether becoming pregnant will increase their risk of having the breast cancer "return." There is no final answer to this question at present, particularly because breast cancer comes in many varieties and with diverse characteristics. However, the good news is that the evidence so far suggests that there is no increase risk of recurrence from pregnancy. And interestingly, there is even a possibility that having a full-term delivery may even be protective against a recurrence.

In a population-based study from Denmark, over 10,000 young (ages 45 and under) breast cancer patients were followed as part of an ongoing long-term research project. Of these 371 became pregnant. Their risk of dying was compared to those women who did not become pregnant. Those women that had a full-term delivery had a 27% lower risk of dying than those that who did not have a pregnancy.

A word of caution. This apparent reduction in risk may not be "real" because it is possible that it results from the so-called ''healthy mother effect,'' that is, women with a better prognosis may be more likely to choose to become pregnant and have a baby. However, the authors performed additional statistical analyses that make that explanation less likely. If this protective effect is confirmed, it would greatly reduce the anxiety that breast cancer survivors live with and give them yet another reason to resume a "normal" life full of joy and anticipation.

Pregnancy after treatment of breast cancer

Ingesting more daily caffeine than is present in one cup of coffee while pregnant is associated with reduced fetal growth according to a well-designed study from a major medical journal.

Caffeine is easily absorbed and passes freely across the placenta. Ingesting the amount of caffeine found in approximately two cups of coffee is associated with a 25% reduction in blood flow across the placenta. It makes logical sense that any substance (or medical condition) that can reduce blood flow to the fetus is a potential cause of reduced fetal weight. A substantial number of scientific studies have examined whether caffeine is associated with "fetal growth retardation." The results have been contradictory, making recommendations in this area controversial. There are significant problems with many of these studies making it difficult to determine if their results are valid. A major underlying problem with the vast majority of these studies is that they are retrospective; they ask women to remember how much caffeine they drank during the pregnancy and then look at outcomes. They include no objective evidence that confirm the accuracy of the women's recollection, and they don't take into account that there are large variations in how quickly people metabolize caffeine, the effect of which is that caffeine levels can vary substantially among even when they ingest the same amount of caffeine.

An excellent article published in one of the world's leading medical journals, the British Medical Journal (BMJ), has provided substantial insight into this question by eliminating many of the problems with earlier studies. They followed 2,635 women through their pregnancy, asking them intermittently about their caffeine ingestion, and then testing caffeine levels in their saliva as double checks of the women's responses. They also measured the rate with which each woman metabolized caffeine. They found that any ingestion of caffeine above 100 mg/day, the rough equivalent of one cup of coffee or two cups of tea, was clearly associated with a reduction in the rate with which fetuses grew.

Although major medical organizations currently set the recommended limit for caffeine at about two to three time that amount (see link below), this study provides strong evidence that these guidelines need to be re-evaluated.

My current advice to a java-loving pregnant woman? If she absolutely can't or won't discontinue drinking caffeine-containing beverages during pregnancy -- which would be the ideal solution given the conflicting evidence about whether any amount of caffeine can be safely ingested during pregnancy -- she should limit her intake to no more than one cup of coffee or two cups of tea per day.

More details about the BMJ study

Current more liberal standards (.pdf file)

In the last week, I have seen three women who tell me there are no "good" men out there. Karen is a 36-year-old professor of molecular biology, Jane a 42-yr-old attorney, and Julie a 34-year-old stem cell scientist. All of these women are attractive, intelligent, and financially comfortable, and all have given up on finding the right man to have a child with. The men they meet, they tell me, are threatened by their careers and the fact that they don't "need" a man for financial security. Many men in these women's age group, they say, are divorced or commitment-averse and want to "play" rather than "settle down" and have a family.

These women are not alone in their decision to become single parents. In a study released earlier this month by the Pew Research Center, over 40% of the babies born in this country are born to unmarried women. This represents a dramatic increase over the past 20 years. In 1990, that number was just only 28%.

What's so interesting about this number is that this increase is largely attributable to women over the age of 30 with the greatest rate of increase being among Caucasian women.

Just how likely is it that a woman will find the man of her dreams and the father of their child in a dating world dominated by Internet dating? That question is the subject of an upcoming blog.

http://pewresearch.org/pubs/1586/changing-demographic-characteristics-american-mothers

Although a great deal of attention has been focused on the negative consequences of delaying childbearing among women, it is becoming clear that men also face significant risks when they delay starting a family. As a group, men over 35, and especially over 45, are more likely to be infertile, since the average quality of men's sperm falls over time.

But of even greater concern, children fathered by "older" men may have a greater risk of a variety of conditions, including autism and schizophrenia. In a subsequent blog, I will explore this association in detail. For now, suffice it to say that this increased risk is present in only some older men, and that tests are available to determine whether the offspring of any given man are at greater risk for these conditions. We do at least one of these tests prior to performing any fertility cycle involving a man over the age of 35.