Women with endometriosis are at a higher risk of obstetric complications, including miscarriages, cesarean delivery, and premature births, according to an analysis of birth records. The study, titled "Endometriosis and obstetrics complications: a systematic review and meta-analysis," was published in Fertility & Sterility. A research team analyzed 24 studies of obstetric complications totaling more than 1.9 million women. The studies included women both with endometriosis and without (as a control group) to assess the effect of endometriosis on pregnancy outcomes. Statistical tools were used to reach conclusions. Of the 250 records gathered through electronic databases and published studies, only 24 were eligible for the analysis. The researchers were from five universities and medical schools in Italy and the Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia. Eligible studies had to include women with and without a diagnosis of endometriosis so that the differences and the interpretation of the data will be statistically representative. The 1,924,114 million women in the studies included 52,111 (2.7%) women who were diagnosed with endometriosis before pregnancy, leaving 1,872,003 women (97.3%) for the control group. In the vast majority of the studies (21 of 24), an endometriosis diagnosis was made by looking microscopically at a tissue sample taken by biopsy. Other methods of diagnosis were ultrasound, magnetic resonance imaging (MRI), or computed tomography scans. The results of the analysis showed that women with endometriosis have a significantly higher risk of preterm birth at less than 37 weeks of gestation and a higher risk of cesarean delivery. A normal time for pregnancy is 40 weeks, or about 280 days. Women with endometriosis also have a significant increase in reported miscarriages as well as placenta previa. Placenta previa is a condition where the placenta partially or completely blocks the neck of the uterus, adding complications to the delivery. This often leads to a cesarean delivery. The researchers also found that these women have a significantly higher risk of delivering babies who are smaller than usual at birth even when reaching full term. Endometriosis diagnoses have no influence in gestational hypertension (high blood pressure) and preeclampsia (high blood pressure and protein in the urine). The authors believe the information gathered in this study can be helpful for women diagnosed with endometriosis and their healthcare providers when managing pregnancies. "Further studies are required to assess whether any modification is needed to conventional pregnancy monitoring for patients with endometriosis," the researchers wrote.