Underweight pregnant women in low risk populations: Does a low BMI (<18.5) predict adverse pregnancy outcomes? Paul de Cock AIRC2012

Midwifery Academy Amsterdam Groningen (AVAG) VU University Medical Center EMGO Instituut - Care and Prevention

Echelon system in perinatal care The Netherlands: echelon system in perinatal care 1st: community: monitored by independent midwife 2nd: hospital: gynaecologist & clinical midwife 3rd: academic referral centre: gynaecologist & clinical midwife http://www.knov.nl/docs/uploads/Midwifery_in_The__Netherlands__20120730__groot.pdf

Midwifery care App. 184000 births in Netherlands A quarter of these are home births Antenatal care by Midwife in 79.6% of pregnancies Remaining pregnancies (20.4%) are under supervision of gynaecologist (hospital/secondary care) Half of these are because of a medical indication.

Risk selection in echelons Women with health complications or known health risks are referred to secondary care setting This means that there is a risk selection in primary care, which is effective. For low BMI women this means that only those with no known additional health risks are under supervision of a primary care midwife.

Reason for this research University of applied science keeps strong links with the field – the field is actively invited to submit research questions to the college Manager of a large midwifery practice asked about the risks attached to low BMI for pregnant women under supervision of a primary care midwife. Women with medical indications have been referred. Is there a risk for the remaining healthy low BMI women with regard to pregnancy outcomes for mother and baby?

Low BMI – risk Increased risk of miscarriage (Maconochie et al., 2007) Preterm birth (Han et al., 2011) Low birth weight (Han et al., 2011) Increased risk of anaemia (Sebire et al., 2007)

Low BMI – lowered risk of… Reduced risk of complications, such as: Gestational diabetes mellitus Pre-eclampsia Obstetric intervention Postpartum haemorrhage (Sebire et al., 2007 - BMI<20)

Low BMI in low-risk population Research question: What are the pregnancy outcomes of low-risk underweight women in primary midwifery care?

Method - sample Retrospective case-control database study 2 large midwifery practices All underweight (< 18.5) women on record (past 5 years) Controls matched on age, smoking, alcohol use, drug use Only controls with normal BMI were included (18.5 – 24.99) Zwangerschapsuitkomsten: Zwangerschapsduur Geboortegewicht  

Method - outcomes Maternal Hypertension Hb (1st consult and at 30 weeks) Suspected intrauterine growth retardation Birth outcomes Duration of pregnancy Prematurity Instrumental delivery Bloodloss Active management of placental delivery

Method - outcomes Neonatal Weight Weight percentile (<2.3; <5.0; <10) APGAR <7 after 5 minutes Consult with paediatrician

Results – Pregnancy outcomes   Low BMI (<18,5) Normal BMI (>18,5-24,99) P-value Hypertension yes no 1 156 0 157 - Hb 1st consult (mmol/l) 7,54 7,74 <0,05* Hb 30 weeks (mmol/l) 7,09 7,29 Hb 1st consult <7,1 mmol/l yes No 30 127 17 140 0,058 Hb 30 weeks <6,3 mmol/l yes no 11 146 3 154 Consulted obstetrician during pregnancy yes no 43 115 29 128 0,099 Suspected IUGR Ja Nee 9 148 0,655 Disturbed glucose levels Ja Nee 0,317

Results – Birth outcomes   Low BMI <18,5 Normal BMI (>18,5-24,99) P-value Gestation (days) 277,38 277,80 0,840 Prematurity yes no 8 149 1,000 Instrumental delivery yes no 23 134 15 142 0,194 Total blood loss (ml) 403,67 389,81 0,717 Active management of placental delivery yes no not known 100 43 14 106 47 4 0,676 0,673 <0,05*

Results – Neonate outcomes   Low BMI <18,5 Normal BMI (>18,5-24,99) P-value Gender boy girl 88 69 76 81 0,349b 0,327b Birth weight (grammes) 2878,48 3532,68 <0,05*a Birth weight percentile 12,62 45,39 <2,3 yes no suspected IUGR <5,0 yes no suspected IUGR <10 yes no suspected IUGR 44 113 6 (13,6 %) 71 86 8 (11,3%) 99 58 9 (9,1%) 6 151 1 (16,6%) 12 145 2 (16,7%) 17 140 3 (17,6%) <0,05*b APGAR score < 7 after 5 minutes yes no 4 153 3 154 0,705b Consulted Peadiatrician yes no 31 126 43 114 0,198b

Discussion Women with low BMI at increased risk of anaemia. Babys are smaller, but no raised levels of suspected IUGR, poor APGAR scores or consults with paediatrician. No difference in prematurity found in this study

Conclusion On the basis of this study pregancy outcomes do not appear to differ much between women with low and normal BMI in primary care. More research is being done in a large prospective cohort study (DELIVER) to assess a broader range of outcomes in a large national sample.

Thank you for listening Paul de Cock PhD ab, Willemijn Perdijk b, MA RM, Aresh Mohammadi BA RM b, Elise Neppelenbroekb, Ingrid Hollemab Thank you for listening a Department of Midwifery Science, AVAG and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands, p.decock@vumc.nl. b Midwifery Academy Amsterdam Groningen, The Netherlands; T: +31 50- 3618886, F: + 31 50- 3619930,