Obstetrical concerns with donor-egg/embryo conceived pregnancies

April 12, 2011Carole 4 Comments »

I don’t usually comment on obstetrical issues because I am not a physician and patients should always talk to their obstetrician, not their embryologist (!),  about pregnancy-related questions. However, I have written numerous posts about donor egg and donor embryo as useful ART methods for women to conceive and evidence continues to accumulate that using donor egg or embryo may have some obstetrical consequences that patients should know about.

Pregnancies conceived from donated eggs or embryos are the medical answer for many women who (because of advanced maternal age or other factors) can’t conceive with their own eggs. Data collected from a number of studies over more than a decade suggest that pregnancies conceived using donated eggs or embryos are more at risk for some pregnancy complications, particularly pregnancy induced hypertension including pre-eclampsia.

Pregnancy induced hypertension (PIH) is a new diagnosis of sustained high blood pressure that arises after 20 weeks of pregnancy. PIH is an umbrella term that can include a number of high-blood pressure related problems including gestational hypertension (BP greater than 140/90), preeclampsia (high blood pressure with protein spill into the urine), eclampsia (seizures) and HELLP syndrome (hemolytic anemia, elevated liver enzymes and low platelets).

Risk factors. A woman’s chances of experiencing these complications are influenced by a variety of risk factors including first pregnancy or first pregnancy with a new partner, family history of pre-eclampsia, diabetes, multiple gestation, obesity and advanced maternal age. Evidence is increasing to suggest that donor-egg or donor-embryo conceived pregnancies need to be added to the risk factor list.

The link between hypertensive pregnancy complications and using donor eggs or embryos seems to be immunological. When you think about it, pregnancy is a very unusual condition for the immune system. Generally speaking, your immune system has a single mission: detect and destroy all foreign invaders be they viruses, bacteria, fungi, or weird cancer cells sporting abnormal proteins. When a woman becomes pregnant, the fetus she is carrying is “half-foreign” because her partner’s contribution of “foreign” genes to the creation of the embryo. These paternal genes encode proteins that are foreign to the maternal body and generally would be detected and destroyed. But this doesn’t normally happen in pregnancy. In ways not completely understood, the mother’s immune system tolerates the embryo and the pregnancy.

This maternal tolerance may be similar to the immune tolerance that allergic people can develop if they are repeatedly exposed to extremely small doses of the allergen they are allergic to in the form of “allergy shots”. But it’s a tricky thing to fool the immune system because if you get too high a dose,  you trigger a full-blown allergic reaction, not tolerance.  Immune tolerance in pregnancy is much more complicated but studies suggest that in some cases, when the fetus is entirely “foreign” immunologically speaking, the mother may be at greater risk of developing some hypertensive pregnancy complications.

In 1999, a group of British researchers compared the frequency of hypertensive pregnancy complications in women who conceived with their own eggs and women who conceived with either donor sperm (group 1), donor egg (group 2) or donor embryo (group 3). Because maternal age and parity (the number of previous pregnancies)  are also factors that can increase the risk of pregnancy-induced hyptertension and eclampsia, women were matched by age and parity with a similar “own-egg” control patient.  Seventy-two women were enrolled in the control group and another seventy-two women were in one of the three “other-egg” conceived groups. Nine out of 72 women in the donor conceived group (12.5%) compared with 2 out of 72 (2.8%) of the control group experienced pregnancy-induced hypertension.  The rate of pre-eclampsia was  18.1% (13/72) in the donated gametes group compared to 1.4% (1/72) in the age- and parity-matched controls.

In 2010, a systemic review of almost eighty published scientific papers also concluded that egg donation was associated with a higher risk of pregnancy-induced hypertension. Other pregnancy complications, like intrauterine growth restriction, prematurity and congenital malformations appears to be similar between both donor-conceived and non-donor pregnancies. A review of all studies on this topic will of course, also find studies that were inconclusive or unable to find a link but these appear to be in the minority.

IVFNews!Direct recently summarized some of the more recent papers. Here’s a few other papers that conclude that donor conceived pregnancies are at higher risk of pregnancy induced hypertension or eclampsia.

Klatsky PC, Delaney SS, Caughey AB, et al. The Role of Embryonic Origin in Preeclampsia: A Comparison of Autologous In Vitro Fertilization and Ovum Donor Pregnancies. Obstet Gynecol. 2010 Dec;116(6):1387-1392. 2.

Keegan DA, Krey LC, Chang HC, Noyes N. Increased risk of pregnancy-induced hypertension in young recipients of donated oocytes. Fertil Steril. 2007 Apr;87(4):776-781. 3.

So does this mean that infertility patients should not consider using donated eggs or embryos? No, because avoiding third party reproduction does not ensure an easy pregnancy. Pregnancies conceived without donor gametes may also experience pregnancy-induced hypertension and eclampsia. The good news is that pregnancy-induced hypertension and eclampsia complications are medically managed every day by obstetricians with various interventions including bed rest, some medications and possibly early delivery.

The “take-home” message is that infertility patients who conceive with donor eggs or embryos should definitely talk to their obstetrician about this part of their medical history so that their obstetrician can be vigilant for early hypertension symptoms, increasing the likelihood of a healthy outcome for both mother and child.

 

© 2011, Carole. All rights reserved.

4 Responses to this entry

  • Anonymous Says:

    I will be a 46 year old female if I use donor egg. I am in good health but I am concerned about health risks. I don’t feel like the clinic is informing me about all the truths and realities of the whole IVF process. Unfortunately, I have not done a lot of research and feel many conflicts about donor egg. Where is a good resource to get all the facts?

  • Carole Says:

    Generally speaking, ASRM (www.asrm.org) has good patient information. .GOV sites are good for information. The CDC reports annual success rates and has some information about rate with donor. The support group Resolve (resolve.org) has good patient info. The best source to get data is anyone who is not trying to match you with a donor. I don’t think there is a single good source. I think that the major risk from using a donor at your age is that you are likely to get pregnant so look at pregnancy related risks (cardiovascular etc) for you at 46. IF you do get pregnant using donor egg, reveal this info to your ObGyn and let them know to watch for possible increased risk of eclampsia or hypertensive disorders of pregnancy. These are manageable, especially if your doctor is on the alert. The other donor risks are psychological (if you have not thoroughly considered the emotional impact of not having a biological link, possible issues with relatives, in some cases , lack of medical history for your child on one side etc etc). That’s why counseling is often recommended prior to a donor cycle. Good Luck!!

  • Jenny Says:

    I am 43 and about to start my second donor cycle. The first problem we encountered was my husbands vasectomy, after repeated miscarriages I was immune tested positive. Now I am too old for my own eggs.
    What I am asking is if I have immune issues, would you think this would cause more of an issue with donor eggs as the embryo is all ‘foreign’?
    I have and will take intrallipids, steroids to suppress my immune system.

  • Carole Says:

    Hi jenny,
    I think this is a much better question for your doctor. But based on the fact that women can acept donor embryos (where both the egg and the sperm came from two people unrrelated to the woman who will carry the baby), it can work and work well. But because of your existing immune issues- it makes sense that you might need steroids to surpress your immune system. I would strongly urge you to discuss these concerns with your doctor. He/She will be able to give you more and specific information. Good Luck!! Carole

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