Women with minor menstrual irregularities have increased risk of preeclampsia and low birth weight in spontaneous pregnancies

INTRODUCTION: Very few studies describe the obstetric and neonatal outcome of spontaneous pregnancies in women with irregular menstrual cycles. However menstrual cycle irregularities are common and may be associated with increased risk, and women who develop pregnancy complications more frequently recollect irregular menstrual cycles before the time of conception in case-control studies.

MATERIAL AND METHODS: This retrospective cohort study compares obstetric and neonatal outcomes in spontaneous singleton pregnancies in 3440 primiparous Danish women stratified according to menstrual cycle regularity. All pregnancies had a, delivery after 22 weeks of gestation and a nuchal translucency examination at Copenhagen University Hospital Hvidovre January 1. 2009 - December 31. 2010. Menstrual cycle irregularity was defined as more than 7 days deviation between self-reported and ultrasound examination based gestational age. Outcome measures were gestational diabetes, hypertension, preeclampsia, preterm premature rupture of membranes, preterm birth, prolonged pregnancy, birth weight, umbilical artery pH<7.1, APGAR<7 after 5 minutes, admission to neonatal intensive care unit and stillbirth. Women with more than 7 days deviation between self-reported and ultrasound examination based gestational age were compared to women with 7 days or less deviation.

RESULTS: Irregular menstrual cycle before conception increases the risk of preeclampsia (7.9% vs. 5.2%, p < 0.05) and low birth weight (6.0% vs. 3.6%, p < 0.05) in spontaneous pregnancies, but reduces the risk of prolonged pregnancy (1.4% vs. 4.7%, p < 0.001).

CONCLUSION: Irregular menstrual cycle before conception is associated with increased risk of adverse obstetric and neonatal outcome. This article is protected by copyright. All rights reserved.