This annual report - Taranaki District Health Board

abnormalities than women who drink the same total amount of alcohol over an extendedperiod of time [180]. The stage of pregnancy during which alcohol is consumed determinesthe cells that are affected in the developing foetus. Animal studies suggest that the firstand third trimesters are critical. Evidence for the effects of lower levels of alcoholconsumption on fetal growth and infant development is inconclusive and it is uncertainwhether there is a clear threshold below which alcohol is non-teratogenic [180,181].However, there is emerging evidence that low to moderate levels of drinking is associatedwith increased risk and the British Medical Association Board of Science hasrecommended that given this uncertainty, current drinking guidelines should recommendno alcohol during pregnancy [180]. New Zealand Ministry of Health guidance and the NewZealand College of Midwives consensus statement on alcohol in pregnancy support thisposition [184,185,186].Associations between other drug use in pregnancy and pregnancy outcomesIn the 2007/2008 New Zealand Drug Use Survey, the prevalence of reported drug useamong 16 to 17 year olds was 27.9% (95% CI 15.5 to 40.3) and fell to 9.9% (95% CI 16.7to 23.2) among 25 to 34 year olds [179]. The use of illicit drugs (opiates andamphetamines) has been linked to a higher risk of adverse obstetric and perinataloutcomes than for women in the general population [187]. Maternal use of a variety ofdrugs, including opiates and non-opiates such as benzodiazepines, caffeine, alcohol, andSSRIs, during pregnancy can result in transient neonatal signs consistent with withdrawalor acute toxicity, or cause sustained signs consistent with a lasting drug effect [188]. Fetalexposure to cannabis, the illicit drug most commonly used in New Zealand, is notassociated with clinically important neonatal withdrawal and does not appear to be linkedto an increased risk of perinatal mortality or morbidity [188,189]. However, cannabis mayhave subtle effects on long-term neurobehavioral outcomes [190].A survey of women attending an opiate treatment programme in Sydney found high ratesof pregnancy and poor use of contraception among sexually active women not wanting toget pregnant [191]. Women who use substances during pregnancy are likely to face acomplex array of family, social, relationship, legal, and psychiatric problems which mayimpair their ability to parent their new born child [192]. However, little is known about theirengagement with antenatal services. A recent New Zealand and United States basedcase-control study found that unlike in the US, where antenatal care is not free and there ismandatory reporting of drug-using mothers to child protection services, methamphetamineuse was not associated with inadequate antenatal care [193].Understanding the link between alcohol and other drug use and adverse pregnancyoutcomesWhile alcohol and some illicit drugs have specific harmful effects on the developing fetus,the associations between substance misuse and pregnancy outcomes are likely to becomplex. Some studies have found that women who are drug dependent have higher ratesof chaotic lifestyles with increased psychosocial problems and polydrug use [192]. It hasbeen suggested that women experiencing these adversities appear to be less likely toaccess or maintain contact with antenatal services [139].Smoking in pregnancyTobacco smoking during pregnancy is considered the most important potentiallypreventable cause of a range of adverse pregnancy outcomes [92]. Smoking in pregnancyis associated with placental abruption, miscarriage, stillbirth, preterm birth and lowbirthweight [93,94]. It affects both fetal growth and neurodevelopment and is a significantrisk factor for Sudden Infant Death Syndrome (SIDS) [95,96,97]. Smoking in pregnancy islinked to a range of other factors, including socioeconomic deprivation and young maternalage [164]. For a further discussion on tobacco use in pregnancy please see page 187.In-Depth Topic: Adversity in Pregnancy - 283