The results of this study highlight the important role of lupus anticoagulant, as well as that of a previous blood clot, in adverse pregnancy outcomes.
Pregnancy Outcomes in Women with Lupus Nephritis
The effect of lupus nephritis on pregnancy outcome and fetal and maternal complications.
Gladman DD, Tandon A, Ibañez D, and Urowitz MB. (2010). Journal of Rheumatology 37: 754-758.
What is the topic?
Lupus primarily affects women during their reproductive years. It has been reported that women having more active disease are at greater risk of flares during pregnancy.
What did the researchers hope to learn?
The researchers hoped to determine the specific effects of active lupus-related kidney disease (lupus nephritis or LN) on pregnancy outcomes, as well as complications that might occur in the mothers or babies.
Who was studied?
193 pregnancies in 104 women with lupus were studied at the University of Toronto Lupus Clinic between 1970 and 2003. 81 patients had active LN at some point during the last six months of pregnancy and 112 patients did not have LN during this time. Of the 112 patients without active LN, 49 never had LN and 63 had LN in the past but it was completely resolved at the time of the study without any damage to the kidneys.
The women included in the study had taken a variety of different medications either before or during the pregnancy or study period, such as anti-malarials, immunosuppressives, steroids, and treatments for high blood pressure.
How was the study conducted?
Outcomes of each pregnancy were recorded as either successful, voluntary abortion, spontaneous abortion (before 20 weeks of pregnancy), stillbirth (after 20 weeks of pregnancy), or death within seven days of birth.
Pregnancy-related complications found in babies included low birth weight, neonatal lupus (usually a rash that gets better and rarely involves heart complications), newborn fever, and infection, among others.
Complications found in mothers included a syndrome known as preeclampsia (dangerously high blood pressure and kidney and/or other organ problems that can occur at the end of a pregnancy), bleeding, infection, surgical complications, and diabetes during pregnancy, among others.
The frequency of lupus flares during pregnancies was compared between those who had LN and those who did not. A lupus flare was defined as an increase of > 4 points in a disease activity scale called the SLEDAI-2K, as compared to what it had been six months prior to pregnancy.
What did the researchers find?
Patients having LN were younger when they got pregnant and had greater disease activity if LN was included in overall disease activity, but not when LN was excluded, suggesting that their organs did not appear to have more active disease activity overall.
Of the 193 pregnancies, 114 resulted in live births. Pregnancies in women with lupus nephritis and those without it were of similar length and resulted in live births with equal frequency.
120 pregnancies resulted in deliveries, but six were stillbirths. Complications were assessed in the 114 live births, 47 of which were in patients having LN. Low birth weight occurred more frequently in the patients having LN than in those without it. There were no statistical differences in the other kinds of complications involving the babies or mothers.
There were three babies born with malformations. One baby had cleft lip. Another baby had cleft lip and palate (roof of mouth) accompanied by facial palsy and visual/hearing impairments. The third baby had toe malformations. All three of these were born to mothers having LN during the pregnancy.
Lupus flares occurred more frequently in pregnancies accompanied by LN than in those without it, even when the kidney measurements were removed from the analysis of the SLEDAI-2K (disease activity).
What were the limitations of the study?
This study reported three congenital malformations in babies born to mothers having LN, but these were too few to perform meaningful statistical analyses on. These findings should be looked at in larger studies to find out whether this was a coincidence or if LN (or its treatments) led to a greater risk for malformations in these babies.
What do the results mean for you?
Women with LN can have successful pregnancy outcomes, but they should be monitored for pregnancy-induced hypertension, and their lupus disease activity should be controlled as much as possible before and during pregnancy.
The use of lupus biomarkers, such as those present in the blood or urine, to help predict and/or manage lupus nephritis over time could be very useful. The results of this study highlight the potential feasibility of using lupus biomarkers to differentiate between acute and chronic kidney disease activity-related changes.