Obstetrical concerns with donor-egg/embryo conceived pregnancies

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, Fertility Lab Insider. All rights reserved.

©2011 Fertility Lab Insider. All Rights Reserved.

.


 
disclaimer

The information provided on ConceivingConcepts.com is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her health professional. This information is solely for informational and educational purposes. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Neither the owners or employees of ConceivingConcepts.com nor the author(s) of site content take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading this site. Always speak with your primary health care provider before engaging in any form of self treatment. See our Legal Statement for more details.

Fertility Clinics Directory

Find a Fertility Clinic

If you or a loved one is suffering from infertility and needs help conceiving then we are here to offer help in any way we can. We have over 450 Fertility Clinics listed on our Directory. Click here to search for a Fertility Clinic that is right for you.

babymaker