Mostafa Metwally, M.R.C.O.G., Sotirios H. Saravelos, M.B.B.S., William L. Ledger, D.Phil., and Tin Chiu Li, Ph.D.
The Academic Unit of Reproductive and Developmental Medicine, The University of Shefﬁeld and Shefﬁeld Teaching Hospitals, The Jessop Wing, Shefﬁeld, United Kingdom
Objective: To investigate the effect ofunderweight, overweight, and obesity on the risk of miscarriage in the subsequent pregnancy in women with recurrent miscarriage. Design: Retrospective analysis of prospectively collected data from the database of a tertiary recurrent miscarriage center. Setting: The recurrent miscarriage clinic at Shefﬁeld Teaching Hospitals. Patient(s): A total of 844 pregnancies from 491 patients with recurrentmiscarriage were included in the analysis. Main Outcome Measure(s): The odds of miscarriage in the subsequent pregnancy for all pregnancies after referral to the recurrent miscarriage clinic as well as the ﬁrst pregnancy post referral. Result(s): When analyzing all pregnancies, and compared to women with a normal body mass index, obese and underweight patients had a signiﬁcantly higher odds ofmiscarriage in the subsequent pregnancy (OR, 1.71; 95% CI, 1.05–2.8; and OR, 3.98; 95% CI, 1.06–14.92; respectively), whereas there was no signiﬁcantly increased odds of miscarriage in overweight women (OR, 1.02; 95% CI, 0.72–1.45). Logistic regression analysis showed that the most important factor predicting the occurrence of miscarriage was advanced maternal age (P¼0.01) followed by an increasedbody mass index (P¼0.04). Conclusion(s): In women with recurrent miscarriage, a mild increase in the body mass index does not increase the risk of miscarriage, whereas obese and underweight patients have a small but signiﬁcant increased risk of miscarriage in the subsequent pregnancy. (Fertil SterilÒ 2010;94:290–5. Ó2010 by American Society for Reproductive Medicine.) Key Words: BMI, recurrentmiscarriage
Recurrent miscarriage is deﬁned as the occurrence of three or more consecutive miscarriages and is one of the most distressing adverse reproductive outcomes affecting approximately 1% of fertile couples (1, 2). Despite the association of recurrent miscarriage with several identiﬁable etiologies (chromosomal abnormalities, uterine pathologies, coagulation abnormalities, and immunologicalconditions), the cause remains unknown in approximately 50% of cases, further adding to the distress associated with this condition (2, 3). Obesity, which has been linked to a number of adverse reproductive outcomes, is increasing in prevalence (4, 5). An association between obesity and miscarriage has been demonstrated in several studies (6–8), possibly owing to adverse effects on the embryo, theendometrium, or both (9). We recently appraised the evidence for miscarriage and obesity and concluded that obese women have a signiﬁcant increased risk of miscarriage regardless of the method of conception (10). However, the effect of obesity on the risk of reReceived November 5, 2008; revised February 16, 2009; accepted March 4, 2009; published online May 12, 2009. M.W. has nothing to disclose.S.H.S. has nothing to disclose. W.L.L. has nothing to disclose. T.C.L. has nothing to disclose. Reprint requests: Mostafa Metwally, M.R.C.O.G., The Academic Unit of Reproductive and Developmental Medicine, The University of Shefﬁeld, The Jessop Wing, Tree Root Walk, S10 4ED, Shefﬁeld, United Kingdom (FAX: 44-114-2261074; E-mail: m.metwally@shefﬁeld.ac.uk).
current miscarriage as well as therelationship between the different degrees of obesity and miscarriage rates has not so far been examined. In this study, we examine the impact of different body mass index (BMI) categories on the risk of miscarriage in a future pregnancy in women with a history of recurrent miscarriage. MATERIALS AND METHODS The current study was a retrospective analysis of prospectively collected data from the...