Two or One?

Over the few days since Brian returned we have been debating on how to proceed with our next try – do we use one surrogate or two? The agreement we have with the clinic allows us to try with two surrogates in order to increase our odds of getting pregnant. On the face value, this seems like an excellent thing to do. We’ve already had three negative surrogacy attempts – tens of thousands of dollars and years of our lives with nothing to show for it. We are discouraged, worn out and trying not to lose hope. Using two surrogates definitely increases the odds of a baby. However, the question that keeps us awake at night is what happens if both surrogates get pregnant? What if one or both of the surrogates are pregnant with more than one baby? How do we proceed?

We’ve been asking ourselves what is the best way to truly get an idea of the likelihood of success? What would be best for us and also for our potential surrogate? In college I studied Combinatorics and Brian and I work on databases for our day jobs where there are discrete data sets and finite answers. Bioinformatics, however, is an entirely different story. One book that has always stuck with me is The Mismeasure of Man by Stephen Jay Gould. In a nutshell, the main theme of the book is basically how a statistical formula can be 100% accurate but completely based on biased data. I find statistics fascinating but am completely aware that you can easily manipulate the figures to make things appear differently than they truly are. I’ve seen several examples of this trend over the last year when different people and clinics talk about surrogacy in India.

So we went back to all the statistics and probability calculations that have been bouncing around in our heads. Brian dusted off his college statistics textbook and below is our attempt to analyze the numbers and make some sense for us.

Because finding accurate statistics is so difficult we used the numbers available from the United States published on the Centers for Disease Control (CDC) website: http://www.cdc.gov/ART/. The CDC compiles assisted reproductive technology (ART) data from most of the fertility clinics practicing in the United States. Since IVF methodology including normal protocol, preparation and suitability of surrogates, age and fertility factors of donors, and stage and number of embryos transferred differ for each distinct attempt and practices in the US differ from what is practiced in India, all the numbers have to be treated in very general terms with a large margin of error.

The first problem was determining what all the possible outcomes were and then estimating the probability of each outcome. A lot of the CDC published information tell you about the outcomes only of the attempts that achieve a pregnancy and only the pregnancy results. Some of the CDC information tells you the outcome of live births. Well, obviously not every surrogacy attempt results in a pregnancy. Not every pregnancy results in a live birth. Some pregnancies will result in multiple developing embryos, and pregnancies of multiple developing embryos don’t necessarily result in multiple or even any live births. On top of that, what are the odds of premature births or problems like down syndrome?

So there are a lot of variables that make it hard to get reliable statistics. But the single most important variable for this attempt is that we are using donor eggs. The odds are better because of that. The outcomes and probability we calculated for one surrogate were:

No pregnancy	47.0%
Failed pregnancy	7.7%
Singleton birth	24.5%
Twins birth	16.8%
Triplets or more birth	3.9%

To calculate the probabilities if two surrogates were used, we treated this as if there were two independent events and used the multiplication rule for independent events

P(A and B) = P(A)*P(B)

No pregnancy or failed pregnancy	29.9%
Singleton birth	26.8%
Two babies born	24.4%
Three babies born	12.5%
Four or more babies born	6.2%

Obviously the odds of any baby are greatly increased by using two surrogates instead of one, 69.9% compared to 45.2%. But the odds of multiples are also higher, 43.1% compared to 20.7%. And the odds of three or more babies are higher, 18.7% compared to 3.9%.

The probability of getting pregnant with multiples is actually much harder to predict because the chances of multiples depend a lot on the skill of the clinic as well as the number and quality of the embryos transferred. Without accurate data from a specific clinic it is basically all guesswork and not very accurate at all.

Considering the choice of whether or not to use two surrogates has forced us to calculate these odds. And we asked ourselves, how comfortable we are taking the risk of having to raise three or more babies simultaneously? What if the attempt fails and we’ve spent all this money (AGAIN) and nothing to show for it? (Recently we calculated that prior to this attempt, we spent about 40% of our combined annual incomes over four years on fertility treatments with nothing to show for it!)

And there are increased phase 2 (post-pregnancy) costs for multiples if we use two surrogates. If one surrogate is pregnant with a singleton, that is $20,000. If one surrogate is pregnant with twins, that is an additional $3,000. If both surrogates are pregnant with singletons, that is $37,000 ($20,000 + $17,000). We are mentally prepared to come up with $20-23,000 (borrowing from friends and family, cashing in retirement savings, selling things, etc), but $37,000-43,000 would definitely be a stretch for us. And if we use two or more surrogates the odds of the cost being $37,000 or more are about 21%, one in five.

Since Planet Hospital and Kiran Clinic have offered a “pregnancy guarantee” – that is, they will perform subsequent attempts using frozen or live transfers until a pregnancy is achieved at no additional phase one cost – we felt comfortable using only one surrogate in this attempt. Without the guarantee, we most likely would have used two surrogates.